In order to estimate
genetic diversity of Chinese endangered grass species
Psathyrostachys huashanica Keng ex Guo, 12 selected
ISSR primers were used to analyze genetic variation of 150 individuals from 20 sub-populations collected in Huashan Mountain in Shaanxi Province. The results indicated that percentage of polymorphic loci ( P ) was 96.8%, and the average effective number of alleles ( Ae ) was 1.411 per locus. The mean expected heterozygosity ( He ) of the total population was 0.251, which was greater than the average value (0.148) of the wind-pollinated and outcrossing plant species. Shannon index of the total population was 0.391, suggesting relatively high
genetic diversity in P. huashanica . The genetic differentiation coefficient ( G (ST )) was 0.304,proposing that most (ca. 70%)of the genetic variation occurred within sub-populations with a certain frequency of gene flow. The sub-populations demonstrated relatively high genetic identity with similarity coefficient varying between 0.796-0.974 (0.903 on average). It is concluded based on the study that the main threat to the existence of P. huashanica is ont associated with the low level of genetic diversity, instead, the survival of this species is significantly related to its unique environmental requirements. The authors suggest that the continued availability of P.huashanica could be preserved if its original ecological habitats could be maintained and restored.