The document provides information about the domestication of crop plants, including:
- Domestication involves adapting wild plants for human use by selecting for desirable traits over generations.
- It began as early as 11,000 BC with rye and included major crops like wheat, peas, and bottle gourd in various regions including the Middle East, Asia, and Americas.
- Key scientists like de Candolle and Vavilov studied the origins and centers of domestication for many crops still important today. The process resulted in morphological and physiological changes collectively known as the domestication syndrome.
N.I. Vavilov identified 8 primary centers and 3 secondary centers of crop diversity. He and his team collected cultivated plants and wild relatives from several countries to use in breeding programs in the USSR. The primary centers had the widest genetic diversity and included wild traits, while secondary centers near cultivation had more desirable traits from natural and artificial selection. Vavilov's work helped establish the importance of conserving genetic resources for crop improvement.
This document discusses Nikolai Vavilov's theory of centres of origin and diversity of crop plants. Vavilov identified eight main centres around the world where crop plants were first domesticated, including centers in China, India, the Mediterranean, and South America. Within these centres, Vavilov also recognized smaller micro centres exhibiting high genetic diversity. The document provides details on Vavilov's centres and the importance of mountainous regions in promoting crop domestication and diversity.
Growth and development in plants involves three main processes: cell division (growth), cell enlargement, and cell differentiation (development). Growth leads to an increase in size and mass through these cellular processes. Development refers to the changes plants undergo throughout their lifecycle from germination through maturation and reproduction. Key events include shoot and root development, flowering and fruit production, before senescence. Hormones and environmental factors influence the pathways and rates of growth and development.
T. aestivum (common bread wheat) is one of the main species of wheat grown in India. It originated in SW Asia around 7000 BC and was first cultivated in places like Egypt, Europe, and America. Wheat is an annual grass that grows 60-150 cm tall. It has hollow jointed stems, linear leaves, and an erect spike made of spikelets containing flowers. The fruit is an oblong caryopsis 5-10 mm long. Wheat is processed through harvesting, threshing, winnowing, and milling to produce flour for many uses like bread, pastries, and alcoholic beverages.
1. Concept of Centres of Origin, their importance with reference to Vavilov’s...Dr. Hem Chander
1. Nikolai Vavilov identified 8 major centers of origin for cultivated plants based on his global expeditions, including the Chinese, Himalayan, Mediterranean, Abyssinian, Central Asian, Asia Minor, Central American, and South American centers.
2. Each center is located in a region with high biodiversity and is home to the wild progenitors of important domesticated crops. For example, the Himalayan center includes regions of Assam, Burma, and Indo-China, and is the origin of rice, chickpeas, mung beans, and other important South Asian crops.
3. Vavilov argued that identifying centers of origin was important for locating wild crop relatives, avoiding
The document provides information about the domestication of crop plants, including:
- Domestication involves adapting wild plants for human use by selecting for desirable traits over generations.
- It began as early as 11,000 BC with rye and included major crops like wheat, peas, and bottle gourd in various regions including the Middle East, Asia, and Americas.
- Key scientists like de Candolle and Vavilov studied the origins and centers of domestication for many crops still important today. The process resulted in morphological and physiological changes collectively known as the domestication syndrome.
N.I. Vavilov identified 8 primary centers and 3 secondary centers of crop diversity. He and his team collected cultivated plants and wild relatives from several countries to use in breeding programs in the USSR. The primary centers had the widest genetic diversity and included wild traits, while secondary centers near cultivation had more desirable traits from natural and artificial selection. Vavilov's work helped establish the importance of conserving genetic resources for crop improvement.
This document discusses Nikolai Vavilov's theory of centres of origin and diversity of crop plants. Vavilov identified eight main centres around the world where crop plants were first domesticated, including centers in China, India, the Mediterranean, and South America. Within these centres, Vavilov also recognized smaller micro centres exhibiting high genetic diversity. The document provides details on Vavilov's centres and the importance of mountainous regions in promoting crop domestication and diversity.
Growth and development in plants involves three main processes: cell division (growth), cell enlargement, and cell differentiation (development). Growth leads to an increase in size and mass through these cellular processes. Development refers to the changes plants undergo throughout their lifecycle from germination through maturation and reproduction. Key events include shoot and root development, flowering and fruit production, before senescence. Hormones and environmental factors influence the pathways and rates of growth and development.
T. aestivum (common bread wheat) is one of the main species of wheat grown in India. It originated in SW Asia around 7000 BC and was first cultivated in places like Egypt, Europe, and America. Wheat is an annual grass that grows 60-150 cm tall. It has hollow jointed stems, linear leaves, and an erect spike made of spikelets containing flowers. The fruit is an oblong caryopsis 5-10 mm long. Wheat is processed through harvesting, threshing, winnowing, and milling to produce flour for many uses like bread, pastries, and alcoholic beverages.
1. Concept of Centres of Origin, their importance with reference to Vavilov’s...Dr. Hem Chander
1. Nikolai Vavilov identified 8 major centers of origin for cultivated plants based on his global expeditions, including the Chinese, Himalayan, Mediterranean, Abyssinian, Central Asian, Asia Minor, Central American, and South American centers.
2. Each center is located in a region with high biodiversity and is home to the wild progenitors of important domesticated crops. For example, the Himalayan center includes regions of Assam, Burma, and Indo-China, and is the origin of rice, chickpeas, mung beans, and other important South Asian crops.
3. Vavilov argued that identifying centers of origin was important for locating wild crop relatives, avoiding
This ppt describes about the origin of cultivated plants along with Vavilov's centres of origin as well as about definition, scope and importance of ethnobotany in Indian context.
The document summarizes several psychoactive substances, including their botanical names, parts used, and common methods of consumption. Tobacco is prepared from dried tobacco plant leaves and commonly consumed via cigarettes, beedis, cigars, and pipes. Cannabis is consumed as bhang, charas, or ganja made from dried cannabis plant parts containing THC. Paan is a preparation containing betel leaf, areca nut, catechu, and sometimes tobacco. Opium is obtained from unripe opium poppy capsules as a latex containing morphine, and poppy seeds are used as a food item. Coca leaves from the coca plant are chewed or used to make tea due to their
This document provides information about taxonomic tools of floras. It begins by defining what a flora is - a description of plants found in a particular region. Floras typically include keys for identification and maps showing plant ranges. The document then classifies different types of floras based on their geographic scope, such as local, regional, continental, and special floras. It also discusses the data commonly presented in floras, including taxonomic hierarchies, identification tools, descriptions, illustrations, and voucher specimens. Finally, it provides details about the Flora of Gujarat, India, which documents over 2,000 plant species found in the region.
This document discusses polyploidy and its applications in plant breeding. It begins by defining polyploidy as having three or more sets of chromosomes, which can occur naturally or through induction. Examples of polyploid plants include wheat, strawberries, and plant endosperm. Polyploidy can originate through somatic doubling during mitosis, non-reduction during meiosis producing unreduced gametes, polyspermy, or endoreplication. Artificial polyploids have been created to study natural allopolyploids or develop new crop species, such as the synthetic allopolyploid Raphanobrassica. Breeding autopolyploids and allopolyploids can bridge
Apomixis in flowering plants is defined as the asexual formation of a seed from the maternal tissues of the ovule, avoiding the processes of meiosis and fertilization, leading to embryo development.
The document discusses several theories about the origin and evolution of angiosperms. It describes theories that proposed various plant groups as possible ancestors of angiosperms including isoetes, conifers, gnetales, bennettitales, caytoniales, and pentoxylales. However, many of these theories were later contradicted or disagreed with based on evidence from vascular anatomy, seed structure, and other characteristics. The document also outlines primitive and advanced characteristics seen in different angiosperm groups, showing their diverse evolutionary lines.
