Study On Inducing Chromosome Translocation Of Wheat-Psathyrostachys Huashanica Using EMS

In recent years, the parents for wheat hybrids are more and more single, and wheat genetic variation is relatively poor. It causes that the wheat genetic basis gets more and more narrow, and the wheat breeding of main yield characters proceeds slowly. Psathyrostachys huashanica is a relative genera and species of wheat, which is rich in genetic variation, and contains a lot beneficial genes that are resistant to disease and stress. So we can transfer the chromosome of Psathyrostachys huashanica to common wheat by distant hybridization. It can enrich the genetic basis of common wheat, and broaden the way of wheat breeding, and provide more excellent germplasm for wheat breeding. A set of Wheat-Psathyrostachys huashanica additional lines and substitution lines, and some of translocation lines have obtained by chromosome engineering. Compared with additional lines and substitution lines, wheat translocation lines are the best way to use alien chromosome fragment. Translocation lines can be induced by the means of ionizing radiation、gametocidal chromosome、tissue culture、chromosome abnormal division and genetic control systems. Wheat germplasm 24-3-1 is a Wheat-Psathyrostachys huashanica derived progeny. It was identified by the agronomic traits investigation, cytology observation and in situ hybridization(GISH) technique, and the result indicated that 24-3-1 is a wheat-Psathyrostachys huashanica disomic alien addition line and has high resistance to wheat stripe rust. On this basis, wheat 24-3-1 was treated with EMS(Ethylmethylsulfone) to induce translocation lines. And M2 plants were identified by cytology analysis and genomic in situ hybridization(GISH) to screen the plants with translocation chromosomes, and the inductive effect of different concentrations of EMS was analyzed. And our aim is to get Wheat-Psathyrostachys huashanica translocation lines. The main results were as below:1. Agronomic traits investigation, cytology observation and in situ hybridization technique(GISH) were used to identify Wheat-Psathyrostachys huashanica derived progeny 24-3-1. Cytogenetic observation of root-tip cell and PMC indicated that the chromosome number of 24-3-1 were 2n=44=22Ⅱ, and genetic stability; GISH analysis of root-tip cell and PMC showed that there were two yellow-green color chromosomes, and they can pair normally. This indicated that 24-3-1 was a wheat-Psathyrostachys huashanica disomic alien addition line, with excellent comprehensive characters, and was of high resistance to wheat stripe rust.2. Wheat-Psathyrostachys huashanica disomic alien addition line 24-3-1 was treated with EMS to induce translocation lines, and we identified plants of M2 with translocation chromosomes by cytology analysis and genomic in situ hybridization(GISH). This study identified 61 plants with wheat- Psathyrostachys huashanica translocation chromosomes from 930 M2 plants. Of the 61 plants, 7 plants were detected with 1 translocation chromosome; 5 plants were detected with 1 translocation chromosome and 1 Psathyrostachys huashanica chromosome; 20 plants were detected with 2 translocation chromosomes; 3 plants were detected with 3 translocation chromosomes; and 26 plants were detected with 4 translocation chromosomes. The cytological observation of root- tip cell and GISH analysis of root- tip cell and PMC indicated that the plants with 2 and 4 translocation chromosomes were wheatPsathyrostachys huashanica translocation lines and wheat-Psathyrostachys huashanica translocation-translocation addition lines, respectively.3. The inductive effect of different concentrations of EMS was analyzed. The result showed that the translocation frequency was 6.56%. And the inductive effect of 0.8%、1.0%、1.2% EMS were 2.67%、9.33% and 11.67%,respectively. The plants of M2 with translocation chromosome treated with 1.0% EMS were mainly with 2 translocation chromosome, and the variety of the plants with translocation chromosome were richer than other concentrations of EMS treatment. What’s more, 1.2% EMS injured more obviously to the individual. So in this study, 1.0% EMS was an optimal concentration to induce wheat- Psathyrostachys huashanica chromosome translocation.4. The plants of M2 with translocation chromosomes were identified by field investigation and agronomic characters observation. The results showed that the phenotypic of the plant with translocation chromosomes were various. And the plants with the excellent characters of dwarf, multi-tillers, large spike and grain, and can be used as the genetic material to improve wheat germplasm. And the seed setting rate of the plants with translocation chromosomes were low.