Abstract: It is of great significance to explore, study and utilize the new dwarf maize resources in maize dwarf breeding. The study compared and analyzed the morphological differences between dwarf mutant K125d and homologous K211 inbred lines. The reciprocal F₁, B₁, B₂ and F₂ populations between K125d and seven inbred lines with different heights were used to analyze the genetic model of dwarf characters in mutant K125d and to locate the dwarf gene by BSA-SSR labeling method. Compared with K211, K125d displayed significantly longer growth period, shorter plant height, dense leaf overlapping, increased leaf number and leaf breadth, and decreased leaf angle. The experiment results were consistent in all populations from two different ecological sites. The height of reciprocal F₁ was taller. The separation proportions of B₁ and F₂ populations were 1:1 and 3:1, respectively. The heights of B₂ populations were tall in six populations except K123d. The plant height of dwarf mutant K125d was controlled by a recessive nuclear gene, which was tentatively named d125. The F₂ population from k125d×K236 was used as the locating population. The dwarf gene d125 was initially located on the long arm of chromosome 1, between SSR markers umc2569 and umc1278 with the genetic distances of 6.6,5.1 cM, respectively. It was concluded that d125 was cloned from gene ID GRMZM2G315375, which had an insertion of 9 bp fragment at +1 651 locus and a deletion of 232 bp fragment at +6 438 locus compared to K211. The deletion led to frameshift mutation, and the loss of functional sites might be the main reason for the loss of transport function.

Key words: Maize, Dwarf mutant, K125d, Genetic analysis, Gene location, Gene cloning

CLC Number: 

• S513.03