Résumé
The feasibility of using Quantitative Trait Loci detection in sugarcane, despite the handicap of a high ploidy, is being tested. One difficulty is to have a well saturated map of this polyploid genome. For this purpose, advantage was taken of AFLP technology as a powerful source of markers. For field trait evaluation, a population of 300 progeny obtained by selfing the cultivar R570 was planted in a complete block design with five replications. The basic plot was a 1.5m row. Similarly a second experiment involving a subset of 80 progeny was planted and was more finely evaluated. Several yield components were measured in plant cane and in first ratoon: brix, pol, fibre, plant height, stalk diameter and tillering. Rust resistance was also assessed. All 300 progeny were genotyped using 38 AFLP primer combinations yielding more than 1200 segregating bands of which about 80% were simplex markers. Over 950 simplex markers have been included in 105 co-segregation groups of the genetic map drawn with Mapmaker at a LOD score of 5. This AFLP map covers more than 6500 centimorgans. We attempted a first QTL detection on the basis of an analysis of variance. Numerous marker-QTL associations at P<0.005 and at P<0.001 have been found for several traits. Detailed results will be presented in a perspective of marker assisted selection in sugarcane. (Texte intégral)