Welcome to Acta Prataculturae Sinica ! Today is Share:

Acta Prataculturae Sinica ›› 2018, Vol. 27 ›› Issue (10): 147-157.DOI: 10.11686/cyxb2018022

Previous Articles     Next Articles

Screening and genetic diversity analysis of chloroplast non-coding regions in Leymus chinensis

YANG Yan-ting1, HOU Xiang-yang1, WEI Zhen-wu2, QIAO Zhi-hong1, CHANG Chun1, REN Wei-bo1, WU Zi-nian1,*   

  1. 1.Institute of Grassland Research, Chinese Academy of Agriculture Sciences, Hohhot 010010, China;
    2.College of Animal Science &Technique, Yangzhou University, Yangzhou 225009, China;
  • Received:2018-01-15 Revised:2018-04-12 Online:2018-10-20 Published:2018-10-20

Abstract: The aim of this research was to screen for and classify polymorphic loci of chloroplast non-coding fragments in Leymus chinensis. The study evaluated 9 L. chinensis populations from different geographical locations to identify polymorphic loci from 12 chloroplast DNA (cpDNA) non-coding fragments, and then genetic diversity of the polymorphic cpDNA fragments was analyzed. The results showed that the polymorphic loci of ndhF-rpl32, trnL-trnF, trnC-ycf6 and aptI-aptH were rich, and they had a relatively fast evolution rate. Hence, they could be regarded as ideal molecular markers for future research on population genetics and phylogeography. Based on combined sequences there were 15 haplotypes identified. The haplotype diversity (Hd) and nucleotide diversity (Pi) were 0.928 and 0.00101 respectively. The genetic differentiation coefficient Fst was 0.58884 with the low gene flow (Nm=0.17). Tajima’s D and Fu’s Fs values of neutrality tests were negative (Tajima’s D=-1.0854; Fu’s Fs=-5.301), indicating that L. chinensis had experienced historical population expansion. Analysis of molecular variance showed that most of genetic variation was distributed among populations. The Mantel test showed a significantly positive correlation between genetic and geographical distance (r=0.449, P<0.05). The genetic differentiation coefficients Nst (0.386)>Gst (0.234) implied a significant phylogeographic structure for the populations. The neighbor-joining tree based on combined sequences showed that all haplotypes divided into two major clades, H2 and H10 clustered into a category. The network for cpDNA haplotypes based on combined sequence data showed that the relationships among H2 and H12, and H10 and H12 were further than others, which was similar to the pattern identified by the neighbor-joining tree. These results will be useful for future research on germplasm resources and phylogeography.

Key words: Leymus chinensis, chloroplast non-coding fragment, polymorphic locus, haplotype, genetic diversity