Genetic Diversity Of Roegneria .sinica, A Wild Relative Of Wheat

Roegneria sinica(2n=4x=28,StY ) is a long lived and perennial species in Triticeae tribe of Roegneria C.Koch,mainly distributed on highlands of Northern china. It is an important source of genes confering resistance and tolerance to many biological and non-biological stress. So it is valuable in wheat breeding and forage improvement. However, compared with other species of Roegneria C.Koch, Roegneria sinica had not been fully studies except for some some reports on taxology and cytology. The genetic diversity was analyzed based on morphologic traits, tolerances ( including drought-tolerance, salt-tolerance and powdery mildew resistance ) and EST-SSR narkers.The main results are as follows:(1)There is abundant genetic diversity among the populations of Roegneria sinica based on morphologic traits and varieties detected by EST-SSR markers. Genetic variance within populations is greater than that among populations.(2)Genetic distance and dendrogram in morphological traits indicated that the populations in forest area can be assembled together and the diversity index of the populations in forest area is higher than that of the non-forest area. The populations with similar latitude and moisture condition can be easily assembled into one group according to dendrogram in EST-SSR markers. This indicated that latitude and moisture affect the distribution and differentiation of Roegneria inica.(3)Most Roegneria sinica populations have good drought-resistance, average DS percentage is 62.85%, but it has low salt-resistance, it's relative salt injury percentage is reach 66.67%~76.25%.(4)Most of Roegneria sinica populations have good powdery mildew resistant. But is has sufficient difference in period of its life (H'=0.4835~1.6588).In this study, wo find genetic variety remained within populations ( ratio>70%) and powdery mildew resistance have some relationship with its geography distribution. A good powdery mildew resistance resource is found in region that congregate most high resistance populations, this germplasm resource enrich the wheat powdery mildew-resistance study and breeding resource.