【作者】 张笑宇；

【导师】 于卓；

【作者基本信息】 内蒙古农业大学 ， 作物遗传育种， 2012， 博士

【摘要】 马铃薯黑痣病是内蒙古地区的主要病害之一,研究马铃薯抗黑痣病鉴定技术及抗病机制对马铃薯抗病育种及其防治具有重要的理论和实践意义。本试验以28份马铃薯为材料系统地研究了马铃薯抗黑痣病鉴定技术,同时对马铃薯材料进行了抗性评价,并从马铃薯形态、结构及生理生化方面探讨其抗黑痣病机制,结果如下：1.从马铃薯地下茎黑痣病病样上分离到1个菌株,致病性测定结果显示该菌为致病菌。经鉴定该菌为立枯丝核菌AG2-1(Rhizoctonia solani AG2-1)。2.立枯丝核菌AG2-1能产生致病毒素,为致病的关键因子,但低浓度的毒素对马铃薯幼苗生长有促进作用。3.初步建立了马铃薯黑痣病抗性鉴定技术体系,首先利用薯片接种和毒素处理马铃薯脱毒组培苗的方法进行初步鉴定,再以麸皮培养物2～4g田间单株接种鉴定。4.28份马铃薯材料的抗性鉴定结果显示,地下茎和块茎的抗性具有相关性,品种间抗性存在显著性差异,但没有免疫和高抗的品种,品种底西芮表现较高的抗病性,而夏坡蒂、大西洋、费乌瑞它等多数品种表现为感病。生育期长的品种较抗病,生育期短的品种感病。红皮等马铃薯表皮颜色较深的品种较抗病,白皮品种感病。5.病原菌侵染过程的研究表明,侵染块茎、地下茎和地上茎的的最初侵染时间分别为4h、8h、8～12h。侵染过程中产生少量疏松的侵染垫及大量的附着胞,附着胞有二叉状、球状、三叉状、足状及不规则形状,在附着胞的前端有明显的侵染钉。地上茎产生的侵染结构最多,地下茎和块茎相对较少。病原菌侵染块茎的途径主要是角质层裂缝、皮孔、细胞间隙,也可从伤口及直接侵入；对地下茎的侵染途径主要是表皮裂缝、皮孔、细胞间隙；地上茎主要是通过细胞间隙或直接侵入,少量菌丝从气孔侵入。6.感病品种大西洋比抗病品种底西芮侵染结构多,侵入组织内的菌丝也多,皮孔大而多、角质层薄、表皮较粗糙、蜡质含量较少。7.黑痣病菌毒素可诱导马铃薯幼苗体内POD、PPO及SOD活性升高,在毒素处理24～96h,3种酶活性与马铃薯品种抗病性正相关。毒素也能诱导CAT、PAL、几丁质酶、β-1,3-葡聚糖酶活性升高,但几种酶活性的变化和品种的抗病性不相关。毒素处理后马铃薯幼苗体内木质素和游离脯氨酸含量增加,且抗病品种增加值明显多于感病品种。毒素处理后马铃薯体内MDA含量增加,96h以内抗病品种增加幅度大于感病品种。毒素伤害马铃薯幼苗,使其细胞膜透性增加,感病品种的细胞膜透性增加的较早且幅度较大。8.对马铃薯体内的营养物质和抗黑痣病关系研究表明,可溶性淀粉含量和抗病性正相关,可溶性蛋白含量和抗病性负相关,可溶性糖及游离氨基酸和品种的抗病性没有明显的相关性。更多还原

【Abstract】 The stem canker and black scurf in potato by Rhizotonia solani is one of the main diseases in Inner Mongolia. The studies on identification technology and resistance mechanism were important in theory and practice. The resistance and identification technology on28different potato varieties to R. solani were studied. The resistance mechanism were research from potato structure and physiological and biochemical. The results were as follows:1. The pathogen of stem canker and black scurf by R. solani on potato was isolated from underground stems. The isolation had pathogenicity to potato. It’s identification result showed that it was R. solani AG2-1.2. The toxin of R. solani AG2-1had pathogenicity to potao seedling. It was a key pathogenic factor. But the low concentrations toxin can promote seedlings growth of potato.3. The resistance identification technology system was established to stem canker and black scurf in potato. The ways of potato pieces inoculated with R. solani and seedlings treated with toxin can identify preliminaryly. Then the tests of inoculating with wheat bran inoculum2～4g per potato seed were conducted in field.4. The resistance of the28potato cultivars was significantly different to R. solani AG2-1but none of these was completely resistant. Most of them were susceptible. The cultivar Diseree showed the less percentage of infection by R. solani, while the cultivars Atlantic, Favorita, Shepody showed a high percentage of infection on tubers.The potato varieties of long growing period and the deeper epidermis color were resistant than the ones of short growth period and white skin.5. In the infection process of pathogen, the initial infection time were4h,8h and8～12h at tubers, underground stems and stems. The infection structure were a few loose infection cushion, most were appressorium, there were lobate, spherical, trident form, foot and irregular shape, infection pegs were formed from the appressorium. There were more infection structure at stems than the underground stems and tubers.The infection site were mainly cuticle cracks, lenticels, cell gap, wound and a small amount of mycelium direct invasion at tubers. At underground stem the infection site were mainly crack, lenticels, epidermal cell gap and a small amount of hyphae direct invasion. At stems the invasion site were mainly the intercellular and direct invasion breakthrough epidermal, a small amount of mycelium from the stoma invading.6. Susceptible cultivars Atlantic had more infection structures, larger and more lenticels, thin cuticle, rough epidermis, less wax than the resistant varieties Diseree.7. The physiological and biochemical resistance mechanism showed that the toxin of R. solani AG2-1can increase the POD, PPO and SOD activity in potato seedlings, and the several enzyme activitys of resistance varietie were all higher than the susceptible one, at24-96h, The CAT, PAL, chitinase, β-1,3-glucanase activity were increased also, but the changes and resistance were not related. The content of proline and Lignin were all increased after inoculating and the resistance cultivar was greater than the susceptible one. The MDA content and cell membrane permeability were all increased also. O～96h, MDA content of susceptible cultivar was greater than the resistance one. The cell membrane permeability of susceptible varieties increased earlier and more.8. The relations on nutrition of potato and resistance showed that the soluble starch content and resistance was positive correlation, on the other hand, the soluble protein content was negatively correlation with the resistance, soluble sugar and amino acid had no obvious correlation with the resistance.更多还原