title: Mapping quantitative trait loci associated with yield and yield components under reproductive stage salinity stress in rice (Oryza sativa L.).
abstract: Salinity tolerance in rice is critical at reproductive stage because it ultimately determines grain yield. An F2 mapping population derived from a Sadri/FL478 cross was exposed to saline field conditions (6-8 dS m(-1)) after the active tillering stage to identify reproductive stage specific QTLs for salinity tolerance. Genetic linkage map was constructed using 123 microsatellite markers on 232 F2 progenies. Totally 35 QTLs for 11 traits under salinity stress were detected with LOD > 3, out of which 28 QTLs that explained from 5.9 to 30.0% phenotypic variation were found to be significant based on permutation test. Three major QTL clusters were found on chromosomes 2 (RM423-RM174), 4 (RM551-RM518) and 6 (RM20224-RM528) for multiple traits under salinity stress. Both parental lines contributed additively for QTLs identified for the yield components. A majority of the QTLs detected in our study are reported for the first time for reproductive stage salinity stress. Fine-mapping of selected putative QTLs will be the next step to facilitate marker-assisted backcrossing and to detect useful genes for salinity tolerance at the reproductive stage in rice.
authors.affiliation: Plant Breeding, Genetics and Biotechnology Division, International Rice Research Institute, DAPO, Box 7777, Metro Manila, Philippines. r.k.singh@irri.org.
authors.forename: Reza
authors.initials: R
authors.lastname: Mohammadi
authors.forename: Merlyn S
authors.initials: MS
authors.lastname: Mendioro
authors.forename: Genaleen Q
authors.initials: GQ
authors.lastname: Diaz
authors.forename: Glenn B
authors.initials: GB
authors.lastname: Gregorio
authors.forename: Rakesh K
authors.initials: RK
authors.lastname: Singh
mesh_terms: D002874:Chromosome Mapping; D017343:Genes, Plant; D056726:Genetic Association Studies; D008126:Lod Score; D018895:Microsatellite Repeats; D012275:Oryza / Q000235:genetics* / Q000254:growth & development; D010641:Phenotype; D040641:Quantitative Trait Loci; D012098:Reproduction; D055049:Salt Tolerance / Q000235:genetics*; D055051:Salt-Tolerant Plants / Q000235:genetics / Q000254:growth & development; D013312:Stress, Physiological