Genetic Diversity Of High Quality Winter Wheat Varieties (Lines) Based On SSR Marker

Wheat is one of the most important crops in the world. In China, both the total yield and trade volume are the first in the world. However, the quality of wheat in China is poorer than that in developed countries. The main problems are a shortage of strong gluten wheat varieties and weak gluten wheat varieties, especially the varieties making good bread and noodles. So it is urgent that we breed and utilize strong gluten wheat varieties.The genetic diversity is the core of biodiversity. Generally speaking, genetic diversity is the total variation of all the lives in the earth as well as in narrow sense it is the genetic variation of a species. The genetic diversity is the base for crop genetic improvement, researches on which will have important effects on the conservation, evaluation and utilization of crop germplasm.The experiment studied the genetic diversity of 144 high quality winter wheat cultivars through SSR marker, then the genetic differentiation extent of the tested varieties was understanded;Based on the cluster dengrogram of SSR, some quality characters such as developtent time, stable time, broke time and sedimentation value of 49 representative samples selected in different types were detected and clustered;then two clustered results were compared.The main results are as follows:1 Wheat genetic diversity is important for wheat breeding program. 21 primers out of 51 SSR markers were used to investigate the genetic diversity of 144 elite high quality winter wheat cultivars (lines).Totally 135 alleles were revealed among 144 cultivars in 21 SSR, at each SSR locus, 2 to 13 alleles could be detected, with the average of 6.4 alleles per SSR marker;the range of PIC is 0.49 to 0.90, with the average of 0.76.2 Based on SSR data, with clustering analysis, 144 materials were clustered 2 SGs, there were 107 varieties in SG I ,36 varieties in SGII ,and one special variety was R0179.SG I was divided into 5 subtypes.SGII was divided into 3 subtypes.The first subtype of SG I contained 25 cultivars such as Linfenl38,Nongdal35,Iinyoul45, Linyou2031;The second subtype of SG I contained Zhongyou9701,Zhongyou9507 and Zhongyou9508;The third one of SG I contained 20 varieties such as Taiyuan752, Xin79-2060,Nongdal95,Jinanl7,Jimail9;The cultivars of the forth one came from AUC;The fifth one of SG I consisted of 20 varieties,for example Qinyou5, Shan225,Shixin733.The first subtype of SGII contained Zheng366-29, Zheng366-69 and several foreign varieties.The second subtype of SGII included Gaocheng 8901 and its offsprings;the third one of SGII contained Hengyou 18, Allalinlll.12545 and Zheng 99327-0-2-4-1.3 The genetic similarity (GS) among 144 high quality winter wheat cultivars was calculated according to SSR data. The mean GS was 0.63, varying from 0.34 to 0.96. The GS between wheat Han 00-7050 and Henong 93(342)-l-5-l-l was thesmallest (0.34), while the GS between wheat Yi 441 and Lankao 906-4 was the greatest (0.96). The result indicated that the germplasm base of these cultivars was relatively narrow, and it was very important to improve high quality wheat in China by strengthening the utility of various cultivars and breeding special parents.4 The CV of each trait was calculated. The CV of Stable time and Mixing Tolerance Index was the biggest seperately 46.5% and 43.0%.The CV of Development time^ broke time and SD was 29.1%^ 35.4% and 31.6%. The CV of Water absorption was the smallest, 4.1%.Quality characters were analyzed among 49 wheat varieties. Based on the result of dendrogram, 49 wheat varieties were divided into 6 types.Analyzing the average of every quality character: The Mixing Tolerance Index and Softening Dough of FG I was the greatest, 48.00FU and 75.76FU.The sedimentation value of FGIH was the biggest, 35.46ml.The Stable time and Broke time of FGV was the longest, 10.46min and 15.5min.