Question

After stem cutting, induction of rooting by auxin treatment would be beneficial in which of the following?
A. Marchantia
B. Wheat
C. Cuscuta
D. Bougainvillea

Answer 1

Auxin is a plant growth regulator that is generally produced from growing apices of stems and roots of plants. After their production, they reach their site of action. Basically in some plants in which roots may be produced from stem cuttings such as plants of rose they are used.

Complete answer: In option -A- Marchantia is a liverwort that comes under Bryophytes. They lack true differentiation i.e. roots, stem and leaves are absent. They reproduce by sexual reproduction via the production of spores and by asexual reproduction via the formation of gemmae.
In option -B- Wheat comes under Angiosperms, the wheat grows via seed, it is not possible to grow wheat through stem propagation. It is not possible to grow roots from its stem to grow this plant, not via any plant hormone such as auxin.
In option -C- Cuscuta or Dodder plant is a parasitic plant on many other plants as it lacks chlorophyll. This plant depends on the host to derive its nutrition. These plants lack roots and the main function is only by its stem which wraps around the host plant.
In option -D- In some plants like rose plants and plants of Bougainvillea , vegetative propagation may occur through stem cuttings. Such plants are commercially propagated in horticulture and botanical gardens from stem cuttings. For this propagation synthetic auxins such as indole butyric acid (IBA), is used commercially. These produce roots in such plants from the stem.
So, the correct answer to this question is the option ”D” Bougainvillea

Note: Basically in horticulture and agriculture science some plant hormones such as auxin is used extensively to grow roots from the stem of some plants. These plants propagate by stem cuttings efficiently.