Hand outs for applications of plant tissue culture

1. Table A 1.2. Different Techniques of Plant Tissue Culture and Their Applications in
Plant Improvement (Adapted from: Murashige, 1979; Pierik, 1987; Brar and Khush,
1994; Brown and Thorpe, 1995).
Tissue Culture Technique Applications
Seed Culture  Increasing efficiency of germination and germling production in seeds,
difficult to germinate in vivo.
 Precocious germination by application of plant growth regulators.
 Induction of multiple shoot formation and organogenesis by
application of plant growth regulators.
 Elimination of viruses as seeds do not carry viruses.
Embryo Culture  Overcoming embryo abortion due to incompatibility barriers.
 Overcoming seed dormancy and self-sterility of seeds.
 Embryo rescue in distant (interspecific or intergeneric) hybridization
where endosperm development is poor.
 Production of monoploids.
 Shortening of breeding cycle.
 For development of callus cultures.
Ovary or Ovule Culture  Production of haploid plants.
 Recovery of hybrid embryos overcoming embryo abortion at very
early stages of development of zygote due to incompatibility barriers.
 Achievement of In vitro fertillization.
Anther and Microspore Culture  Production of haploid plants.
 Production of homozygous diploid lines through chromosome
doubling, thus reducing the breeding cycle.
 Genetic transformation using microspores.
 Production of useful gametoclonal variations.
 Mutation investigations easier with single set of chromosomes.
 Fixation of certain genetic characters from heterozygous source
materials.
In vitro Pollination  Production of hybrids difficult to produce by embryo rescue.
In vitro Fertilization  Production of distant hybrids avoiding style and stigmatic
incompatibility that inhibits pollen germination and pollen tube growth.
 Production of transgenics by injecting exogenous DNA in the nuclei
of gametes and zygotes.
Organ Culture  Mass production of plants of elite and rare germplasm.
 Production of calli, shoots and roots for production of secondary
metabolites.

2.  Development of germplasm banks for rare and endangered plants.
Shoot Apical Meristem Culture  Production of virus free germplasm.
 Mass production of desirable genotypes.
 Facilitation of international exchange.
 Cryopreservation or In vitro conservation of germplasm.
 Phytosanitary transport.
Somatic Embryogenesis  Mass multiplication of elite germplasm.
 Production of artificial seeds.
 As source material for embryogenic protoplasts.
 For genetic transformation.
 Production of primary metabolites specific to seeds such as lipids in
oil seeds.
 Amenable to mechanization and for bioreactors.
Organognesis and Enhanced Axillary
Budding
 Mass multiplication of elite germplasm.
 As source material for protoplast work, genetic transformation and
mirografting.
 Conservation of endangered genotypes either at normal or at sub-
zero temperatures.
Callus Cultures  Production of plantlets through somatic embryogenesis or
organogenesis.
 For obtaining virus-free plants.
 For generation of useful somaclonal and gametoclonal variants.
 As a source of protoplasts and suspension cultures.
 Production of useful secondary metabolites.
 For biotransformation studies.
 Selection of cell lines with valuable properties such as resistance to
disease, herbicides, overproduction of secondary metabolites etc.
 For mutagenetic studies.
In vitro Production of Secondary
Metabolites
 Production of useful compounds such as drugs, aromatic substances,
pigments, flavors etc. without destruction of mother plants.
 Production of novel metabolites normally not produced by the parent
plant.
 Biotransformation and elicitor studies.
Cell Culture and In vitro Selection at  Production of somatic embryos, morphognetic nodules and entire

3. Cellular Level plantlets.
 Over-production of secondary metabolites.
 Over-production of primary metabolites.
 Induction and selection of useful mutants or somaclones at cell level
for disease resistance, stress tolerance and improved nutritional
quality in less time and space.
Somaclonal Variations
(Genetic or Epigenetic)
 Isolation of useful variants in well-adapted, high yielding genotypes
lacking in a few desirable traits.
 Isolation of useful variants overproducing primary or secondary
metabolites.
 Isolation of useful variants with better disease resistance, stress
tolerance capacities.
 Creation of additional genetic variation without hybridization in useful
cultivars.
In vitro Mutagenesis  Induction of polyploidy for consequent increase in biomass or yield.
 Introduction of genetic variability and rapid selection as well as
multiplication of useful mutants.
 As a tool for developmental genetics and for elucidation of
biochemical processes.
Protoplast Isolation, Culture and Fusion  Combining distant genomes to produce somatic hybrids,asymmetric
hybrids and cybrids.
 Production of organelle recombinants.
 Transfer of CMS (cytoplasmic male sterility) in elite lines.
 Source material for genetic transformation.
 Creation of genetic variants.
Genetic Transformation  Introduction of foreign DNA to generate novel genetic combinations.
 Transfer of desirable genes for disease and pest resistance from
related or unrelated plant species into high yielding susceptible
cultivars.
 Study of structure and function of genes.
 Induction of hairy roots or shooty terratomas for over-production of
secondary metabolites, naturally present in mother plant.
 Production of novel secondary metabolites absent in parent plant.
In vitro Flowering  Reduction in long life cycle in perennials such as Bamboo.
 Continuous supply of flowers, fruits and seeds irrespective of season.
Micrografting  Overcoming graft incompatibility.
 Rapid mass propagation of elite scions grafted on rootstocks having
desirable traits like resistance to soil-borne pathogens and diseases.
 Multiplication and survival of difficult to root species as well as of
transformants.

4.  Development of virus free plants.
Cryopreservation or Storage at Low
Temperature
 Long term preservation of useful germplasm (cell lines, meristems,
plant organs, morphogenetic callus cultures).
 Conservation of natural genetic variability.
Culture of protoplasts, cells, tissues and
organs
As a tool in Phytopathological Research.
 Virus preparation and replication.
 Culture of obligate parasites.
 Host-parasite interactions.
 Culture of nematodes (Excised root cultures).
 Testing of phytoalexins and phytotoxins.
 Nodulation studies.
As a tool in Plant Physiological Research.
 Cell cycle studies.
 Metabolic studies.
 Nutritional studies.
 Morphogenetical and developmental studies.
Culture of hairy roots  For understanding and manipulating root-specific metabolism.
 For co-culture with VAM fungi to increase secondary metabolite
production.
 For co-culture with insects to study pathogenesis.
 For study and commercial exploitation of bioactive root exudates.
 For co-culture with shooty teratomas to exploit both root and shoot
based metabolism for biotransformations and also for metabolite
production specific with both these locations.
 For development of "green hairy roots" which are photoautotrophic
and hence display a different spectrum of secondary metabolites.