Flower development is controlled by floral developmental genes that are induced in response to environmental signals like photoperiod and temperature. The ABC model describes how MADS-box transcription factors encoded by ABC genes control floral organ identity in four whorls. Class A genes specify sepals, Class B genes specify petals, Class C genes specify stamens, and the combination of B and C genes specify carpels. Mutations in these ABC genes result in homeotic transformations of floral organs. The ABC model was later expanded to the ABCDE model with the addition of SEPALLATA genes that act redundantly with ABC genes.
This document discusses apogamy and apospory in plants. It defines apogamy as asexual reproduction in ferns where a haploid gametophyte develops into a haploid sporophyte without gamete fusion. Apospory is defined as the development of a diploid gametophyte from the vegetative cells of a diploid sporophyte, without meiosis or spore formation. The key difference between the two is that apogamy produces a haploid embryo while apospory produces a diploid embryo. Causes of each include environmental stresses that prevent normal sexual reproduction. Similarities include that both are asexual reproductive processes that occur in bryophytes and involve alternation of generations
The document provides information about the fundamentals of plant breeding course including the introduction and acclimatization topic. It defines introduction as growing genotypes in a new environment and lists objectives like obtaining new crops, serving as high yielding varieties, and being used in crop improvement. It also discusses the history of plant introductions to India, types of introductions, procedures involving procurement, quarantine, evaluation and distribution. Important plant introduction agencies and some prominent introductions are listed. The merits and demerits of introductions are outlined. Acclimatization is defined as the process where organisms adjust to environmental changes and performance improves over generations in the new environment through natural selection.
The International Code of Botanical Nomenclature (ICBN) governs the formal scientific names used for plants. Some key points:
- Carl Linnaeus is considered the father of modern taxonomy and introduced the system of scientific naming for species in 1753.
- Names are determined by nomenclature types and are based on priority of publication. Each taxonomic group can have only one correct scientific name.
- Names are revised in subsequent International Botanical Congresses starting in 1892 to establish standards for effective/valid publication, author citation, typification, and rejection of illegitimate names.
- Related codes also exist for zoological nomenclature, cultivated plants, bacteria,
Polyembryony is the phenomenon of two or more embryos developing from a single fertilized egg. Due to the embryos resulting from the same egg, the embryos are identical to one another, but are genetically diverse from the parents.
The document discusses endosperm, which is a nutritive tissue stored in seeds to provide nutrients for the embryo. There are three main types of endosperm based on development - nuclear, cellular, and helobial. Nuclear endosperm is the most common type and involves repeated nuclear division without cell wall formation initially. Cellular endosperm involves cell wall formation after each nuclear division. Helobial endosperm involves initial division into two cells like cellular endosperm, but further divisions are like nuclear endosperm. Endosperm can also have haustorial variations and can be ruminate, with an irregularly folded surface. Endosperm plays an important role in seed nutrition and development.
This document provides an introduction to melissopalynology, which is the study of botanical and geographic origins of honey through microscopic pollen analysis. It discusses honey and nectar formation by bees, the types of honey, honey bees species, bee pasturage plants, chemical and physical properties of honey. It also covers deterioration of honey through fermentation or heating, potential heavy metal contamination, adulteration risks, and other bee products beyond honey like bee venom, bee bread, royal jelly, propolis, beeswax, mead, bee pollen. The document emphasizes the importance of bees as Albert Einstein is quoted saying that without bees, humans would only have four years left to live.
The stem consists of nodes and internodes. Axillary and apical buds form branches and elongate the shoot tip. The shoot apex contains a dome-shaped apical meristem that produces leaves and axillary buds. It is organized into an outer layer called the tunica and inner region called the corpus. Leaf primordia develop from the sides of the apical meristem.
Totipotency refers to a plant cell's genetic potential to regenerate an entire plant. In plant tissue culture, cells taken from plant parts can form an unorganized mass of cells called callus tissue when placed in a sterile nutrient medium. The cells within callus tissue are totipotent, meaning they have the ability to regenerate into a whole plant under the right conditions and hormone manipulations. Totipotency is important for plant science applications like vegetative propagation of crops, genetic modification of plants, and preservation of endangered plant species through long-term storage of totipotent cells.
This document discusses centers of origin of crop plants as proposed by N.I. Vavilov. It outlines the eight major centers including East Asia, Hindustan, Central Asia, Near East, Mediterranean, Abyssinia, South Mexico/Central America, and South America. Key crops that originated from each center are provided. The document also discusses primary and secondary centers of diversity, microcenters, mega gene centers, and Vavilov's contributions to the study of crop origins.
This ppt describes about the origin of cultivated plants along with Vavilov's centres of origin as well as about definition, scope and importance of ethnobotany in Indian context.
The document summarizes several psychoactive substances, including their botanical names, parts used, and common methods of consumption. Tobacco is prepared from dried tobacco plant leaves and commonly consumed via cigarettes, beedis, cigars, and pipes. Cannabis is consumed as bhang, charas, or ganja made from dried cannabis plant parts containing THC. Paan is a preparation containing betel leaf, areca nut, catechu, and sometimes tobacco. Opium is obtained from unripe opium poppy capsules as a latex containing morphine, and poppy seeds are used as a food item. Coca leaves from the coca plant are chewed or used to make tea due to their
This document provides information about taxonomic tools of floras. It begins by defining what a flora is - a description of plants found in a particular region. Floras typically include keys for identification and maps showing plant ranges. The document then classifies different types of floras based on their geographic scope, such as local, regional, continental, and special floras. It also discusses the data commonly presented in floras, including taxonomic hierarchies, identification tools, descriptions, illustrations, and voucher specimens. Finally, it provides details about the Flora of Gujarat, India, which documents over 2,000 plant species found in the region.
This document discusses polyploidy and its applications in plant breeding. It begins by defining polyploidy as having three or more sets of chromosomes, which can occur naturally or through induction. Examples of polyploid plants include wheat, strawberries, and plant endosperm. Polyploidy can originate through somatic doubling during mitosis, non-reduction during meiosis producing unreduced gametes, polyspermy, or endoreplication. Artificial polyploids have been created to study natural allopolyploids or develop new crop species, such as the synthetic allopolyploid Raphanobrassica. Breeding autopolyploids and allopolyploids can bridge
Apomixis in flowering plants is defined as the asexual formation of a seed from the maternal tissues of the ovule, avoiding the processes of meiosis and fertilization, leading to embryo development.
The document discusses several theories about the origin and evolution of angiosperms. It describes theories that proposed various plant groups as possible ancestors of angiosperms including isoetes, conifers, gnetales, bennettitales, caytoniales, and pentoxylales. However, many of these theories were later contradicted or disagreed with based on evidence from vascular anatomy, seed structure, and other characteristics. The document also outlines primitive and advanced characteristics seen in different angiosperm groups, showing their diverse evolutionary lines.
Flower development is controlled by floral developmental genes that are induced in response to environmental signals like photoperiod and temperature. The ABC model describes how MADS-box transcription factors encoded by ABC genes control floral organ identity in four whorls. Class A genes specify sepals, Class B genes specify petals, Class C genes specify stamens, and the combination of B and C genes specify carpels. Mutations in these ABC genes result in homeotic transformations of floral organs. The ABC model was later expanded to the ABCDE model with the addition of SEPALLATA genes that act redundantly with ABC genes.
This document discusses apogamy and apospory in plants. It defines apogamy as asexual reproduction in ferns where a haploid gametophyte develops into a haploid sporophyte without gamete fusion. Apospory is defined as the development of a diploid gametophyte from the vegetative cells of a diploid sporophyte, without meiosis or spore formation. The key difference between the two is that apogamy produces a haploid embryo while apospory produces a diploid embryo. Causes of each include environmental stresses that prevent normal sexual reproduction. Similarities include that both are asexual reproductive processes that occur in bryophytes and involve alternation of generations
The document provides information about the fundamentals of plant breeding course including the introduction and acclimatization topic. It defines introduction as growing genotypes in a new environment and lists objectives like obtaining new crops, serving as high yielding varieties, and being used in crop improvement. It also discusses the history of plant introductions to India, types of introductions, procedures involving procurement, quarantine, evaluation and distribution. Important plant introduction agencies and some prominent introductions are listed. The merits and demerits of introductions are outlined. Acclimatization is defined as the process where organisms adjust to environmental changes and performance improves over generations in the new environment through natural selection.
