Plant & Animal Genomes XVI Conference Plant & Animal Genomes XVI ConferenceJanuary 12-16, 2008
Town & Country Convention Center
San Diego, CA
I. Vroh-Bi1, A. Tenkouano2, R. Bandyopadhyay3
1Central Biotechnology Laboratory, and 3Plant Pathology Laboratory, International Institute of Tropical Agriculture (IITA), Oyo Road, P.M.B. 5320, Ibadan, Nigeria, 2the IITA, Humid Forest Ecoregional Center, BP 2008, Messa, Yaoundé, Cameroon
Bananas and plantains rank among the four most important crops for food security in tropical and sub-tropical regions of the world. Over the past few years, banana production has declined substantially, diseases such as black Sigatoka and nematodes being among the major constraints behind this decline. The main cultivars are triploid (mostly sterile), with a long-generation time. Conventional breeding to improve these triploids is challenging. The wild diploid progenitors of bananas and plantains contain most of the agronomic traits needed for the improvement of current cultivars. However, these wild species are seeded (non-parthenocarpic). Crosses involving the wild diploids result to seeded and non-edible progenies.
Bottlenecks to marker-assisted breeding in Musa include the lack of segregating populations of good sizes due to various fertility problems. We use embryo rescue to generated two mapping populations of over 200 progenies that segregate for resistance to black Sigatoka disease and parthenocarpy, respectively, offering a unique opportunity to map and select for these traits. Ninety-six individuals were drawn randomly from each population and analyzed with AFLP and SSR markers for QTL mapping.
Linkage disequilibrium (LD) was assessed also in a population of triploid landraces and at genes in specific pathways to test association mapping in Musa. In this presentation, we discuss the number of QTL found, the extent of LD, the tag markers and the application in breeding.