Chin J Plant Ecol ›› 2024, Vol. 48 ›› Issue (1): 56-67.DOI: 10.17521/cjpe.2022.0343

• Research Articles • Previous Articles     Next Articles

Diversity pattern and formation mechanism of sympatric Haloxylon ammodendron and Haloxylon persicum in Xinjiang, China

CHEN Yu-Ting1, MA Song-Mei1,*()(), ZHANG Dan2, ZHANG Lin1, WANG Chun-Cheng2   

  1. 1Xinjiang Production and Construction Corps Key Laboratory of Oasis Town and Mountain-basin System Ecology, College of Science, Shihezi University, Shihezi, Xinjiang 832000, China
    2Xinjiang Production and Construction Corps Key Laboratory of Oasis Town and Mountain-basin System Ecology, College of Life Sciences, Shihezi University, Shihezi, Xinjiang 832000, China
  • Received:2022-08-24 Accepted:2023-02-08 Online:2024-01-20 Published:2023-03-01
  • Contact: (shzmsm@126.com)
  • Supported by:
    National Natural Science Foundation of China(41561007);National Natural Science Foundation of China(41261011)

Abstract:

Aims In order to understand the development and evolution of xerophyte flora, it is important to explore the effects of the Quaternary climatic fluctuations and geological events on the distribution, genetic differentiation and evolution of Haloxylon ammodendron and H. persicum in the Gurbantünggüt Desert.

Methods Two chloroplast DNA spacers (trnS-trnG and trnV) were sequenced for 225 individuals from 19 naturally distributed H. ammodendron populations and 106 individuals from 12 H. persicum populations in Xinjiang. Haplotype Network analysis (Network), Principal Co-ordinates Analysis (PCoA), Analysis of Molecular Variance (AMOVA), Bayesian inference trees (BEAST), and Geographically weighted regression (GWR) were integrated to reveal the genetic diversity and environmental interpretation of different geographic populations within and between species, to estimate the time of interspecific lineage divergence and to analyze the demographical history.

Important findings (1) A total of 21 chloroplast haplotypes were identified, and H. ammodendron and H. persicum were clustered into independent clades. (2) Nearly 80% of the genetic variation occurred between species and among different geographical populations of H. ammodendron. The interspecies differentiation occurred from the late Pliocene to the early Pleistocene, which may have been affected by increasing aridity, mountain uplift on the Qingzang Plateau and desert expansion. (3) The results of the geographically weighted regression model showed distinct effects of the environmental factors on spatial heterogeneity of genetic diversity for H. ammodendron and H. persicum. On the whole, the climatic and soil factors had dominated the spatial pattern of genetic diversity for H. ammodendron and H. persicum. In the southern margin of the Gurbantünggüt Desert, climatic factors had positive effects on genetic diversity of H. ammodendron and H. persicum. In the southwestern margin of the desert, climatic factors had a positive effect on H. persicum, while soil factors had a negative effect on H. ammodendron. In the southeastern part of the desert, soil factors had a positive effect on H. ammodendron and a negative effect on H. persicum. In the Altay Region, climatic factors positively influenced both H. ammodendron and H. persicum.

Key words: Haloxylon ammodendron, Haloxylon persicum, genetic variation pattern, species differentiation, geographically weighted regression