Gene-associated single nucleotide polymorphism discovery in perennial ryegrass (Lolium perenne L.).
Molecular genetic marker development in perennial ryegrass has largely been dependent on anonymous sequence variation. The availability of a large-scale EST resource permits the development of functionally-associated genetic markers based on SNP variation in candidate genes. Genic SNP loci and associated haplotypes are suitable for implementation in molecular breeding of outbreeding forage species. Strategies for in vitro SNP discovery through amplicon cloning and sequencing have been designed and implemented. Putative SNPs were identified within and between the parents of the F(1)(NA(6) x AU(6)) genetic mapping family and were validated among progeny individuals. Proof-of-concept for the process was obtained using the drought tolerance-associated LpASRa2 gene. SNP haplotype structures were determined and correlated with predicted amino acid changes. Gene-length LD was evaluated across diverse germplasm collections. A survey of SNP variation across 100 candidate genes revealed a high frequency of SNP incidence (c. 1 per 54 bp), with similar proportions in exons and introns. A proportion (c. 50%) of the validated genic SNPs were assigned to the F(1)(NA(6) x AU(6)) genetic map, showing high levels of coincidence with previously mapped RFLP loci. The perennial ryegrass SNP resource will enable genetic map integration, detailed LD studies and selection of superior allele content during varietal development.
Cogan
Noel O I
NO
Primary Industries Research Victoria and Molecular Plant Breeding Cooperative Research Centre, Victorian AgriBiosciences Centre, La Trobe Research and Development Park, Bundoora, VIC, 3083, Australia.
Ponting
Rebecca C
RC
Vecchies
Anita C
AC
Drayton
Michelle C
MC
George
Julie
J
Dracatos
Peter M
PM
Dobrowolski
Mark P
MP
Sawbridge
Timothy I
TI
Smith
Kevin F
KF
Spangenberg
Germán C
GC
Forster
John W
JW
D001947:Breeding; D003001:Cloning, Molecular; D005091:Exons / Q000235:genetics; D020224:Expressed Sequence Tags; D017343:Genes, Plant / Q000235:genetics*; D005819:Genetic Markers; D007438:Introns; D008129:Lolium / Q000235:genetics*; D010940:Plant Proteins / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci / Q000235:genetics*; D017422:Sequence Analysis, DNA
D005819:Genetic Markers; D010940:Plant Proteins