title: Mapping of seed shattering loci provides insights into origin of weedy rice and rice domestication.
abstract: Seed shattering is an important trait that distinguishes crop cultivars from the wild and weedy species. The genetics of seed shattering was investigated in this study to provide insights into rice domestication and the evolution of weedy rice. Quantitative trait locus (QTL) analysis, conducted in 2 recombinant inbred populations involving 2 rice cultivars and a weedy rice accession of the southern United States, revealed 3-5 QTLs that controlled seed shattering with 38-45% of the total phenotypic variation. Two QTLs on chromosomes 4 and 10 were consistent in both populations. Both cultivar and weedy rice contributed alleles for increased seed shattering. Genetic backgrounds affected both QTL number and the magnitude of QTL effects. The major QTL qSH4 and a minor QTL qSH3 were validated in near-isogenic lines, with the former conferring a significantly higher degree of seed shattering than the latter. Although the major QTL qSH4 overlapped with the sh4, the presence of the nonshattering single nucleotide polymorphism allele in the weedy rice accession suggested involvement of a linked locus or an alternative molecular genetic mechanism. Overlapping of several QTLs with those from earlier studies indicated that weedy rice may have been derived from the wild species Oryza rufipogon. Natural hybridization of rice cultivars with the highly variable O. rufipogon present in different geographic regions might be responsible for the evolution of a wide range of phenotypic and genotypic variabilities seen in weedy rice populations worldwide.
authors: the School of Plant, Environmental, and Soil Sciences, Louisiana State University Agricultural Center, 215 MB Sturgis Hall, Baton Rouge, LA 70803.
authors: Prasanta K
authors: PK
authors: Subudhi
authors: Pradeep K
authors: PK
authors: Singh
authors: Teresa
authors: T
authors: DeLeon
authors: Arnold
authors: A
authors: Parco
authors: Ratna
authors: R
authors: Karan
authors: Hanamareddy
authors: H
authors: Biradar
authors: Marc A
authors: MA
authors: Cohn
authors: Takuji
authors: T
authors: Sasaki
mesh_terms: D000483:Alleles; D002874:Chromosome Mapping; D018556:Crops, Agricultural / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D014644:Genetic Variation; D005838:Genotype; D006824:Hybridization, Genetic; D012275:Oryza / Q000235:genetics*; D010641:Phenotype; D058974:Phylogeography; D010940:Plant Proteins / Q000235:genetics*; D040641:Quantitative Trait Loci; D015203:Reproducibility of Results; D012639:Seeds / Q000235:genetics*; D017422:Sequence Analysis, DNA; D014481:United States
chemical_list: D018744:DNA, Plant; D010940:Plant Proteins
keywords: Oryza rufipogon; Oryza sativa; evolution; quantitative trait locus; red rice; sh4