title: Fine mapping and candidate gene analysis of qFL-chr1, a fiber length QTL in cotton.
abstract: A fiber length QTL, qFL-chr1, was fine mapped to a 0.9 cM interval of cotton chromosome 1. Two positional candidate genes showed positive correlation between gene expression level and fiber length. Prior analysis of a backcross-self mapping population derived from a cross between Gossypium hirsutum L. and G. barbadense L. revealed a QTL on chromosome 1 associated with increased fiber length (qFL-chr1), which was confirmed in three independent populations of near-isogenic introgression lines (NIILs). Here, a single NIIL, R01-40-08, was used to develop a large population segregating for the target region. Twenty-two PCR-based polymorphic markers used to genotype 1672 BC4F2plants identified 432 recombinants containing breakpoints in the target region. Substitution mapping using 141 informative recombinants narrowed the position of qFL-chr1 to a 1.0-cM interval between SSR markers MUSS084 and CIR018. To exclude possible effects of non-target introgressions on fiber length, different heterozygous BC4F3plants introgressed between SSR markers NAU3384 and CGR5144 were selected to develop sub-NILs. The qFL-chr1 was further mapped at 0.9-cM interval between MUSS422 and CIR018 by comparisons of sub-NIL phenotype, and increased fiber length by ~1 mm. The 2.38-Mb region between MUSS422 and CIR018 in G. barbadense contained 19 annotated genes. Expression levels of two of these genes, GOBAR07705 (encoding 1-aminocyclopropane-1-carboxylate synthase) and GOBAR25992 (encoding amino acid permease), were positively correlated with fiber length in a small F2population, supporting these genes as candidates for qFL-chr1.
authors.affiliation: Key Laboratory of Cotton and Rapeseed (Nanjing), Ministry of Agriculture, Nanjing, People's Republic of China.|The Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, People's Republic of China.
authors.forename: Peng
authors.initials: P
authors.lastname: Xu
authors.affiliation: Key Laboratory of Cotton and Rapeseed (Nanjing), Ministry of Agriculture, Nanjing, People's Republic of China.|The Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, People's Republic of China.
authors.forename: Jin
authors.initials: J
authors.lastname: Gao
authors.affiliation: Key Laboratory of Cotton and Rapeseed (Nanjing), Ministry of Agriculture, Nanjing, People's Republic of China.|The Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, People's Republic of China.
authors.forename: Zhibin
authors.initials: Z
authors.lastname: Cao
authors.affiliation: Molecular Cotton Breeding Laboratory, University of Georgia, Tifton, GA, 3179, USA.
authors.forename: Peng W
authors.initials: PW
authors.lastname: Chee
authors.affiliation: Key Laboratory of Cotton and Rapeseed (Nanjing), Ministry of Agriculture, Nanjing, People's Republic of China.|The Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, People's Republic of China.
authors.forename: Qi
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Key Laboratory of Cotton and Rapeseed (Nanjing), Ministry of Agriculture, Nanjing, People's Republic of China.|The Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, People's Republic of China.
authors.forename: Zhenzhen
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Plant Genome Mapping Laboratory, University of Georgia, Athens, GA, 30602, USA.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Paterson
authors.affiliation: Key Laboratory of Cotton and Rapeseed (Nanjing), Ministry of Agriculture, Nanjing, People's Republic of China.|The Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, People's Republic of China.
authors.forename: Xianggui
authors.initials: X
authors.lastname: Zhang
authors.affiliation: Key Laboratory of Cotton and Rapeseed (Nanjing), Ministry of Agriculture, Nanjing, People's Republic of China. xlshen68@126.com.|The Institute of Industrial Crops, Jiangsu Academy of Agricultural Sciences, Nanjing, 210014, People's Republic of China. xlshen68@126.com.
authors.forename: Xinlian
authors.initials: X
authors.lastname: Shen
mesh_terms: D026905:Amino Acid Transport Systems / Q000235:genetics; D002874:Chromosome Mapping; D032561:Cotton Fiber; D017343:Genes, Plant; D005819:Genetic Markers; D005838:Genotype; D003368:Gossypium / Q000235:genetics*; D008190:Lyases / Q000235:genetics; D010641:Phenotype; D040641:Quantitative Trait Loci
chemical_list: D026905:Amino Acid Transport Systems; D005819:Genetic Markers; D008190:Lyases; C021773:1-aminocyclopropanecarboxylate synthase
keywords: Fiber length; Gossypium hirsutum; Near-isogenic line (NIL); Quantitative trait loci (QTLs); Sub-NILs