Question

Vegetative propagation in Pistia occurs by
A. Stolon
B. Offset
C. Runner
D. Sucker

Answer 1

Hint:- Stem is the above-ground part of the plants. Its main function is to keep the plant upright and to transport the substances between roots and leaves. Besides, stems of some plants are modified to store food and to serve in vegetative reproduction.

 Complete step-by-step solution:-
When a vegetative part of a plant is modified to serve in reproduction, it is called vegetative propagation. Leaves, stem, or roots are modified to serve as vegetive propagules.
Stolon represents a slender lateral branch that originates from the base of the stem and grows upright to some distance and then downward to produce new plantlets. Example: Mint and strawberries.
A runner represents a horizontal stem that has long internodes and runs parallel to or just below the surface. Roots originate as nodes and new plantlet is produced. Oxalis develops runners for vegetative reproduction.
A sucker is a shoot that originates from the underground root or stem of the plant. These shoots originate from the adventitious buds and give rise to more roots to become an individual plant. Pear, apple, blackberries have suckers for vegetative propagation.
Offset is a modified stem that serves as a vegetive propagule. It is a long internode that grows horizontally for some distance and then gives rise to a bunch of leaves aboveground and a group of roots below. Pistia is a floating aquatic plant and belongs to the family Araceae. It develops offset for vegetative propagation.
So, the correct answer is option B. Offset.

Note:- Stem modification for vegetative propagation includes runner, stolon, offset, and sucker. Since vegetative propagation includes only a single parent, it represents asexual reproduction. It is a quick method to produce a large progeny and also maintains the desired genetic traits of the parents in the offspring.