Physiological character and gene fine mapping of a virescent mutant v13(t) in rice (oryza sativa l.) | 水稻白化转绿突变体v13(t)的生理特性和基因定位

Chino. 目的在温敏型白化转绿突变体v13(t)的表型特征鉴定的基础上，对其控制基因V13(t)进行精细定位。方法在籼稻品种9311中获得一个白化转绿自然突变体，并对其进行表型特征、温度敏感临界值的确定，同时对不同温度下叶片中叶绿体的超微结构进行观察，并以v13(t)与武运粳7号的正反交F2群体对其进行遗传分析和基因的精细定位。结果在低温（26℃）条件下，v13(t)前3张叶片均表现为白色，只有叶尖和叶鞘表现出少许绿色，以后逐渐死亡；在28℃条件下，1―3张叶片抽出时叶尖和边缘表现为白色，以后逐渐转绿；在30℃条件下，叶片表现正常。遗传分析表明，该突变体叶色性状受1对隐性核基因控制，利用SSR分子标记将V13(t)初步定位在水稻第5染色体上的RM3638与RM459标记之间，其遗传距离分别为3.2和0.5 cM。进一步利用已公布的SSR标记和新发展的InDel标记将V13(t)定位在InDel5-11与InDel5-8之间的98.9 kb范围内，同时获得一个与V13(t)共分离的标记InDel5-2。结论白化转绿突变体v13(t)受1对隐性核基因V13(t)控制，V13(t)被定位在AC130729上约98.9 kb的物理距离区间内。

Inglés. ObjectiveOn the basis of phenotypic characterizations of temperature sensitive virescent mutant v13(t), the gene virescent 13(t) was finely mapped. Method One natural virescent mutant, named virescent 13(t), was identified from the indica rice cultivar 9311. The physiological basis of the phenotypic variation was observed by transmission electron microscope. And a map-based cloning strategy was employed to reveal the genetic basis of this variation. Result At low temperature conditions (26℃), the initial three leaves of v13(t) showed white, with little green tips and sheath, and the seedling gradually died. At 28℃, only the leaf tips and edge appeared white, and then the leaves turned green. While at 30℃, a significant difference between it and wild-type was not observed. To uncover the genetic basis of this variation, an F2 segregating population, v13(t) mutant, was developed by crossing v13(t) and Wuyunjing 7. Genetic analysis indicated that this leaf color variation was controlled by one recessive nuclear gene. Gene V13(t) was initially mapped between the SSR markers RM3638 and RM459 on chromosome 5, with the genetic distance of 3.2 cM and 0.5 cM, respectively. Several new InDel markers around the V13(t) region were further developed for fine mapping. The target gene was finally delimited to a 98.9 kb region between markers InDel5-11 and InDel5-8 on BAC AC130729, and segregated with marker InDel5-2. Conclusion One new temperature sensitive virescent mutant v13(t) was controlled by one recessive nuclear gene V13(t), and V13(t) was finally delimited to a 98.9 kb region on BAC AC130729.