Impact of mating systems on genetic variability in a cross of Gossypium barbadense.

摘要

The impact of mating systems for generating variability in an intra barbadense cross (10-98-P1 X 11-181-P2) was studied in the F4 generation. A variable response was observed specific to character and the mating system used to advance the generations. Linkage disequilibrium could be a serious factor causing reduced genetic variability observed for some of the traits in the populations advanced through random intermating and open pollination as compared to self pollination. Significant changes in character association were observed in F4 populations of the barbadense cross 10-98-P1 X 11-18-P2 advanced following three mating systems. Such changes are expected if predominantly repulsion phase linkages are broken down due to recombination. The selective intermating system offered good opportunity to release a wider range of yield transgressants over the other two mating systems. However, the study also indicated that in the populations linkage disequilibrium is still a contributing factor to cause difficulties in improving yield with both high boll number and boll weight.