More arguments against intermating F2 plants of a self-fertilizing crop

Yield Improvement in a Soybean Population by Utilizing Alternative Strategies of Recurrent Selection1

“…Both Pederson (1974) and Bos (1977) demonstrated that random intermating would not be expected to be superior to early-generation selection.…”

“…Theoretical and computer simulation studies have evaluated the effect of intermating on the breakup of linkage blocks (Hanson, 1959)» genotypic frequency (Baker, 1968;Pederson, 1974;Bos, 1977), response to selection (Baker, 1968;Bos, 1977;and Pederson, 1974J and genetic variance (Hanson and Hayman, 1963;Baker, 1968;Pederson, 1974). In general, these studies have assumed a completely additive gene model and have derived populations in which 50$ of the favorable alleles came from each parent.…”

“…Hanson ( have up to 25% more favorable homozygotes than a population derived from selfing (Baker, 1968;Bos, 1977;Stam, 1977). The advantage was maximum with the tightest linkages and decreased as linkage became less tight.…”

“…If selection can be performed in the F2 generation, the advantage of intermating to obtain a higher frequency of favorable homozygous lines was eliminated (Bos, 1977). The 25% increase in favorable homozygotes of the intermated population was equivalent to approximately 2% of the total lines in the population.…”

Effect of random intermatings in early generations on seed yield in interracial populations of common bean

“…Bos (1977) and Pederson (1974) argued against random intermatings in self-pollinating crops, especially for a trait such as seed yield that is contolied by genes of many loci with small effects' distributed over the-entire genome, and segregating independently.…”