Biodiv Sci ›› 2010, Vol. 18 ›› Issue (3): 233-240.  DOI: 10.3724/SP.J.1003.2010.233

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Genetic diversity in six natural populations of Betula luminifera from southern China

Junhong Zhang1, Huahong Huang1, Zaikang Tong1,*(), Longjun Cheng1, Yuelong Liang2, Yiliang Chen3   

  1. 1 Zhejiang Forestry University, Lin'an, Zhejiang 311300
    2 Jiulianshan National Forestry Park, Longnan, Jiangxi 341701
    3 Qingyuan Forestry Farm of Lishui City in Zhejiang Province, Qingyuan, Zhejiang 323800
  • Received:2009-11-11 Accepted:2010-04-24 Online:2010-05-20 Published:2012-02-08
  • Contact: Zaikang Tong

Abstract:

Betula luminifera, a precious timber species in southern mountain areas of China, can be found only in natural reserves because of over harvesting. We examined the genetic diversity and genetic structure of six natural populations of B. luminifera distributed in Zhejiang, Fujian, Jiangxi, Guangxi, and Guizhou using AFLP markers. A total of 323 polymorphic loci were amplified and 355 alleles were detected using nine pairs of primers. Percentage of polymorphism loci (PPL) ranged 93.20-98.60% and Nei’s gene diversity (hj) ranged 0.3143-0.3645, suggesting a high genetic diversity in natural populations of B. luminifera. At the species level, the total genetic diversity (Ht) was 0.3616. High gene flow (Nm = 3.5962) was detected among populations, and the genetic differentiation coefficient was 0.0650. AMOVA analysis showed that genetic variation among the populations accounted for 11.49% of the total. Genetic distance was the largest (0.0665) between Zhejiang (LA) and Guizhou (XW) populations and the smallest (0.0173) between Jiangxi (LN) and Guangxi (LS) populations, indicating that LN and LS populations may originate from the same ancestor. Mantel test revealed that genetic distance was not significantly related to geographical distance (r = 0.423,P = 0.113) but was significantly relative to average temperature difference of each location (r = 0.449, P = 0.017). In combination with on-site investigation, we conclude that the present status of genetic diversity and genetic structure of natural populations of B. luminifera was strongly affected by harvesting and habitat fragmentation. We propose some suggestions on its conservation.

Key words: Betula luminifera, AFLP marker, genetic structure, genetic differentiation, genetic diversity