Heterosis in Interspecific Hybrids of Gossypium

In India intraspecific and interspecific (G. kirsutum × G. barbadense) hybrids of cotton are cultivated in a large scale. The interspecific hybrids have certain drawbacks like late flowering, late maturity, tall plants and low boll weight. The present study was undertaken to see whether heterosis for early maturity can combine with heterosis for yield and yield components. Three varieties of G. hirsutum were crossed with two varieties of G. barbadense. A comparison of the parents with hybrids showed significant degree of heterosis for all the characters studied. Heterosis was high and positive for plant height, boll number and seed cotton yield and negative for squaring, flowering, maturity and boll weight. Results indicate it is possible to obtain early maturing interspecies crosses which show a high degree of hybrid vigour for yield and possess good fibre qualities.