Establishment and Application of Multiplex PCR System Based on Molecular Markers of Glutenin Subunit Genes (Loci) Related to Strong-gluten in Wheat

Abstract

Wheat strong-gluten quality is closely correlated with combinations of high-molecular-weight glutenin subunits (HMW-GS) and low-molecular-weight glutenin subunits (LMW-GS). The multiplex PCR system is a rapid and efficient approach to evaluate wheat germplasm and its quality in wheat. In this study, we developed a multiplex PCR system confering molecular markers on Ax1/Ax2*, Bx7OE, Dx5, Glu-A3d, Glu-B3i genes, and Glu-B3 locus and validated it with 12 cultivars with known subunit at each locus. This multiplex PCR system was proved to be effective and stable to amplify target bands for these genes (locus), and used to evaluate the glutenin subunit genes (locus) accociated with strong-gluten in 62 major cultivars in wheat production in Shaanxi province, China. The results showed that the frequencies of genes Ax1/Ax2*, Dx5, Glu-A3d, Glu-B3i, and locus Glu-B3 in the 62 cultivars were 56.5%, 9.6%, 33.9%, 1.6%, and 64.4%, respectively, whereas gene Bx7OE was not found. Most of the cultivars carried two-gene (locus) combinations with the frequency of 48.3%, a few cultivars carried a single gene or locus (33.9%). The frequency of cultivars carrying three or four-gene (locus) combinations was 11.3%. The remaining cultivars (6.5%) were free of above elite gene (locus). Therefore, the frequency of combination of multiple strong-gluten subunits gene (locus) was low in cultivars from Shaanxi Province, which could be promoted through germplasm introduction and traditional breeding aided by molecular marker selection. The multiplex PCR system developed in this study may serve as a rapid and efficient method to select materials pyrimiding multiple genes (loci) associated with strong-gluten in wheat breeding for quality.