Method of Plant Breeding in Self Pollinated Plants – Population Approach


Method of Plant Breeding in Self Pollinated Plants – Population Approach

Self-fertilization of F1 hybrid leads to very rapid increase in homozygosity. Only after 4 generation of selfing about 94% of genes would become homozygous, even in F2 half of the genes are in homozygous state. Thus, self- fertilization quickly separates the progeny from a hybrid into a large number of pure lines. As a result in such segregating population, selection only picks out the gene combination present in the population, which reduces the chances of recombination, between tightly linked genes and rare Transgressive segregants. Similarly, there is no possibility for recovery of changing genotypes of plants produced by recombination of genes in F1, F2 and F3 generation.

Merits of Population Approach:

1) This method provides greater opportunity for recombination by restoring heterozygosity through intermating of selected plants.     
2) This approach help in accumulation of desirable genes in the population through intermating of selected plants.

Demerits of Population Approach:

1) Identification of desirable plants in the F2 or subsequent segregating generation is difficult, for complex characters like yield and the success of this method is depending on this only.
2) This method has limitation in some crops because selfing in many self pollinated crop is difficult and time consuming.
3) The time required develop variety is more than the pedigree method.
4) There is no convincing evidence for the benefits from the population approach.

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