Electronic Journal of Plant Breeding (Jun 2020)
Interspecific hybrid confirmation in wide crosses of cotton (Gossypium spp) through morphological, cytological and molecular analysis
Abstract
Interspecific triploid hybrids were developed between tetraploid cultivated species Gossypium barbadense cv. Suvin and TCB 37 and diploid wild species Gossypium armourianum. The F1 hybridity was confirmed by morphological, cytological and molecular approaches. The ploidy level of interspecific F1 hybrid was triploid and completely male sterile. Female parents Suvin and TCB 37 had erect growth habit, yellow petals, palmate leaves, green stem, thick and prominent leaf veins, but Suvin had dense yellow anthers while TCB 37 was with dense creamy anthers whereas male parent has a spreading growth habit, yellow petals, cordate leaves, reddish green stem, medium dense yellow anthers, thin leaf veins, protruded stigma and glabrous plant body. The growth habit, petal colour, leaf shape and size of interspecific F1 hybrid were intermediate. Plant stem colour, hairyness, leaf pubescence and anther colour of Gossypium armourianum were observed to be dominant as hybrid fully resembled Gossypium armourianum for these characters. Petal spot was observed in both male and female parents but F1 hybrids had different intensity of petal spot in their petals. Variable expression of petal spot, anther colour and filament colour was observed in the F1 hybrids. Gossypium barbadense cv. Suvin and TCB 37 had 52 chromosomes, Gossypium armourianum had 26 chromosomes and the interspecific F1 was with 39 chromosomes. Significant differences were observed between pollen size, pollen fertility of parents and their hybrids. The F1 interspecific hybrid having more than 97% of sterile pollen grains. Out of 6 polymorphic SSR markers between parents, 3 markers unambiguously confirmed the hybrid status of interspecific hybrid. This hybrid may serve as useful genetic resource for the transfer of jassid resistance gene to Gossypium barbadense cultivars.
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