title: Mapping of quantitative trait loci for canopy-wilting trait in soybean (Glycine max L. Merr).
abstract: Drought stress adversely affects [Glycine max (L.) Merr] soybean at most developmental stages, which collectively results in yield reduction. Little information is available on relative contribution and chromosomal locations of quantitative trait loci (QTL) conditioning drought tolerance in soybean. A Japanese germplasm accession, PI 416937, was found to possess drought resistance. Under moisture-deficit conditions, PI 416937 wilted more slowly in the field than elite cultivars and has been used as a parent in breeding programs to improve soybean productivity. A recombinant inbred line (RIL) population was derived from a cross between PI 416937 and Benning, and the population was phenotyped for canopy wilting under rain-fed field conditions in five distinct environments to identify the QTL associated with the canopy-wilting trait. In a combined analysis over environments, seven QTL that explained 75 % of the variation in canopy-wilting trait were identified on different chromosomes, implying the complexity of this trait. Five QTL inherited their positive alleles from PI 416937. Surprisingly, the other two QTL inherited their positive alleles from Benning. These putative QTL were co-localized with other QTL previously identified as related to plant abiotic stresses in soybean, suggesting that canopy-wilting QTL may be associated with additional morpho-physiological traits in soybean. A locus on chromosome 12 (Gm12) from PI 416937 was detected in the combined analysis as well as in each individual environment, and explained 27 % of the variation in canopy-wilting. QTL identified in PI 416937 could provide an efficient means to augment field-oriented development of drought-tolerant soybean cultivars.
authors.affiliation: Institute for Plant Breeding, Genetics and Genomics, Center for Applied Genetic Technologies, University of Georgia, 111 Riverbend Rd., Athens, GA 30602-6810, USA. hussein@uga.edu
authors.forename: Hussein
authors.initials: H
authors.lastname: Abdel-Haleem
authors.forename: Thomas E
authors.initials: TE
authors.lastname: Carter
authors.forename: Larry C
authors.initials: LC
authors.lastname: Purcell
authors.forename: C Andy
authors.initials: CA
authors.lastname: King
authors.forename: Landon L
authors.initials: LL
authors.lastname: Ries
authors.forename: Pengyin
authors.initials: P
authors.lastname: Chen
authors.forename: William
authors.initials: W
authors.lastname: Schapaugh
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Sinclair
authors.forename: H Roger
authors.initials: HR
authors.lastname: Boerma
mesh_terms: D002874:Chromosome Mapping; D003433:Crosses, Genetic; D055864:Droughts; D005819:Genetic Markers; D020412:Multifactorial Inheritance / Q000235:genetics*; D010641:Phenotype; D040641:Quantitative Trait Loci; D013025:Glycine max / Q000235:genetics* / Q000254:growth & development
chemical_list: D005819:Genetic Markers