Chin J Plant Ecol ›› 2020, Vol. 44 ›› Issue (6): 661-668.DOI: 10.17521/cjpe.2019.0298

• Research Articles • Previous Articles     Next Articles

Spatial genetic structure of Lycium ruthenicum in the Qaidam Basin

WANG Chun-Cheng1, MA Song-Mei2,*(), ZHANG Dan1, WANG Shao-Ming1   

  1. 1Key Laboratory of Ecological Corps for Oasis City and Mountain Basin System, College of Life Sciences, Shihezi University, Shihezi, Xinjiang 832000, China
    2Key Laboratory of Ecological Corps for Oasis City and Mountain Basin System, College of Science, Shihezi University, Shihezi, Xinjiang 832000, China
  • Received:2019-11-04 Accepted:2020-03-27 Online:2020-06-20 Published:2020-04-30
  • Contact: MA Song-Mei: ORCID:0000-0002-3107-2256, shzmsm@126.com
  • Supported by:
    National Natural Science Foundation of China(41261011);National Natural Science Foundation of China(41561007)

Abstract:

Aims Based on the cpDNA sequences, we studied the genetic diversity, genetic structure and haplotype evolution of wild Lycium ruthenicum in the Qaidam Basin and provided the scientific basis for the genetic conservation of this species.
Methods We used three filtered high polymorphic cpDNA fragments (psbA-trnH, psbK-psbI and trnV) to study the genetic variation pattern of L. ruthenicum in the Qaidam Basin by employing the population genetic analysis methods. The molecular diversity indices were calculated by using the software of DnaSP 6.0 and Permut 2.0. Genetic differentiation among populations and the defined groups was estimated by the AMOVA analysis. The median-joining network and principal coordinate analysis (PCoA) were used to identify the clustering relationship of haplotype. The maximum likelihood method and Bayesian method were used to reconstruct the phylogenetic tree based on cpDNA haplotypes.
Important findings The combined length of psbA-trnH, psbK-psbI and trnV was 1 454 bp. 14 polymorphic sites were detected, and a total of seven haplotypes were identified. The total genetic diversity (hT) and within-population genetic diversity (hS) were 0.916 and 0.512, respectively. Results from AMOVA suggested that more than 80% of the observed variation was due to differences among groups and populations. The maximum likelihood analysis and Beast analysis revealed that seven haplotypes clustered into two clusters, corresponding to Golmud and Delingha regions and Nuomuhong region, respectively. The revealed topological structure and clusters of haplotype network and PCoA analyses were consistent with the phylogenetic trees. Results of the Mantel test (r = 0.591 1, p = 0.000 9) indicated a non-significant correlation between geographical distance and genetic distance. The L. ruthenicum populations in the Qaidam Basin have high levels of genetic diversity and significant genetic differentiation among populations. In relation to conservation management, we identified the Nuomuhong forestry station and Xinle Village of Golmud City as having a high degree of genetic diversity and these should be the areas of the greatest focus for conservation.

Key words: Lycium ruthenicum, Qaidam Basin, chloroplast fragments, genetic variation, genetic structure