The Research Of SSR For Distinctness And Uniformity Evaluation Of Henan Wheat (Triticum Aestivum) Varieties

Wheat is one of China's important food crops, combined with scientific and technological development, making selection and promotion of new varieties was the fast-growing trend, the annual participation in national or local validation of the new wheat species as many as hundreds.New varieties must have the distinctness uniformity and stability. At present, China and internationally accepted standards for wheat varieties DUS testing is mainly based on some morphological traits, developmental traits, quality traits and resistance-shaped, and identification of the results susceptible to environmental factors, and the cycle longer. The technology is based on modern molecular markers have not season, time-saving. SSR technology has a high level of polymorphism, technical simplicity, low cost, easy to operate, and good repeatability and stability. This paper discusses the characteristics of the SSR is suitable for DUS. Screening out SSR molecular markers which were suitable for DUS identification in Henan Province varieties of wheat.In this study, using 18 closer genetic relationship wheat varieties make up group A (Table 2-1), This paper discusses the characteristics of the SSR is suitable for distinctness and uniformity. The SSR molecular markers had high power on discriminating power was analyzed stability. The main molecular markers for DUS evaluation of Henan provinces' wheat varieties were screened out. The discernibility of these molecular markers were tested in 10 variety series from Zhoul3 and Zhou16 make up group B and 41 wheat varieties during the recent 60 years in Henan provinces make up group C. The main contents are as follows:1.252 pairs of SSR markers involved in the whole genome, there were significant differences in polymorphism loci between each marker. At least there was also more than one polymorphic locus, and the most was 31 polymorphic loci. There were significant differences in discrimination power between each marker, the least DP was 0 (band was fuzzy or messy), the most DP is 13. 2. Correlation analysis to SSR molecular marker, there was significant positive correlation between polymorphism loci and discrimination power, correlation coefficient was 0.64; the relativity between number of chromosome and discrimination power was not prominent, correlation coefficient was 0.15. These show that polymorphism loci have significant positive impact to discrimination power.3. Based on the relativity between polymorphism loci of SSR molecular and discrimination of SSR molecular, six pairs of markers were screened out from 252 pairs of primers, respectively:Xwmc574, Xwmc500, Xgwm637, Xwmc679, Xwmc388, Xgwm497, the number of polymorphic loci were9,11,14,6,31,18respectively, the DP value of each marker were 9,11,10,9,13,13 respectively (identified material number>50%).4. The uniformity analysis of the group A by six pairs makers show that, the uniformity rate of species (r) was ranging from 0.667～1.000, the average uniformity rate of species was ranging from 0.861-0.993. Preliminary determine the indicators to estimate uniformity of species and grading standards. The uniformity of species was high or low has a relationship with the single uniformity rate(r) and average uniformity rate(R), According to the standard classification, the best uniformity was species Taixue838, Zhou9823, P9805 and Zhou16, it was first level; the uniformity of species Huaimai0566, Junmai5, Xuke1018, Luomai23, Yuyanmai10, Yuzhan9914, Pingmai97108-1,Yanshi891, Yuyanmai11, Zhengmai7449, Luomai21 and Zhoumail3 were second level; the uniformity of Pu02060 was ordinary, it was third level; only the uniformity of species Guomai201 was worst, it was fourth level.5. In the use of group B material and group C material on the backbone of primers to verify, The six primers had a high DP value in these two group materials in the same way, in the group B material (10 kinds of material), the smallest of the DP was 4, the largest DP was 7; in the group C material (41 kinds of material), the smallest of the DP was 18, the largest DP was 21. Material B and material C could be distinguished completely by the 6 pair markers.