Question

While planning for an artificial hybridisation programme involving dioecious plants, which of the following steps would not be relevant?
A. Bagging of female flower
B. Dusting of pollen on stigma
C. Emasculation
D. Collection of pollen

Answer 1

Hint: Dioecious plants are those plants in which either male or female reproductive parts are present in the flower. It is commonly called unisexual condition. On the other hand, monoecious (bisexual) are the plants where both male and female reproductive parts are present in the same flower.

Complete answer:
Artificial hybridisation is done to obtain a plant or crop with desirable characteristics. It is a technique in which only desired pollen grains are used for pollination and fertilisation. This technique is used by plant breeders to improve their crops. This process is attained by emasculation and bagging technique.
Emasculation is a process in which anthers are removed from the flower buds before it dehisces. It is done in bisexual flowers so that to avoid the unwanted pollination from incompatible pollen grains. In case, if the plant is dioecious then the emasculation process is not carried out. After that the emasculated flower is covered with a suitable bag, generally, butter papers are used to cover the flower. This technique is called bagging. Bagging is done to prevent the stigma from the contamination of unwanted pollen grains. Finally when the stigma attains its receptivity, then mature pollen grains from the desired male parent are collected and are dusted on the stigma. Again the flower is rebagged and allowed to develop fruit.
If the flower is dioecious then only bagging, collection of desired pollen grains and a dusting of pollen grains on stigma are done. The technique of emasculation is not carried out.

Therefore the correct answer is option C, that is emasculation.

Note: In case of plants both male and female gametes are non-motile, so the gametes are brought together to occur the fertilisation process. This is done by the pollination process. The pollination is the process by which pollen grains are transferred to stigma with the help of the pollinating agent. The pollination can be self-pollination or cross-pollination.