【作者】 侯永翠；

【导师】 郑有良；

【作者基本信息】 四川农业大学 ， 作物遗传育种， 2003， 硕士

【摘要】 小麦赤霉病(Head Scab)主要是由禾谷镰刀菌(Fusarium graminearum Schw)引起的一种温湿地带麦区广泛流行的真菌病害。带菌籽粒不同程度地影响品质，严重时会造成人畜伤害，丧失商用价值。应用抗病品种是保证小麦高产、稳产、优质最安全经济的措施。抗源利用是小麦赤霉病抗性遗传改良的直接途径。为了寻找对赤霉病免疫或高抗的基因资源以便应用于小麦抗赤霉病育种，国内外许多研究者对小麦品种进行了大量筛选。由于赤霉菌是腐生性较强的寄生菌，迄今还未在普通小麦中发现对赤霉病免疫的品种，只有极少数品种表现为高抗或中抗，绝大多数为感病品种。万永芳等(1998)采孢子悬浮液注射接种法对1197份麦类作物材料进行鉴定时，也没有发现免疫的类型。所有测试的材料均不抗侵入，只有极少数表现为高抗扩展。普通小麦中有3.42％高抗扩展和12.43％抗扩展的材料。在中国小麦地方品种中，至少已鉴定出30多份小麦地方品种比“苏麦3号”具有更好的抗病性。本研究利用酸性聚丙烯酰胺凝胶电泳(A-PAGE)和十二烷基硫酸钠—聚丙烯酰胺凝胶电泳(SDS-PAGE)两种生化标记以及在普通小麦中多态性极高的微卫星(SSR)标记，对抗赤霉病材料进行了检测与分析，结果如下： 1、采用A-PAGE法，对来自不同地方的23个抗赤霉病小麦地方品种的醇溶蛋白位点进行了检测。结果表明，供试品种具有20种不同的醇溶蛋白带型，共分离出39条相对迁移率不同的谱带，其中31条具有多态性，占86.8％，每份材料可电泳出14-23条带，说明供试材料具有丰富的醇溶蛋白位点等位变异。聚类分析发现，遗传距离变异范围为0.571-1.0，平均值为0.752。供试材料在遗传距离为0.75水平上可聚为4类，具有相同地理来源的材料可首先聚在一起。 2、应用SDS一队GE方法，对来自不同地方的23个高抗赤霉病小麦地方品种的高分子量谷蛋白亚基(Glu一I位点)进行了分析。结果表明，Glu一]位点具有较丰富的遗传变异，共检测到9种亚基及6种亚基组合类型。按Payne(1 987a)的标准计算了品质评分，得分在5一9分之间，平均6.8分。虽然优质亚基及亚基组合类型所占的比例很少，但却发现3份材料品质评分很高(9分)。说明在抗赤霉病育种中，可望协调优质与抗病之间的关系。 3、利用SSR标记对来源于贵州、云南、四川、浙江和江苏等地20份高抗赤霉病小麦地方品种和4份高感赤霉病小麦材料间的遗传多样性进行了检测。在小麦21条染色体的40个SSR位点上，共检测到279个等位变异，每个位点能检测到2一16个，平均为6.98个，所有位点均能够揭示材料间的多态性。供试材料间遗传相似系数(Gs)变幅为0.103一0.673，平均值为0.419。根据SSR标记揭示的遗传相似性来看，虽然高抗赤霉病小麦地方品种间及其与高感材料中国春、繁六等的遗传相似性较高、遗传多样性低，但是它们与高感赤霉病的人工合成双二倍体“RSP”间具有相当高的遗传多样性。因此，可利用高抗赤霉病的小麦地方品种与高感赤霉病的人工合成双二倍体“RSP”杂交，构建分子标记遗传分析群体，可望标记其抗赤霉病基因。更多还原

【Abstract】 Wheat scab or Fusarium head blight (HFB), mainly caused by Fusarium graminearum Schwabe, is one of the most destructive disease in warm and humid regions of the world. It not only significantly reduces grain set and grain weight but also effects the end-use quality. Severe, mycotoxin contamination of the seeds is harmful to humans and livestock. The use of resistant cultivars is the best way to control the disease. Therefore, It is very important to search for scab resistant sources and characterize resistance genes in various resources. One Chinese wheat cultivar, Sumai 3, is considered to be the most useful genetic source for breeding of scab resistance wheat cultivar. In China, 27 more than 30 highly resistance landraces have been identified, which were equal to or superior than Sumai 3. It is essential to identify the resistance genes for scab from the various sources, integrating the various resistance genes to improve combined resistance in wheat. In this study, the genetic diversity among 20 wheat landrances with high resistance to scab was investigated by using SSR. And the same time, using A-PAGE and SDS-PAGE methods, the gliadin and HMW-glutenin subunits of these varieties were analyzed.1. In order to investigate the variation of gliadin and analyze the genetic difference between genotypes of 23 wheat landrances with high resistance to scab, the acid polyacrylamide gel eletrophoresis (A-PAGE) was used. There were 20 gliadin genotypes in the 23 cultivars. A total of 39 gliadin bands with different relative mobility were observed, while 31 bands (86.8%) were polymorphic. These results suggest that abundant gliadin variations exist among thse cultivars. The genetic relationships wereestimated by a UPGMA cluster analysis of GS matrix. It showed that some landrances of same origin clustered together.2. Using sodium dodeeyl sulphate-polyacrylamid gel electrophoric (SDS-PAGE), the HMW-GS (high-molecular-weight glutenin subunits) of 23 wheat Landrances with high resistance to scab were analyzed. The high level of genetic variations at Glu-1 locus was observed. 9 subunit patterns and 6 subunit combinations were detected, respectively. The quality scores of each cultivar at Glu-1 have been calculated according to the methods described by Payne et al (1987). The quality scores of these cultivars were quite low, ranging from 2 to 9, with the mean of 6.0. There were 3 landrances with higher quality scores.3. Using 40 SSR markers with representing all 21 chromosomes of wheat genomes, the genetic diversity among 20 wheat landraces highly resistant to head scab and 4 wheat lines highly susceptible to head scab were evaluated. And revealed a total of 279 alleles with mean of 6.98 alleles per SSR marker. The total of SSR markers were polymorphic among 24 genotypes. The genetic similarity among highly resistance landraces, and these landraces with highly susceptible wheat cultivars ’Chinese Spring’ and ’Fan 6’were very high, but the genetic diversity of these landraces with 1 highly susceptible lines, synthetic wheat ’RSP’ was much higher. These results suggested that it is possible to tag the genes resistant to wheat scab in these highly resistant wheat landraces by choosing synthetic wheat ’RSP’ as another parent for gene mapping.更多还原