Genetic Diversity Of Germplasm Resources Of Agropyron Cristatum In Inner Mongolia

Wheatgrass(Agropyron cristatum), as the perennial, arid-tolerant grass in Triticeae, widely distributed in the steppe of temperate zone in Europe and Asia. Its forage value was high because of the soft straw, palatability and nutrition. In adddition, wheatgrass had strong adaptation and resistance to the extreme environment. Wheatgrass was immune to wheat diseases, such as white powder, yellow dawrf, rust and so on, which was used for breeding improvement of wheat and its relative species. The wheatgrass resources in China were abundant, but the evaluation and genetics research on them were limited. The research, based on the 16 nature populations, discribed the main characters of morphology, karyotyping, allozyme and DNA diversity. 1.Morphology The spike characters were different among the populations and individuals. 16 populations were clustered into 4 groups. The growth period investigation showed, the days of seedling emergence varied among 16 populations(CV=64.3%), while the days of withered and yellow were consistant relatively. The 6 poplations(P) from 16 populations were selected for drought resistance evaluation based on seed germinating rate,vigor index, radicles/plumules, relative conductivity and free proline content.The difference was significant (p=0.05),especially for P7 and P13.So the P7 and P13 could be used for the arid grassland reconstruction and breebing selection. 2.Karyotyping The chromosome karyotype analysis showed the 6 populations differed on the karyotype ,SAT-chromosome and B chromosome existance despite of its homogenous tetraploid character(2n=28). The relative length of homogenous chromosome varied in the chromosome of No.1, No.4, No.9 and No.11 in a higher frequency. 3.Allozyme The Peroxidase and Esterase isozymes of the 16 population showed 11 bands and 10 bands seperately for 4 polymorphic loci. The average heterosity was 77.22%. 4.Random Amplified Polymorphic DNA(RAPD) 11 random primers(10bp) were selected from 57 random primers for RAPD analysis of 342 individuals in the 16 wheatgrass populations.In Shannon diversity index calculation,the average genetic diversity was 2.19.The ratio of genetic variation of inner popoulations and inter populations were 60% and 40% seperately; Based on RAPD marker, the 16 populations were clustered into 3 groups in Unweighted Pair-Group Method with Arithmetic Means (UPGMA) . The synthetic results showed wheatgrass had abundant genetic diversity as a good germplasms.The different levels of reseach had similar results on the evaluation of the wheatgrass germplasms.The 16 populations were allocated into the 3 ecotypes of sand,mountain and meadow.