Study On Chemical Methods Of Maize Haploid Doubling

As one of the corn breeding techniques for modern inbred lines,maize haplotype breeding technology has the advantages of shortening breeding period and improving the breeding efficiency compared with the traditional inbred breeding.However,in the practice of breeding,there are a series of problems in how to induce haploid,how to double,and how to transplant.In this experiment,the processing of cutting mature haploid embryos and the processing of immature embryos tissue culture were carried out to study the concentration and time treatment of haploid doubling optimal colchicine,and a set of technical methods with high doubling efficiency and simple operation flow were summarized.The results of this pilot study are as follows:(1)In this experiment,the improved induction line TY1 was used as the male parent,whose induction rate was between 5-10%.The maize hybrid combination PH6WC×TX3-2,XL21×Zheng58 were used as female parent,by inducing the produced haploid,by double processing the mature haploid grain embryo.The results showed that the early embryogenesis,emergence rate and late loosening rate of haploid plants were significantly different from those haploid plants.The haploid mature embryos were treated with colchicine with a mass fraction of 0,0.04%,0.06%,0.08% and 0.12%,respectively,and the time gradient were 0h,3h,6h.The seedling rate and the pollen shedding rate of haploid plants were statistically analyzed,and the best combination of colchicine treatment under the conditions of cutting embryos was obtained.The results showed that the colchicine mass fraction of 0.04% and the treatment time of 3 h was the best for the mature embryo cuted,the doubling efficiency was 12.23%.(2)Due to the efficiency of embryoping doubling of mature haploid seeds was still low,a better effective doubling method was further explored.In this experiment,the induction line TY1 was used as the male parent,the maize embryo tissue culture,and the colchicine set the mass fraction 0,0.01%,0.015%,0.02%,0.025%,0.03%,0.035%,the treatment time is 0 h,24 h,36 h,through the statistical analysis of the seedling rate,survival rate,pollen shedding rate,etc,of the doubled treatments,selected the best condition of doubling.The conclusion was the best doubling treatment of colchicine mass fraction is 0.025%,24h,the doubling efficiency was 26.46%.