A microsatellite marker associated with a QTL for grain protein content onchromosome arm 2DL of bread wheat

This study was undertaken with a view to tag gene(s) controlling grain prot ein content (GPC) using molecular markers in bread wheat. For this purpose, the genotype PH 132 with high protein content (13.5%) was crossed with gen otype WL711 with significantly lower protein content (9.7%), and 100 RILs w ere derived. These RILs showed normal distribution for protein content. The parental genotypes were analysed with 232 STMS primer pairs for detection of polymorphism. Of these, 167 primer pairs gave scorable amplification pro ducts, and 57 detected polymorphism between the parents. Using each of thes e 57 primer pairs, we carried out bulked segregant analysis on RILs represe nting the two extremes of the distribution. One primer pair for the locus w mc41 showed association with protein content. This was further confirmed th rough selective genotyping. The co-segregation data on the molecular marker (I wmc41) and protein content on 100 RILs was analysed by means of a singl e-marker linear regression approach. Significant regression suggested linka ge between wcm41 and a QTL (designated as QGpc.ccsu-2D.) for protein conten t. The results showed that this marker-linked QTL accounted for 18.73% of t he variation for protein content between the parents. The marker has been l ocated on chromosome arm 2DL using nulli-tetrasomic lines and two ditelocen tric stocks for chromosome 2D.