PLANT BREEDING PRACTICAL

1. PLANT BREEDING PRACTICAL MANUAL
1. BOTANICAL DESCRIPTION AND FLORAL BIOLOGY
-Pavan kumar naik
What is a flower?
A flower is a functional unit concerned with reproduction. A flower can be pictured as a very
short stem (the receptacle) which holds the components of the flower in sequence at the very
tip of this stem, so they appear in the centre of the flower, c/a female organs (the gynoecium).
Next to them are the male organs (the androecium) and next to them are the petals (corolla)
and sepals (calyx).
Flower Structure
Gynoecium-(=pistil)- collective term for all the female reproductive organs of a flower
comprising one or more free or fused carpels
 Carpel-One of the flower’s female reproductive organs comprising a stigma, a style
and an ovary
1. Stigma- The receptive part of the female reproductive organ on which pollen
germinates.
2. Style-the elongated part of a carpel bearing the stigma, usually at the tip.
3. Ovary-the hollow basal region of a carpel, consisting one or more ovules.
4. Ovules- the structures in the chamber of an ovary containing the egg cell, within the
embryosac.The ovules develop into the seeds after fertilization.

2. Androecium-collective term for all the male reproductive organs of a flower comprising one
or more free or fused stamens.
 Stamen-the male reproductive organ of a flower consisting of an anther and a
filament.
1. Anthers- usually bilobed, contains the pollen.
2. Filament-the stalk bearing the anther
Perianth-the floral envelop usually divisible into an outer whorl (calyx) of sepals and inner
whorl of petals (corolla).
 Corolla collective term for all the petals of a flower.
1. Petal- a non-reproductive accessory organ of a flower. This is sterile and
usually brightly colored, attracts insect pollinators.
 Calyx collective term for all the sepals of a flower.
1) Sepal- a floral leaf or individual segment of the calyx of a flower, generally
green, that forms the outer protective layer of a flower bud.
2) Receptacle- flat, concave or convex part of the stem from which all parts of a
flower arise.
{A complete flower is one with all parts (calyx, corolla, androecium and gynoecium)
present. A flower lacking one or more of these parts is said to be incomplete. A perfect
flower is one with both androecium and gynoecium present. If either are lacking, the
flower is said to be imperfect.}

3. 2. PLANT BREEDERS KIT
FINE POINTED FORCEPS
USE: It is used for incising the floral buds and for removing the anthers from it. E.g.
Tobacco, Sesamum etc.
BUTTER PAPER BAG
USE: It is used for protecting the individual flowers or small twigs during selfing or crossing
e.g. Mungbean, Tur, Cotton, Okra, Brinjal and Earheads of Sorghum, Bajra, Wheat and
Maize.
Being white and semi-transparent it is more suitable than paper bags even enthesis or
blooming can be seen from outside

4. SMALL/ CURVED SCISSOR
USE: For cutting the small florest in cereals and small flowers in the crops like Lucerne,
Guar etc.
LONG STRAIGHT SCISSOR
USE: It is used for clipping, cutting the vegetable parts and large size floral parts in cereals
like Wheta, Sorghum, Bajra and Tobacco.

5. SHARP POINTER
USE: It is used for incising the floral parts and for removing the anthers from the crops like
bajra.
EYE LENS OR MAGNIFYING LENS
USE: For observing the reproductive parts to confirm that there should not be any part of the
anther left on the stigma or stigma is free from any foreign pollens.

6. AUTOMIZER
USE: It is used for spraying the gametocides during emasculation of flowers e.g. 57% ethyl
alcohol can be filled in it for killing the pollens of Lucerne.
U-PINS(U- CLIPS)
USE: It is used for fasting the bags on earheads or flowers to keep the bag in proper position.

7. HAIR BRUSH
USE: It is used for transferring the pollen grains in crops like Castor, Sorghum etc.
ADVANTAGE: Without injuring to stigmas or pollens, pollination is a accomplished very
smoothly.
WASHING BOTTLE
USE : It is used for filling sterilizing agent like alcohol or spirit to sterilize the scissors,
pointers, forceps and brush during crossing work.

8. SMALL WHITE TAG
 USE : It is used for identifying the internal flower or a small twig during crossing
programme. The detailed information about crossing is written on it with pencil and then it is
inserted on pedicel or peduncle e.g. Cotton, Bajra, Wheat, Sorghum, Sesamum etc.
ALUMINIUM LABEL WITH WIRE
 USE : It is used for tagging the flowers in fruit crops or tree species after crossing. It
is also used for identification of selected trees.

