Huang, Bing-Hong , Ruan, Yu , Lai, Shih-Jie , Wan, Yu-Ting , Li, Jun-Qing , Huang, Shong , Liao, Pei-Chun .
Geographic isolation, local adaptation, and biased sampling for reforestation in consequence of structured populations in Kandelia obovata.
Several phylogeographic studies have shown that the barriers of oceans and lands play important roles for structuring populations in mangrove species. However, several conservation businesses such as reforestation accelerate gene flow between populations and destruct population structures. In this study, genetic structure of natural and restored populations of Kandelia obovata which distributed in the northern Southeast Asia was explored by AFLP for clarifying effects of geographic isolation, local adaptation, and biased sampling in reforestation. Significant genetic differentiation between Taiwanese and Chinese natural populations in neutral loci (PhiCT = 0.084, P = 0.001) but no differences in positive-outlier loci (PhiCT = -0.048, P = 1.000) indicating the drift-related geographic isolation between natural populations instead of local adaptation. Such results were supported by positive correlations of heterozygosity between populations detected by neutral loci (P < 0.001) but negatively or insignificantly correlated by positive-outlier loci. However, the PCoA showed different distribution patterns between neutral loci and positive outliers: the Taiwanese population is distinct from Chinese populations in neutral loci but incorporate with several Chinese populations in positive-outlier loci. The ShenZhen (SZ) population in China is distinct from others in positive-outlier analysis but mixed with others in neutral loci. These results implied small-scaled local adaptation in specific population instead of regional adaptation. We also examined the genetic composition of restored populations in LongGang, coded the LG1 and LG2, sourced from natural population FuDing (FD) in 1999 and 2008, respectively. The results of PCoA in neutral loci showed similar distribution among FD and LG1 but distinct from the LG2. Only small fraction of the FD samples incorporated into the LG2 and significant lower genetic diversity in LG2 was estimated, indicating the founder effect of LG2 sourced from the biased sampling of seedlings from FD. Similar distribution pattern was also seen in the analysis of positive outliers. The distinct distribution of LG1 and LG2 of the positive-outlier PCoA indicating that they did not suffer identical selective pressures but could be artificial selected by sampling bias. This speculation was also supported by the highly significant correlation of heterozygosity between the FD and LG1 in positive-outlier loci. This study illustrated a pattern of extant population structure of mangroves affected by factors of geographic isolation, local adaptation, and reforestation. More considerations on the sampling strategy and areas for planting should be paid attention when carrying out the forest management and conservation business.
Log in to add this item to your schedule
1 - National Pingtung University of Science and Technology, Department of Biological Sciences and Technology, 1, Shuefu Road, Neipu, Pingtung, 91201, Taiwan
2 - Beijing Forestry University, The Academy of Forestry, Beijing, 100083, China
3 - National Taiwan Normal University, Department of Life Science, Taipei, 116, Taiwan
Presentation Type: Poster:Posters for Topics
Location: Battelle South/Convention Center
Date: Monday, July 9th, 2012
Time: 5:30 PM