Biodiversity Science ›› 2007, Vol. 15 ›› Issue (1): 1-22.doi: 10.1360/biodiv.060277

• 论文 •     Next Article

Genetic diversity, gene introgression and homoplasy in sympatric popu-lations of the genus Actinidia as revealed by chloroplast microsatellite markers

Tian Zhang 1, 2**, Zuozhou Li 1**, Yaling Liu 1, 3, Zhengwang Jiang 1, Hongwen Huang 1*   

  1. 1 Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074
    2 Graduate School of the Chinese Academy of Sciences, Beijing 100049
    3 College of Horticulture and Forestry, Huazhong Agricultural University, Wuhan 430074
  • Received:2006-11-16 Revised:2006-12-11 Online:2007-01-20
  • Zuozhou Li

Gene introgression usually results from spontaneous hybridization occurring among closely related species in sympatric populations and thus has great impact on the genetic structure of natural populations. This phenomenon has recently become one of the most active subjects in study of evolutionary and conservation biology. In the present study, eight chloroplast microsatellite (cpSSR) primers were used to examine genetic diversity, population genetic structure and hybridization introgression among seven Actinidia species with overlapping distributions in transitional regions ranging from the western China plateau to the middle-eastern China hilly mountains. The results showed: (1) A total of 42 haplotypes designated by 18 alleles at six polymorphic loci were detected across 655 individuals of the ten sympatric populations sampled. Although a reticulate evolutionary relationship was revealed among cpSSR haplotypes, there existed a strong species-specific tendency. (2) The intra-specific genetic diversity was generally high but varied greatly among different species. A. fulvicoma var. lanata showed the highest genetic diversity (P = 62.50%, hT = 0.173, HT = 0.897) whereas A. deliciosa exhibited the lowest (P = 37.5%, hT = 0.041, HT = 0.516). (3) High level of inter-population genetic differentiation (GST and FST varied from 0.319 to 0.780 and 0.40 to 0.695, respectively) and limited gene flow (Nm ranged from 0.219 to 0.747<1) were detected among the different species, of which A. deliciosa showed the highest inter-population genetic differentiation (GST = 0.780, FST = 695). (4) No significant difference was found between Gst (unordered alleles) and Nst (ordered alleles), sug-gesting a lack of phylogeographical structure for most Actinidia species. This is consistent with the Mantel test which revealed no significant relationship between genetic distance and geographical distance. (5) Inter-estingly, a relatively high level of inter-specific genetic differentiation was detected among species in sym-patric populations (FST ranged from 0.476 to 0.990), except for two populations (HW and GZ) of the A. chinensis/A. deliciosa complex. The result was also well in accordance with UPGMA analysis, which re-vealed that the populations tended to cluster together into the same species. Further analysis indicated that the A. chinensis/A. deliciosa complex was probably highly influenced by both shared ancestral chloroplast polymorphism and recent hybridization introgression. However, hybridization introgression rarely occurred between less related species, suggesting homoplasy events may have also played an important role in shaping phylogenetic relationships in the genus. The results have important implications for understanding population genetics and evolutionary patterns in the genus Actinidia and provide baseline data for formulating conserva-tion and management strategies.

No related articles found!
Viewed
Full text


Abstract

Cited

  Shared   
  Discussed   
[1] . [J]. Chin Bull Bot, 1994, 11(专辑): 77 .
[2] . Studies on physiology of floral induction and zearalenone[J]. Chin Bull Bot, 1995, 12(专辑3): 18 -29 .
[3] Zhao GOng-peng Fang Ji-you Jiang Ji-quan Yang Hui-jian Su Shu-xin Wang Zhan-wen Yu Guang-xue. A Preliminary Results of the Cold-Resister CR-4 Applied to Spring-maize in the Cold Mountain Areas[J]. Chin Bull Bot, 1994, 11(特辑): 132 -136 .
[4] Chenlu Xu, Xiaomei Sun, Shougong Zhang. Characteristics of Conifer Genome and Recent Advances in Conifer Sequence Resources Mining[J]. Chin Bull Bot, 2013, 48(6): 684 -693 .
[5] SUN Qi-Gao CHEN Li-Qun. Stomatal Observation on Compression Fossils from the Middle Miocene Shanwang Flora in Shandong and its Implications[J]. Chin Bull Bot, 2000, 17(专辑): 256 -258 .
[6] Xinxiong Lu. Design and Construction of Plant Germplasm Banks[J]. Chin Bull Bot, 2006, 23(1): 119 -125 .
[7] Ge Yao;Shulian Xie. Progress in Molecular Systematics of Batrachospermales[J]. Chin Bull Bot, 2007, 24(02): 141 -146 .
[8] . [J]. Chin Bull Bot, 2007, 24(03): 433 .
[9] . [J]. Chin Bull Bot, 1994, 11(专辑): 64 .
[10] Shusi Chen. Anatomy of Vessel Elements in the Secondary Xylem of Syzygium samarangense[J]. Chin Bull Bot, 2006, 23(6): 677 -683 .