ADVERTISEMENTS:
Learn about the comparison of Embryogeny and Seed of Cycas and Embryogeny and Seed of Pinus.
Comparison # Embryogeny and Seed of Cycas:
1. The wall formation of cycas in the oospore starts only when numerous nuclei have been formed.
2. Pro-embryo in cycas, has no clear tiers in the young stage.
ADVERTISEMENTS:
3 Only one potential embryo develops in cycas, and hence there is no cleavage polyembryony.
4. Rosette poly-embryonic is absent in cycas.
ADVERTISEMENTS:
5. In cycas, seed has no perisperm.
6. Only two cotyledons are formed in it.
ADVERTISEMENTS:
7. In cycas, the outer part of the testa is fleshy and coloured.
8. Cotyledons do not come out of seed in cycas and usually dry inside.
9. Seeds are un-winged in cycas.
Comparison # Embryogeny and Seed of Pinus:
1. Wall formation starts after eight-nucleate stage in pinus.
2. Pro-embryo has four distinct tiers in pinus (viz. embryonal tier, suspensor tier, rosette tier and open tier).
3. Four potential embryos develop in pinus, and thus cleavage polyembryony is very common.
4. In pinus, rosette polyembryony is seen in several species.
5. In pinus, the perisperm in the seed is present in the form of nucellar cap.
ADVERTISEMENTS:
6. Numerous cotyledons are formed in each seed of pinus.
7. Testa is dry and firm in it.
8. In pinus, cotyledons come out of the ground during germination and survive for a long period.
9. Seeds are winged in pinus.
