title: Genetic diversity of thewxflanking region in rice landraces in northern Laos.
abstract: A glutinous texture of endosperm is one of the important traits of rice (Oyza sativaL.). Northern Laos is known as a center of glutinous rice diversity. We genotyped INDEL, SSR and SNP markers in a sample of 297 rice landraces collected in northern Laos. These glutinous varieties were confirmed to share a loss-of-function mutation inGranule bound starch synthase I(Wx). INDEL markers revealed a high frequency of recombinant genotypes betweenindicaandjaponica. Principal component analysis using SSR genotypes ofWxflanking region revealed that glutinousindicalandraces were scattered between non-glutinousindicaand glutinous-japonicatypes. High ratios of heterozygosity were found especially in glutinousindica. Haplotype analysis using SNP markers aroundWxlocus revealed that glutinousindicalandraces would have a few chromosome segments of glutinousjaponica. Frequent recombinations were confirmed outside of this region in glutinousindica. This intricate genetic structure of landraces suggested that glutinousindicalandraces in Laos were generated through repeated natural crossing with glutinous-japonicalandraces and severe selection by local farmers.
authors: Genetic Resources Center, National Agriculture and Food Research Organization , Tsukuba, Ibaraki 305-8602 , Japan.
authors: Chiaki
authors: C
authors: Muto
authors: Faculty of Agriculture and Life Science, Hirosaki University , Hirosaki, Aomori 036-8560 , Japan.
authors: Ryuji
authors: R
authors: Ishikawa
authors: Biology Department, Washington University , St. Louis 63130-4899 , USA.
authors: Kenneth M
authors: KM
authors: Olsen
authors: Institute of Southern Cultural Folklore , Kirishima, Kagoshima 899-4201 , Japan.
authors: Kazuaki
authors: K
authors: Kawano
authors: Agricultural Research Centre, National Agriculture and Forestry Research Institute , Nongviengkham, Vientiane 7170 , Lao P.D.R .
authors: Chay
authors: C
authors: Bounphanousay
authors: Graduate School of Agriculture, Kyoto University , Kyoto 606-8502 , Japan.
authors: Toru
authors: T
authors: Matoh
authors: National Institutes for the Humanities , Minato-ku, Tokyo 105-0001 , Japan.
authors: Yo-Ichiro
authors: YI
authors: Sato
keywords: Laos; Wx; indica; outcrossing; rice landrace; selective sweep