ISSR Analysis On Population Genetic Diversity Of Genus Nitraria L.

Using ISSR molecule marker, 17 populations of 5 species of Nitraria L., including N.spaerocarpa Maxim.,N.tangutorum Bobr.,N.sibirica Pall.,N. roborowskii Kom.,N.praevisa Bobr., were adopted as materials to research the genetic diversity of Nitraria L. in molecular level. Using 10 ISSR primers amplify 170 samples. The results of POPGENE analyze indicated that was moderate level of the genetic diversity of Nitraria L., mean PPB (percentage of polymorphic bands),h and I of 5 species of Nitraria L. as below: Nspaerocarpa(PPB=55.46%, h=0.1727, I=0.2641), N.tangutorum(PPB=44.08%, h=0.1325, I=0.2029), N.sibirica (PPB=68.89%, h=0.2242, I=0.3381), N. roborowskii (PPB=51.71%, h=0.1452, I=0.2265), N.praevisa (PPB=59.76%, h=0.1844, I=0.2817).But ZHNP(PPB=29.20%, h=0.1042, I=0.1552) and ZHNT(PPB=34.58%, h=0.1053, I=0.1608) population'genetic diversity is lower. It is possible that the limitation and isolated ecotope may cause the reduce of species' genetic diversity.The result showed that genetic diversity of N.sibirica L. (PPB=68.89%, h=0.2242, I=0.3381)is highest among compared species. It is possible that the abroad distributing and complex ecotope bring on.Analysis of genetic differentiation showed that N.spaerocarpa (Hs, gene diversity within population)Hs=0.1729±(0.0170), (Gst,coefficient of population differentiation) mean Gst=0.2447; N.tangutorum Hs=0.1325±(0.0184), mean Gst=0.2767; N.sibirica Hs=0.2241±(0.0239), mean Gst=0.1114; N. roborowskii Hs=0.1452±(0.0225), mean Gst=0.073.As a result, the genetic differentiation of Nitraria L. consist in within population.The dendrograms of genetic relationships among population and among individual were constructed based on Nei's genetic distance. Close genetic relationships was revealed between N.spaerocarpa and N.sibirica. It is the closest that the genetic relationships between N. roborowskii and N.praevisa. As a result, five species of Nitraria L. disparted two groups: one group is N.spaerocarpa and N.sibirica. another group is N.tangutorum,N. roborowskii and N.praevisa.