Progress In Breeding Diploid Genetic Stocks Of Banana With Resistance To Black Sigatoka
Selected genetically related diploid Musa materials of the base, first, and second generations of the breeding programme in the International Institute of Tropical Agriculture (IITA) high rainfall station, Onne were evaluated for black Sigatoka resistance and agronomic performance. This was done in order to assess the progress made over time in the breeding programme. The results obtained showed that progress has been made from the base generation to generation 1 and from generation 1 to generation 2 in the improvement of the yield attributes of the highly black Sigatoka resistant diploid Musa cultivars- Calcutta 4 and pisang lilin. The diploid hybrids selected in generations 1 and 2 were not as resistant to black Sigatoka disease as the parents. However, improvement at generation 2 has succeeded in bringing together, productivity and resistance traits which seemed to oppose each other in generation 1 as revealed by the biplots. The clones, 2625-5, 9007-4, 1518-4, and 2829-62
from the crosses between Bobby tannap and Calcutta 4 in generation 1 were strongly associated with index of non-spotted leaves in the biplot. The clones, 25291-S26, 25291-S32, 25291-S62, and 25291- 1A from the double-cross (BT x C4) x (TL x PL) were associated with most of the yield, disease response and phenological traits. The clones, 25291-S89, 25291-S26, 25291-S32, 25291-S62, 25291- S58, 25233-S3, and 27398 had combination of positive and relatively high heterosis both for black
Sigatoka resistance and productivity traits.
Key words: Genetic progress, black Sigatoka resistance, agronomic performance, diploid bananas