Question

A fungal disease that spreads by seeds and flowers is:
a. Loose smut of wheat
b. Corn smut
c. Covered smut of barley
d. Soft rot of potato

Answer 1

Hint: A disease is a physical condition which does not allow a being to function normally rather it creates an abnormal condition which can be harmful for its survival. There are many diseases that are caused by various organisms in plants.

Complete answer:
The fungal disease is any disease that is primarily caused by the fungus. The members of group fungi are known to cause numerous diseases in plants causing destruction of crops and low yield. These diseases causing microorganisms can spread by various means such as wind, water, touch, etc.

The fungal disease that can spread via seeds and flowers is loose smut of wheat. This disease can only spread by infected seeds to non infected flowers. Loose smut is caused by fungus named Ustilago tritici. This fungus survives as a mycelium in dormant stage in the embryo of the infected wheat seed. When the seed starts to germinate, the fungus becomes active and starts developing along with the growing plant. When the plant grows, rather than flowers, only black spots on the spikelets on the plant are seen. And by the time of harvesting season, only a bare rachis is visible.

> This diseased spores spread from the infected plants to the healthy plants by the medium of air or wind. The infection in the healthy wheat plant takes place during the flowering time where the spores enter their dormant stage and become inactive till the seeds of the plant will germinate.

> Corn smut is caused by fungus Ustilago maydis, which affects the plant parts above the ground. The symptoms of this disease are the appearance of whitish bodies which then rupture to release many dark colored spores which infect the other healthy plants.

> Covered smut of barley is caused by fungus Ustilago hordei in which diseased plants can be recognized by having blackened ears that emerge from leaf sheaths. All the grains in the covered sheath are infected and are converted into spores which are covered with a protective layer of tough grayish membrane.

> Soft rot of potatoes is a bacterial disease caused by a wide range of bacteria. This causes the retention of water in potatoes leading to soaking of water in the whole tuber which is accompanied by the foul smelling odor and invasion of other microbes as well.

Hence, The correct answer is option (A).

Note: Sometimes the diseases that are caused in plants, especially seed borne diseases are not easily detectable and can lead to huge loss in productivity. In this case, if one observes any symptom, the crop must be treated as soon as possible or if it could not be treated then, the whole crop must be sold and new seeds must be planted for avoiding loss.