【作者】 王亚娟；

【导师】 张显；

【作者基本信息】 西北农林科技大学 ， 蔬菜学， 2005， 硕士

【摘要】 黄瓜枯萎病（Fusarium oxysporum f.sp. Cucumerinum）是一种典型的土传病害。随着栽培面积的不断扩大,尤其是保护地温室和塑料大棚等黄瓜的大面积发展,土壤含菌量逐年累积,致使黄瓜枯萎病的发生日趋严重,每年因为枯萎病的发生造成的黄瓜减产率高达35%～50%。培育抗病品种,利用品种自身的防御机制来减少病害的发生,可以同时解决环境污染、农药残留和防治病害三方面问题,是一条安全、经济、有效的途径。常规抗病育种方法对抗病材料的选择主要依赖田间人工鉴定,由于黄瓜枯萎病在黄瓜整个生育期都可发病,而且易受环境影响,田间鉴定工作费时费力,鉴定周期长,鉴定结果不尽准确。现代分子生物学技术的发展,为分子抗病育种提供了比以往任何时候都强有力的研究手段。近年来发展起来的RFLP、RAPD、SSR、AFLP 等技术,是对目标性状在基因组水平的连锁标记的选择,不受环境影响,不受等位基因显隐性关系干扰,选择结果稳定可靠;同时分子标记辅助选择还可以在育种早代进行选择,从而大大缩短育种周期,提高育种效率。目前利用分子标记已找到了与黄瓜白粉病和霜霉病抗性相关基因连锁的分子标记,但与黄瓜枯萎病抗性相关基因连锁的分子标记研究国内目前尚未见报道。本研究以黄瓜抗枯萎病和感枯萎病亲本组合的F₂ 分离群体为试材,采用AFLP 与SSR 技术,结合极端个体分组和隐性基因组分析法,研究了与黄瓜枯萎病抗性相关基因连锁的分子标记,主要得到以下结果: 1.对F₂ 分离群体进行黄瓜枯萎病的田间鉴定,结果表明:在本试验所用试材的遗传背景下,黄瓜对枯萎病的抗性由一个单隐性基因控制,且感性相对于抗性表现为完全显性。2.利用AFLP 技术结合极端个体分组和隐性基因组分析法,找到了一个与黄瓜枯萎病抗性相关基因连锁的共显性标记（E25M70-170bp/167bp）。该标记在抗病组和感病组间表现多态性,对所有F2 单株进行验证,结果显示:234 个F₂ 单株中,田间表现抗病的47 个单株中3 株发生了交换,扩增出与感病单株相同的带型;187 株表现极感的单株中,16 个单株发生了交换,扩增出与抗病单株相同的带型。由此推算,所筛选到的标记与目标基因-枯萎病抗性基因之间的连锁距离为8.12cM。3.利用适合于黄瓜的SSR 体系,找到一个与黄瓜枯萎病抗性相关基因连锁的SSR标记（CSWCT06A）,对所有F₂ 单株进行验证,在47 株抗病植株中,2 株扩增出感病更多还原

【Abstract】 Cucumber fusarium wilt（Fusarium oxysporum f. sp. Cucumerinum） is a typic soil-borne disease .With the extend of planting areas ,cucumber wilt become a severe disease all over the world to affect badly output and quality of cucumber. The output reduction in cucumber gives amount to 35%～50% every year because of the occurrence of the disease. Breeding of resistant variety is a safe, economy and effective way to prenvent the pollution of the environment,pesticide remnant and to control the disease at the same time. Conventional breeding methods have been successful in variety development. Identification of resistance to wilt mainly depends on field observation . Due to the disease occurs in the whole life cycle ,there are many difficulties in field identification. Development of molecular markers,such as RFLP,RAPD,AFLP and SSR, provides a convenient, effective way to select resistant material in plant breeding and have been used in many fields .For AFLP and SSR possesses less DNA ,more sensitive ,informative, rapid and efficient ,it can be applied to more aspects than other molecular markers in breeding research . Now ,the markers of powdery mildew and downy mildew in cucumber have been found,but there was no report on molecular markers of cucumber wilt up to date. In this paper, AFLP ,SSR technology and Bulked-extremes and recessive class analysis（BERCA） were applied to study the markers linked to the resistance related gene of cucumber wilt using a F₂ population of a cross（jinchun No3.） between a highly resistant parent and a susceptible parent. The main results were as follows: 1.The field identification of F₂ progeny shows that the material resistance of cucumber is controlled by a recessive gene in the test of materials used in this paper. 2. A co-dominant AFLP marker closely linked to cucumber wilt resistant gene was discovered. By checking the polymorphism between the five resistant plants and the five susceptible plants, a co-dominant marker,E25M70-170bp/167bp,was found. Population analysis indicated that among 234 F₂ plants,47 resistant ones possessed two fragments ,which were in accordance with their resistant parent.While the 187 susceptible plants possessed one fragment which was in accordance with their susceptible parent.But there were 3 resistant plants that possessed one fragment and 16 susceptible plants that possessed two fragments.Linkage analysis indicated that the AFLP marker was linked to cucumber wilt gene,and the genetic distance was 8.12cM. 3. A SSR marker （CSWCT06A）closely linked to cucumber wilt resistant gene was found .Population analysis indicated that among 234 F2 plants,47 resistant plants possessed two fragments which were in accordance with their resistant parent.While the 187 susceptible plants possessed one fragment which was in accordance with their susceptible parent.But there were 2 resistant plants that possessed one fragment and 12 susceptible plants that possessed two fragments.Linkage analysis indicated that the SSR marker was closely linked to cucumber wilt gene,and the genetic distance was 5.98cM.更多还原