SSR-Based Genetic Dversity Assessment Among Forty Identified Wheat Cultivars In Henan Province

Wheat (Triticum asetivum L.) is one of the most important crops in the world. As the other crops, the genetic diversity of cultivated wheat has been greatly eroded by the frequent use of same parental genotypes for breeding cultivars. Using the heterosis is one of the important ways in breeding cultivars. Heterosis is based on the heterozygosity of heterozygotic genotypes. Many scientists have concluded that the farmer the genetic distance between parents and the more different genome numbers, the more remarkable the heterosis. Furthermore, it is important for breeding cultivars mat parents have greater genetic diversity, which had been succeed in other crop breedings. The results of much research indicated mat there were correlation between genetic diversity and heterosis. Therefore, more attention should be paid to study the genetic varieties of cultivars to properly match the parents in breeding. Besides its easy operation, SSR markers has more alleles in wheat than those of RFLP and RAPD markers, and reliable results as well as greater diversity can be presented. In addition, it is wheat genome specific. Thus it has been extensively used to study the genetic diversity in wheatWheat is popular crop in Henan province . The genetic diversity among forty identified Henan wheat (Triticum aestirum L) cultivars was investigated to give some help to the wheat breeding of Henan province, and several conclusions were drawn in the following:(1) A set of 43 wheat SSR primers located on 21 wheat chromosomes was used to investigate the genetic diversity of 40 Henan wheat cultivars. 31 out of 43 SSR loci(72%) were polymorphic. On the 31 SSR loci, a total of 186 alleles had been detected in these elite cultivars. At each SSR locus, 2 (WMS154 Xdgm114 WMS182) to 14(WMC175) alleles could be detected, with an average of 6.(2) Based on SSR data, the genetic distance (GD) among 40 Henan elite wheat cultivars was calculated. Forty cultivars could be clustered together in genetic distance range of 0.231-0.593. Themean GD was 0.404. The GD between wheat Yumai55 and Yumai59 was smallest(0.231),while the GD between wheat Yumai17 and Yumai37 was greatest(0.S93). The result indicated that the germplasm base of these cultivars was related narrow, and it was very important for Henan province that strengthen the using of various cultivars and breeding of special parents.(3) Those 40 cultivars were distinguished by less SSR primers, which showed that SSR is a suitable tool to study the genetic diversity of wheat...