| Triticum aestivum ssp. tibetanum Shao is one of the unique hexaploid wheat in western China. There is uniquely geographical distributions, highly genetic polymorphisms and distnctly morphological character such as glume color, rachis fragility and glume tenacity in Triticum aestivum ssp. tibetanum Shao. Meanwhile, it has many useful traits, such as resistance to preharvest sprouting, cold tolerance for wheat breeding. The genome of Triticum aestivum ssp. tibetanum Shao is AABBDD, so it is crossable with common wheat. The utilization of desirable genes from Triticum aestivum ssp. tibetanum Shao was important to develop modern wheat cultivars. 142 accessions of Triticum aestivum ssp. tibetanum Shao were analysed by means of SDS-PAGE, A-PAGE and STS to evaluate the genetic diversity .The main results as follow:1 Analysis of genetic diversity of four majors agronomic characters for all tested materials showed that in the aspect of height , spike length , 1000 kernel weight and kernel number. In plant height , the average value was around 121 cm ; Spike length was varied from 6 to 19 cm and the mean was 11.5 cm ; Kernel number was varied from 36 to 94 and the mean was 66.6 ; 1000 kernel weight was varied from 17.4 to 55.1 gram and the mean was 32.3 gram . According to the mean of genetic diversity index of four characteristics, the highest one was the diversity index of spike length and the diversity index of kernel number was next, the diversity index of height was the third and the last one was mean of 1000 kernel weight.2. The SDS-PAGE analysed results showed that there were 12 alleles on Glu-1 loci, 2 alleles on Glu-A1 loci, 5 alleles on Glu-B1 loci, 5 alleles on Glu-D1 loci in the allele variations of high molecular weight gluten subunits (HWM-GS). The frequencies of null , 7+8 , 2+12 subunits were highest respectively on the Glu-A1 , Glu-B1 and Glu-D1 loci , reaching 97.18%,80.28%,91.55% respectively . There were 12 types of subunits composition and the predominant type were null/7+8/2+12, the frequency reached 73.24%.3. The results from gliadin analysis indicated that, in tha total of 142 materials.ω-,γ-,β-andα-gliadins had enough diversity of genertics. The frequency of each gliadin was 1.408~31.690,0.704~38.732,1.408~34.507 and 2.817~29.577 ; Diversity index from high to low in turn wasα>β>γ>ω; Diversity index was between 0 and 0.368. Genetics similarities among 142 varieties ranged from 0.583 to 0.965. 4 In order to fully exploit the wheat germplasm resources in quality breeding programs, the genetic diversity of low molecular weight glutenin subunit Glu-B3 was investigated with STS primers using 136 accessions Triticum aestivum ssp. tibetanum Shao . The data indicated that the number of alleles at the Glu-B3 locus was 6 for Triticum aestivum ssp. tibetanum Shao, Glu-B3c was observed with the highest frequency (88.24%) and Glu-B3i with the lowest frequency (16.91%). The combinations of the Glu-B3 locus were 31in Triticum aestivum ssp. tibetanum Shao, type c was observed with the highest frequency (17.65%). The genetic diversity index was 1.8108 at the Glu-B3 locus for Triticum aestivum ssp. tibetanum Shao. |
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