The International Code of Botanical Nomenclature (ICBN) governs the formal scientific names used for plants. Some key points:
- Carl Linnaeus is considered the father of modern taxonomy and introduced the system of scientific naming for species in 1753.
- Names are determined by nomenclature types and are based on priority of publication. Each taxonomic group can have only one correct scientific name.
- Names are revised in subsequent International Botanical Congresses starting in 1892 to establish standards for effective/valid publication, author citation, typification, and rejection of illegitimate names.
- Related codes also exist for zoological nomenclature, cultivated plants, bacteria,
Polyembryony is the phenomenon of two or more embryos developing from a single fertilized egg. Due to the embryos resulting from the same egg, the embryos are identical to one another, but are genetically diverse from the parents.
The document discusses endosperm, which is a nutritive tissue stored in seeds to provide nutrients for the embryo. There are three main types of endosperm based on development - nuclear, cellular, and helobial. Nuclear endosperm is the most common type and involves repeated nuclear division without cell wall formation initially. Cellular endosperm involves cell wall formation after each nuclear division. Helobial endosperm involves initial division into two cells like cellular endosperm, but further divisions are like nuclear endosperm. Endosperm can also have haustorial variations and can be ruminate, with an irregularly folded surface. Endosperm plays an important role in seed nutrition and development.
This document provides an introduction to melissopalynology, which is the study of botanical and geographic origins of honey through microscopic pollen analysis. It discusses honey and nectar formation by bees, the types of honey, honey bees species, bee pasturage plants, chemical and physical properties of honey. It also covers deterioration of honey through fermentation or heating, potential heavy metal contamination, adulteration risks, and other bee products beyond honey like bee venom, bee bread, royal jelly, propolis, beeswax, mead, bee pollen. The document emphasizes the importance of bees as Albert Einstein is quoted saying that without bees, humans would only have four years left to live.
The stem consists of nodes and internodes. Axillary and apical buds form branches and elongate the shoot tip. The shoot apex contains a dome-shaped apical meristem that produces leaves and axillary buds. It is organized into an outer layer called the tunica and inner region called the corpus. Leaf primordia develop from the sides of the apical meristem.
Totipotency refers to a plant cell's genetic potential to regenerate an entire plant. In plant tissue culture, cells taken from plant parts can form an unorganized mass of cells called callus tissue when placed in a sterile nutrient medium. The cells within callus tissue are totipotent, meaning they have the ability to regenerate into a whole plant under the right conditions and hormone manipulations. Totipotency is important for plant science applications like vegetative propagation of crops, genetic modification of plants, and preservation of endangered plant species through long-term storage of totipotent cells.
This document discusses centers of origin of crop plants as proposed by N.I. Vavilov. It outlines the eight major centers including East Asia, Hindustan, Central Asia, Near East, Mediterranean, Abyssinia, South Mexico/Central America, and South America. Key crops that originated from each center are provided. The document also discusses primary and secondary centers of diversity, microcenters, mega gene centers, and Vavilov's contributions to the study of crop origins.
centres of origin-biodiversity and its significance.pptx19BAG7124SAHIL
Centres of origin are regions where crops are believed to have originated based on archaeological and botanical evidence. In the late 1800s, Alphonse De Candolle identified three main centres - Mesoamerica, the Fertile Crescent, and Southeast Asia. In the 1920s, Nikolai Vavilov expanded on this work and proposed eight centres of crop diversity that he believed were also the centres of origin. These included China, the Mediterranean, the Middle East, Ethiopia, Central Asia, the Indo-Burma region, and South America. Vavilov argued that identifying centres of origin and diversity was important for plant breeding and conservation of crop wild relatives. While other scientists have since modified V
Presentation entitled "Centres of origin- biodiversity and its significance" explains all the basics and some recent aspects regarding center of origins of some crops.
Vavilov identified eight primary centers of origin for cultivated plants based on his global expeditions collecting crop diversity. These included China, India, Central Asia, the Near East, the Mediterranean, Ethiopia, South Mexico/Central America, and the Andes region of South America. He recognized that centers of origin generally occurred in mountainous regions and had the greatest diversity, including wild relatives of crops. Plant introduction involves transferring plants to new environments and can have objectives like increasing food production or enriching germplasm collections, but also risks introducing new pests or weeds.
Centers of origin are geographical areas where crop plants first developed distinctive traits. Russian geneticist Nikolai Vavilov identified eight main centers and three subsidiary centers of crop origin and diversity based on plant exploration. These centers include areas like China, India, Central Asia, and South America. Primary centers of diversity contain vast genetic resources in wild areas, while secondary centers have cultivated varieties with crossing over. Microcenters within centers exhibit high diversity and rapid evolution. Gene sanctuaries protect genetic resources in natural habitats from human impacts and allow natural selection.
ASSESSMENT OF TOXIC PRODUCING FUNGI IN STORED GRAINS (RICE, BEANS, WHEAT, GRO...EngrNwigwePromiseChu
This document appears to be a student research project assessing toxins produced by fungi in stored grains like rice, beans, wheat and groundnuts. It includes an introduction outlining fungi and mycotoxins, as well as a literature review covering the grains being studied, common fungal diseases and infections that affect these grains. It discusses factors that influence fungal growth in storage and the health impacts of mycotoxins on humans and livestock. The student declares the work as their own and it receives approval from their supervisor and department head.
1. Renowned Russian botanist Nikolai Vavilov proposed the theory of centers of origin of cultivated plants in the 1920s, identifying 8 major centers around the world where wild ancestors of crops were originally domesticated, including centers in China, India, Central Asia, the Mediterranean, Ethiopia, and the Americas.
2. Vavilov led extensive plant collecting expeditions between 1921-1934, visiting over 50 countries and amassing a collection of over 250,000 plant specimens.
3. Vavilov proposed that centers of origin had the greatest genetic diversity of wild relatives of crops. Diversity decreased moving outwards from centers of origin due to factors like selection pressure and isolation.
Plant Genetic Resources: Conservation and Sustainable Useanswervivek
Plant genetic resources are the most valuable and essential basic raw materials to meet the current and future needs of crop improvement programs.
It has become increasingly clear during the last few decades that meeting the food needs of the world's growing population depends, to a large extent, on the conservation and use of the world's remaining plant genetic resources.
This document provides an overview of a course on basic plant breeding techniques. The course objectives are to understand how breeders meet breeding goals, learn classical and modern breeding methods, and see examples of genetics' importance in modern breeding. Key learning outcomes are to understand plant breeding developments, basics of genetics, and breeding concepts. The document then discusses the history and milestones of plant breeding, achievements in various crops, activities in plant breeding like creation of variation and selection, and breeding objectives like increasing yield and improving quality. It also covers concepts of centers of origin and diversity first proposed by Vavilov.
This document outlines the lecture-wise course breakdown for a course titled "Principles of Crop Production". It includes 22 lectures covering topics such as agriculture, crop classification, crop rotation, cropping systems, tillage, seeds, water and irrigation, weed control, soil fertility, pest management, harvesting, and cultivation practices and techniques for major crops. It also describes the examination structure which includes sessions, quizzes, assignments, and a final exam. Recommended books and reference materials on topics related to agricultural biotechnology and crop improvement are provided.
Weed seeds can persist in the soil for many years through dormancy and produce large numbers of seeds. Integrated weed management aims to reduce weed seed production and dispersal through techniques like crop rotation, mulching, stale seedbeds, and biological control. Knowledge of a weed's biology, including its seed dormancy mechanisms and longevity, reproduction methods, and dispersal pathways, is important for developing effective long-term management strategies.
