Question

What is vegetative propagation? Mention the vegetative propagules in
a) Bryophyllum
b) Spirogyra

Answer 1

Hint: Many plants reproduce naturally, but it can be artificially induced as well. Asexual propagation techniques have been developed by horticulturalists that use vegetative plant parts to reproduce plants. Success rates and propagation difficulties differ greatly.

Complete Answer:
a) Bryophyllum is a succulent tropical herb of the Crassulaceae family and is one of the few plants that can develop vegetative buds from the leaf tissue. New shoots emerge at a special point in the leaf margins. Also, the bryophyllum tissue is very life-threatening, which greatly facilitates the laboratory study of plant habits and reactions to various growing conditions.
- The pigments move towards the most active region of growth which is the base of the leaf. It forms new shoots even when it is hung up using a string and so it is often called as Air Plants.
- The Bryophyllum leaf is wide and has many notches. The notch has buds known as epiphyllous buds that fall to the soil and germinate to form a new plant. Forms The bud has an adventitious root that helps to anchor.

b) Spirogyra are free-floating green algae found in freshwater environments such as wetlands, lakes, etc. Spirogyra is generally referred to as "water silk or pond silk." They have a filamentous, unbranched vegetative structure.
- Spirogyra undergoes vegetative, asexual and sexual reproduction. The life cycle of Spirogyra is haplontic, i.e. the dominant stage is the free-living haploid (n) gametophyte and the sporophyte is only represented by the diploid zygote (2n).The vegetative reproduction is fragmented. Under favourable conditions, vegetative reproduction is the favoured form of reproduction.
- After fragmentation, the vegetative filament transforms into a new filament. Each fragment undergoes several divisions and elongations to form a new filament.
- Fragmentation can be due to mechanical damage or breakdown of the middle lamella with a change in salinity and temperature of the water. Often the middle lamella of a cell protrudes into an adjacent cell, resulting in a filament breakup.

Note: Vegetative propagation occurs in its leaves , roots, and stem as an asexual method of plant reproduction. This can happen through the fragmentation and regeneration of particular plant vegetative sections.