The Quality Effects Of Wheat With One HMW-GS And Sequence Analysis Of Wx Genes From Taeniatherum Nevski

The genetic improvement of wheat quality is one of the most important target for wheat breeding. Many genetic factors such as high molecular weight glutenin subunits (HMW-GS) and starch have the profound influence on the quality of wheat. We studied the quality potential of wheat with one HMW-GS by using two F4 populations with different numbers and combinations of HMW-GS. At the same time, for the purpose of understanding and utilization of new Wx alleles from wheat wild relative species, we cloned and analysised the Wx genes from wheat wild relatives Taeniatherum. The main results are as follows:1. There is no direct relationships between the protein content and the numbers and the combinations of HMW-GS.2. Compared with the lines with HMW-GS varied from 2-4, the lines with one HMW-GS had reduced sedimentation values, wet gluten contents, dry gluten contents and gluten indeices than them, suggesting that reduction in HMW-GS may weaken the gluten strength.3. A total of eight Wx genes, named Wx-Tal-Ta8, were isolated from eight accessions belonging to three diploid Taeniatherum species. The eight Wx genes all had 2.8 Kb in nucleotides, and had 11 exons and 10 introns.4. Wx genes from Taeniatherum share highly sequence similarity from 95% to 99% among themseleves, and shares 87.4%-92.8% and 93.5%-97.4%, respetively in the nucleotides and in the amino acid sequneces with the known Wx alleles from Triticeae species. The main difference between the Wx from Taeniatherum and the Wx from other Triticeae species were the indels of single base or small fragments.5. Phylogenetic analysis showed that eight Wx from Taeniatherum could be divided into two classes, and they formed a new branches independent of wheat Wx genes. The Wx gene from Taeniatherm showed higher similarity with Wx from D genome of wheat and diploid Aegilops species except for S genome than Wx from B and A genomes of wheat.