This document outlines the lecture-wise course breakdown for the course Principles of Crop Production (ABT-320). It includes 18 lectures covering topics like importance of agriculture, factors affecting crop production, classification and major crops, crop rotation, cropping systems, tillage, seed treatment, water management, intercultural operations, weed control, plant nutrients, soil fertility, pest management, harvesting, and cultivation practices and techniques for important crops like maize, mustard, cotton, sugarcane and wheat. The course assessments include two sessionals, six quizzes and a final exam. Recommended books and reference materials are also provided.
This document outlines the lecture-wise course breakdown for the course Principles of Crop Production (ABT-320). It includes 18 lectures covering topics like agriculture, importance of agriculture, crop production methods, factors affecting crop production, classification and major crops, cropping systems, tillage, seed production, water management, fertilizers, pest management, and modern techniques for crops like maize, mustard, cotton, and sugarcane. The course assesses students through sessionals, quizzes, a final exam and assignment. Recommended books and references are also provided.
This document outlines the lecture-wise course breakdown for the course Principles of Crop Production (ABT-320). It includes 18 lectures covering topics like importance of agriculture, factors affecting crop production, classification and major crops, crop rotation, cropping systems, tillage, seed treatment, water management, intercultural operations, weed control, plant nutrients, soil fertility, pest management, harvesting, and cultivation practices and techniques for important crops like maize, mustard, cotton, sugarcane and wheat. The course assessments include two sessionals, six quizzes and a final exam. Recommended books and reference materials are also provided.
This document outlines the lecture-wise course breakdown for the course Principles of Crop Production (ABT-320). It includes 18 lectures covering topics like importance of agriculture, factors affecting crop production, classification and major crops, crop rotation, cropping systems, tillage, seed treatment, water management, intercultural operations, weed control, plant nutrients, soil fertility, pest management, harvesting, and cultivation practices and techniques for important crops like maize, mustard, cotton, sugarcane and wheat. The course assessments include two sessionals, six quizzes and a final exam. Recommended books and reference materials are also provided.
This document outlines the lecture-wise course breakdown for the course Principles of Crop Production (ABT-320). It includes 18 lectures covering topics like agriculture, importance of agriculture, crop production methods, factors affecting crop production, classification and major crops, cropping systems, tillage, seed production, water management, fertilizers, pest management, and modern techniques for crops like maize, mustard, cotton, and sugarcane. The course assesses students through sessionals, quizzes, a final exam and assignment. Recommended books and references are also provided.
This document outlines the lecture-wise course breakdown for the course Principles of Crop Production (ABT-320). It includes 18 lectures covering topics like importance of agriculture, factors affecting crop production, classification and major crops, crop rotation, cropping systems, tillage, seed treatment, water management, intercultural operations, weed control, plant nutrients, soil fertility, pest management, harvesting, and cultivation practices and techniques for important crops like maize, mustard, cotton, sugarcane and wheat. The course assessments include two sessionals, six quizzes and a final exam. Recommended books and reference materials are also provided.
This document provides information about red raspberry (Rubus idaeus L.). It discusses the plant's botanical name, family, origin, chromosome number, description of plants, flowers, pollination, and fruit. The core objectives of raspberry breeding programs are also summarized, which include high quality fruit, good yield, shelf life, adaptation to the local environment, and improved pathogen resistance. Breeding methods mentioned include hybridization, mutation, conservation of germplasm, and use of genetic markers.
This document presents a report on crop domestication authored by three students. It discusses the key concepts of domestication including the genetic modification of wild plants by humans to meet their needs. Some major findings are summarized as follows:
- Crop domestication began as early as 11,000 BC with rye and progressed with grains like peas and wheat in the Middle East around 9000 BC. Major centers of early domestication included the Near East, China, Mesoamerica, and South America.
- Domestication results in morphological and physiological changes in plants through human selection over generations. Traits like seed shattering are reduced while fruit and seed size often increase.
- Pioneer scientists like De Cand
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
This presentation intends to explore the communication of the cell within and others for sustainability along the regulation mechanisms by the cellular neural networks and others to sing the song of the life.
Bioenergetics is an important domain in biology. This presentation has explored ATP production and its optimum utilization in biological systems along with certain theories and experiments to give a bird's eye view of this important issue.
This presentation offers the bird's eye view of the cell as the basic structural and functional unit of life. It also addresses the origin of eukaryotic cells from the prokaryotic cell by the endosymbiotic theory.
This presentation has been intended to offer a bird's eye view about the phylogenetic classification of the plant kingdom in general and the Engler and Prantl system in particular with merits and demerits.
This PPT has been made to explore the plant classification in general and the classification as made by Bentham & Hooker for the classification of the flowering plants. It also offers the history of plant classification along with the merits and demerits of this aforesaid classification.
Energy and the biological systems are joined together and no biological world is almost impossible without ATP. This study material intends to explore the beauty of ATP to drive different biological processes.
This PPT offers a bird's eye view of ICBN and its different rules along with regulations for the naming of plants. It also highlights the history of IBC and its contribution to plant taxonomy.
This presentation intends to offer the basic features of plant metabolism along with the different types of mechanisms to regulate and control the metabolic pathways.
This presentation has been designed to give the foundation of taxonomy in general and Plant Taxonomy in particular as a matter of pleasure to explore the diversity of the plant world.
Sex and sexuality are very common words in biology but para-sexuality is a little bit uncommon, several organisms in general and fungi in particular have the pleasure of sexuality to bring variations by beside sex. This PPT explores the beauty of para-sexuality for the academic fraternity.
Sex life in fungi is not less fascinating than in other organisms. Heterosexuality is a matter of pleasure to explore the diversity of sex in fungi along with its cause and consequences. You can find a pleasure to go through the content.
This PowerPoint wants to explore the bird's eye view of the reproduction of bacteria in general and the genetic recombination of bacteria in particular.
The document discusses nutrition in bacteria. It explains that bacteria require carbon, hydrogen, oxygen, nitrogen, metals, and water for their biochemical processes. Bacteria are classified as autotrophs or heterotrophs based on their ability to produce or require organic carbon compounds. Autotrophs can produce organic compounds from inorganic sources like carbon dioxide, while heterotrophs require organic carbon sources. The document further describes different types of autotrophs and heterotrophs based on their energy and carbon sources. These include photoautotrophs, chemoautotrophs, photoheterotrophs, and chemoheterotrophs. Parasitic, saprophytic, and symbiotic bacteria are also discussed
This presentation explores the food value of mushrooms along with the long-term and short-term storage procedures. It also offers a detailed account of the nutrients that remain present in the edible mushrooms.
Cyanobacteria and their role in nitrogen fixation and rice cultivation are discussed. Cyanobacteria can live in many environments and colonize barren areas due to their photosynthetic abilities. They exist as unicellular, colonial, or filamentous forms. Some cyanobacteria can fix nitrogen symbiotically through associations with plants like Azolla. The Azolla-Anabaena association is an example of biological nitrogen fixation. Application of Azolla mats in rice fields can provide nitrogen and improve soil fertility and rice growth. Other factors like temperature, soil pH and nutrients also impact nitrogen fixation.
The document discusses the isolation and mass multiplication of Azospirillum bacteria for use as a biofertilizer. It describes the isolation process from plant roots using selective media. Mass multiplication is done by growing the bacteria in large fermenters with controlled temperature and agitation. The cultured bacteria are then mixed with an inert carrier like peat soil or lignite to produce packaged biofertilizer products containing approximately 109 cells/g. The document also outlines the benefits of using Azospirillum and other biofertilizers like Azotobacter for improving soil fertility and sustainability.
