Principles of Plant Breeding (2+1)

Merits and Demerits of Back cross breeding

Merits:
1. Back cross method retains all desirable character of a popular adapted varieties and replaces undesirable allele at particular locus
2. Useful for the transfer of disease resistance and incorporation of quality traits into a variety
3. This is used for the development of isogenic lines,
4. Extensive tests are not required 2-3 generation can be raised in off season nurseries green houses, it would save time.
5. This is the only method for the inter specific gene transfer and transfer of cytoplasm.
6. Male sterility and fertility restoration genes can be transferred to various back ground.

Demerits:
1. New variety cannot be superior to recurrent parent except for the character transferred
2. It involves lot of crossing work. 6-8 back cross is often difficult and time consuming.
3. Sometime undesirable gene linked with desirable also may be transferred.
4. By the time the back cross programme the recurrent parent may have been replaced by other varieties superior in yield and other character.