Genetic mapping of wild introgressions into cultivated peanut: a way toward enlarging the genetic basis of a recent allotetraploid
Foncéka D., Hodo-Abalo T., Rivallan R., Faye I., Ndoye Sall M., Ndoye O., Favero A.P., Bertioli D.J., Glaszmann J.C., Courtois B., Rami J.F.. 2009. BMC Plant Biology, 9 (103) : 13 p..
Background: Peanut (Arachis hypogaea L.) is widely used as a food and cash crop around the world. It is considered to be an allotetraploid (2n = 4x = 40) originated from a single hybridization event between two wild diploids. The most probable hypothesis gave A. duranensis as the wild donor of the A genome and A. ipaënsis as the wild donor of the B genome. A low level of molecular polymorphism is found in cultivated germplasm and up to date few genetic linkage maps have been published. The utilization of wild germplasm in breeding programs has received little attention due to the reproductive barriers between wild and cultivated species and to the technical difficulties encountered in making large number of crosses. We report here the development of a SSR based genetic map and the analysis of genome-wide segment introgressions into the background of a cultivated variety through the utilization of a synthetic amphidiploid between A. duranensis and A. ipaënsis. Results: Two hundred ninety eight (298) loci were mapped in 21 linkage groups (LGs), spanning a total map distance of 1843.7 cM with an average distance of 6.1 cM between adjacent markers. The level of polymorphism observed between the parent of the amphidiploid and the cultivated variety is consistent with A. duranensis and A. ipaënsis being the most probable donor of the A and B genomes respectively. The synteny analysis between the A and B genomes revealed an overall good collinearity of the homeologous LGs. The comparison with the diploid and tetraploid maps shed new light on the evolutionary forces that contributed to the divergence of the A and B genome species and raised the question of the classification of the B genome species. Structural modifications such as chromosomal segment inversions and a major translocation event prior to the tetraploidisation of the cultivated species were revealed. Marker assisted selection of BC1F1 and then BC2F1 lines carrying the desirable donor segment with the best poss
Mots-clés : arachis; sénégal; arachis duranensis; arachis ipaensis
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Agents Cirad, auteurs de cette publication :
- Foncéka Daniel — Bios / UMR AGAP
- Rami Jean-François — Bios / UMR AGAP
- Rivallan Ronan — Bios / UMR AGAP
