Learn about the comparison between Male Gametophytes of Cycas and Male Gametophytes of Pinus.
Comparison # Male Gametophyte of Cycas:
1. Microspores, which develop into male gametophytes, are un-winged in Cycas.
2. Only one prothallial cell is present in cycas.
3. In cycas the lone prothallial cell persists almost till the end of the male gametophyte development.
4. Pollination takes place at 3-celled stage in cycas, i.e. a prothallial cell, a generative cell and a tube cell.
5. Two motile male gametes, with several spiral bands of cilia, develop from generative cells in cycas.
6. Entire developmental process of male gametophyte in cycas completes within a few months.
7. Pollen tube grows sideways in cycas into the tissue of the nucellus.
8. In cycas the pollen tube is haustorial in function.
Comparison # Male Gametophyte of Pinus:
1. in pinus microspores are winged.
2. Two prothallial cells are present in pinus.
3. In pinus prothallial cells start disintegrating even prior to pollination.
4. Pollination takes place at 4-celled stage in pinus, i.e. two prothallial cells, a generative cell and a tube cell.
5. there are two non-motile male gametes in pinus, without any cilia, develop from generative cell.
6. About one full year is required to complete the entire process of male gametophyte development in pinus.
7. Pollen, tube hangs downwardly into the archegonial chamber of pinus.
8. In pinus pollen tube is sperm-carrier in function.