一个水稻显性短根突变体的遗传分析和基因定位

摘要

A leaky rice mutant is singled out from an ethylmethane sulfonate (EMS)-mutagenized rice library based on its short root phenotype. The primary root, lateral root and crown root of ksr3 are found to be shorter in length, and accompanied with distortion. Opposite to what is expected, the root hairs of the mutant are thicker and longer. The plants are shorter than the wild type. The genetic analysis indicates that the mutation is controlled by a single dominant nuclear gene. To map KSR3, an F2 population is formed by crossing the mutant ksr3 with Nipponbare wild type. Using the published SSR markers and newly designed STS markers, KSR3 is first mapped between the microsatellite markers S3569 and S5817 on chromosome 7. Then, four new polymorphic sequence-tagged site markers are developed in the region. KSR3 is finally mapped between markers S3702 and S4046 with a physical distance of 312 kb. The finding is expected to help in cloning, functional study and breeding applications.%研究所用的水稻短根突变材料ksr3是从甲基磺酸乙酯诱变的籼稻品种Kasalath突变体库中筛选获得。该突变体在苗期表现为主根、侧根和不定根明显变短且扭曲，根毛异常浓密，长度明显增加，成熟期植株明显矮化。遗传分析表明该短根突变性状受一对显性基因控制。用突变体ksr3和Nipponbare杂交构建的F2群体进行基因定位，将该基因定位于第7染色体上，与STS标记S3569和S5817连锁，在2个标记间发展4个新的STS标记，最终将KSR3定位在S3702和S4046之间的312 kb范围内。