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

CLC Number: 

• S513.03