Question

Explain the significance of each of the following features present in plants given below:

(a) In rose-bay plant the stamens ripen before the stigma. 

(b) In certain species of primrose, the flowers have short stamen and long style. 

(c) The bisexual flower of mustard exhibits rejection of self-pollen grain.

Answer 1

(a) In rose – bay plant, the time of maturation of stamen and pistil is not same, the pollen will not be able to germinate on the stigma. This prevents autogamy in rose-bay.

(b) Different position and incompatible placement of the reproductive structure prevent successful pollination and thus autogamy in primrose.

(c) Pollen pistil interaction for same species is not possible; this is a genetic mechanism which prevent the pollen grain from forming pollen tube on the pistil of the same flower.