籼稻品种遗传变异性初探

 选用水稻RFLP图谱上的50个DNA探针，分析了25个水稻早、中籼品种的RFLP，其中26个能在研究材料间检测到多态性，共检测到73条多态性带。根据各品种之间的等长片段比值，分析了各品种的相似性程度。结果表明，现代早、中籼矮秆品种及其主要原始亲本的遗传背景比较单一，但广东省育成的品种的遗传背景尚较丰富，各地的稻瘟病抗源材料和抗性品种的遗传变异性则相当丰富。本文还讨论了品种抗性与遗传背景的可能联系以及籼稻品种遗传单一性的原因。

Preliminary Study on the Genetic Variability of Commercial Indica Rice Varieties in China

RFLPs among 25 indica rice varieties were assayed with 50 DNA probes. Twenty-six probes detected polymorphisms within tested varieties and produced 73 polymorphic fragments. Similarities between rice varieties were then analyzed based on the proportions of shared DNA fragments. Results indicated that the genetic variability of modern semidwarf rice varieties and their primary parents were generally limited. On the other hand, varieties developed by breeders in Guangdong Province have maintained a fairly high level of variability and the genetic background of donor parents for blast resistance were highly variable. Possible effects of the genetic variability of rice varieties on the blast resistant level and durability, and factors causing the genetic vulnerability of commercial indica rice varieties in China were discussed.