Submitted to: Sugar Journal
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2005
Publication Date: 6/1/2005
Citation: Edme, S.J., Glynn, N.C., Comstock, J.C. 2005. Identification of microsatellite markers associated with yield-traits in sugarcane. Sugar Journal 68(1):17.
Technical Abstract: Identification of molecular markers associated with quantitative trait loci (QTL) offers the potential to increase the overall efficiency of sugarcane breeding programs. Co-dominant segregation of 12 microsatellite (SSR) loci was evaluated in the F1 progeny population obtained from an interspecific cross between Saccharum officinarum (cv. Green German) and S. spontaneum (cv. IND 81-146). The objectives of this study were to follow the inheritance of these alleles in 162 fullsibs through a linkage analysis and to explore the putative association between the markers and three phenotypic traits (Brix, pol, and sucrose content) measured at two locations and for two crop-years. A total of 107 polymorphic markers, generated by single-dose markers that segregated in a Mendelian fashion, were used for linkage analysis in this interspecific cross. Twice as many markers were specific to the officinarum as to the spontaneum parent. Twelve linkage groups (LG) were identified with LOD'3.0, of which 11 belong to the Green German parent and the other one belongs to the male parent. This map covers 366 cM of the sugarcane genome. Polymorphic profiles were also subjected to composite interval mapping for QTL analysis using significant markers as cofactors and LOD'2.5. Strong evidence for a sucrose-QTL was found on LG1 in a region that spans 50cM and that was associated with three alleles of SMC17CG for both the plant cane and ratoon crops. The segregation patterns of these markers to different linkage groups and their association with sugarcane yield-component traits will be discussed in the context of this two-location/two-crop year study. The linkage/QTL map developed in this study will be useful for identification of markers linked to genes that control QTL of economic importance in sugarcane and for marker-assisted selection. It also serves as a first step in producing a saturated map of the Saccharum genome with more molecular markers used in different pedigrees.