5. 1. Roots: It has a tap root system with a depth of
50cm or more.
2. Stem: Growth habit is erect to prostate. Plant
height is 2-4m. The stem is solid, coarse, hairy and
glandular.
3. Leaf: are spirally arranged, 15-50cm long and 10-
30cm wide. They are odd pinnate with 5-9 leaflets
which are ovate to oblong, covered with glandular
hairs having serrated margins.
Botanical Description:
8. 5. Flower: Ebracteate, Bright yellow, Chasmogamous,
Pentamerous, Actinomorphic, Hypogynous,
Hermaphrodite, with a pistil enveloped with a solid
tube formed by stamens.
13. c) Androecium:
* 5 Stamens
* Epipetalous
* Small filaments
* Large anthers
* Stamens from a solid enclosing the pistil
* Anther dehiscence is longitudinal
14. d) Gynoecium:
* Ovary: superior, bicarpellary and syncarpous.
* Style: Single
* Stigma: Bilobed
15. • Starts in morning around 6am and continues till 11am.
• Maximum flower opening is from 7 to 9 am.
• Stigma receptivity: 16 to 18 hrs before anthesis to 5
to days after anthesis.
• Pollen viability: 2 to 5 days(18 – 25 ˚C) and up to 6
months in a dessicator (5˚C).
Anthesis:
16. • Essentially a Self Pollinated crop as stamens form a
solid cone enclosing the pistil.
• Self pollination varies between 94 - 99%.
17. • But 1.5 – 47% Natural Cross pollination have been
reported depending on
– Temperature
– Insect population & activity at flowering time
– Planting design
– Plant population
– Wind velocity & direction
– Genotypic nature
18. Selfing techniques:
• Bagging of young bud
• Manual transfer of freshly collected pollen on
stigmas of flowers of the same plant.
Pollination:
20. • Select the bud in which anthesis will commence 12-
16hrs later
• Petals just out of bud
• Corolla colour is yellow or even paler
Selection of flower bud:
21. A) Emasculation:
• Removal of male organs from flower of female
parent
• Use sharp-pointed forceps to force open the
selected buds
• Then split open the anther cone
22. • Grasp the anther cone with forceps with one tip
inserted between style & anther and the other
between anther and calyx
• Gently pulling away from the floral axis carefully
remove the anther cone out of the bud, leaving the
calyx, corolla and pistil
23. • Or the stamens can also be removed individually
• Bag the emasculated flowers
• Normally emasculation is done in the afternoon and
pollination in the next morning
• To avoid emasculation CGMS or GMS lines can be
used
24. B) Pollen collection:
• Collect flowers from the male parent during early
morning hours
• Remove the anther cones from the flowers and put
them in glassine envelopes
25. • Dry the anthers by placing the envelopes 30 cm below
a 100-watt lamp for 24 hours. The temperature is
around 30˚C
26. • Put the dried anther cones in a vial. Cover the vial
with a fine mesh screen (200-300 mesh) and then
seal it with a similar tight-fitting cup, serving as a lid
• Shake the vial about 10- 20 times so that the pollen is
collected in the “lid” cup.
27. • Transfer the pollen into a small suitable container for
pollination. Fresh pollen is best for good fruit-set. It
can be kept for one day at moderate room
temperature
• Or can be placed in dehydrator with silica gel & kept
in a refrigerator at 10°C to maintain viability for 10 -
15 days
28. • Tap or vibrate the flower to release the pollen and
collect it in a glass tube
• Or use a flattened dissecting needle or forceps to
gather pollen by cutting a slit in the anther cone and
scraping the contents of one antheridia at a time
29. C) Artificial pollination:
• On complete blossoming of the emasculated flowers
cut their calyx and corolla to expose the stigma
30. • Dip the stigma into the pool of pollen in the pollen
container
• Or pollinate by touching the stigma with the tip of
the index finger dipped in the pollen pool
31. • Freshly collected pollen can also be applied with a
camel hair brush or by using a pollination syringe
• Hybridized flowers are tagged properly
• Pollination is usually done 3 times weekly on alternate
days over a 3-5 week period depending upon rate of
flower development
32. After pollination:
• Successful pollination results in ovary enlargement
within 4 - 5 days
• Success rate - 50 to 70%
• It depends upon temperature and humidity
• 22 - 28°C and 70 - 80% RH are optimum for good
seed set
• Pollinate only first 3 - 4 flowers in each
inflorescence as basal flowers set seeds better than
terminal ones
33. • Maximum, if pollination is at the time of anthesis
• Fertilization occurs 24 to 50 hrs after pollination
• 6 to 8 weeks from first flower to ripe fruit
• Fruit is a berry
Fertilization and fruit set:
34. a) Internal structure:
• Each seed consists of a embryo which in future grows
in to a plant.
• This embryo consists of an embryonic root called
radicle and one or more embryonic leaves called
cotyledons. Immature embryo also has a plumule, which
develops in to shoot.
• A protective shell called a seed coat or testa,
surrounds the embryonic plant.
Seed structure:
35. • Embryo gets the energy they need to germinate from
stored energy inside the seed called endosperm,
which is usually starch.
36. b) External structure:
• They are kidney or pear shaped
• Hairs are present on seed
• Are light brown in colour
• Are 3-5 mm long and 2-4mm wide
37. Chemical composition of seed:
Substance Percentage(%)
Moisture 8.95
Protein 27.62
fat 24.40
lecithin 0.56
Fiber 13.60
Ash 40.20
N-free extracts 21
39. • 2nd most consumed vegetable after potato in the
world
• 1st in terms of total contribution of nutrients to
human diet among vegetables
• Consumed in fresh form and various processed forms
like soup, sauce, ketchup, paste, puree, canned etc.
• Tops the list of processed vegetables
• Also an ideal model plant for physiological,
biochemical, cytological and molecular investigations
Economic importance: