title: Dominance, overdominance and epistasis condition the heterosis in two heterotic rice hybrids.
abstract: Two recombinant inbred (RI) populations having 194 and 222 lines each, derived, respectively, from a highly heterotic inter- (IJ) and intrasubspecific (II) hybrid, were backcrossed to their respective parents. The RI and two backcross populations along with F1 and its two parents of each hybrid were evaluated for nine important traits, including grain yield and eight other yield-related traits. A total of 76 quantitative trait loci (QTL) for the IJ hybrid and 41 QTL for the II hybrid were detected in the RI population, midparent heterosis of two backcross populations, and two independent sets of data by summation (L1 + L2) and by subtraction (L1 - L2) of two backcross populations (L1 and L2). The variance explained by each QTL ranged from 2.6 to 58.3%. In the IJ hybrid, 42% (32) of the QTL showed an additive effect, 32% (24) a partial-to-complete dominant effect, and 26% (20) an overdominant effect. In the II hybrid, 32% (13) of the QTL demonstrated an additive effect, 29% (12) a partial-to-complete dominant effect, and 39% (16) an overdominant effect. There were 195 digenic interactions detected in the IJ hybrid and 328 in the II hybrid. The variance explained by each digenic interaction ranged from 2.0 to 14.9%. These results suggest that the heterosis in these two hybrids is attributable to the orchestrated outcome of partial-to-complete dominance, overdominance, and epistasis.
authors.affiliation: Key Lab of the Ministry of Education for Plant Developmental Biology, College of Life Science, Wuhan University, Wuhan, China.
authors.forename: Lanzhi
authors.initials: L
authors.lastname: Li
authors.forename: Kaiyang
authors.initials: K
authors.lastname: Lu
authors.forename: Zhaoming
authors.initials: Z
authors.lastname: Chen
authors.forename: Tongmin
authors.initials: T
authors.lastname: Mu
authors.forename: Zhongli
authors.initials: Z
authors.lastname: Hu
authors.forename: Xinqi
authors.initials: X
authors.lastname: Li
mesh_terms: D002874:Chromosome Mapping; D003433:Crosses, Genetic; D004843:Epistasis, Genetic; D005799:Genes, Dominant; D017343:Genes, Plant; D008040:Genetic Linkage; D005819:Genetic Markers; D006823:Hybrid Vigor / Q000235:genetics*; D008957:Models, Genetic; D012275:Oryza / Q000235:genetics*; D010641:Phenotype; D040641:Quantitative Trait Loci
chemical_list: D005819:Genetic Markers
references.citation: Genetics. 1994 Dec;138(4):1251-74
references.pmid: 7896104
references.citation: Genetics. 1992 Nov;132(3):823-39
references.pmid: 1468633
references.citation: Genetics. 2001 Aug;158(4):1737-53
references.pmid: 11514459
references.citation: Trends Biotechnol. 1998 Jul;16(7):301-6
references.pmid: 9675914
references.citation: Genetics. 2007 Nov;177(3):1815-25
references.pmid: 18039883
references.citation: Genetics. 1994 Apr;136(4):1457-68
references.pmid: 8013918
references.citation: Genetics. 1996 Jul;143(3):1437-56
references.pmid: 8807314
references.citation: Heredity (Edinb). 2005 Mar;94(3):295-304
references.pmid: 15316557
references.citation: Science. 1908 Oct 2;28(718):454-5
references.pmid: 17771943
references.citation: Theor Appl Genet. 1995 Jun;90(7-8):1074-8
references.pmid: 24173065
references.citation: Proc Natl Acad Sci U S A. 1917 Apr;3(4):310-2
references.pmid: 16586724
references.citation: Theor Appl Genet. 2002 Aug;105(2-3):248-257
references.pmid: 12582526
references.citation: Science. 1910 Nov 4;32(827):627-8
references.pmid: 17816706
references.citation: Proc Natl Acad Sci U S A. 2003 Mar 4;100(5):2574-9
references.pmid: 12604771
references.citation: Proc Natl Acad Sci U S A. 2006 May 2;103(18):6805-10
references.pmid: 16641103
references.citation: Genetics. 2007 May;176(1):625-44
references.pmid: 17339211
references.citation: Proc Natl Acad Sci U S A. 2006 Aug 29;103(35):12981-6
references.pmid: 16938842
references.citation: Proc Natl Acad Sci U S A. 1997 Aug 19;94(17):9226-31
references.pmid: 11038567
references.citation: Genetics. 1992 Jun;131(2):461-9
references.pmid: 1644280
references.citation: Theor Appl Genet. 2006 Feb;112(3):421-9
references.pmid: 16362278
references.citation: Genetics. 2006 Aug;173(4):2199-210
references.pmid: 16702414
references.citation: Genetics. 2001 Aug;158(4):1755-71
references.pmid: 11514460
references.citation: Genetics. 2007 Nov;177(3):1827-37
references.pmid: 18039884
references.citation: Genetics. 2002 Dec;162(4):1885-95
references.pmid: 12524357
references.citation: Heredity (Edinb). 1968 Aug;23(3):403-9
references.pmid: 5250122
references.citation: J Hered. 1988 Jul-Aug;79(4):225-38
references.pmid: 3166481
references.citation: Genetics. 1995 Jun;140(2):745-54
references.pmid: 7498751
references.citation: Theor Appl Genet. 2005 Feb;110(4):649-59
references.pmid: 15647921
references.citation: Genetics. 1997 Feb;145(2):453-65
references.pmid: 9071598
references.citation: Heredity (Edinb). 2003 Nov;91(5):456-64
references.pmid: 14576738
references.citation: Trends Genet. 2007 Feb;23(2):60-6
references.pmid: 17188398
references.citation: Genetics. 2007 Apr;175(4):2009-17
references.pmid: 17287529
references.citation: Genetics. 2007 Nov;177(3):1839-50
references.pmid: 18039885