Please enable JavaScript.
Coggle requires JavaScript to display documents.
DEVELOPMENT OF SEED AND FRUIT IN ANGIOSPERMS (Seed Development (Pollen…
DEVELOPMENT OF SEED AND FRUIT IN ANGIOSPERMS
Seed Development
Pollen grain contain 2 cell
Tube cell
Form pollen tube
Generative cell
Form sperm nuclei
1) Pollen grains travel from the stamen to flower
2) Pollen grains land on the pistil germinate to form pollen tube
3) Pollen tubes travel to the ovary
4) 1 pollen nuclei fuses egg cell to form a zygote
Zygote divided into to form embryo assisted by hormones (cytokinin and auxin)
5) Another 1 pollen nuclei fuses two polar nuclei to form triploid cell (endosperm)
Endosperm serves as food resources to the embryo
Both embryo and endosperm enclosed with seed coat
Seed Types
Monocotyledon
One cotyledon (scutellum)
E.g : Maize
Dicotyledon
Two cotyledon
E.g: Bean
Seed Structure
Seed coat
Dicot
Testa (outer layer)
Tegmen (inner layer)
Monocot
Testa and tegmen fused
Embryo axis
Plumule
First true leave
SAM
Epicotyle
Develop shoot
Hypocotyle
Develop stem
Radical
Develop root
Cotyledon
Absorb nutrient from endosperm
Flower to fruit
1) Flower pollinated and fertilized
2) Petal dry up
3) Ovary start to swell
4) Petal fall out
5) Ovule develop seed
6) Ovary enlarge to become fruit
7) Seed develop in the ovary, ovary develop more bigger
Production of fruit
No pollination and no fertilization
Pollination and no fertilization
Fruit types
True fruit
Derived from ovary after pollination and fertilization
E.g :Maize, Mango, Grape
False fruit or Pseudo-fruit
Derived from floral parts
Thalamus
E.g Apple, pear, cucumber
Fused perianth
E.g : Mulberry
Peduncle
E.g : Cashew nut
Calyx
E.g : Elephant apple (Dillenia sp.)
Fruit Morphology
Simple
Type
Dry
Succulent (Fleshy)
Derived from single carpel
E.g : Nut, Bean
Multiple
Derived from cluster of flowers (inflorescence)
E.g : Jackfruit, fig
Aggregate
Derived from single flower, more than one carpel
E.g : Pineapple
Accessory
Derived from ripened ovary or part outside ovary
E.g : Strawberry, apple, pear
Parthenocarpy
Factor
Lack of pollination
Pollination without fertilization
Fertilization followed by embryo abortion
Types
Vegetative
Develop without fertilization and seedless
E.g : pear, fig
Stimulative
Develop with pollination, without fertilization
stimulated by air-blowing or hormone
E.g : grapes, papaya, watermelon
Stenospermacarpy
Develop with fertilization followed by embryo abortion
Pollination trigger the mature seed
Hormone auxin, cytokinin, giberellin involved
E.g :Seedless grape
Artificial Parthenocarpy
Induce parthenocarpy of seedless fruit
Hormone : auxin, cytokinin, giberellin
E.g : grape, orange, strawberry, tomato
Stimulate with pollen
Pollen tube enter embryo sac through micropyle
Male gamete does not fertilize egg cell
Advantages
Provide seedless fruit and improve quality
Reduce complete cultivation cost
Improved crop yield without using organic pesticide
Natural plant growth produce large fruit
Prevent insects and pests without using chemical
Protect the plants from pesticide
Parthenogenesis
A component process of apomixis
Develop without fertilization, produce seed
Types
Diploid parthenogenesis
Produce seed with 2n embryo
Causes by megaspore mother cell (2n)
E.g : Strawberry
Develop from nucellus cell (2n)
Haploid parthenogenesis
Produce seed with haploid embryo
Apomixis
Asexual formation of seeds from the maternal tissues of the ovule
Production seed without fertilization and pollination
Embyo develop from tissue : nucellus cells or integument undergo mitosis
known as polyembryony
E.g : Dandelion, citrus, kentucky bluegrass
Parthenocarpic fruit
Seedless fruit derived without fertilization
E.g : Pineapple, banana, orange, grape
