title: Estimation of loci involved in non-shattering of seeds in early rice domestication.
abstract: Rice (Oryza sativa L.) is widely cultivated around the world and is known to be domesticated from its wild form, O. rufipogon. A loss of seed shattering is one of the most obvious phenotypic changes selected for during rice domestication. Previously, three seed-shattering loci, qSH1, sh4, and qSH3 were reported to be involved in non-shattering of seeds of Japonica-type cultivated rice, O. sativa cv. Nipponbare. In this study, we focused on non-shattering characteristics of O. sativa Indica cv. IR36 having functional allele at qSH1. We produced backcross recombinant inbred lines having chromosomal segments from IR36 in the genetic background of wild rice, O. rufipogon W630. Histological and quantitative trait loci analyses of abscission layer formation were conducted. In the analysis of quantitative trait loci, a strong peak was observed close to sh4. We, nevertheless, found that some lines showed complete abscission layer formation despite carrying the IR36 allele at sh4, implying that non-shattering of seeds of IR36 could be regulated by the combination of mutations at sh4 and other seed-shattering loci. We also genotyped qSH3, a recently identified seed-shattering locus. Lines that have the IR36 alleles at sh4 and qSH3 showed inhibition of abscission layer formation but the degree of seed shattering was different from that of IR36. On the basis of these results, we estimated that non-shattering of seeds in early rice domestication involved mutations in at least three loci, and these genetic materials produced in this study may help to identify novel seed-shattering loci.
authors.affiliation: Laboratory of Plant Breeding, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501, Japan. r-ishika@port.kobe-u.ac.jp.
authors.forename: Ryo
authors.identifier: http://orcid.org/0000-0003-1848-2493
authors.initials: R
authors.lastname: Ishikawa
authors.affiliation: Laboratory of Plant Breeding, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501, Japan.
authors.forename: Akinori
authors.initials: A
authors.lastname: Nishimura
authors.affiliation: Laboratory of Plant Breeding, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501, Japan.|Department of Plant Breeding, Physiology and Ecology, Yezin Agricultural University, Yezin, Nay Pyi Taw, 15013, Myanmar.
authors.forename: Than Myint
authors.initials: TM
authors.lastname: Htun
authors.affiliation: Laboratory of Plant Breeding, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Nishioka
authors.affiliation: Laboratory of Plant Breeding, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Oka
authors.affiliation: Laboratory of Plant Breeding, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501, Japan.
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tsujimura
authors.affiliation: Laboratory of Plant Breeding, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501, Japan.
authors.forename: Chizuru
authors.initials: C
authors.lastname: Inoue
authors.affiliation: Laboratory of Plant Breeding, Graduate School of Agricultural Science, Kobe University, 1-1 Rokkodai, Nada-ku, Kobe, 657-8501, Japan.
authors.forename: Takashige
authors.initials: T
authors.lastname: Ishii
mesh_terms: D000383:Agriculture / Q000379:methods; D000483:Alleles; D032461:Chromosomes, Plant / Q000235:genetics; D018556:Crops, Agricultural / Q000235:genetics*; D003433:Crosses, Genetic; D018744:DNA, Plant / Q000235:genetics; D000071278:Domestication; D017343:Genes, Plant / Q000235:genetics*; D005838:Genotype; D009154:Mutation; D012275:Oryza / Q000145:classification / Q000235:genetics*; D010641:Phenotype; D040641:Quantitative Trait Loci / Q000235:genetics*; D012639:Seeds / Q000235:genetics*; D013045:Species Specificity
chemical_list: D018744:DNA, Plant
keywords: Oryza rufipogon; Rice (Oryza sativa); Seed shattering; qSH3; sh4