Heterosis studies for fibre quality traits in upland cotton [Gossypium hirsutum L.]

The present investigation was undertaken to assess the extent of heterosis for fibre quality traits in 54 hybrids of cotton developed by crossing 9 lines with 6 testers in Line × Tester mating design during kharif 2009 at Main Agricultural Research Station, University of Agricultural Sciences, Dharwad. The mean sum of squares of parent's vs hybrids was significant for all fibre quality characters, indicating presence of heterosis for these traits. None of the crosses were superior for all the traits studied. However, the cross ‘L2 x T 2′ and ‘L9 x T 5′ were the best, as it had highest seed cotton yield, desirable span length and fibre strength. Majority of the crosses exhibited positive mid parent, better parent heterosis for fibre quality characters except for elongation percentage, uniformity ratio and maturity ratio where they showed negative heterosis, indicating predominance of non-additive gene action in the genetic control of these traits. Most of the hybrids expressed significant standard heterosis for all the characters over both the checks.