Mais de Nistarini College, Purulia (W.B) India (20)
Discovery of An Apparent Red, High-Velocity Type Ia Supernova at 𝐳 = 2.9 wi...Sérgio Sacani
We present the JWST discovery of SN 2023adsy, a transient object located in a host galaxy JADES-GS
+
53.13485
−
27.82088
with a host spectroscopic redshift of
2.903
±
0.007
. The transient was identified in deep James Webb Space Telescope (JWST)/NIRCam imaging from the JWST Advanced Deep Extragalactic Survey (JADES) program. Photometric and spectroscopic followup with NIRCam and NIRSpec, respectively, confirm the redshift and yield UV-NIR light-curve, NIR color, and spectroscopic information all consistent with a Type Ia classification. Despite its classification as a likely SN Ia, SN 2023adsy is both fairly red (
�
(
�
−
�
)
∼
0.9
) despite a host galaxy with low-extinction and has a high Ca II velocity (
19
,
000
±
2
,
000
km/s) compared to the general population of SNe Ia. While these characteristics are consistent with some Ca-rich SNe Ia, particularly SN 2016hnk, SN 2023adsy is intrinsically brighter than the low-
�
Ca-rich population. Although such an object is too red for any low-
�
cosmological sample, we apply a fiducial standardization approach to SN 2023adsy and find that the SN 2023adsy luminosity distance measurement is in excellent agreement (
≲
1
�
) with
Λ
CDM. Therefore unlike low-
�
Ca-rich SNe Ia, SN 2023adsy is standardizable and gives no indication that SN Ia standardized luminosities change significantly with redshift. A larger sample of distant SNe Ia is required to determine if SN Ia population characteristics at high-
�
truly diverge from their low-
�
counterparts, and to confirm that standardized luminosities nevertheless remain constant with redshift.
Evidence of Jet Activity from the Secondary Black Hole in the OJ 287 Binary S...Sérgio Sacani
Wereport the study of a huge optical intraday flare on 2021 November 12 at 2 a.m. UT in the blazar OJ287. In the binary black hole model, it is associated with an impact of the secondary black hole on the accretion disk of the primary. Our multifrequency observing campaign was set up to search for such a signature of the impact based on a prediction made 8 yr earlier. The first I-band results of the flare have already been reported by Kishore et al. (2024). Here we combine these data with our monitoring in the R-band. There is a big change in the R–I spectral index by 1.0 ±0.1 between the normal background and the flare, suggesting a new component of radiation. The polarization variation during the rise of the flare suggests the same. The limits on the source size place it most reasonably in the jet of the secondary BH. We then ask why we have not seen this phenomenon before. We show that OJ287 was never before observed with sufficient sensitivity on the night when the flare should have happened according to the binary model. We also study the probability that this flare is just an oversized example of intraday variability using the Krakow data set of intense monitoring between 2015 and 2023. We find that the occurrence of a flare of this size and rapidity is unlikely. In machine-readable Tables 1 and 2, we give the full orbit-linked historical light curve of OJ287 as well as the dense monitoring sample of Krakow.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
CLASS 12th CHEMISTRY SOLID STATE ppt (Animated)eitps1506
Description:
Dive into the fascinating realm of solid-state physics with our meticulously crafted online PowerPoint presentation. This immersive educational resource offers a comprehensive exploration of the fundamental concepts, theories, and applications within the realm of solid-state physics.
From crystalline structures to semiconductor devices, this presentation delves into the intricate principles governing the behavior of solids, providing clear explanations and illustrative examples to enhance understanding. Whether you're a student delving into the subject for the first time or a seasoned researcher seeking to deepen your knowledge, our presentation offers valuable insights and in-depth analyses to cater to various levels of expertise.
Key topics covered include:
Crystal Structures: Unravel the mysteries of crystalline arrangements and their significance in determining material properties.
Band Theory: Explore the electronic band structure of solids and understand how it influences their conductive properties.
Semiconductor Physics: Delve into the behavior of semiconductors, including doping, carrier transport, and device applications.
Magnetic Properties: Investigate the magnetic behavior of solids, including ferromagnetism, antiferromagnetism, and ferrimagnetism.
Optical Properties: Examine the interaction of light with solids, including absorption, reflection, and transmission phenomena.
With visually engaging slides, informative content, and interactive elements, our online PowerPoint presentation serves as a valuable resource for students, educators, and enthusiasts alike, facilitating a deeper understanding of the captivating world of solid-state physics. Explore the intricacies of solid-state materials and unlock the secrets behind their remarkable properties with our comprehensive presentation.
(June 12, 2024) Webinar: Development of PET theranostics targeting the molecu...Scintica Instrumentation
Targeting Hsp90 and its pathogen Orthologs with Tethered Inhibitors as a Diagnostic and Therapeutic Strategy for cancer and infectious diseases with Dr. Timothy Haystead.
Anti-Universe And Emergent Gravity and the Dark UniverseSérgio Sacani
Recent theoretical progress indicates that spacetime and gravity emerge together from the entanglement structure of an underlying microscopic theory. These ideas are best understood in Anti-de Sitter space, where they rely on the area law for entanglement entropy. The extension to de Sitter space requires taking into account the entropy and temperature associated with the cosmological horizon. Using insights from string theory, black hole physics and quantum information theory we argue that the positive dark energy leads to a thermal volume law contribution to the entropy that overtakes the area law precisely at the cosmological horizon. Due to the competition between area and volume law entanglement the microscopic de Sitter states do not thermalise at sub-Hubble scales: they exhibit memory effects in the form of an entropy displacement caused by matter. The emergent laws of gravity contain an additional ‘dark’ gravitational force describing the ‘elastic’ response due to the entropy displacement. We derive an estimate of the strength of this extra force in terms of the baryonic mass, Newton’s constant and the Hubble acceleration scale a0 = cH0, and provide evidence for the fact that this additional ‘dark gravity force’ explains the observed phenomena in galaxies and clusters currently attributed to dark matter.
PPT on Alternate Wetting and Drying presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
Travis Hills of MN is Making Clean Water Accessible to All Through High Flux ...Travis Hills MN
By harnessing the power of High Flux Vacuum Membrane Distillation, Travis Hills from MN envisions a future where clean and safe drinking water is accessible to all, regardless of geographical location or economic status.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
Mending Clothing to Support Sustainable Fashion_CIMaR 2024.pdfSelcen Ozturkcan
Ozturkcan, S., Berndt, A., & Angelakis, A. (2024). Mending clothing to support sustainable fashion. Presented at the 31st Annual Conference by the Consortium for International Marketing Research (CIMaR), 10-13 Jun 2024, University of Gävle, Sweden.
The binding of cosmological structures by massless topological defectsSérgio Sacani
Assuming spherical symmetry and weak field, it is shown that if one solves the Poisson equation or the Einstein field
equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
field capable of driving flat rotation (i.e. Keplerian circular orbits at a constant speed for all radii) of test masses on a thin
spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
JAMES WEBB STUDY THE MASSIVE BLACK HOLE SEEDSSérgio Sacani
The pathway(s) to seeding the massive black holes (MBHs) that exist at the heart of galaxies in the present and distant Universe remains an unsolved problem. Here we categorise, describe and quantitatively discuss the formation pathways of both light and heavy seeds. We emphasise that the most recent computational models suggest that rather than a bimodal-like mass spectrum between light and heavy seeds with light at one end and heavy at the other that instead a continuum exists. Light seeds being more ubiquitous and the heavier seeds becoming less and less abundant due the rarer environmental conditions required for their formation. We therefore examine the different mechanisms that give rise to different seed mass spectrums. We show how and why the mechanisms that produce the heaviest seeds are also among the rarest events in the Universe and are hence extremely unlikely to be the seeds for the vast majority of the MBH population. We quantify, within the limits of the current large uncertainties in the seeding processes, the expected number densities of the seed mass spectrum. We argue that light seeds must be at least 103 to 105 times more numerous than heavy seeds to explain the MBH population as a whole. Based on our current understanding of the seed population this makes heavy seeds (Mseed > 103 M⊙) a significantly more likely pathway given that heavy seeds have an abundance pattern than is close to and likely in excess of 10−4 compared to light seeds. Finally, we examine the current state-of-the-art in numerical calculations and recent observations and plot a path forward for near-future advances in both domains.
PPT on Direct Seeded Rice presented at the three-day 'Training and Validation Workshop on Modules of Climate Smart Agriculture (CSA) Technologies in South Asia' workshop on April 22, 2024.
