JUVENILITY AND FLOWER BUD DIFFERENTIATION BY DR PADMAKHI THAKUR MAM IGKV

1. *Juvenility & Flower bud Differentiation
*Unfruitfullness
*Pollination, pollinizers and pollinators
*Fertilization and Parthenocarpy
By
Dr. Padmakshi Thakur

2. Plant growth is the process by which a plant
increases in size, creating more leaves and stems.
Plant development is the process by which plants
change from one stage of growth to the next. These
stages include juvenility, maturity, flowering and
seeding.

3. Juvenility
•A plant goes through different stages in its life cycle.
These stages are embryonic growth, juvenility, maturity,
senescence, and death. Flowering is essential to fruit
production. Each species need certain of time to form
flower.
•Juvenility is a developmental stage in a plant during
which it is unable to induce flower.
•Transition period to generative maturity.
•The length of juvenility varies among plant species.

5. Flower bud Differentiation
• “Flower bud differentiation is the turning point from
vegetative to reproductive growth, which occurs
after the plant has had time to accumulate the
required nutrients ”.
• Flower bud differentiation- It is also known as flower
induction. Enhanced cell division occurs below the
apical part of the meristem in the central region for
bud differentiation to occur. Due to cell division,
parenchyma cells differentiate into flower primordia
that surround the meristem.

7. Bearing
• Bearing is cannotation of flowering & fruiting.
• When a fruit tree flowers and fruits, it is said in
bearing condition.
• Different fruits have different bearing habits,
inflorescences, types of flower, mode and
medium of pollination, pollen viability.

8. Bearing Habit
• Bearing habit indicates the position of flower
bud with respect to vegetative growth of the
plant after the cessation of juvenility.

9. Type of fruit tress depending upon position of
the fruit bud -
1. Shoot Bearing
a) Terminal bearing : Banana, Pineapple, mango, litchi, avocadp
b) Lateral flowering: Coconut, papaya, guava, orange, ber etc.
2. Stem or branch bearing (caulifluorous bearing habit)
-flower and fruits appears directly from the main stem or branch.
-Eg- Jackfruit, cocoa etc.
3.Spur Bearing
-short shoot, more than one year age, when bears flowers and
fruits.
-Eg- Some varieties of grapes, apple, pear, cherry, plum.

11. Unfruitfulness
• Unfruitfulness is a major problem in many
fruit crops and their varieties result in huge
loss to grower sand make fruit cultivation less
profitable.
• “Unfruitfulness in fruit crops refers to the
state where the plant is not capable off
lowering and bearing fruit”.

12. Unfruitfulness in Fruit Crops: Causes
• Lack of balance between vegetative growth and
fruiting.
• Lack of flowering and pollination is a cause of
poor fruit set.
• Heavy cropping, leading to inhibition of fruit bud
production and poor crop in the following year.
• Sterility also leads to unfruitfulness due to
impotence, incompatibility or the abortion of
embryo.

13. Factors for Unfruitfulness in Fruit Crops
• External factors – Environment, Insect-pest-
diseases, Chemicals and pesticides, Nutrient
supply, Locality, Cultural practices, Moisture
deficiency, Age and vigour of plant.
• Internal Factor - Evolutionary Tendencies,
Genetic Influences, Physiological Influences

14. Pollination, pollinizers and pollinators
• Pollination is the act of transferring pollen-
grains from the male anther of a flower to the
female stigma.
• The goal of every living organism, including
plants, is to create offspring for the next
generation.
• One of the ways that plants can produce off-
springis by making seeds.

15. Pollinizers and pollinators
• “A pollenizer or polleniser, sometimes pollinizer or
polliniser is a plant that provides pollen”.
• The word pollinator is often used when pollenizer is more
precise.
• A pollinator is the biotic agent that moves the pollen, such as
bees, moths, bats, and birds. Bees are thus often referred to as
'pollinating insects'.
• The verb form to pollenize is to be the source of pollen, or to
be the sire of the next plant generation.
• Insect pollinators include bees, (honeybees, solitary species,
bumblebees); pollen wasps (Masarinae); ants; flies including
beeflies, hoverflies and mosquitoes; lepidopterans, both
butterflies and moths; and flower beetles.

16. Fertilization
• Plant fertilization is the union of male and female
gametes (reproductive cells) to produce a zygote
(fertilized egg). It's a pretty straight forward process
that's similar for both flowering plants (angiosperms)
and seed-bearing plants (gymnosperms).

17. Parthenocarpy
• In botany and horticulture, parthenocarpy is the
natural or artificially induced production of fruit with
out fertilization of ovules. The fruit is therefore
seedless. Eg- Banana.
• Stenospermocarpy may also produce apparently
seedless fruit, but the seeds are actually aborted while
still small. OR ‘production of abortive incompletely
developed seeds with normal development of berry’.
Eg- Grape