3. Growth & Development
• Growth
• Development
• Stages of Plant Growth
1. Germination
2. Vegetative Stage
3. Reproductive Stage
4. Ripening Stage
5. Senescence
4. Growth & Development
• Quantitative and irreversible change/increase in number,
volume (size) or weight of cell, tissue or organ in plant
life cycle.
• Development is qualitative change in function, no. of
cells, tissues, organs or the entire plant.
• Stages of Plant Growth
i. Germination
ii. Vegetative Stage
iii. Reproductive Stage
iv. Ripening Stage
v. Senescence
7. Floral Biology & Pollination
Pollination:
•Pollination is the act of transferring pollen grains from
the male anther of a flower to the female stigma.
•Self-pollination is when pollen from anther of flower
arrives at the stigma of a the same flower.
8. Floral Biology & Pollination
• Cross-pollination is the transfer of pollen from the
male reproductive organ of one plant to the female
reproductive organ of another plant.
• Insects and wind are the main agents of cross-
pollination.
9. Floral Biology & Pollination
Fertilization :
Fertilization is the union of male and female gametes
(reproductive cells) to produce a zygote (fertilized egg).
•Step 1: Pollination
•Step 2: Germination
•Step 3: Penetration in the Ovule
•Step 4: Fertilization
10. Floral Biology & Pollination
Double
Fertilization:
Fertilization process in
which one sperm cell of a
pollen grain fertilizes an egg
cell while a second fuses
with two polar nuclei to
produce a triploid body that
gives rise to the endosperm.
20. Floral Morphology Supporting
Cross Pollination
• Dioecious Plants (Date palm, Papaya)
• Monoecious plants (Maize)
• Dichogamy:
The ripening time of pistil and anthers in a
flower do not coincide. It is of two types:
1. Protandry (Pearl Millet)
2. Protogyny (Plantago)
21. Floral Morphology Supporting
Cross Pollination
Heterostyly:
Stamens & pistils are of different lengths.
a.Pin Flowers
b.Thrum Flowers
c.Natal Plum
22. Incompatibility Mechanism
• Physiological reasons
– Pollen on stigma fails to germinate
– Pollen may germinate but tube growth is slow.
• Genetic Reasons
– Gene ‘S’ in Nicotiana shows multiple
allelomorphism.
24. Male Sterility
• Male sterility
– Genetic Male sterility
– Cytoplasmic Male Sterility
– Cytoplasmic-Genetic Male Sterility
25. Male Sterility
• Male sterility is defined as an absence or non-
function of pollen grain in plant or incapability of
plants to produce or release functional pollen grains.
26. Male Sterility
Genetic Male sterility:
•The pollen sterility, which is caused by nuclear genes,
is termed as genic or genetic male sterility.
•It is usually governed by a single recessive gene “ms”
or ‘s’, but dominant gene governing male sterility are
also known.
27. Male Sterility
Cytoplasmic Male sterility:
•The pollen sterility which is controlled by cytoplasmic
genes is known as cytoplasmic male sterility (CMS).
•Usually the cytoplasm of zygote comes primarily from
the eggs cell and due to this progeny of such male
sterile plants would always be male sterile.