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...Sérgio Sacani
Context. The observation of several L-band emission sources in the S cluster has led to a rich discussion of their nature. However, a definitive answer to the classification of the dusty objects requires an explanation for the detection of compact Doppler-shifted Brγ emission. The ionized hydrogen in combination with the observation of mid-infrared L-band continuum emission suggests that most of these sources are embedded in a dusty envelope. These embedded sources are part of the S-cluster, and their relationship to the S-stars is still under debate. To date, the question of the origin of these two populations has been vague, although all explanations favor migration processes for the individual cluster members. Aims. This work revisits the S-cluster and its dusty members orbiting the supermassive black hole SgrA* on bound Keplerian orbits from a kinematic perspective. The aim is to explore the Keplerian parameters for patterns that might imply a nonrandom distribution of the sample. Additionally, various analytical aspects are considered to address the nature of the dusty sources. Methods. Based on the photometric analysis, we estimated the individual H−K and K−L colors for the source sample and compared the results to known cluster members. The classification revealed a noticeable contrast between the S-stars and the dusty sources. To fit the flux-density distribution, we utilized the radiative transfer code HYPERION and implemented a young stellar object Class I model. We obtained the position angle from the Keplerian fit results; additionally, we analyzed the distribution of the inclinations and the longitudes of the ascending node. Results. The colors of the dusty sources suggest a stellar nature consistent with the spectral energy distribution in the near and midinfrared domains. Furthermore, the evaporation timescales of dusty and gaseous clumps in the vicinity of SgrA* are much shorter ( 2yr) than the epochs covered by the observations (≈15yr). In addition to the strong evidence for the stellar classification of the D-sources, we also find a clear disk-like pattern following the arrangements of S-stars proposed in the literature. Furthermore, we find a global intrinsic inclination for all dusty sources of 60 ± 20◦, implying a common formation process. Conclusions. The pattern of the dusty sources manifested in the distribution of the position angles, inclinations, and longitudes of the ascending node strongly suggests two different scenarios: the main-sequence stars and the dusty stellar S-cluster sources share a common formation history or migrated with a similar formation channel in the vicinity of SgrA*. Alternatively, the gravitational influence of SgrA* in combination with a massive perturber, such as a putative intermediate mass black hole in the IRS 13 cluster, forces the dusty objects and S-stars to follow a particular orbital arrangement. Key words. stars: black holes– stars: formation– Galaxy: center– galaxies: star formation
Candidate young stellar objects in the S-cluster: Kinematic analysis of a sub...
Economic Botany 1
1. WELCOME TO ECONOMIC BOTANY
Origin of Cultivated Plants : Concept of Centres of Origin,
their importance with reference to Vavilov’s work.
Examples of major plant introductions; Crop
domestication and loss of genetic diversity; evolution of
new crops/varieties, importance of germplasm diversity.
By
N. Sannigrahi, Associate Professor,
Department of Botany,
Nistarini College, Purulia (W.B) India
3. INTRODUCTION
The basic needs of the human beings are food, clothing &
shelter. The all the above indispensible items are obtained
from plants directly or indirectly. The angiosperms along with
many fungi, algae, bryophytes, pteridophytes and
gymnosperms play a very crucial role to address the above
needs of the civilization. They can be grouped as follows:
Food plant cereals
Legumes for pulses Nuts
Fruits of diverse types
Fiber yielding plants
Tannins and Dyes
Rubber and its diverse products
Fatty oils & vegetable fats,
Essential oils
4. ECONMIC BOTANY
Organic acids
Sugar yielding Plants
Pulp & paper
Gums & resins
Mucilage
Proteins
Medicinal plants and drugs
Food adjuncts
Apart from these , there are also many plants of great
economic importance which are directly used from the plants
or by the processing , different secondary products are
available and all these substances are used for the
development of civilization and to drive the wheel of
economy of any country. The plant or plant parts used for the
welfare of human beings are addressed in the domain of
economic Botany.
5. PRIMARY AND SECONDARY ORIGIN
All the agricultural crops have been originated from
would ancestor but it is very difficult to find out the wild
ancestors and loci of the domestication of economic
important plants as most of them were developed in the
remote past. Many started to domesticate the crops in the
ancient pasts. De Candolle ( 1883) used many
archeological and ethnological data, historical findings
and philogy to determine the origin and the spread of the
cultivated plants used in the recent times. But it is
generally accepted that cultivated plants were not
distributed uniform throughout the world and even today,
certain regions show greater diversity than other
cultivated crop plants. These areas are called the primary
centre of origin and those plants showing considerable
diversity in forms but not being originated there are
treated as secondary centre of the origin of that species.
6. CROP DOMESTICATION
The centre of origin is a geographical area where the particular
group of organisms (either domesticated or wild) first
originated on earth. Many people believed that centers of origin
are also centers of diversity. But, the centers of diversity may
not represent the centers of origin of crop plants. Although a
few species may have been originated separately at more than
one place, but most species had their origin at a certain place
and then spread elsewhere. In other words, in the centre of
origin a crop is generally confined to one place, whereas the
centre of diversity may be found at more than one place. The
exact location of origin of species is only a matter of
speculation based on indirect evidences. The information on
origin of crop plants is important in plant breeding to locate
wild relatives, related species and new genes. Knowledge of
the origins of crop plants is important to avoid genetic erosion,
the loss of germplasm due to the loss of ecotypes and habitat.
8. VAVILOV SYNDROME
The Russian scientist Nikolai Ivanovich Vavilov and his
colleagues visited several countries and collected a large
number of crop plants and their wild relatives. They used this
collection in Russian breeding programme of developing
improved varieties. His deductions were based on evidences
from morphology, anatomy, cytology, genetics, plant
geography and distribution. He considered that great centers of
origin were always located in lower mountains and hills of
tropical, sub-tropical regions. He also recognizes some
secondary centers of origin where two or more species crossed
together. Secondary centers of origin are the places where
natural and artificial selection occurred on after another. He
stated that plants were not domesticated at random but it was a
continuous process.
9. VAVILOV CENTRES OF ORIGIN
1. Chinese centre: It is considered to be one of the
earliest and largest independent centers of origin of
cultivated plants. This centre includes mountain
regions of central and western China. The endemic
species listed from this centre include Soya bean,
radish, Turnip, Pear, Peach, Plum, Colacasia,
Buckwheat, opium poppy, brinjal, apricots, oranges,
china tea etc.
2. Himalayan centre: It also known as the Indian
centre of origin. This centre includes regions of Assam,
Burma, Indo-china and Malayan Archipelago. The
endemic species listed from this centre include Rice,
red gram, chick pea, cowpea, Mung dal, brinjal,
cucumber, sugar cane, black pepper, Moth bean, rice
bean, cotton, turmeric, indigo, millets etc
10. VAVILOV CENTRES OF ORIGIN
3.Mediterranean centre: This centre includes borders of
Mediterranean Sea. Most of the cultivated vegetables have their
origin in this region. The endemic species listed from this
centre include Durum wheat, emmer wheat, oat, barley, lentil,
pea, grass pea, broad bean, cabbage, asparagus, pepper mint
etc.
4. Abyssinian centre: This region includes Ethiopia and parts of
Somalia. The endemic species listed from this centre include
Wheat, sorghum, bajra, safflower, castor, broad bean, okra,
coffee etc.
5. Central Asian centre: This centre includes north-west India,
Afghanistan, Uzbekistan and western China. The endemic
species listed from this centre include Bread wheat, club wheat,
sesame, linseed, muskmelon, carrot, onion, garlic, apricot,
grape, hemp, cotton etc
12. VAVILOV CENTRES OF ORIGIN
6. Asia minor centre: This centre covers near East Asian
regions like Iran and Turkmenistan. The endemic species listed
from this centre include Wheat, rye, Pomegranate, Almond,
Fig, Cherry, Walnut, Alfa Alfa, Persian clover etc.
