大麦抗条纹病基因定位及7H短臂SSR引物开发检测

发布时间：2018-09-08 15:37

【摘要】：大麦(Hordeum vulgare L.)作为最主要的谷物类作物之一,在遗传上的优势和经济的重要性被当作禾本科的模式作物进行研究。近年来,由于啤酒工业的大力发展,啤酒大麦的重要性愈加明显。在啤酒大麦的发展和生产过程中,大麦条纹病爆发较为严重,并逐年增加,对啤酒大麦的质量和产量产生严重的影响。由于国内大麦抗条纹病种质资源稀缺,急需培育抗病新品种。本研究利用100份大麦亲本材料进行抗性鉴定,筛选免疫品种与高感品种进行杂交,利用BSA分析法对抗条纹病基因进行定位,后期在定位到的7H短臂开发新的SSR标记,并对这些标记进行多态性分析。本研究中将新发现的抗大麦条纹病基因命名为Rdg3,该基因是国内首次定位的大麦抗条纹病基因,也是世界上第三个定位的抗大麦条纹病基因。该成果对培育抗条纹病大麦新品种具有重要作用,并对降低农药使用、减轻环境污染具有重要意义。主要结果总结如下:1、利用QWC菌株对100份大麦材料进行接菌,通过抗性鉴定,筛选出免疫材料1份,高抗材料10份,22份材料表现为抗病,感病材料和高感材料分别37份和30份;其中免疫品种为甘啤2号,高感品种Alexis感病最为严重,发病率为88.24%。2、利用免疫品种甘啤2号和高感品种Alexis同时进行正反交,构建杂交组合,F1抗性鉴定发病率为0;对F2群体的276个单株进行接菌,统计发病后抗病单株197株,感病单株79株,经卡方检测抗/感比符合3:1的分离比例,确定抗病基因对感病为显性,且该抗大麦条纹病基因是由单基因控制的。3、利用大麦染色体1-7H的525对引物在两亲本间进行多态性筛选,共筛选103对有多态的引物(其中7H多态性引物11对);利用BSA分析法发现位于7H短臂的标记Bmag206、Bmag7和scssr07970与目标基因Rdg3连锁,因此将抗条纹病基因定位到染色体7H短臂上。在7H短臂开发SSR标记42对,其中在甘啤2号和Alexis中表现多态的共6对,利用该6对引物和7H有多态的11对SSR标记扫描群体,绘制遗传连锁图谱,发现目标基因位于Bmag206和Bmag7中间,且距这两个标记之间的遗传距离分别是1.78cM和2.86cM。4、选取大麦亲本材料48份,利用新开发的42对SSR引物进行多态性扫描。其中有多态的引物共29对。29对引物检测出的等位变异为125个,变幅在2-9之间,平均每个标记4.3个。标记Bmg24和Bmg25检测到等位变异最多,为9个;等位变异频率的变幅为0.2979-0.9130;标记Bmg1的等位变异频率最低,为0.2979。29对引物PIC变幅介于0.1462-0.8234之间,平均值为0.5132。标记Bmg25的PIC值最高,为0.8234,标记Bmg43的值最低,为0.1462。多样性的平均值为0.5596,杂合度平均值为2.98%。
[Abstract]:Barley (Hordeum vulgare L.) As one of the most important cereal crops, genetic superiority and economic importance are studied as model crops of Gramineae. In recent years, with the development of beer industry, the importance of malting barley has become more and more obvious. In the course of development and production of malting barley, the outbreak of barley stripe disease is more serious and increases year by year, which has a serious effect on the quality and yield of beer barley. Because germplasm resources of barley resistant to stripe disease are scarce in China, it is urgent to develop new resistant varieties. In this study, 100 barley parents were used to identify the resistance, to select the immune varieties and to cross with the highly susceptible varieties, to use BSA analysis to localize the gene against stripe disease, and to develop a new SSR marker in the located 7H short arm at the later stage. The polymorphism of these markers was analyzed. In this study, the new gene of resistance to barley stripe disease was named Rdg3, which is the first gene of barley resistance to stripe disease located in China, and the third gene of resistance to barley stripe disease in the world. It is important for breeding new barley varieties resistant to stripe disease, reducing pesticide use and reducing environmental pollution. The main results were summarized as follows: 1 strain of QWC was used to inoculate 100 barley materials. Through identification of resistance, 1 strain of immune material was screened out, and 22 materials of 10 high resistant materials showed resistance to disease, 37 and 30 of susceptible materials and highly susceptible materials, respectively. Gan Beer 2 was the immunized variety, and the highly susceptible variety Alexis was the most serious, the incidence rate was 88.24.2. The positive and negative cross was carried out by using the immunized variety Gan Beer 2 and the highly susceptible variety Alexis at the same time. The incidence of F _ 1 resistance identification in F _ 2 population was 0, 197 resistant plants and 79 susceptible plants were collected from 276 F _ 2 population, and the ratio of resistance to disease was in accordance with the 3:1 isolation ratio by chi-square test. It was determined that the resistance gene was dominant to the susceptible disease, and the resistance gene was controlled by single gene. 525pairs of primers from chromosome 1-7H of barley were used to select polymorphism between the two parents. A total of 103 pairs of polymorphic primers (including 11 pairs of 7H polymorphic primers) were screened, and the marker Bmag206,Bmag7 and scssr07970 located on the 7H short arm were identified by BSA analysis to be linked to the target gene Rdg3, so the gene resistant to stripe disease was located on the chromosome 7H short arm. 42 pairs of SSR markers were developed in 7H short arm, of which 6 pairs were polymorphic in Gan Beer 2 and Alexis. Using the 6 pairs of primers and 11 pairs of SSR markers with 7H polymorphism, the genetic linkage map was drawn, and the target gene was found to be located between Bmag206 and Bmag7. The genetic distance between the two markers was 1.78cM and 2.86cM.4. 48 barley parents were selected, and 42 pairs of SSR primers were used to carry out polymorphic scanning. The alleles of 29 pairs of polymorphic primers were 125, ranging from 2 to 9, with an average of 4.3 markers per marker. The highest allelic variation was detected by marker Bmg24 and Bmg25, and the frequency of allelic variation was 0.2979-0.9130, while that of marker Bmg1 was the lowest, ranging from 0.1462-0.8234 to 0.2979.29, with an average of 0.5132. The PIC value of marked Bmg25 was the highest (0.8234), and the value of marked Bmg43 was lowest (0.1462). The average diversity and heterozygosity were 0.5596 and 2.98 respectively.
【学位授予单位】：甘肃农业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S435.123

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