|YU, XIAOQING - Iowa State University|
|PIJUT, PAULA - Us Forest Service (FS)|
|BYRNE, STEPHEN - Aarhus University|
|ASP, TORBEN - Aarhus University|
|JIANG, YIWEI - Purdue University|
Submitted to: Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2015
Publication Date: 3/11/2015
Citation: Yu, X., Pijut, P., Byrne, S., Asp, T., Bai, G., Jiang, Y. 2015. Candidate gene association mapping for winter survival and spring regrowth in perennial ryegrass. Plant Science. 235:37-35.
Interpretive Summary: High forage and turf quality makes perennial ryegrass a widely grown cool-season grass species. However its vulnerability to freezing damage limits its growth in temperate zones. To identify genes significantly associated with winter survival and spring regrowth, we evaluated a global collection of 192 perennial ryegrass accessions for cold tolerance. Tested accessions differed significantly in winter survival, percentage of canopy green cover, chlorophyll index, and normalized difference vegetation index. We demonstrated that allelic variation in genes for a late embryongenesis abundant group 3 protein and a C-repeat binding factor were closely related to winter survival and spring regrowth in perennial ryegrass.
Technical Abstract: Perennial ryegrass (Lolium perenne L.) is a widely cultivated cool-season grass species because of its high quality for forage and turf. Susceptibility to freezing damage limits its further use in temperate zones. The objective of this study was to identify candidate genes significantly associated with winter survival and spring regrowth in a global collection of 192 perennial ryegrass accessions. Significant differences in winter survival (WS), percentage of canopy green cover (CGC), chlorophyll index (Chl), and normalized difference vegetation index (NDVI) were found among accessions. After controlling population structure, LpLEA3 encoding a late embryogenesis abundant group 3 protein and LpCAT encoding a catalase were associated with CGC and Chl, while LpMnSOD encoding a magnesium superoxide dismutase and LpChl Cu-ZnSOD encoding a chlorophyll copper-zinc superoxide dismutase were associated with NDVI or Chl. Significant association was also discovered between C-repeat binding factor LpCBF1b and WS. Three sequence variations identified in LpCAT, LpMnSOD, and LpChl Cu-ZnSOD were synonymous substitutions, whereas one pair of adjacent single nucleotide polymorphisms (SNPs) in LpLEA3 and one SNP in LpCBF1b resulted in amino acid change. The results demonstrated that allelic variation in LpLEA3 and LpCBF1b were closely related to winter survival and spring regrowth in perennial ryegrass.