7. Central American centre: This centre includes southern parts
of Mexico, Costa Rica, Guatemala and Honduras region. The
endemic species listed from this centre include Maize, rajma,
lima bean, melon, pumpkin, sweet potato, arrow root, chilly,
cotton, papaya, guava, avocado etc.
8. South American centre: This centre includes Peruvian
regions, islands of southern Chile, Brazil and Paraguay regions.
The endemic species listed from this centre include Potato,
sweet potato, lima bean, tomato, papaya, tobacco, quinine,
cassava, rubber, Ground nut, Cocoa, pineapple etc
13. LIMITATIONS OF VAVILOV
The expansion of our understanding on cultivated plants
pointed certain limitations on Vavilov’s views. These views
require some modifications, 1. Vavilov considered the region
with greatest genetic diversity of a species as the centre of
origin of that species. But now, many such species are known
whose centers of origin and genetic diversity are different. For
example, Maize and Tomato
2. The centers of origin of cultivated plants as per Vavilov are
limited to the mountains and small hills in tropical and sub-
tropical regions. But recent evidences also suggest plains as the
centers of origin of many cultivated plants.
3. Today several crops are known whose centers of origin are
different from the ones suggested by Vavilov. Moreover there is
more than one centre of origin. Also, the origin of many of the
species cannot be traced due to lack of sufficient evidence
14. MAJOR PLANT INTRODUCTIONS
Plant introduction is a process of introducing plants (a
genotype or a group of genotypes) from their own environment
to a new environment. The process of introduction may involve
new varieties of crop or the wild relatives of crop species or
totally a new crop species for the area. The process of plant
introduction is the successful compliance of two important
aspects, viz., domestication and acclimatization. Domestication
is the process of bringing of a wild species under cultivation by
making them changed in behavior suitable for new
environment.
Acclimatization is the ability of a crop to become adapted to a
new climatic and edaphic condition.
15. PRIMARY & SECONDARY
Primary Introduction: When the introduced variety
is well suited to new environment then it is released
for commercial cultivation without any alteration of
genotype. For example, dwarf wheat varieties like
‘Sonora-64’, ‘Lerma rojo’ and dwarf rice varieties like
‘Taichung Native 1’, ‘IR-8’ are the examples of primary
introduction.
Secondary introduction:
When the introduced variety is subjected to Selection
or used in hybridization programme with local
varieties to get the improved varieties with some new
characters introduced called secondary introduction.
For example, the varieties like ‘Kalyan Sona’ and
‘Sonalika’ of wheat have been selected from material
introduced from CIMMYT, Mexico.
16. CROP DOMESTICATION & LOSS OF GENETIC
DIVERSITY
Crop domestication is the process of artificially selecting
plants to increase their suitability to human requirements:
taste, yield, storage, and cultivation practices. There is
increasing evidence that crop domestication can profoundly
alter interactions among plants, herbivores, and their natural
enemies. The process of crop domestication is driven by human
selection, cultivation practices, and agricultural environments.
Any selection imposes the reduction of diversity in genomic
regions controlling desirable traits, such as non-shattering
seeds or increased palatability. Furthermore, agricultural
practices greatly reduced effective population sizes of crops,
allowing genetic drift to alter genotype frequencies, including
the random loss of alleles.
17. DOMESTICATION & GENETIC EROSION
Domestication implies the action of selective sweeps on
standing genetic variation, as well as new genetic variation
introduced via mutation or introgression. Furthermore, genetic
bottlenecks during domestication or during founding events as
crops moved away from their centers of origin may have
further altered gene pools. To date, a few hundred genes and
loci have been identified by classical genetic and association
mapping as targets of domestication and post domestication
divergence. However, only a few of these have been
characterized, and for even fewer is the role of the wild-type
allele in natural populations understood. After domestication,
only favorable haplotypes are retained around selected genes,
which creates a genetic valley with extremely low genetic
diversity. These “selective sweeps” can allow mildly
deleterious alleles to come to fixation and may create a genetic
load in the cultivated gene pool.
18. LOSS OF GENETIC DIVERSITY
The term biodiversity was coined by Walter and Rosen (1985)
and is the abbreviated word for Biological Diversity. Life
originated on earth almost four billion years ago and nature
took more than 1 billion year to develop this wide and complex
spectrum of life on earth. Scientists believe that the total
number of species on earth is in between 10-80 million (Wilson
1988) of which 1.4 million species have been enlisted so far.
i) Biodiversity is the variety of life in all its forms, levels and
combinations. It includes species diversity, genetic diversity
and ecosystem diversity (International Union for Conservation
of Nature and Natural Resources—IUCN, United Nations
Environment Programme—UNEP and World Wildlife Fund—
WWF 1991).
19. BIODIVERSITY-DEFINITIONS
ii) United Nations Earth Summit in Rio de Janeiro defined
biodiversity as – The variability among living organisms from
all sources, including terrestrial, marine and other aquatic
ecosystems and the ecological complexes of which they are
part. This includes diversity within species, between species
and of ecosystems.
(iii) According to U.S. Congressional Biodiversity Act –
Biological Diversity is the variety and variability among living
organisms and the ecological complexes in which they occur
and encompases ecosystem diversity, species diversity and
genetic diversity. iv) In the simplest terms, biological diversity
is the variety of life and its processes and it includes the variety
of living organisms, the genetic differences among them and
the communities and ecosystems in which they occur.
21. TYPES OF BIODIVERSITY
Biodiversity is usually studied at three different levels—Species
diversity, Genetic diversity and Ecosystem diversity. It actually refers
to species richness, in terms of number of species in a site or habitat.
Global diversity is typically represented in terms of total number of
species of different taxonomic groups. As mentioned before, an
estimated 1.4 million species have been identified to date. Species
diversity, again, is studied at three levels: alpha diversity (number of
species coexisting at a site), beta diversity (difference in species
complement between patches) and gamma diversity (number of
species in a large area, e.g. a country). This series can further be
extended to delta diversity for biomes (biomes are climatically and
geographically defined areas of ecologically similar climatic
conditions such as communities of plants, animals and soil organisms
and are often referred to as ecosystems) and omega diversity for the
entire biosphere.
23. CAUSES OF LOSS OF GENETIC DIVERSITY
Alteration and loss of the habitats: The transformation of the
natural areas determines not only the loss of the vegetable
species, but also a decrease in the animal species associated to
them.
Introduction of exotic species and genetically modified
organisms: Species originating from a particular area,
introduced into new natural environments can lead to different
forms of imbalance in the ecological equilibrium. Refer to,
“Introduction of exotic species and genetically modified
organisms”.
Pollution: Human activity influences the natural environment
producing negative, direct or indirect, effects that alter the flow
of energy, the chemical and physical constitution of the
environment and abundance of the species.
24. CAUSES OF LOSS OF GENETIC DIVERSITY
Climate change: For example, heating of the Earth’s
surface affects biodiversity because it endangers all
the species that adapted to the cold due to the latitude (the
Polar species) or the altitude (mountain species).
Overexploitation of resources: When the activities connected
with capturing and harvesting (hunting, fishing, farming) a
renewable natural resource in a particular area is excessively
intense, the resource itself may become exhausted, as for
example, is the case of sardines, herrings, cod, tuna and many
other species that man captures without leaving enough time
for the organisms to reproduce.
The introduction of invasive species is the tremendous
threat to biodiversity crisis. The species, which is not
native to the ecosystem, arrives or is introduced mostly
via humans in the
25. CAUSES OF LOSS OF GENETIC DIVERSITY
new ecosystem and start to pullulate is called as invasive species.
Such species are detrimental as they effect the ecosystem
disproportionately compared to any other species. Most of the new
species introduced in the ecosystem do not become invasive, but few
of them turn into invasive species and adversely affect the
ecosystem.
