摘要： 发掘新的玉米矮秆资源，并研究其遗传特性，可为玉米矮化育种提供新的物质基础。以自然突变获得的矮秆突变体K718d和野生型K718为材料，比较表型差异和对外源激素的敏感性；K718d与5个高秆自交系组配正反交F₁、BC₁、BC₂和F₂群体，分析矮秆性状的遗传模式，通过BSA-SSR标记法定位矮秆基因，用等位杂交法鉴定基因的等位性。结果表明，与K718相比，K718d株高、穗位高、节间数和节间长度分别降低48.23%，75.57%，30.83%和65.92%，穗长缩短28.57%，产量降低36.44%，差异均达极显著水平；突变体K718d对GA₃和IAA均不敏感。2个生态点试验结果，正反交F₁均为高秆；BC₁和F₂群体高矮秆植株分离比例分别符合1：1和3：1，BC₂群体为高秆，表明K718d株高由1对隐性细胞核基因控制。将矮秆基因d718定位于1号染色体SSR标记umc2569 和umc1278之间，遗传距离分别为1.0，2.5 cM，是一个br1等位基因。该结果为d718的进一步精细定位和克隆奠定了基础。

关键词: 玉米, 矮秆突变体K718d, 遗传模式, SSR标记, 基因定位, 激素敏感性

Abstract: In order to explore new maize dwarf resources and study their genetic characteristics to provide a new material basis for maize dwarf breeding.The dwarf mutant K718d obtained from spontaneous mutation,and the wild-type K718 were used as materials to compare their phenotypic differences and the sensitivities to exogenous hormones;the genetic model of dwarf trait was analyzed based on the reciprocal F₁,BC₁,BC₂ and F₂ populations obtained from K718d mated with 5 high stalk inbred lines,the dwarf gene was mapped by BSA-SSR marker method,and the gene alleles were identified by allelic hybridization.The results showed that the plant height,ear height,number of internodes and internode length of K718d were reduced by 48.23%,75.57%,30.83% and 65.92% respectively compared with that of K718,and ear length was shortened by 28.57%,the yield was reduced by 36.44%,the differences reached extremely significant levels;the mutant K718d was not sensitive to GA₃ and IAA.According to the experimental results of the two ecological sites,the reciprocal F₁ populations were high stalks;the separation ratios of high plants and dwarf plants in the BC₁ and F₂ populations were accorded with 1:1 and 3:1 respectively,but the BC₂ populations were high stalks;which indicated that the plant height of K718d was controlled by one pairs of recessive nuclear genes.The dwarf gene d718 was located between the SSR markers umc2569 and umc1278 on chromosome 1,and the genetic distances were 1.0,2.5 cM respectively,which was a br1 allele.The results lay the foundation for the further fine mapping and cloning of d718.

Key words: Maize, Dwarf mutant K718d, Genetic model, SSR marker, Gene mapping, Hormone sensitivity

中图分类号: 

• S513.03