Abstract:

Banana diploids are used both as male parents and materials for genetic studies in breeding programmes. In this study a range of synthetic diploid hybrids were assessed for their response to black Sigatoka, male fertility and their genetic relationship to East African Highland banana, so as to evaluate the potential of using them in the improvement of the East African Highland Bananas. Synthetic diploid progeny obtained from 2x-2x, 3x-2x and 4x-2x crosses, were evaluated along with their parents in a completely randomized design for response to black Sigatoka and were rated for the production and viability of pollen. Genomic DNA isolated from the different genotypes was used in RAPDs analysis to estimate the genetic distances among the genotypes. Genotypes ‘2858K-8’, ‘3550K-1’, ‘OPP2-861’, ‘OPP1-861’, ‘12468S-3’ and ‘3162K-3’ were found to show hypersensitive response to black Sigatoka. Seven synthetic diploid banana genotypes’ 12506S-29’, ‘OPP2-861’, ‘3162K-3’, ‘3162K-1’, ‘3162K-5’ and ‘3146K-2’ whose pollen rating was not significantly (p dD.05) different from that of the reference wild diploid banana were considered male fertile. All tested synthetic diploid hybrids except ‘1537K-1’, ‘11025S-1’ and ‘12515S-2’ were found to be genetically closer to 'Calcutta'}', than to 'Enyeru' the East African Highland Banana, indicating the potential to generate heterotic hybrids when crossed with East African Flighland Bananas.