Natural catastrophes, for instance volcanoes, wildfires, floods,
hurricanes, draughts, epidemics, tsunamis etc. cause a heavy loss of
biodiversity . In humid tropical areas such as central Africa, eastern
and northern Australia, some areas of South America floods are
common. The tropical areas harbor lot of vegetation and vast number
of animals survive in the vegetation. Due to flooding, large amount
of nutrients from the soil gets washed away. Drought too led to dry
soil and decline in the level of water table [29]. In this situation, both
animals as well as plants suffer.
26. EVOLUTION OF NEW CROPS/VARITIES
Domestication is a good model for the study of evolutionary
processes because of the recent evolution of crop species
(<12,000 years ago), the key role of selection in their origins,
and good archaeological and historical data on their spread and
diversification. Recent studies, such as quantitative trait locus
mapping, genome-wide association studies and whole-genome
resequencing studies, have identified genes that are associated
with the initial domestication and subsequent diversification of
crops. Together, these studies reveal the functions of genes that
are involved in the evolution of crops that are under
domestication, the types of mutations that occur during this
process and the parallelism of mutations that occur in the same
pathways and proteins, as well as the selective forces that are
acting on these mutations and that are associated with
geographical adaptation of crop species.
27. EVOLUTION OF CROPS
A divergent process which increases genetic diversity and leads
to change in allelic frequencies in a population is known as
evolution. In other words, a process which leads to significant
deviation in the characteristic features of existing individuals as
compared to their pre-existing individuals is termed evolution.
Evolution –Natural & Man made. In case of natural evolution,
natural selection operates, while in man-made evolution human
selection operates. Thus, both natural and human selections
play significant role in the process of evolution. Plant breeding
is considered as current phase of crop evolution. Changes
which are brought out as a result of evolution are measured in
terms of morphological, anatomical, embryological,
physiological, biochemical and genetic modifications in the
present forms of individuals as compared with their past forms.
28. FACTORS OF EVOLUTION
(1) Polyploidy,
(2) Introgression, and
(3) Mutations have played significant role in the evolution of
various crop plants.
These three factors aid in the process of evolution by way of
inducing additional genetic variability, which is a basic
requirement for selection to operate.
Polyploidy:
Polyploidy refers to numerical change in the genome (A basic
set of chromosomes)-Auto polyploidy & Allopolyploids.
Allopolyploid bears strong significance as per as the speciation
is concerned as it results from doubling of chromosomes of
interspecific hybrid.
29. AUTOPOLYPLOIDS
This is also known as simple polyploidy or single species
polyploidy, because the increase in chromosome number
relates to the same species. This type of polyploidy can occur
in nature as well as can be induced by colchicine treatment.
Increase in chromosome from diploid to tetraploid state leads
to increase in vigour and size of flowers and fruits over diploid
forms. However, polyploid plants exhibit slow growth rate and
reduced fertility due to chromosomal imbalance.
Autopolyploidy has been used in crops like banana, apples,
sugarbeet, watermelon, potato, oranges, tulips, etc. The
commercial banana is autotriploid (3n), which has seedless and
larger fruits than diploid forms. Some varieties of apples in
USA are triploids, which are propagated asexually by
budding and grafting. Triploid varieties of sugarbeet
have higher sugar content than diploids Triploid
watermelons.
31. INTROGRESSION
Incorporation of gene of one species into the genetic
background of another species by means of interspecific
hybridization and backcrossing is known as introgression
(Anderson, 1949). The interspecific hybrid backcrosses in
nature with one of the parental species.
As a result of introgression, genes from two divergent species
are combined. A true breeding recombinant form favored by
natural selection may give rise to a new species. Introgressive
hybridization between primitive maize and wild grass
Tripsacum is considered to be responsible for the evolution of
modern forms of maize.
33. MUTATIONS
Mutations are important sources of creating variability in a
genetic population. Mutations can occur in nature as well as
can be induced by the use of physical or chemical mutagenic
agents. In hexaploid wheat, a natural mutation is responsible
for homologous pairing. Spontaneous mutations have played
significant role in the evolution of crop plants. Spontaneous
mutations can be used either as a cultivar or as a parent in the
hybridization programme. Induced mutations have played key
role in improving yield, quality, earliness, adaptation, and
disease and insect resistance in various crop plants.
The bread wheat is hexaploid, combining diploid chromosome
complements from three different species. In nature, hexaploid
bread wheat behaves as diploid [n = 21 and 2n = 42]. It has
been found that hexaploid wheat has acquired this property of
diploid pairing from a mutation on chromosome number 5B,
which inhibits pairing between homologous chromosomes
(chromosomes of different genomes).
35. DIFFERENT TYPES OF CROP EVOLUTION
The genetic evolution of some important field crops such as
wheat, cotton, tobacco, Brassica, potato, maize and rice is
briefly described below:
The tetraploid species developed as an amphidiploids between
two diploid species, and hexaploid species originated from a
cross between tetraploid and diploid species. It is believed that
tetraploid species Triticum turgidum evolved as an
amphidiploids between Triticum monococcum (AA) and an
unknown species (now probably extinct) with BB genome. The
hexaploid bread wheat originated as an amphidiploids between
Triticum turgidum (AABB) and T. tauschii (DD). The overall
process can be represented as follows.
38. ALLOPOLYPLOIDS
This is also known as hybrid polyploidy or bispecies or
multispecies polyploidy depending upon the species involved.
Such polyploidy is obtained by doubling of chromosome
number by colchicines treatment. Allopolyploid has been more
instrumental in evolution of crop plants, because 50% of the
crop plants are allopolyploids.
Hybrid polyploidy has played significant role in the evolution
of crops like wheat, tobacco, cotton, Brassica, oat, etc.
Examples of artificially produced allopolyploids include
triticale, strawberry and loganberry.
Triticale is a man-made new cereal (between wheat and rye),
which combines high yield of wheat and disease and drought
resistance of rye.
39. GERMPLASM & IMPORTANCE
Germplasm contains the information for a species' genetic
makeup, a valuable natural resource of plant diversity.
Agriculture benefits from uniformity among crop plants within
a variety, which ensures consistent yields and make
management easier. Germplasm in a broad way can be
defined as the hereditary material i.e. total content of
genes which is inherited by the off springs through
germ cells. Germplasm serves as the raw material for
the breeder to produce various crops. Therefore,
conservation of germplasm has importance in all
breeding programmes.In previous days, humans
gained the knowledge about the use of plants for food ,
shelter and many more, thus they started saving
selected seeds or vegetative propagules from one
season to the next one. The possibility of life on earth
is mainly due to the plants as it is
40. GERMPLASM & IMPORTANCE
the crucial component of the ecosystem, thus its preservation is
our responsibility for the continuation of life. In other words, it
may be regarded as the conventional germplasm preservation
and management, which is highly precious in breeding
programmes. The main objective of germplasm conservation is
to preserve the genetic diversity of selected plants or genetic
stock for its utilization at any time in future.
In recent years, the primitive and conventionally used
agricultural plants are being replaced by many new plant
species with desired and improved characteristics. It is very
crucial to conserve the endangered plants otherwise some of
the important genetic traits possessed by the primitive plants
may be lost. It has been estimated that up to 100,000 plants,
depicting more than one third of all the world’s plant species,
are currently threatened or face extinction in the wild.
41. PROSPECTS OF GERMPLASM
As previously stated, Genetic resource is treated as
Germplasm and the germplasm are used extensively for
the following attributes:1. Varieties used in cultivation-
There are good sources of genes for quality yield
because they can be introduced into new geographical
region for the cultivation to add economic
gain,2.Breeding lines- In the different breeding
programmes, the different narrow genetic base with
valuable gene combinations are used and they can be
used for the wide scale breeding exercises.3.For special
genetic stocks-These lines are carrying chromosomal
aberrations , gene mutations etc and these will be set of
monosomic or bisomic lines to be induced artificially,
Wild relatives and forms- These are valuable source of
genes for development of GMP through genetic
engineering programmes.
43. ACKNOWLEDGMENTS
1. For images: Google
2. Different web pages or free resources
Different articles from different web sites
Economic Botany- Bhabananda Baruah,
Economic Botany- S.Chand & company
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