Biodiv Sci ›› 2005, Vol. 13 ›› Issue (2): 122-129.DOI: 10.1360/biodiv.040117

• Editorial • Previous Articles     Next Articles

Genetic diversity of the natural populations of Adiantum reniforme var. sinense

Liqin Pan1,2, Hua Ji, Longqing Chen1*   

  1. 1 College of Horticulture and Forestry Sciences, Huazhong Agricultural University, Wuhan 430070
    2 Agricultural College of Yangzhou University, Yangzhou 225009
  • Received:2004-08-12 Revised:2004-12-12 Online:2005-03-20 Published:2005-03-20
  • Contact: Longqing Chen

Abstract:

Adiantum reniforme var. sinense is an economically important plant species endemic to China. It is only found in a few regions of the Chongqing Municipal Region. For decades, its distribution has been shrinking as a result of over-exploitation, which has caused endangerment of this species. To assist in efforts to effectively conserve this species, we investigated the genetic variation of six natural populations using isoelectric focusing in thin-layer polyacrylamide slab gels. Fourteen loci of five enzyme systems were detected, of which seven were polymorphic. The mean number of effective alleles per locus (Ae) = 1.778, the percentage of polymorphic loci (P) = 0.441, the mean expected heterozygosity (He)= 0.199, and the mean observed heterozygosity (Ho)= 0.235. The results revealed that low levels of genetic diversity existed within the natural populations of A. reniforme var. sinense in comparison with other species of ferns. Only 1.49% of the genetic variation occurred among populations whereas 98.51% existed within populations, suggesting a very low genetic divergence among the populations. The equilibrium state of the populations was measured using Hardy-Weinberg equilibrium and the Fixation Index (F). The results showed that a mixed mating system was possibly the main heterogamy of this species, and its endangerment was caused by overexploitation and habitat loss.