Diversity In Alleles Of Wheat Landraces From China

China has a wide terrain and many types of entironments. After planting for a long period, many wheat (Triticum aestivumL.) landraces formed. At present, 13902 wheat landraces were conserved in the national bank of germplasm and resources, which was much more than any other country. Chinese wheat landraces possessed eurytopicity and excellent characters, and they are deemed as the useful genebank for wheat breeding, so interrelated researches are meaningful to wheat breeding and modern variety improvement.Reaction type diversities among the populations of 5 widegrown wheat landraces were analyzed. At the same time, sixty seeds of every landrace were cut into two parts. The half kernels without embryos were crushed to analyze glutenin composition using sodium dodecyl sulphate polyacrylamide-gel electrophoresis (SDS-PAGE). The other half kernels with embryos were germinated and the bulked leaf samples were used to extract DNA for SSR analysis. 42 pairs of SSR primers were used to detect the allelic diversity within wheat landraces; meanwhile, the HMW-GS composition of 200 wheat landraces that originated from 22 provinces and regions were also determined.(1)Diversity in alleles whthin the population of wheat landraces from chinaThe stripe rust resistant analysis indicated that there were various difference in response types to stripe rust among every population of wheat landraces and cultivars. The segeragations of response types to the same physiological race were different among different landrace colony. Infection types to CY17 within landraces ranged from 3 and 7, 7 infection types were determined witnin'Sanyuehuang', which was the landrace with the most response types. The infection types to CY24 of each material were 2 to 8,'Hulutou'was the most. There was 1 infectoin type within'Dalibanmang', the other 4 landraces all had 4 infection types.HMW-GS analysis indicated that 13 types of glutenin patterns were observed in all materials, and the number of HMW-GS composition within each wheat landrace ranged from 1 to 4. The richest variations on HMW-GS combination were observed in wheat landraces'Dalibanmang'and'Hulutou'with 4 types of glutenin patterns. No variation was determined in'Sanyuehuang', HMW-GS combinations of other materials were between 2 and 3.SSR result showed that 40 of the 42 primer pairs were polymorphic among different accessions. A total of 289 alleles were detected with an average of 6.88 and a range of 1 to17 alleles for each primer pair. The allelic number that each primer pair can detect in every landrace varied from 0 to 9. The PIC indexes of all primer pairs ranged from 0.000 to 0.304 with 0.141 in average. The highest PIC index was found by primer barc171. The PIC indexes within 5Landraces ranged from 0.0435to 0.328, while its average was 0.187.The highest PIC was observed in'Dalibanmang'and theowest was in'Huixianhong'.Comparison between glutenin banding patterns and SSR analysis indicated that the number of allelic variance observed by SSR and the allelic diversity on whole wheat genome were all increased as the adding of the HMW-GS combination. HMW-GS were controlled by genes at theLong arms of the chromosomes 1A,1Band1D,so we concluded that the diversity of HMW-GS combination and the allelic diversity on wheat genome has a same change trend(2)Research of glutenin composition diversity among 200 wheatlandraces.Thirty-five kinds of glutenin patterns were observed among 200 wheat landraces. Null,7+8,2+12 was the most frequent subunit combination that was detected in 118 landraces ( 59%). The frequencies of the other subunit combinations are all less than 10%.Some rare HMW-GS also been determined, and need to be researched ulteriorlyBased on the results above, we conclude that: (1) a high percentage of Chinese wheat landraces are genetically heterogeneity populations based on glutenin composition analysis, SSR and the resistance to strip rust; (2) Based on the genetic heterogeneity of wheat landraces, a large population should be conserved in order to maintain the genetic completeness during their collection and conservation.