RFLP markers associated with high grain protein from Triticum turgidum L. var. dicoccoides introgressed into hard red spring wheat

Increased grain protein is desirable for many bread and pasta products. Because of its importance to end-use quality and human nutrition, this trait has been widely studied. This study was conducted to (i) identify genomic regions associated with high grain protein concentration (GPC) inherited from Triticum turgidum L. var. dicoccoides in three hard red spring wheat recombinant inbred (RI) populations (ND683/'Bergen', 'Glupro'/'Keene', and Glupro/Bergen); (ii) examine the effects of genetic background and environment on these genes; and (iii) determine the genetic size of the Triticum turgidum L. var. dicoccoides chromosomal segment introgressed into hard red spring wheat genotypes. The F₅-derived RI lines were grown at five environments for the ND683/Bergen population and at three environments for the other two populations. The range of GPC in the ND683/Bergen, Glupro/Keene, and Glupro/Bergen population was 142 to 179, 149 to 182, and 139 to 183 g kg^-1, respectively. The four parental genotypes were surveyed for polymorphisms with 96 low copy DNA clones located on group 5 and 6 chromosomes. A single region associated with high GPC was detected with five RFLP markers (Xcdo365, Xmwg79, Xbcd102, Xbcd357, and Xcdo1380) located near the centromere on chromosome 6B. One of the markers (Xcdo365) identified a 6.5-kb restriction fragment in Triticum turgidum var. L. dicoccoides, Glupro, ND645, and ND683. Hence, this fragment is in coupling linkage to high GPC gene(s). This marker explained 21 to 35% of the phenotypic variation in GPC in the three populations. The DNA marker in this region might be used to rapidly introgress this gene for high GPC into other wheat germplasm.