Study On The Genetic Diversity Of The Glu-1Loci In Chinese Common Wheat (Triticum Aestivum L.) Varieties Released In The Past30Years

The wheat processing quality mainly includes the food processing and grain millingquality. The quality of food processing and milling determines the processing quality ofwheat. The high molecular weight glutenin is an important component of wheat grainstorage proteins, whose composition and quantity have enormous influence on theprocessing quality of wheat. There is great value to analyze the composition of HMWglutenin subunit and then exploring quality alleles for wheat breeding, which is veryimportant to evaluate the genetic diversity of germplasm resources and breeding for wheatquality.To clarify the genetic variations of high-molecular-weight glutenin subunits(HMW-GS) of Chinese wheat (Triticum aestivum L.) varieties, alleles encoded at Glu-1loci were identified by sodium dodecyl sulphate polyacrylamide gel electrophoresis(SDS-PAGE) analysis from72Chinese elite cultivars grown in the Huang and Huaifacultative wheat zone and Yangtze-River region. This work contributes to a betterunderstanding of the allele frequencies at Glu-1loci on germplasm released in the pastthree decades in China. The main results are as follows:1)In this study, a total of16alleles were detected at the three Glu-1loci from72Chinese elite varieties.Two novel alleles is being found.The allelic identification ofHMW-GS in these varieties revealed considerable diversity.2)Among all the Chinese elite cultivars, the most common compositions of HMW-GS(present in36.85%of the cultivars in together) were null,7+8,2+2and null,7+9,2+12.3)In order to analyze the temporal changes of genetic diversity at the Glu-1loci over thepast30years, the72cultivars in this study, as well as59Chinese released varieties withtheir HMW-GS compositions being described previously, were divided into three decadalgroups (the1980s,1990s and2000s decadal groups). Genetic diversity parameters ofthese decadal groups were calculated. Consequently, the genetic variation of Glu-1lociwas found to be decreased from the1980s to2000s, with no significant loss of diversitybeing detected.4) By comparing the allele frequencies of Glu-1loci in different decadal groups, we found that positive artificial selection of alleles related with good bread-makingquality have improved the qualities of Chinese elite varieties to certain extent.