Question

Parbhani Kranti, a variety of bhindi (lady’s finger), is resistant to

A. Bacterial blight

B. Yellow mosaic virus

C. Black rot

D. Leaf curl

Answer 1

Hint: Parbhani Kranti is resistant to an organism which is obligate parasites. Beijerinck called them contagium vivum fluidum or infectious living fluid. These organisms usually have either RNA or DNA as the genetic material but not both.

Complete answer:

Parbhani Kranti is the name of a lady’s finger variety scientifically known as Abelmoschus esculentus. It is resistant to yellow mosaic virus. The resistance to the yellow mosaic virus was transferred from another wild species known as Abelmoschus manihot land. This was done by the process of mutation breeding.

So the correct answer is ‘Yellow mosaic virus’.

Additional Information:

- Mutations are random, sudden, and inheritable changes in the character of an organism. Mutagens of chemical and physical types are used to achieve this. These are referred to as induced mutations and the process by which improved varieties of plants are produced with the help of induced mutation is known as mutation breeding.

- Many useful varieties have been developed using the technique of mutation breeding:

- Sonora-64 and Lerma Rojo-64 were developed by treating gamma radiations. These were high yielding Mexican wheat varieties. Developed amber grain varieties included Sharbati Sonora and Pusa Lerma.

- High yielding rice varieties were produced by the treatment of Pelita-1 rice using gamma rays. These plants were also resistant to brown planthoppers. 

- Another high rice yielding variety known as Reimei was developed using gamma radiation.

- A variety of wheat named NP836 was also developed using mutation breeding.

Note:
Mutation breeding has also helped in developing resistance against powdery mildew in mungbeans. Besides gamma rays, other mutagens like X Rays, dimethyl sulphate, ethyl methyl sulphates, etc are also used for inducing mutations. Other methods such as plant breeding have been developed to make insect and pest-resistant plants. They help in the production of plants having resistance against aphids, jassids, shoot and fruit borer insects.