title: Partial Dominance, Overdominance, Epistasis and QTL by Environment Interactions Contribute to Heterosis in Two Upland Cotton Hybrids.
abstract: Based on two recombinant inbred line (RIL) populations, two corresponding backcross (BC) populations were constructed to elucidate the genetic basis of heterosis in Upland cotton (Gossypium hirsutum L.). The yield, and yield components, of these populations were evaluated in three environments. At the single-locus level, 78 and 66 quantitative trait loci (QTL) were detected using composite interval mapping in RIL and BC populations, respectively, and 29 QTL were identified based on mid-parental heterosis (MPH) data of two hybrids. Considering all traits together, a total of 50 (64.9%) QTL with partial dominance effect, and 27 (35.1%) QTL for overdominance effect were identified in two BC populations. At the two-locus level, 120 and 88 QTL with main effects (M-QTL), and 335 and 99 QTL involved in digenic interactions (E-QTL), were detected by inclusive composite interval mapping in RIL and BC populations, respectively. A large number of QTL by environment interactions (QEs) for M-QTL and E-QTL were detected in three environments. For most traits, average E-QTL explained a larger proportion of phenotypic variation than did M-QTL in two RIL populations and two BC populations. It was concluded that partial dominance, overdominance, epistasis, and QEs all contribute to heterosis in Upland cotton, and that partial dominance resulting from single loci and epistasis play a relatively more important role than other genetic effects in heterosis in Upland cotton.
authors.affiliation: Department of Plant Genetics and Breeding, Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.
authors.forename: Lianguang
authors.initials: L
authors.lastname: Shang
authors.affiliation: Research Institute of Cash Crops, Hubei Academy of Agricultural Sciences, Wuhan 430064, Hubei, China.
authors.forename: Yumei
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Plant Genetics and Breeding, Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.
authors.forename: Shihu
authors.initials: S
authors.lastname: Cai
authors.affiliation: Department of Plant Genetics and Breeding, Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.
authors.forename: Xiaocui
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Plant Genetics and Breeding, Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Li
authors.affiliation: Department of Plant Genetics and Breeding, Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China.
authors.forename: Abdugheni
authors.initials: A
authors.lastname: Abduweli
authors.affiliation: Department of Plant Genetics and Breeding, Key Laboratory of Crop Heterosis and Utilization of Ministry of Education, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing 100193, China jinping_hua@cau.edu.cn.
authors.forename: Jinping
authors.initials: J
authors.lastname: Hua
mesh_terms: D005075:Biological Evolution; D002874:Chromosome Mapping; D004777:Environment; D004843:Epistasis, Genetic; D059647:Gene-Environment Interaction; D005799:Genes, Dominant; D008040:Genetic Linkage; D018745:Genome, Plant; D005838:Genotype; D003368:Gossypium / Q000235:genetics*; D006823:Hybrid Vigor; D040641:Quantitative Trait Loci; D019655:Quantitative Trait, Heritable
keywords: QTLs; Upland cotton; epistasis; heterosis; overdominace; partial dominance