9. MUSLIN CLOTH BAG (LARGE SIZE)
 USE : To cover the whole plant while selfing or crossing in the crops like Chillies,
Brinjal etc. In large sized plants like Tur it can be used for protecting individual branch also.
YELLOW SAMPLE BAG
 USE : For storing the crossed seeds in small quantity.

10. BROWN PAPER BAG
 USE : For selfing Bajra, Wheat, Sorghum, Castor etc.

11. 3. DIFFERENT EMASCULATION AND CROSSING TECHNIQUES IN
IMPORTANT HORTICULTURAL CROPS
 Emasculation is the
process of removing
anthers from bisexual
flowers without affecting
the female reproductive
part (pistil).
Emasculation is performed
by plant breeders in
bisexual flowers to obtain
the desired variety of a
plant by crossing a
particular plant with the
desired pollen grain.
 To remove the anthers, the
flowers are covered with a bag before they open. This ensures that the flower is
pollinated by pollen grains obtained from desirable varieties only. Later, the mature,
viable, and stored pollen grains are dusted on the bagged stigma by breeders to allow
artificial pollination to take place and obtain the desired plant variety.
Methods of Emasculation
HAND EMASCULATION
In species with large flowers, removal of anthers is possible with the help of forceps.
It is done before anther dehiscence. It is generally done between 4 and 6 PM one day
before anthers dehisce. The corolla of the selected flower is opened with the help of
forceps and the anthers are carefully removed with the help of forceps. Sometimes
corolla may be totally removed along with epipetalous stamens e.g. gingelly. In
cereals, one third of the empty glumes will be clipped off with scissors to expose
anthers.
SUCTION METHOD
It is useful in species with small flowers. A thin rubber or a glass tube attached to a
suction hose is used to suck the anthers from the flowers. The amount of suction used
is very important which should be sufficient to suck the pollen and anthers but not
gynoecium.

12. HOT WATER TREATMENT
In case of hot water emasculation, the temperature of water and duration of treatment
vary from crop to crop. It is determined for every species. For sorghum 42-48OC for
10 minutes is found to be suitable. In the case of rice, 10 minutes treatments with 40-
44OC is adequate.
ALCOHOL TREATMENT
In Lucerne the inflorescence immersed in 57% alcohol for10 second was highly
effective. It is better method of emasculation than suction method.
Selfing and Crossing techniques in important horticultural crops
Selfing
1. Bag the tassel before anthesis with a paper cover. Bagging of tassels should be done
in the previous day evening to avoid contamination from foreign pollen.
2. Cut the tip of the cob before the silks emerge and cover with a paper cover.
3. After 3-4 days, the silks will emerge in the form of a ‘saving brush’ in which the silks
will be of same height and stand erect.
4. Remove the cover of the tassel containing pollen and insert it over the cob after
removing the cob-cover. The inserted cover is then tied.
Crossing technique
Female parent
a. Detassel
b. Cut the tip of the cob before the silks emerge and cover with a butter paper cover.
Male parent
a. Cover the tassel before anthesis begins or as soon as the tassel emerges.
When the silks emerges in the female parent in the form of a brush, pollination is done by
transferring the freshly shed pollen cover form the male parent and inserting it over the cob of
the female parent after removing the cover from the cob.
The details like date of pollination, parentage and breeding programme to be carried out are
clearly written by water proof pencil. The date or pollination will be one day later than the
date of tasselling. Pollination should be completed within one week of silk
emergence. Isolation distance for maize = 400M.

13. 4. BREEDING OBJECTIVES FLORAL BIOLOGY, SELFING-
EMASCULATION CROSSING TECHNIQUES IN TOMATO, BHENDI
AND CHILLIES.

15. BRINJAL
 Floral biology
 Brinjal flowers are large, violet coloured and solitary or in clusters of two or
more.
 Calyx: sepals 5, united
Corolla: petals 5, united, usually cup shaped
• Androecium : stamens 5, alternate with corolla; Gynoecium: carpels are united,
ovary superior. The hypogynus gynoecium is syncarpus.
• The perfect flowers are borne singly and opposite to the leaves. In brinjal,
heterostyly is a common feature. Four types of flowers have been reported
depending on the length of styles, viz. (i) long-styled with large ovary, (ii)
medium-styled with medium size ovary, (iii) Pseudoshort-styled with
rudimentary ovary and (iv) true short-styled with very rudimentary ovary
(Krishnamurthi and Subramaniam, 1954).

