【作者】 万瑶；

【导师】 马青； 张敬泽；

【作者基本信息】 西北农林科技大学 ， 植物病理学， 2006， 硕士

【摘要】 草莓炭疽病是全世界草莓种植业的重要病害之一，它是多种炭疽菌复合侵染引起的。病原菌包括胶孢炭疽菌Colletotrichum gloeosporioides Penz.、草莓炭疽菌C.fragariae Brooks和尖孢炭疽菌C.acutatum Simmonds，其中尖孢炭疽菌在一些国家作为检疫性病原菌。我国虽然早已有草莓炭疽病害的文献，但还未见系统研究的报道。本文主要报道浙江和上海两地草莓炭疽病病原菌的形态学鉴定和分子系统学研究的结果，以及附着胞形成过程中核相变化的特征。 通过对上海、浙江建德和浙江杭州三处草莓炭疽病菌的分离(采取组织分离法、保湿培养法和冷冻处理法)和形态学鉴定，结果表明，从草莓上分离的炭疽菌有胶孢炭疽菌、草莓炭疽菌和尖孢炭疽菌。选择35个代表性菌系，在形态学鉴定的基础上对rDNA的ITS序列进行比较和形态学分析，明确了尖孢炭疽菌的存在，但不能区分胶孢炭疽菌和草莓炭疽菌。 通过冷冻处理检测无症状草莓植株上定殖的炭疽菌病菌，结果表明，在建德地区草莓叶片上，炭疽菌的定殖率最高，其中尖孢炭疽菌所占比例高达58.33％；在杭州(下沙和农科院)，炭疽菌的定殖率次之，但无尖孢炭疽菌检出；在上海地区，炭疽菌的定殖率最低，但有尖孢炭疽菌的存在。冷冻检测的方法也表明，潜伏侵染的炭疽菌在3天后产生分生孢子团，5～7天后达到最大值。观察分生孢子团出现的部位结果显示，炭疽菌在叶片主要定殖在距离叶片边缘1cm的中部，这为分子检测潜伏侵染的炭疽菌的取样提供了科学依据。 通过DAPI荧光染料染色观察胶孢炭疽菌附着胞发育过程中的核相动态变化，结果显示，第2次有丝分裂发生的部位在分生孢子产生芽管的一端中；分裂后，最接近芽管的一个子核移入芽管顶端，或通过芽管移入附着胞中。0.10μg／mL的三环唑可完全抑制附着胞中黑色素形成，但不影响核的分裂。三环唑处理12h后，发生2次有丝分裂数量约为73％，而发生3次有丝分裂的数量约为23.9％；绝大多数附着胞中是单核，双核数量小于5％。更多还原

【Abstract】 Strawberry anthracnose is one of the most serious diseases of strawberry in the world, caused by Colletotrichum spp., including C. gloeosporioides, C. fragariae and C. acutatum. Among them, C. acutatum is considered as a quarantine organism in most countries in the world including China. Although there are some reports on strawberry anthracnose in China, there is no systemic study until now. Here we mainly report the results of morphological and molecular identification for Colletotrichum spp. from Zhejing and Shanghai, and the nuclear behavior during the appressium formation..The isolates of Colletotrichum spp. were obtained by tissue isolating, incubating diseased organ in moist condition and incubating after freezing treatment from strawberry field in Shanghai, Jiande and Hangzhou in Zhejiang. Based on the morphological characterization, 35 isolates were selected to compare and analyze the ITS sequence of rDNA. The results confirmed C. acutatum occurred in our country, but C. gloeosporioides and C. fragariae cannot be distinguished from each other by this method.Using freezing method to detect commonly existed Colletotrichum spp in symptomless strawberry plants, we found that strawberry leaves with highest frequency of colonization is from Jiande, of which, the percentage of C. acutatum is about 58.33%, followed by Hangzhou(Xiasha and Zhejiang Agricultural Academy), but no C. acutatum is detected. In Shanghai, the frequency of colonization is the lowest, but C. catutam is also detected. Using freezing method to diagnosis latent infection, we find that after 3 days’ incubation, conidial mass began to form and after 5 to 7 days, all the colonized pathogens can be detected by conidial mass’s formation. The relation between leaf part and colonization frequency had been observed, which indicated that the pathogens colonized mainly in the middle part of the leaf, 1cm away from the margin. The results provided the ways to sample and trace latent infection of Colletotrichum on strawberry by molecular method.Dynamic changcs of nuclear behavior were visualized during appressorial更多还原