Question

Aeciospores of Puccinia are produced on
A. Berberis leaves
B. Wheat leaves
C. Mustard leaves
D. Raphanus leaves

Answer 1

Hint: Stem rust is caused by Puccinia on rye, oats, rice, etc. but the Puccinia have many species that are specific for specific plants and depending on this the pathogen are divided into different strains or subspecies.

Complete Answer:
- In the northern and southern part of India, the wheat crop is affected by Puccinia graminis tritici. The vegetative body of Puccinia graminis is mycelium.
- Mycelia are of two types; dikaryotic and monokaryotic, both grow intracellularly, septate, produce special haustoria that penetrate the host cell. If pores are found in the septum, controls the protoplasmic between neighboring cells.
- The cell wall is made up of glucan and chitin. The cytoplasmic also consists of glycogen bodies, vacuoles, and oil globules. The dikaryotic mycelium occurs in wheat plants, that is, the primary host.
- The monokaryotic mycelium forms on barberry plants, that is, the alternate host of the pathogen. The Puccinia graminis has five different types of spores in the life cycle; uredospore, teleutospore, basidiospore, pycniospores, and aeciospores.
- The uredospores and teleutospores grow in the primary host that is on wheat, the basidiospores grows on dead plants and developed from teleutospore, and the aeciospores and pycniospores grow on barberry plants the alternate host.

Thus, the correct option is ‘B’. Barberis leaves.

Note: The uredospores are grown on uredospores that develop on the wheat plant from the dikaryotic mycelium produced by germination of aeciospores that formed from barberry plant generally with dissemination of wind. The wheat plants may also attack the glumes and stem after aeciospore reaching the wheat plant.