Question

What is the correct for stages of Puccinia?
A. Telia and aecia on wheat
B. Telia and uredo stage on wheat
C. Telia and aecia on barberry
D. None of the above

Answer 1

Fungi are eukaryotic organisms that are mostly saprophytic in nature but some species are pathogenic or parasites of animals and plants. Puccinia is a genus of fungi and it is known as rusts. It is an obligate pathogen of plants.

Complete answer:
Puccinia is a fungus and causes certain diseases and pathogenic conditions in cereal crops such as wheat, barberry, corn, maize etc. The fungi is the significant cause of disease known as stem rust in cereal crops. It also causes black stem rust or cereal rust. The disease can be visualized as symptoms like black, orange or rusty colored structures which are easily shaken off from the plant.
The life cycle of the fungus requires two hosts to complete its life cycle. The different stages of the rust are exhibited by the presence of uredinia on the wheat plant. The uredinia are present on the leaf sheaths as well as stems and leaves of the wheat plants. The uredinia are brick-red, elongated, blister like pustules.
The pustules are ruptures and provide a ragged appearance. On the plants, towards the end of growing season black telia are produced which are known as black rust. The telia are black, thick-walled dikaryotic spores which are known as teliospores. They further undergo karyogamy to produce basidiospores. The basidiospores germinate into haploid mycelium. This stage is not infected in wheat but is infectious to the alternative host which is barberry.
In barberry, the fungi completes the other part of the life cycle by the formation of pycnia and aecia. The aecia develop on the abaxial surfaces of the leaves of barberry. Upon maturation, the aecia appear as bright-orange, closely-packed, raised clusters. They appear as a grouping of rings within the aecial cluster. Pycnia are found on the upper surface of the leaves and are often in small clusters.

Hence, the correct answer is option (C).

Note: Puccinia is the causative agent of the rust disease in cereal plants such as wheat, maize, corn etc. The fungus completes its life cycle in two hosts which are the cereal plants and barberry. The important stages of the fungus in wheat are the tedia and uredo stages. In barberry, pycnia and aecial stages are found.