| Glutenin are the important components of wheat storage proteins, which consist of high molecular weight glutenin subunits (HMW-GS) and low molecular weight glutenin subunits (LMW-GS). It was obvious that good composition subunits had great influence on the wheat qualities. Research of glutenin subunit composition is an important part of genetic improvement. It is guidable significance for wheat breeding, Cultivars Popularizing and food processing to identify and analysis wheat glutenin subunit composition, and establish multiplex PCR system based on molecular markers of glutenin subunit genes (locus) related to strong-gluten quality, determine genetic composition of varieties and planting resources, and establish technology system of selecting strong-gluten wheat.Wheat is one of important food crops in Shaanxi. Wheat Cultivars (lines) bred have played an important role in wheat production and breeding in China. Composition and distribution of high molecular weight glutenin subunits or their genes encoded of 175 wheat varieties (lines) were analyzed by using SDS-PAGE and STS molecular marker, and composition and distribution of low molecular weight glutenin subunits of these varieties (lines) were analyzed by a series of allele-specific STS markers for genes at Glu-A3 and Glu-B3 loci in this study. Through using 12 cultivars determined by predecessors as control materials in the past, a multiplex PCR system was established to detect glutenin subunit genes (locus) related to strong-gluten quality at 5 loci. It is effective to further confirm the system by testing and verifying 62 cultivars identified by SDS-PAGE and STS marker as validation materials in this study. The main results obtained in this study are summarized below.1. There were three subunits at the Glu-A1 in Shaanxi wheats. Null (44.6%), 1 (53.7%) and 2* (1.7%) in Shaanxi wheats at Glu-A1 were found. There were eleven subunits at the Glu-B1 in Shaanxi wheats. 6+8 (0.6%), 6+8* (1.1%), 7 (1.1%), 7+8 (6.9%), 7*+8(14.3%), 7+8* (2.3%), 7*+8* (10.2%), 7+9 (5.7%), 7*+9(38.9%), 14+15(17.2%) and 17+18 (1.7%) at Glu-B1 were found. There were four subunits at the Glu-D1 in Shaanxi wheats. 2+12 (84.0%), 3+12 (0.6%), 4+12 (5.7%), 5+10(9.7%) at Glu-D1 were found. There were eighteen types and thirty-six combinations at this three loci. The frequencies of subunits combinations for 1/7+9/2+12 and N/7*+9/2+12 (the highest) at Glu-A1, Glu-B1 and Glu-D1 loci were 13.1% and 13.1%, respectively. The frequency of less than three materials in a combination is 50.0% in all.2. The frequencies of subunits combinations and types of subunits at the Glu-A1, Glu-B1 and Glu-D1 in Shaanxi wheats were also different. There were twenty four types of combinations in Southern Shaanixi region, and the frequencies of combinations 1/7*+9/2+12 and N/7*+9/2+12 were 15.9% and 12.7%, respectively. There were twenty one types of combinations in Central Shaanxi plain, and the frequencies of combinations 1/7*+9/2+12 and N/7*+9/2+12 were 24.2% and 15.4%, respectively. There were fifteen types of combinations in Northen Wei plateau, and the frequency of combination 1/7+8*/2+12 was 19.0%.3. There were four allelic variations at the Glu-A3 in Shaanxi wheats. Glu-A3a (12.6%), Glu-A3b (1.7%), Glu-A3c (58.3%) and Glu-A3d (27.4%) in Shaanxi wheats at Glu-A3 were found. There were eight allelic variations at the Glu-B3 in Shaanxi wheats. Glu-B3a (4.6%), Glu-B3b (2.9%), Glu-B3d (45.7%), Glu-B3e (0.6%), Glu-B3f (2.9%), Glu-B3g (8.5%), Glu-B3i (4.0%) and Glu-B3j (30.8%) at Glu-B3 were found. There were twelve types and twenty one combinations at Glu-A3 and Glu-B3 loci. The frequencies of allelic variations combinations for Glu-A3c/Glu-B3d and Glu-A3c/Glu-B3i (the highest) at Glu-A3 and Glu-B3 loci were 23.4% and 18.3%, respectively. The frequency of less than three materials in a combination is 71.4% in all.4. The frequencies of subunits combinations distribution and types of allelic variations at the Glu-A3 and Glu-B3 in Shaanxi wheats were also different. There were sixteen types of combinations in Southern Shaanixi region, and the frequencies of combinations Glu-A3c/Glu-B3j and Glu-A3c/Glu-B3g were 19.0% and 15.9%, respectively. There were fifteen types of combinations in Central Shaanxi plain, and the frequencies of combinations Glu-A3c/Glu-B3d and Glu-A3c/Glu-B3j were 24.1% and 20.9%, respectively. There were eight types of combinations in Northen Wei plateau, and the frequency of combination Glu-A3c/Glu-B3d was 52.3%.5. Through continuous commissioning and optimization, a multiplex PCR system was developed. This system indirectly detected 7 genes or loci related to dough strength, such as Ax1/Ax2*, Bx7OE, Dx5, Glu-A3d, Glu-B3i and Glu-B3j. The result showed that 12 control materials are coincident with their results of previous research, and 62 wheat cultivars are also coincident with result of these materials determined by SDS-PAGE and a singe PCR system in Shaanxi. Therefore, the multiplex PCR system developed is stable and reliable in this study. In this study, composition of Shaanxi wheat was detected by STS markers and SDS-PAGE, and define characteristic of HMW-GS composition and distribution in Shaanxi wheat. Subunit 7* and 8* were tested. Composition and distribution of genes encoded of LMW-GS at Glu-A3 and Glu-B3 loci was also first analyzed in Shaanxi wheat. The multiplex PCR system was develop for evaluation of wheat quality characters related to strong gluten. It was used to detect Axnull, Bx7OE, Dx5, Glu-A3d, Glu-B3i and Glu-B3 genes (locus), which were located at Glu-A1, Glu-B1, Glu-D1, Glu-A3 and Glu-B3 loci , respectively. It achieve the ultimate test Ax1 or Ax2*, Bx7OE, Dx5(+Dy10), Glu-A3d and Glu-B3i genes, and analyze presence or absence of 1B?1R translocaton, the result will offer useful informations for improving wheat genetic quality, growing and food processing et al. |
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