Abstract:

In the early stage, the dwarf dwarf-12 was successfully selected by distant hybridization of dwarf sorghum and local maize.After previous studies, the dwarf gene may be controlled by br2.Since there were no adverse traits, in order to utilize and discover excellent dwarf inbred lines, and then crossed dwarf-12 with local white maize, and selected the excellent dwarf inbred line d8227. The dwarf maize material d8227 obtained by predecessors was combined with maize of different heights, and it was identified that it has good combining ability. In order to increase the germplasm resources of dwarf maize and improve the yield of maize, in-depth research was carried out.d8227 and dwarf-12 were used as research materials to compare the differences in main agronomic traits between dwarf parents and progeny to observe the differences in stem cytology;d8227 and four inbred lines with different backgrounds were used for genetic mating design to analyze dwarf culm.Inheritance mode of genes; construct a targeting population, perform high-throughput sequencing with BSA method, conduct preliminary mapping of dwarf genes, and perform allelic identification of dwarf materials with known positioning intervals to clarify target genes and known genes relationship. The results showed that the plant height of d8227 increased by 9.35%, the ear position increased by 31.50%, the leaves of d8227 decreased, and the length of stem nodes increased.dwarf-12 increased by 52.21%, 5.26%, 23.76%, 6.93%, 12.02%; using the paraffin section method, observe the characteristics of transverse and longitudinal cells on the upper, ear and lower ear of d8227 and dwarf-12 with a microscope, and d8227 was longitudinally sectioned.The cells were loosely arranged and the cells were obviously elongated;the dwarf-12 cells were arranged regularly and compactly.After measuring the cell area, ear and lower ear cell area of the d8227 were significantly increased than that of the dwarf-12, which was mainly caused by the elongation of the d8227 cells. Through genetic analysis, the dwarf stalk gene was a single recessive gene, and the gene was preliminarily located.The dwarf stalk gene were located at 190-215 Mb of chromosome 1.The dwarf maize that had been located in the interval was selected for allelic identification.The two-year planting results showed that d8227 and 123d, Na360 were not alleles, but may be alleles with 125d and 123d, which needed follow-up fine mapping and in-depth research. On the whole, d8227 is a medium dwarf material with excellent characters and has breeding potential, but further studies such as fine positioning are needed to judge its utilization value.

Key words: Maize, Dwarf, Paraffin section, Genetic analysis, Gene mapping