Inheritance and heterosis related to yield and its components in interspecific hybrids of cotton (Gossypium hirsutum X G. barbadense)

Abstract

F1 and F2 hybrids from reciprocal G. hirsutum X G. barbadense crosses were evaluated in 1989-91 at Chirpan. Overdominance appeared to govern the inheritance of number of retained bolls per plant in the F1. The trait showed clear heterosis in the F1 with slight to moderate depression in the F2. Weight of raw cotton and the number of mature bolls per plant showed positive overdominance, with complete and incomplete dominance of the G. hirsutum parent. The hybrids showed higher yields when G. barbadense was used as maternal parent. Heterosis for yield was closely correlated with the number of bolls per plant and earliness. Inheritance of boll weight showed partial dominance of G. hirsutum and was additive. Inheritance of the trait was moderately high in the F2. The hybrids 8386B X Beli Izvor and 8386B X Balkan showed 28.6 and 33.4% higher yields, respectively, than the G. hirsutum parent. It was concluded that heterosis could not be utilized in the F2 because of strongly expressed depression.