title: Screening of candidate genes and fine mapping of drought tolerance quantitative trait loci on chromosome 4 in rice (Oryza sativa L.) under drought stress.
abstract: Due to severe water resource shortage, genetics of and breeding for DT (drought tolerance) in rice (Oryza sativa L.) have become one of the hot research topics. Identification of grain yield QTLs (quantitative trait loci) directly related to the DT trait of rice can provide useful information for breeding new drought-resistant and water-saving rice varieties via marker-assisted selection. A population of 105 advanced BILs (backcross introgression lines) derived from a cross between Zhenshan97B and IRAT109 in Zhenshan97B background were grown under drought stress in a field experiment and phenotypic traits were investigated. The results showed that in the target interval of RM273-RM255 on chromosome 4, three main-effect QTLs related to panicle length, panicle number, and spikelet number per panicle were identified (LOD [logarithm of the odds] > 2.0). The panicle length-related QTL had two loci located in the neighboring intervals of RM17308-RM17305 and RM17349-RM17190, which explained 18.80% and 20.42%, respectively, of the phenotypic variation, while the panicle number-related QTL was identified in the interval of RM1354-RM17308, explaining 11.47% of the phenotypic variation. As far as the spikelet number per panicle-related QTL was concerned, it was found to be located in the interval of RM17308-RM17305, which explained 28.08% of the phenotypic variation. Using the online Plant-GE query system, a total of 13 matched ESTs (expressed sequence tags) were found in the target region, and of the 13 ESTs, 12 had corresponding predicted genes. For instance, the two ESTs CB096766 and CA765747 were corresponded to the same predicted gene LOC_Os04g46370, while the other four ESTs, CA754286, CB000011, CX056247, and CX056240, were corresponded to the same predicted gene LOC_Os04g46390.
authors.affiliation: College of Bioscience and Engineering Jiangxi Agricultural University Nanchang 330045 China ; Jiangxi Super-rice Research and Development Center/National Engineering Laboratory for Rice Nanchang 330200 China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Nie
authors.affiliation: College of Bioscience and Engineering Jiangxi Agricultural University Nanchang 330045 China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.affiliation: College of Bioscience and Engineering Jiangxi Agricultural University Nanchang 330045 China.
authors.forename: Yun-Hua
authors.initials: YH
authors.lastname: Wu
authors.affiliation: College of Bioscience and Engineering Jiangxi Agricultural University Nanchang 330045 China.
authors.forename: Hao-Jie
authors.initials: HJ
authors.lastname: Liu
authors.affiliation: College of Bioscience and Engineering Jiangxi Agricultural University Nanchang 330045 China.
authors.forename: Wei-Wei
authors.initials: WW
authors.lastname: Mao
authors.affiliation: College of Bioscience and Engineering Jiangxi Agricultural University Nanchang 330045 China.
authors.forename: Juan
authors.initials: J
authors.lastname: Du
authors.affiliation: College of Bioscience and Engineering Jiangxi Agricultural University Nanchang 330045 China.
authors.forename: Hai-Lin
authors.initials: HL
authors.lastname: Xiu
authors.affiliation: College of Bioscience and Engineering Jiangxi Agricultural University Nanchang 330045 China.
authors.forename: Xiao-Yu
authors.initials: XY
authors.lastname: Wu
authors.affiliation: Jiangxi Super-rice Research and Development Center/National Engineering Laboratory for Rice Nanchang 330200 China.
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Plant and Microbial Biology UC Berkeley Berkeley California 94720.
authors.forename: Yu-Wei
authors.initials: YW
authors.lastname: Yan
authors.affiliation: Shanghai Agrobiological Gene Center Shanghai 201106 China.
authors.forename: Guo-Lan
authors.initials: GL
authors.lastname: Liu
authors.affiliation: Shanghai Agrobiological Gene Center Shanghai 201106 China.
authors.forename: Hong-Yan
authors.initials: HY
authors.lastname: Liu
authors.affiliation: College of Bioscience and Engineering Jiangxi Agricultural University Nanchang 330045 China ; Department of Plant and Microbial Biology UC Berkeley Berkeley California 94720.
authors.forename: Song-Ping
authors.initials: SP
authors.lastname: Hu
keywords: Candidate genes; drought stress; drought tolerance; fine mapping; quantitative trait loci; rice (Oryza sativa L.)