水稻闭花授粉基因cl7(t)的遗传分析与基因定位

Genetic Analysis and Mapping of Novel Cleistogamy Gene,cl7(t) in Rice

【目的】鉴定、遗传分析和定位水稻闭花授粉突变体新基因,了解水稻开花机理,利用闭花授粉基因防止转基因作物花粉漂移。【方法】通过EMS对优良粳稻品种H02进行诱变,发现了一个新的闭花授粉突变体8m30。利用突变体8m30与正常开花授粉材料广恢102配制的杂交种和相应的自交分离群体,采用形态特征观察、杂交后代的表型分离统计和遗传分析、基于图位克隆的基因定位等技术方法,对突变体8m30的表型、遗传和基因定位进行研究。【结果】突变体8m30与野生型H02相比,株高变矮,株型变紧,穗着粒密,在整个抽穗授粉过程中,颖花不张开。遗传分析表明该突变性状受1对隐性核基因控制,位于第7染色体长臂的RM21964和RM234之间,遗传距离分别为0.1 cM和0.3 cM,两者间的物理距离为160 kb,与标记RM21971共分离,是一个尚未报道的基因,暂命名为cl7(t)(Cleistogamy 7(t))。【结论】水稻闭花授粉突变体8m30由位于第7染色体1对隐性核基因控制,位于第7染色体的RM21964和RM234之间160 kb范围内。

[Objective] Identification, genetic analysis and mapping of novel cleistogamy ge：aes in rice would play an important role in understanding the molecular genetic mechanisms of floral development. At the same time, the cleistogamy is an ideal strategy to prevent pollen explosion in transgenic rice. [Method] A rice cleistogamy mutant 8m30 with japonica cultivar H02 background was isolated in M2 population treated with 0.5% EMS （Ethane Methyl Sulfonare）. Phenotypic study, genetic analysis and gene mapping by map-based cloning were conducted with the population from F1 of 8m30 and Guanghuil02 and its self-cross progenies. [Result] The mutant with lower plant height, compatible plant style and closed paleas at flowering stage. Genetic analysis indicated that the mutant was controlled by a single recessive nuclear gene. The cleistogamy locus was mapped on the long arm of chromosome 7 between the microsatellite markers RM21964 and RM234 with 0.1 cM and 0.3 cM genetic distance, about 160 kb of the physical distance and cosegregated with RM21971, which suggests the mutant locus be novel allele and is tentatively named cl7（t） （Cleistogamy 7 （t））. [Conclusion] The 8m30 mutant is controlled by a recessive nuclear gene, which is located on chromosome7 between RM21964 and RM234 with physical distance of 160 kb.