Biodiv Sci

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Genetic structure of Cryptocarya chinensis in fragmented lower sub-tropical forests in China based on ISSR markers

Zhengfeng Wang1*, Sanhong Gao2, Shengni Tian1, Shenglei Fu1, Hai Ren1, Shaolin Peng2   

  1. 1 Guangdong Key Laboratory of Digital Botanical Garden, Academy of Sciences, GSouth China Botanical Garden, Chineseuangzhou 510650
    2 School of Life Science, Sun Yat-sen University, Guangzhou 510275
  • Received:2005-03-08 Revised:2005-05-24 Online:2005-07-20 Published:2005-07-20
  • Contact: Zhengfeng Wang


Forest fragmentation is the main threat to global biodiversity. However, genetic information concerning the effects of fragmentation is currently lacking for plant species in lower subtropical China. To enrich scientific understanding of this issue, we employed the ISSR (inter-simple sequence repeat) markers to determine the genetic structure in Cryptocarya chinensis. Four hundred and forty-eight individuals from six fragmented populations in Guangdong Province were sampled according to age classes. Four of these populations, DHS, HSD, DWL and GT, were in nature reserves, and the other two, LG and RP, were near villages. Seven ISSR primers produced a total of 209 polymorphic bands which were used to evaluate genetic variation. The results showed that C. chinensis displayed unexpectedly low genetic variation within populations (HP =0.0537) and high genetic differentiation among populations (GST=0.6489, φST=0.6797). Genetic variations in LG (0.0251) and RP (0.0000) populations were lower than in the other four well-conserved populations. Considering age classes, low but significant genetic differentiation characterized DHS and HSD populations. These results indicate that C. chinensis has experienced a recent decrease in population size which may cause a bottleneck effect. The resulting fragmentation increased genetic drift and inbreeding, causing theloss of genetic variation. Our results for C. chinensis may be general for other species in this area and there-fore more work related to conservation is urgently needed.