Producing Double Haploid Of Wheat By Hybridization Between Wheat-h.Villosa Translocation Lines And Maize

Haynaldia villosa (syn.Dasyyrum villosa L.,2n=14, VV) is annual cross-pollinated herb, a wild relative of common wheat and native to the Mediterranean coast and Caucasus. It resistant to many wheat diseases, as well as frost and drought tolerance, high grain protein content features. The development of small alien segment translocation lines will be helpful for better utilization of its useful genes. Producing double haploid of wheat by hybridization between wheat and maize is an efficient way for wheat haploid breeding. By this method, homozygous translocation materials can be quickly obtained in a short period.The wheat-H.villosa translocation lines were selected as female and then were pollinated with maize pollen. After24hours, the spikes were cut down and then sprayed with2,4-D of100ppm and cultured in vitro in climatic cabinate.14-15days later, cut down the spikes, stripping ovary enlargement and stripping young embryo under anatomical lens in superclean bench, cultured on the medium of1/2MS. When there were more than2-3true leaves of a haploid plant, the haploid plants were transferred from the culture medium into the soil. When there were more than3tillers of a haploid plant, the haploid plants were treated with colchicine for chromosome doubling. Plants treated with colchicine were transplanted into the soil. At anthesis, paper bags were used to cover the spikes. Harvested seeds were identified through cytogenetics and molecular markers analysis to select the doubled haploid individuals with H.villosa fragments.By the above method,1031and66haploid embryos were obtained respectively in two years. Also,42ans12plants fertiled were obtained accordingly.Analysis of the chromosome numbers of the42plants show that these plants were double haploid plants. By GISH, C-banging-FISH, molecular markers, chromosome pairing of PMCs at meiosis metaphase I and Self-pollinating seed-set rate analysis,7double haploid materials with wheat-H.villosa translocation chromosomes were obtained, including6whole arm translocation lines, and1large alien segment translocation line. And all of the translocation chromosomes could be judged their wheat and H.villosa chromosome fragments. Six whole arm translocation material were T4VS·4DL homozygous translocation lines, one large fragment translocation material was T2BS-1VS·1VL homozygous translocation lines. In this research, through sexual hybridization between maize pollen and wheat-H. villosa translocation heterozygotes, the haploid plants were induced and treated with colchicines. Genetically stable wheat-H. villosa doubled haploid were successfully obtained.