Somatic Cell Hybrid Wheat Hmw-gs Composition H1bx14 + H1by15 Coding Sequence

In order to investigate the possible contribution of the common wheat (Triticum aestivum c.v. Jinan 177) /Agropyron elongatum somatic hybrid introgression lines to the bread-making quality of wheat cultivar, HMW-GS compositions in eleven selected hybrid F₆ lines were analyzed based on their agronomic traits and SDS sedimentation values. Among them, five lines C06081, C06094, C06110, C06112, C06117 contain high-quality HMW-GS compositions H1Bx13+H1By16, H1Bx14+H1By15 and H1Dx5+H1Dy12 similar to common wheat cultivars, but different from its parent Jinan 177(1AxNull, 1Bx7+1By9, 1Dx2+1Dy12), while the remainder six have the same HMW-GS as Jinan 177. Four of the former, C06081, C06094, C06110, C06117 and one of the latter C06116 possess higher SDS sedimentation value than parent Jinan 177. The result shows that most hybrid lines possessing high-quality HMW-GS/composition have high SDS sedimentation value.For the statistical analysis, the HMW-GS compositions of ninety somatic hybrid lines were selected as samples. The genetic index for Glu-A1, Glu-B1 and Glu-D1 loci were 0.52, 0.58 and 0.46, respectively. These hybrid lines could be divided into twenty-seven groups based on allelic compositions, in which H1AxNull, H1Bx7+H1By9, H1Dx2+H1Dy12 distributed in the highest frequency, while H1Ax2*, H1Bx7+H1By8+H1By9, H1Dx2+H1Dx5+H1Dy12 appeared in the lowest rate. The high-quality HMW-GS H1Bx13+H1By16 and H1Dx5+H1Dy12 occupied frequencies about 31.1% and 33.5%, respectively. According to parts of data including HMW-GS composition and SDS sedimentation value we obtained previously and a theoretical quality score based on Payne's Glu-1 quality assignments, we constructed a simple score model of H1Dx5+H1Dy12 and assigned the score 3.3. Subsequently, we obtained all twenty-seven HMW-GS compositions' quality score, which ranged from 5 to 13.3 with average score 6.64±0.03.To understand the genetic basic of somatic hybrid with high-quality deeply, we isolate and sequence the open reading frame of HMW-GS genes, which were labeled 94-2 and 94-3, from the somatic hybrid line C06094, which expresses high-quality HMW-GS composition of wheat-like 1Bx14+1By15 and has comparatively high SDS sedimentation value. Sequence analysis based on both DNA and deduced peptide indicated that 94-3 and 94-2 were homologous to 1Bx14+1By15 from common wheat, although they were deduced from variation of 1Bx7+1By9 of parent Jinan177. Therefore, we conclude that somatic hybridization is able to generate novel high-quality HMW-GS alleles.