16. CHILLI
 Habit: Casicum annnum (Capsicum and Chilli) is a perennial herb but grown as
annual.
 Root: Tap root numerous profusely branched lateral roots develop. Height
extending to 1 meter.
 Shoots: Main shoot is radial but lateral branches are cincinnate.
 Leaves: Simple, petiole 0.5-2.5 cm long, lamina broadly lanceolate to ovate,
entire, thin, 1.5 to 12 cm long and 0.5 to 7.5 cm broad, tip acuminate, base acute.
 Flowers: Flower of capsicum species are pentamerous but large fruited cultivars
have 5-7 corolla lobes. Usually borne singly and are terminal but dueto
branching they appear to be auxillary, pedicels upto 1.5 cm long.
 Calyx: Campanulate, about 2 mm long enlaging and enclosing base of fruits.
 Corolla: Rotate, companulate, deeply 5-partile, 8-15 mm in diameter.
 Androecium: White or greenish stamens, 5-6 inserted nea base of corolla.
Occasionally anthersare yellow in colour. Stamens alternate with the petals and
correspond with them in number.
 Gynoecium: Ovary superior, style simple, white or purple, stigma capitate.
 Fruit: Indehiscent, many seeded bery. Variable in size, shape, colour, and degree
of pungency.
 Seeds: Seeds 3-5 mm long, pale yellow.
 Pollination:
 Crossing time: any time of day light hours but best times are in early morning or
in late afternoon. Anthers with two pollen sacs, pollen release is from lateral
sutures longitudinally.
 Out crossing: less in bell pepper types and more in chilli types.
According to various reports it varies from 7.62 to 36.8%.

17. 5. BREEDING OBJECTIVES FLORAL BIOLOGY, SELFING- EMASCULATION
CROSSING TECHNIQUES IN BOTTLE GOURD AND RIDGE GOURD.
Diagnostic characters of Bottle gourd and Ridge gourd
Vegetative Characters:
Habit: The plants are mostly succulent, trailing annual or perennial herbs. These
plants climb by means of laterally spirally coiled, simple or branched tendrils.
Roots: These plants have woody tap root system.
Stem: The stem is branched, hairy and five angular with two alternate rings of five
vascular bundles each.
Leaves: The leaves are simple, alternate, long petiole, and cordate. The leaves are
often palmately lobed. The petioles are often hollow and stipules are absent. Leaves
bear tendrils in their axils.
Floral characters:
Inflorescence: Inflorescence is cymose type. It may be axillary and bears a solitary
female flower. The male flowers may be solitary and in the form of racemes. The
plants are monoecious or sometimes dioecious as in Coccinia indica and Momordica
dioca.
Flower: The flowers are yellow or white, unisexual (rarely bisexual), actinomorphic,
pentamerous and epigynous. The thalamus forms a cup above the ovary.
Calyx: The calyx is of 5 sepals forming a tube, which is wholly adnate to the ovary in
female flowers. The aestivation is valvate.
Corolla: The corolla consists of 5 petals which are united to form a tube
(Trichosanthes). The corolla is campanulate (Coccinia, Cucurbita) form. Petals are
white or yellow in color. The petals are free in Luffa, Trichosanthes.
Androecium: The Androecium is present in the male flowers only. In female flowers it
may be represented by staminodes. The Androecium shows much variation. The
simplest condition is where 5 free stamens are present (Luffa cylindrica) with
dithecous/monothecous anthers.
In Lagenaria, Cucumis and Citrullus there are three stamens with one monothecous
anther and other two as dithecous anthers.

18. Gynoecium: The gynoecium is present only in the female flowers. It consists of 3
syncarpous carpels with completely inferior ovary. Ovary becomes spuriously three
loculed. They have only one style with three stigmas.
Fruit: The fruit is fleshy-berry with soft or hard pericarp. This type of fruit is called
pepo.
Seed: The seeds are compressed and non-endospermic.
Breeding objectives floral biology, selfing- emasculation crossing techniques in Mango.

19. 6. DETERMINATION OF MODE OF REPRODUCTION IN PLANTS.

24. 7. CALCULATION OF HETEROSIS , HETEROBELTIONSIS AND
STANDARD HETEROSIS AND INBREEDING DEPRESSION.
1. Average heterosis:
 It is the heterosis where F1 is superior to mid parent value. In otherwords superior to
average of two parents.
F1 - MP
--------- x 100
MP
Where F1 = Mean of hybrid
MP = Mid parental value.
(P1 + P2) where P1 = Parent 1
MP = ---------- P2 = Parent 2
This type of heterosis is of no use in agriculture since the superiority is below the
better parent value
2. Heterobeltiosis:
 Superiority of F1 over the better parent.
F1 - BP
--------- x 100
BP
Where BP = Mean of Better Parent.
3. Economic heterosis:
 Superiority of the F1 compared to the high yielding commercial variety in a particular
crop.
F1 - CV
--------- x 100
CV

25. Where CV = Mean of Commercial Variety.
4. Negative heterosis:
 Performance of F1 inferior to better parent / mid parent value. - e.g. Duration.