Biodiv Sci ›› 2013, Vol. 21 ›› Issue (1): 71-79.DOI: 10.3724/SP.J.1003.2013.09138

• Orginal Article • Previous Articles     Next Articles

Genetic diversity of natural and planted populations of Tsoongiodendron odorum from the Nanling Mountains

Xueqin Wu, Gangbiao Xu*(), Yan Liang, Xiangbao Shen   

  1. The Laboratory of Forestry Genetics, Central South University of Forestry and Technology, Changsha 410004
  • Received:2012-07-03 Accepted:2012-12-18 Online:2013-01-20 Published:2013-02-04
  • Contact: Xu Gangbiao

Abstract:

Ex situ conservation, complementary to in situ conservation, plays an important role in preservation and recovery of endangered species. Tsoongiodendron odorum is a relic species that was listed in the Second Grade of the List of Wild Plants Under State Protection (First Batch) in China. For protection of its genetic diversity, ex situ conservation populations have been established and managed outside of natural habitats in several nature reserves since 1980. However, only dozens of individuals are currently saved from each planted population. To assess the actual protective effectiveness of these planted populations, we detected and compared the genetic diversity of three planted populations from Nanling Mountains with four natural populations using ISSR markers. Overall, we detected 362 total ISSR discernible bands with 16 ISSR primers, of which 301 were polymorphic. The percentage of polymorphic bands (P) was 83.2%. At the population level, the percent of polymorphic bands ranged from 37.9% to 62.2%, with an average value of 53.1%. This result showed that T. odorum had high genetic diversity both at population and species levels. However, the percentage of polymorphic bands and Shannon information index (I) of ex situ conservation populations (66.6% and 0.2990) were much lower than those of natural populations (80.9% and 0.3629). We deduced that there was a narrow genetic base for plantations of T. odorum. Population structure analysis revealed that three planted populations could be collected from the same wild population (i.e., YK population). The genetic variation of four natural populations (GST=0.2495) showed that there was significant isolation among populations, which would limit gene flow and population differentiation among populations. We present suggestions on regulating seed collection from different natural habitats to establish planted populations and strengthening research on the reproductive biology of T. odorum.

Key words: Tsoongiodendron odorum, ISSR, genetic diversity, natural population, ex situ conservation