In________, resistance to yellow mosaic virus was developed by mutation breeding.

1. chilli
2. cowpea
3. mung bean
4. cauliflower

The correct option is C mung bean
To overcome the problem of pathogens that cause serious infections in plants, the plant breeders have developed certain techniques like conventional breeding and mutation breeding.

In conventional breeding, the plants having disease resistance genes are selected and are crossed with plants that are high yielding but have poor resistance to pathogens. The aim of this cross hybridisation is to have the hybrids which will have a combination of desired characteristics from both the parents (disease resistance and high yield). The superior hybrids among the progeny are selected and tested for various agronomic traits and finally these varieties are released into the market.

But due to the limited number of disease resistance genes in various crop varieties or wild relatives, it is often not possible to generate plants through conventional breeding. To overcome this problem, mutation breeding is carried out. Mutation is a process by which variations are generated through changes in the base sequences within the genes. The new characters obtained through mutations are not found in the parent plant. Mutation breeding is a process by which the mutations can be induced in plants by exposing them to certain radiations.

Yellow mosaic disease is a plant disease caused by yellow mosaic virus. It infects crops like mung bean. Breeders had attempted to make mung bean resistant to yellow mosaic disease by inducing mutations via gamma radiations. They successfully produced mung bean resistant to yellow mosaic virus.