Resistance to take-all disease and diversity in glutenin subunits of different bread wheat genotypes

Take-all is a devastating soil-borne disease of wheat Triticum aestivum L. The disease is caused by the pathogenic fungus Gaeumannomyces tritici, a pathogen distributed worldwide in major wheat production areas that causes severe damage to wheat production. Identification of genotypes with the high nutritional value of seeds can be considered in controlling this disease and in wheat breeding programs. Variation of high molecular weight glutenin subunits (HMW-GS) at the Glu-A۱, Glu-B۱, and Glu-D۱ loci was studied using SDS-PAGE electrophoresis in ۱۵ genotypes of bread wheat. A positive correlation was found between ۱۰۰۰-seed weight and the ۵ + ۱۰ allele (r = ۰.۵۹۴), indicating that presence of this allele will increase ۱۰۰۰-seed weight. A simple corresponding analysis was conducted to show the relationship between the take-all index and the genetic diversity of genotypes and the association between the bilateral groupings of individuals based on two criteria (genetic diversity and disease response). The result of stepwise regression showed that glutenin subunit null, ۷ + ۸, ۲*, ۷ + ۹, ۵ + ۱۰ have linkage with resistance to take-all disease. Findings are useful in breeding programs to improve baking quality, develop uniformity and improve heterogeneous genotypes by selecting the best genotypes.

Keywords:

glutenin subunit , take-all index , chi-square test , correlation , ۱۰۰۰-kernel weight , stepwise regression