Impact of mating systems on genetic variability in segregating generations of Asiatic cotton (Gossypium Sp.)

The impact of mating systems in generation of variability in an intra and interspecific cross of Asiatic cotton (Gossypium sp.) were studied and compared in F₄ generation. Both intra and interspecific crosses exhibited variable response specific to character and the mating system used to advance the generations. Reduced variability observed in the intra-specific cross for some of the characters in the populations advanced through random intermating and open pollination as compared to self pollination could be attributed to linkage disequilibrium. On the contrary, reverse trend was observed in the inter-specific cross where open pollination and selective intermating showed higher genetic variability as compared to self pollinated population. Significant changes in character association were observed in F₄ population of both intra and inter-specific crosses following three mating systems. Such changes are expected if linkages are broken due to recombination. Population raised through selective intermating in the intra-specific cross offered good scope to release a wider range of transgressive segregants over the other two mating systems while self and open pollination provided similar advantage in the inter-specific cross.