title: QTLs and candidate genes for rice root growth under flooding and upland conditions.
abstract: To investigate the genetic factors underlying constitutive and adaptive root growth under different water-supply conditions, a double haploid (DH) population, derived from a cross between lowland rice variety IR64 and upland rice variety Azucena, with 284 molecular markers was used in cylindrical pot experiments. Several QTLs for seminal root length (SRL), adventitious root number (ARN) and total root dry weight (RW) respectively, under both flooding and upland conditions were detected. Two identical QTLs for SRL and RW were found under flooding and upland conditions. The relative parameters defined as the ratio of parameters under the two water-supply conditions were also used for QTL analysis. A comparative analysis among different genetic populations was performed for the QTLs for root traits and several consistent QTLs for root traits across genetic backgrounds were detected. Candidate genes for cell expansion and elongation were used for comparative mapping with the detected QTLs. Four cell wall-related expressed sequence tags (ESTs) for OsEXP2, OsEXP4, EXT and Xet were mapped on the intervals carrying the QTLs for root traits.
authors.affiliation: The State Key Laboratory of Plant Physiology and Biochemistry, College of Life Sciences, Zhejiang University, Hangzhou 310029, China.
authors.forename: Bing-Song
authors.initials: BS
authors.lastname: Zheng
authors.forename: Ling
authors.initials: L
authors.lastname: Yang
authors.forename: Chuan-Zao
authors.initials: CZ
authors.lastname: Mao
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Zhang
authors.forename: Ping
authors.initials: P
authors.lastname: Wu
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D002874:Chromosome Mapping; D032461:Chromosomes, Plant / Q000235:genetics; D003433:Crosses, Genetic; D055864:Droughts; D020224:Expressed Sequence Tags; D055868:Floods; D017343:Genes, Plant / Q000235:genetics*; D018895:Microsatellite Repeats; D012275:Oryza / Q000145:classification / Q000235:genetics* / Q000254:growth & development; D018517:Plant Roots / Q000235:genetics* / Q000254:growth & development; D012150:Polymorphism, Restriction Fragment Length; D040641:Quantitative Trait Loci