Genetic Diversity Of Natural Population In Psathyrostachys Huashanica Keng

Psathyrostachys huashanica Keng is a perennial grass and belongs to genus Psathyrostachys in Triticeae.Psathyrostachys distributes in center of middle Asia and Caucasus M t., while P. huashanica, a species endemic to China, is only located in Mountain Hua in Shaanxi Province. At present, it has been considered as the first class of national protected rare plants. Genomic-SSR and EST-SSR markers of wheat were used to conducte the genetic diversity of Psathyrostachys huashanica Keng in this study.1. Two different altitude distributed natural populations-Huangpu Yu(500m) and Dafu Yu(1218m) were studied by 10 pairs simple sequence repeat (SSR) markers in 7 sample levels according to the sample size. The results showed that: The average number of alleles (6.3)and genetic diversity index (0.713) of low altitude population Huangpu Yu were higher than that of high altitude population Dafu Yu (5.1 and 0.662 , respectively);The number of alleles (42～63and 43～51)and genetic diversity index (0.643～0.717 and 0.618～0.662)of Huangpu Yu and Dafu Yu increased along with sampling number increased from 6 to 30 plants, and became relatively uniform while the sample size surpass 26; As the sample size was 18, the number of alleles and genetic diversity index of 2 populations included 95 percentage genetic variations of the total population respectively, therefore, we suggested that 18 individuals could represent the whole population of Psathyrostachys huashanica Keng based on the genetic diversity of SSR.2. The genetic diversity and genetic structure as well as genetic differentiation of natural populations of Psathyrostachys huashanica were investigated based on 10 microsatellite loci. The results showed that:(1) 96 alleles were detected by 10 pairs of SSR primers selected from 285 pairs SSR primers, the number of alleles was detected by each primer ranged from3～15 and the mean number of alleles per locus were 9.6.The total genetic diversity of the 8 populations was 0.766, meaning that relatively high genetic diversity in Psathyrostachys huashanica. Among the 8 populations, the lowest genetic diversity presented in Huashan dongfeng, which is 0.643, and the highest ones are Huangpu Yu and Huashn Yu(0.746 and 0.712 respectively). (2)As for the distribution pattern of genetic diversity, the genetic variation within populations (86.19 %) was greater than that among populations (13.09 %), which may be due to the out-breeding system of Psathyrostachys huashanica.(3)The number of alleles as...