Mosaic microecological differential stress causes adaptive microsatellite divergence in wild barley, Hordeum spontaneum, at Neve Yaar, Israel

Qingyang Huang, Alex Beharav, Youchun Li, Valery Kirzhner, Eviatar Nevo

Research output: Contribution to journalArticlepeer-review

Abstract

Genetic diversity at 38 microsatellite (short sequence repeats (SSRs)) loci was studied in a sample of 54 plants representing a natural population of wild barley, Hordeum spontaneum, at the Neve Yaar microsite in Israel. Wild barley at the microsite was organized in a mosaic pattern over an area of 3180 m 2 in the open Tabor oak forest, which was subdivided into four microniches: (i) sun-rock (11 genotypes), (ii) sun-soil (18 genotypes), (iii) shade-soil (11 genotypes), and (iv) shade-rock (14 genotypes). Fifty-four genotypes were tested for ecological-genetic microniche correlates. Analysis of 36 loci showed that allele distributions at SSR loci were nonrandom but structured by ecological stresses (climatic and edaphic). Sixteen (45.7%) of 35 polymorphic loci varied significantly (p < 0.05) in allele frequencies among the microniches. Significant genetic divergence and diversity were found among the four subpopulations. The soil and shade subpopulations showed higher genetic diversities at SSR loci than the rock and sun subpopulations, and the lowest genetic diversity was observed in the sun-rock subpopulation, in contrast with the previous allozyme and RAPD studies. On average, of 36 loci, 88.75% of the total genetic diversity exists within the four microniches, while 11.25% exists between the microniches. In a permutation test, GST was lower for 4999 out of 5000 randomized data sets (p < 0.001) when compared with real data (0.1125). The highest genetic distance was between shade-soil and sun-rock (D = 0.222). Our results suggest that diversifying natural selection may act upon some regulatory regions, resulting in adaptive SSR divergence. Fixation of some loci (GMS61, GMS1, and EBMAC824) at a specific microniche seems to suggest directional selection. The pattern of other SSR loci suggests the operation of balancing selection. SSRs may be either direct targets of selection or markers of selected haplotypes (selective sweep).

Original languageEnglish
Pages (from-to)1216-1229
Number of pages14
JournalGenome
Volume45
Issue number6
DOIs
StatePublished - 2002

Keywords

  • Adaptation
  • Genetic diversity
  • Hordeum spontaneum
  • Microsatellites
  • Microsite divergence
  • Natural selection
  • Wild barley

ASJC Scopus subject areas

  • Genetics
  • Molecular Biology
  • Biotechnology

Fingerprint

Dive into the research topics of 'Mosaic microecological differential stress causes adaptive microsatellite divergence in wild barley, Hordeum spontaneum, at Neve Yaar, Israel'. Together they form a unique fingerprint.

Cite this