Study On Technology Optimization Of Rapidly Selecting Lines By Chemical Induction Of Maize Parthenogenesis

At present,the use of Stock 6 and its derived or improved lines to hybridize to induce haploid doubling to rapidly select maize inbred lines has become the main technology of maize breeding.However,there are many problems such as low induction rate,cumbersome procedure,troublesome operation,especially the difficulty of identification of haploid grains and the rate of natural doubling,which is difficult to meet the high demand of breeding.Through the years of research,this topic has created a rapid breeding maize inbred line technology using low toxicity reagent,that is herbicide-induced maize parthenogenesis,and obtained national invention patent.The technique can directly obtain diploid seeds in the induction of contemporary,and can induce homozygous lines in the induction of second generation to obtain homozygous line.The selection cycle is shorter than the generation of the Stock 6 derived line,and the technology is expected to be used in breeding for large areas.But the technology in the inducer varieties,concentration,treatment methods and treatment period and other aspects of the study are not perfect.Thus,in this study,trifluralin and acetophenamide were used as a new inducer,and combined with conventional pesticide colchicine,maize germplasm resources with different genetic backgrounds were selected as test materials.Through different reagents,different concentrations,and to induce the rate of induced strains in different periods.The systematic study of chemical induced maize parthenogenesis was carried out to provide theoretical and technical support for large-scale popularization and application.The main contents and results were as follows:1.The effects of trifluralin and propyzamide and colchicine on the induction of parthenogenesis reproduction of special maize hybrids Shen waxy 7,the results showed that the induced plants rate of propyzamide was significantly higher than that of colchicine,colchicine was significantly higher than that of trifluralin?9.09%and 3.24%.respectively?.2.The maize hybrids Shen waxy 7 were induced by the concentrations of 20,40,80,160 and 320?mol·L^-1 of trifluralin and acetophenone.The results showed that the best induced concentration of the two herbicides was 80?mol·L^-1,and the plant yields were 24.03%and 36.36%,respectively,which were significantly higher than those of the other four treatments.3.Comparison of induction effects of trifluralin and propyzamide at different treatment periods,the results showed that the optimal treatment period of the two herbicides was the fifth day after the silking.4.The results showed that the induction rate of hybrid maize was significantly higher than that of different self-generation material.The waxy maize was higher than that of common maize and Lancaster group was higher than Reid group.5.A total of 163 maize parthenogenesis lines were obtained by field phenotypic identification of the plant?Pal generation?grown after 671 seeds.6.Identification of the plant?that is Pa2 generation?to parthenogenetic materials,the result shows that 447 induction materials were all consistent.