Origin of weedy rice grown in Bhutan and the force of genetic diversity
Origin of weedy rice grown in Bhutan and the force of genetic diversity
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DOI：
10.1007/s10722-005-2257-x
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发表时间：
2005-06-01
影响因子：
2
通讯作者：
Sato, T
中科院分区：
文献类型：
--
作者：
Ishikawa, R;Toki, N;Sato, T
在不丹，杂草稻（Oryza sativa L.）在海拔2620 m以下的梯田上与栽培稻混种。在海拔1000 - 2620 m的22个采集点采集了栽培种和杂草种子。在海拔2250 m以上的田块中，种子圆形的品种较多，而在海拔1630 m以下的田块中，种子细长的品种较多。通过同工酶（多位点）和形态生理（多性状）分析，将所有品种和杂草株系分为籼型和粳型。高原以粳稻品种为主，低地以籼稻品种为主。质体类型通过ORF 100区域的长度多态性来确认。粳稻品种携带非缺失型ORF 100。籼稻品种携带ORF 100缺失型。相反，杂草株表现出的核和细胞质类型的组合的差异。杂草菌株的同工酶基因型为中间型。在杂草品系中经常发现一种重组类型，该类型具有供同功酶分析用的籼型和供同功酶分析用的粳型，反之亦然。这些结果表明，杂草株系可能是通过籼粳自然杂交产生的。此外，他们可能无法重组其先前的同工酶和细胞质基因型集。形态生理性状则没有这种趋势。高原植物的形态生理学分析，特别是，籼稻品种和杂草株与粳稻细胞质。高变核微卫星分析，然后比较品种和杂草株。相同的等位基因在籼稻和粳稻之间，也在品种和杂草株系之间。这表明自然杂交导致了基因流动。
In Bhutan, weedy rice (Oryza sativa L.) was grown together with cultivated rice on terraced paddy fields lower than 2620 m above sea level. Seeds of cultivars and weedy strains were collected at 22 collection sites located from 1000 to 2620 m above sea level. Cultivars with round seeds were frequently found in fields higher than 2250 m, and those with slender seeds in fields lower than 1630 m. All cultivars and weedy strains were divided into indica or japonica types by isozyme (multi-locus) and morpho-physiological (multicharacter) analyses. Japonica cultivars predominated in highland; Indica cultivars predominated in lowland. Plastid type was confirmed by the length polymorphism for the ORF100 region. The japonica cultivars carried non-deletion type ORF100. The indica cultivars carried deletion type ORF100. In contrast, weedy strains showed discrepancy in the combination of the nuclear and cytoplasm types. An intermediate type was found in weedy strains for isozyme genotypes. A recombinant type, which has indica genotypes for isozyme analysis with japonica cytoplasm, and vice versa, was frequently found in weedy strains. These findings suggested that weedy strains would be generated by natural hybridization between indica and japonica. Further, they might fail to recombine their prior genotypes sets for isozyme and cytoplasm. Morphophysiological characters did not show such a tendency. Morpho-physiological analysis of highland plants, in particular, showed indica cultivars and weedy strains with japonica cytoplasm. Hypervariable nuclear microsatellite analysis was then used to compare cultivars and weedy strains. Identical alleles were shared between indica and japonica, and also between cultivars and weedy strains. This suggested that there was gene-flow resulting from natural hybridization.