| Triticum sphaerococcum Perc. is cultivated specices in hexaploid wheat (2n=6x=42, AABBDD). It is one of the primary resources of common wheat. In this study, the agronomic traits and storage proteins were investigated, and someα-gliadin genes were cloned in T. sphaerococcum accessions from different countries. The main results were described as following:1. The main agronomic traits were evaluated in T. sphaerococcum accessions. Higher variations of the agronomic traits were observed. The lower plant height, better plant shape, stronger tillering ability, and lower 1000-grains weight were found in all accessions. The significant partial-correlations were detected between tiller number and number of the spikelet per spike, the plant height and 1000-grains weight, 1000-grains weight and grains per spike, 1000-grains weight and grains weight per spike in correlation analysis. The significant positive correlation was also observed between the 1000-grains weight and the plant height, whereas the significant negative correlation between 1000-grains weight and the number of spikelet per spike, the kernels per spike. The grains weight per spike had significant positive correlations with the kernels per spike, the 1000-grain weight and plant height, respectively.2. The abundance genetic diversity of gliadins was observed in 29 accessions using acid polyacrylamide gel electrophoresis (A-PAGE). A total of 25 bands and 27 gliadin patterns were detected, and the number for each accession ranged from 10 to 19, with an average of 16. The genetic similarity (GS) among all accessions ranged from 0.593 to 1.000, with the mean of 0.788. All accessions could be clustered into 4 groups at the level of GS 0.766. And the results indicated that the genetic variations of all accessions in gliadin locus were associated with its geographical distribution.3. Only one subunit presented at Glu-A1 locus (null) and Glu-D1 locus (2＋12), and four subunits at Glu-B1, were detected using sodium dodecyl sulphate polyacrylamide get eleetrophoresis (SDS-PAGE). The subunit 22 was the most frequent subunit (75.9%) in the Glu-B1 locus. There were lower genetic diversity in HMW-GS locus. The subunits about high quality were not found in all accessions. The genetic variations of HMW-GS were not associated with its geographical distribution.4. Fifteen complete coding region ofα-gliadin genes and one partial sequences, which were designated as GliTs-1(EF569971) to GliTs-16 (EF569986), were obtained using PCR cloned method. Six sequences, including Gli-Ts1, Gli-Ts2, Gli-Ts4, Gli-Ts5, Gli-Ts8 and Gli-Ts14, are considered as putative functional genes, whereas the others are pseudogenes. Optimal codons patterns ofα-gliadin genes were also identified by comparing with 16 sequences of T. sphaerococcum, four sequences of T. dicoccoides and six sequences of T. aestivum. The appearance of in-frame stop codons had site-specific. A nonsense mutation of CAG and a C→T substitution of CAA were found. The percentages of G＋C at the first position were relatively higher, while more A＋T were involved in the second and third position. A little difference of the codon usage of theα-gliadin genes among T. sphaerococcum, T. dicoccoides and T. aestivum. The five cysteine residues in sequences Gli-Ts6 and Gli-Ts12, and six cysteine residues in the other sequences, were detected were detected, respectively. There are higher similarity among the 16 sequences of T. sphaerococcum. |
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