Categorize pollination methods, understand vectors, and explore the chemical dialogue between pollen and pistil.
An obligate mutualistic relationship.
The Yucca plant and a specific species of moth cannot complete their life cycles without each other. The moth deposits its eggs safely inside the plant's ovary while simultaneously pollinating the flower! Later, the moth larvae feed on the developing seeds.
Autogamy, Geitonogamy, and Xenogamy.
Pollination is the transfer of pollen grains from the anther to the stigma. In autogamy, this transfer is achieved within the same flower.
Plants like Viola and Oxalis produce two distinct types of flowers to manage this:
How plants prevent inbreeding and guide the right pollen.
To prevent inbreeding depression, flowering plants have evolved several mechanisms to discourage self-pollination:
The journey of a compatible pollen tube from the stigma down into the ovule.
a) Pollen grains germinating on the stigma;
(b) Pollen tubes growing through the style;
(c) L.S. of pistil showing path of pollen tube growth;
(d) enlarged view of an egg apparatus showing entry of pollen tube into a synergid;
e) Discharge of male gametes into a synergid and the movements of the sperms, one into the egg and the other into the central cell
Test understanding of vectors and breeding devices.
An agricultural scientist is trying to breed a plant variety that naturally and completely avoids both autogamy (self-pollination) and geitonogamy (pollination between flowers of the same plant). Which of the following plant conditions guarantees this outcome?