Question

Name any two techniques by which new crop strains are produced. 

Answer 1

1. Combination Breeding: The main aim of combination breeding is the transfer of one or more characters into a single variety from other varieties. In this approach, an increase in the yield of a variety is obtained by correcting the weakness in the yield-contributing traits, e.g., tiller number, grains per spike, test weight, etc., of the concerned variety. One of the parents must have a sufficient intensity of the character(s) under transfer, while the other parent is generally a popular variety.
2. Transgressive Breeding: Transgressive breeding aims at improving yield or its contributing characters through transgressive segregation. Transgressive segregation is the production of plants in an F2 generation that are superior to both the parents for one or more characters.
3. Hybrid Varieties: In most self-pollinated crops, F1 is more vigorous and higher yielding than the parents. Wherever it is commercially feasible, F1 may be used directly as a variety. In such cases, it is important that the two parents produce an outstanding F1.