通过 EMS诱变处理栽培稻粳籼 89(Oryza sative L .indica JX89)种子 ,从 M2 代植株中筛选得到一株突变体 ,其植株形态表现为叶细、色谈、植株矮化和极度分蘖。在将近一年的营养生长过程中 ,分蘖总数达到 2 0 0 0多个 ,命名为极度分蘖突变体 (Excessive tillering mutant) ext37.ext37自交所得 M3和 M4 代植株表现同一表型。突变体自交及其与 JX89和丰矮占 5号 (FAZ- 5 )杂交的 F1 、F2 代结果表明该突变为显性遗传方式 ,可能涉及两对等位基因。为了观察突变基因对下游基因表达影响的程度 ,取生长期 4 4天的亲本 JX89和突变体 ext 37的节间分生组织提纯细胞总 RNA,进行基因表达谱差异显示分析。结果表明突变体与亲本的基因表达模式有明显的差异 ,说明可能是处在上游调控基因的突变影响了下游许多基因的表达。目前有关分子生物学的进一步研究正在进行中 A mutant strain was screened from the M2 generation by EMS mutagenesis of Oryza sative L.indica JX89 seeds. The morphological characteristics of the mutant were as follows: leaf color, color tone, plant dwarfing and extreme tillering. During the course of nearly one year of vegetative growth, the total number of tillers reached over 20000, and the plants were named as Excessive tillering mutant ext37.ext37. The M3 and M4 plants showed the same phenotype. Mutant inbreds and F1 and F2 generations that crossed with JX89 and FAZ-5 showed that the mutation was a dominant mode of inheritance, which may involve two pairs of alleles. In order to observe the effect of the mutant gene on the downstream gene expression, total RNA was isolated from the internode meristematic tissues of JX89 and mutant ext 37 in the growth stage, and the difference of gene expression profiles was analyzed. The results showed that there was a significant difference in the gene expression pattern between the mutant and the parent, indicating that the mutation in the upstream regulatory gene may affect the expression of many downstream genes. Further research on molecular biology is currently underway