DNA sequence-based mapping and comparative genomics of the St genome of Pseudoroegneria spicata (Pursh) Á. Löve versus wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.)

Genome. 2020 Sep;63(9):445-457. doi: 10.1139/gen-2019-0152. Epub 2020 May 8.

Abstract

Bluebunch wheatgrass (referred to as BBWG) [Pseudoroegneria spicata (Pursh) Á. Löve] is an important rangeland Triticeae grass used for forage, conservation, and restoration. This diploid has the basic St genome that occurs also in many polyploid Triticeae species, which serve as a gene reservoir for wheat improvement. Until now, the St genome in diploid species of Pseudoroegneria has not been mapped. Using a double-cross mapping populations, we mapped 230 expressed sequence tag derived simple sequence repeat (EST-SSR) and 3468 genotyping-by-sequencing (GBS) markers to 14 linkage groups (LGs), two each for the seven homologous groups of the St genome. The 227 GBS markers of BBWG that matched those in a previous study helped identify the unclassified seven LGs of the St sub-genome among 21 LGs of Thinopyrum intermedium (Host) Barkworth & D.R. Dewey. Comparisons of GBS sequences in BBWG to whole-genome sequences in bread wheat (Triticum aestivum L.) and barley (Hordeum vulgare L.) revealed that the St genome shared a homology of 35% and 24%, a synteny of 86% and 84%, and a collinearity of 0.85 and 0.86, with ABD and H, respectively. This first-draft molecular map of the St genome will be useful in breeding cereal and forage crops.

Keywords: EST-SSR; colinéarité; collinearity; genotyping-by-sequencing; génotypage par séquençage; homologie; homology; synteny; synténie.

MeSH terms

  • Chromosome Mapping*
  • Chromosomes, Plant
  • Diploidy
  • Expressed Sequence Tags
  • Genetic Linkage
  • Genetic Markers
  • Genome, Plant
  • Genomics*
  • Hordeum / genetics*
  • Microsatellite Repeats
  • Poaceae / genetics*
  • Polyploidy
  • Synteny
  • Triticum / genetics*

Substances

  • Genetic Markers