Early generation intermating for yield improvement in groundnut (Arachis hypogaea L.).

Seeds of 4 crosses of groundnut (Arachis hypogaea L.), 'Robut 33-1' x 'Chico', 'Robut 33-1' x 'NC Ac 17090', 'Robut 33-1' x 'PI 298115' and 'MK 374' x 'GAUG 1', were irradiated with 30 kR. In the F1, some branches of each plant were intermated with other plants at random and others selfed in each cross to produce S2 and F2 seeds. They were evaluated for pod yield, shelling percentage and 100-kernel weight. The frequency of plants superior to F[in1] was much higher in S2 than in F2, which was, in general, true for the values of yield and its components. The S2 and F2 were advanced to third generation by selfing. The families descending from S2 showed clear superiority over those from F2. The reason for such superiority was suggested to be the recombination of genes from the upper and lower ends of the genotypic distribution under intermating.