title: Genetic basis of drought resistance at reproductive stage in rice: separation of drought tolerance from drought avoidance.
abstract: Drought tolerance (DT) and drought avoidance (DA) are two major mechanisms in drought resistance of higher plants. In this study, the genetic bases of DT and DA at reproductive stage in rice were analyzed using a recombinant inbred line population from a cross between an indica lowland and a tropical japonica upland cultivar. The plants were grown individually in PVC pipes and two cycles of drought stress were applied to individual plants with unstressed plants as the control. A total of 21 traits measuring fitness, yield, and the root system were investigated. Little correlation of relative yield traits with potential yield, plant size, and root traits was detected, suggesting that DT and DA were well separated in the experiment. A genetic linkage map consisting of 245 SSR markers was constructed for mapping QTL for these traits. A total of 27 QTL were resolved for 7 traits of relative performance of fitness and yield, 36 QTL for 5 root traits under control, and 38 for 7 root traits under drought stress conditions, suggesting the complexity of the genetic bases of both DT and DA. Only a small portion of QTL for fitness- and yield-related traits overlapped with QTL for root traits, indicating that DT and DA had distinct genetic bases.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research (Wuhan), Huazhong Agricultural University, Wuhan, China.
authors.forename: Bing
authors.initials: B
authors.lastname: Yue
authors.forename: Weiya
authors.initials: W
authors.lastname: Xue
authors.forename: Lizhong
authors.initials: L
authors.lastname: Xiong
authors.forename: Xinqiao
authors.initials: X
authors.lastname: Yu
authors.forename: Lijun
authors.initials: L
authors.lastname: Luo
authors.forename: Kehui
authors.initials: K
authors.lastname: Cui
authors.forename: Deming
authors.initials: D
authors.lastname: Jin
authors.forename: Yongzhong
authors.initials: Y
authors.lastname: Xing
authors.forename: Qifa
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000704:Analysis of Variance; D002874:Chromosome Mapping; D003681:Dehydration / Q000378:metabolism*; D004190:Disasters; D005819:Genetic Markers; D014644:Genetic Variation; D012275:Oryza / Q000235:genetics* / Q000502:physiology; D010641:Phenotype; D018517:Plant Roots / Q000502:physiology; D040641:Quantitative Trait Loci
chemical_list: D005819:Genetic Markers