Identification of some quantitative trait loci for lodging in durum wheat (Triticum turgidum L. var. Durum) using microsatellite markers

The purpose of the present study was to identify QTLs for lodging in durum wheat (Triticum turgidum L. var durum) using a doubled haploid population. The population included a set of 155 lines that were developed from the cross (Kyle*2/Biodur)/Kofa using maize pollen method. The Kofa parent shows more resistance than Kyle*2/Biodur, to lodging. Phnotypic data of resistance to lodging of the doubled haploid population lines and the parents was scored in 2000-2001 cropping seasons in Regina and Indian Head, Saskatchewan, Canada. There was highly significant differenc between the population lines for this trait. Parents were tested with 517 wheat microsatellite (Simple Sequence Repeat) markers. The primers that were polymorphic in the parents were tested on the whole population to prepare the genotypic data. The genetic linkage map of the 53 polymorphic loci covered about 970 cM and converged into 14 linkage groups. Eleven markers remained unlinked. Linkage between the markers and the lodging genes done based on single marker analysis, simple interval mapping and composit interval mapping using least square means. Three linkage marker groups were associated with lodging trait. The first QTL is located on the chromosome 4BL and its effects were highly significant (P<0.0001) in four environments and explained 20% of lodging phenotypic variation. The other two loci were located on the 2AL, also have highly significant effects on the trait at least at one environment and explained 4-8 percents of lodging phenotypic variation, depending on environments.