CONTRIBUTION OF Glu-B1, Glu-D1 AND Glu-B3 LOCI TO DOUGH QUALITY OF BREAD WHEAT

Abstract

The aim of this research was to identify the combinations and allelic variants of high and low molecular weight glutenins (HMWG and LMWG) to determine their effects on the rheological characteristics of dough of bread wheat (Triticum aestivum L.). A set of 98 lines derived by single seed descent from F₂ to F₆ of the cross ‘Bacanora T88 x Salamanca’ was used. Genotypes were sown at Celaya, Guanajuato, México, 2008 during the Winter-Spring cycle. Variables evaluated were:mixing time, mixing stability, tolerance to overmixing, dough strength and the tenacity/extensibility ratio. Both HMWG and LMWG were identified with sodium dodecyl sulfate in polyacrylamide gel. It was found that loci Glu-B1, Glu-D1 and Glu-B3 affected both dough strength and extensibility. The combination 2*, 7+9, 5 +10, c, g, b was associated to strong gluten and excellent extensibility, suitable for bread-making; in contrast, combination 2*, 7+9, 2+12, c, g, b showed weak and extensible gluten, useful for manufacturing cookies and tortillas. The combination 2*, 7+9, 2+12 c, j, b showed lowest dough strength and 2*, 7+8, 2+12 c, j, b showed the highest extensibility. Alleles 7+9 and 5+10 were associated with higher gluten strength than alleles 7+8 and 2+12. The highest tenacity and lowest ratio tenacity/extensibility values were presented by the allele j, compared to g allele. Therefore, by recombination of progenitors and selection of specific alleles it is possible to obtain bread wheat genotypes with specific quality of dough.