Allelic interaction at seed-shattering loci in the genetic backgrounds of wild and cultivated rice species
Allelic interaction at seed-shattering loci in the genetic backgrounds of wild and cultivated rice species
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DOI：
10.1266/ggs.85.265
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发表时间：
2010-08-01
影响因子：
1.1
通讯作者：
Ishii, Takashige
中科院分区：
文献类型：
--
作者：
Ishikawa, Ryo;Thanh, Pham Thien;Ishii, Takashige
普通栽培稻（Oryza sativa）是由亚洲野生稻（O.鲁菲波贡。在它们之间的形态差异中，种子脱落是栽培型特有的显著特征之一。为了解落粒习性的遗传控制，利用稻粒型和穗粒型回交的BC2F1群体进行了QTL分析。青花菜轮回亲本日本晴（Nipponbare）和O.普通草属acc.W630（供体亲本）。结果表明，在第1和第4染色体上检测到2个强QTL，分别与两个主要落粒位点qSH 1和sh 4一致。在这些位点的等位基因的相互作用，进一步研究了使用两套回交群体具有互惠的遗传背景，栽培和野生。在栽培稻遗传背景下，野生型qSH 1等位基因对落粒的影响强于sh4。此外，qSH 1和sh4位点的野生型等位基因均表现为半显性效应。另一方面，在野生稻的遗传背景下，对两个位点的日本晴等位基因的不落粒效应进行了检查，以从种子落粒的角度检查水稻驯化。偶然的是，在任一落粒位点（qSH 1或sh 4）上单独具有日本晴纯合等位基因的回交植物脱落了所有种子。这一事实有力地表明，不落粒行为不是由野生稻遗传背景中的单一突变获得的。可能还有一些微效基因仍与促进种子落粒的落粒层的形成或激活有关。
It is known that the common cultivated rice (Oryza sativa) was domesticated from Asian wild rice, O. rufipogon. Among the morphological differences between them, loss of seed shattering is one of the striking characters specific for the cultivated forms. In order to understand the genetic control on shattering habit, QTL analysis was carried out using BC2F1 backcross population between O. sativa cv. Nipponbare (a recurrent parent) and O. rufipogon acc. W630 (a donor parent). As a result, two strong QTLs were detected on chromosomes 1 and 4, and they were found to be identical to the two major seed-shattering loci, qSH1 and sh4, respectively. The allelic interaction at these loci was further examined using two sets of backcross populations having reciprocal genetic backgrounds, cultivated and wild. In the genetic background of cultivated rice, the wild qSH1 allele has stronger effect on seed shattering than that of sh4. In addition, the wild alleles at both qSH1 and sh4 loci showed semi-dominant effects. On the other hand, in the genetic background of wild rice, non-shattering effects of Nipponbare alleles at both loci were examined to inspect rice domestication from a viewpoint of seed shattering. It was serendipitous that the backcross plants individually having Nipponbare homozygous alleles at either shattering locus (qSH1 or sh4) shed all the seeds. This fact strongly indicates that the non-shattering behavior was not obtained by a single mutation in the genetic background of wild rice. Probably, some other minor genes are still associated with the formation or activation of abscission layer, which enhance the seed shattering.