1、 魔芋论文：岚皋县魔芋软腐病和白绢病病原菌的分离鉴定和生物防控初探【中文摘要】本文主要是对陕西省安康市岚皋县蔺河乡光明村和立新村等不同自然村魔芋软腐病与白绢病病原微生物的分离纯化,致病性测试,生物学特性的研究,运用生理生化和分子生物学方法鉴定其病原微生物。通过室内特定条件对病原菌在不同温度、不同酸碱度、不同抗生素与不同药剂等条件下的生长状况及生物学特性表现的差异性进行试验,提出防控措施。对岚皋县分离得到的魔芋软腐病病原菌的形态特征,生物学特性,致病性等进行了初步研究,结果表明导致魔芋致病的病原菌最适生长温度 25-30,40以上均不能生长;它可利用葡萄糖和乳糖,不能利用麦芽糖、蔗糖和淀粉。通过
2、致病性试验发现此病菌主要以土壤传播和伤口感染为主。通过 16S rDNA 序列分析,初步确定该致病菌为 Pectobacterium sp.,在系统发育地位上与胡萝卜软腐果胶菌胡萝卜(Pectobacterium carotovora sub sp. carotovora, p.c.c.)关系最近,相似性为 98.64%。通过对种芋的处理以及温度,酸碱度等室内条件下试验,发现在种芋的处理上,对种芋处理的时间要把握好,最多不超过 1 小时。软腐病原菌最适宜生长的酸碱度范围为 pH 5.08.0 之间,其它范围较不适宜,尤其以强酸区表现更为明显。魔芋软腐病原菌最适生长的温度范围为2530之间,不适
3、生长的温度范围为 6以下和 38以上区间,其中停止生长的上、下限温度各为 40和 5。从安康市岚皋县魔芋中分离得到白绢病病原菌,观察其形态特征和生物学特性,考察其致病性特点,并测定其 ITS 序列。白绢病菌丝最适生长温度为 25-35,pH 为 6-9,可利用乳糖,半乳糖,葡萄糖,甘露醇,麦芽糖等为唯一碳源;利用甲硫氨酸、尿素、硝酸钾、硫酸铵和蛋白胨为唯一氮源;由ITS 序列鉴定分离自岚皋县魔芋白绢病的病原菌为半知菌亚门,丝孢纲,无孢目,小核菌属的齐整小核菌(Sclerotium rolfsii Sacc.)。通过 ITS 鉴定技术,准确鉴定出引起魔芋白绢病的致病菌种类,并研究了该致病菌的生物
4、学特性,为实际种植防治该病提供了理论依据。生物防控方法研究中,主要选用了 10 种抗生素做药敏实验,氨苄青霉素的效果最好,其次是青霉素,氯霉素,井冈霉素。在拮抗菌的筛选中,其中 J-1 的拮抗效果最明显,拮抗机理需要再深入研究,为魔芋软腐病害的生物防治提供理论。【英文摘要】This paper is mainly for soft rot and southern blight of konjac purification of pathogens, pathogenicity tests, biological characteristics, the use of biochemical
5、and physiological identified by molecular methods of pathogenic microorganisms in different villages such as Guangming and LixinVillage, Langao County, Ankang City, Shaanxi Province. Specific conditions of the laboratory pathogens at different temperatures, different pH, different agents such as ant
6、ibiotics, and under different growth conditions and differences in biological characteristics to test the performance of proposed control measures.The pathogenicity, morphological character and biological character of soft rot-causing bacteria, which isolated from Amorphalluskon jac growing in Langa
7、o county, Shaanxi province, were determined firstly. The results showed that the optimum temperature for these isolates were 25-30, but cant grow beyond 40. They can utilize glucose and lactose, but not maltose or starch or maltose. The test of pathogenicity to Konjac reavealed that the pathway to w
8、idely spread was by soil and infection was through cutting of plants. 16S rDNA sequence analysis of strains showed that they belonged to Pectobacterium sp. and were very closely related to Pectobacterium carotovora sub sp. carotovora, p.c.c. with 98.64% sequence identity. From line treatment, by spe
9、cies and temperature, pH and other tests under laboratory conditions, found in the handling of species of taro, taro on the kinds of processing time to grasp, no more than 1 hour. The best optimum growth of soft rot bacterias pH range between pH5.0 8.0, other than the appropriate range of areas, par
10、ticularly in the strong acid is more obvious. This bacteria of the original optimum growth temperature range between 25-30, the temperature range of above 38and below 6is not suitable, when the temperature below 5or above 40, the bacteria stopped growing.The southern blight-causing bacteria were iso
11、lated from Amorphalluskon jac collected in Langao county. The becteria were identified by an almost complete ITS gene sequence analysis together with the morphological and biological propertiesThe results showed that the optimum temperature and pH for these isolates were 25 to 35and pH 4-7, respecti
12、vely. They can utilize glucose, lactose, maltose, galactose and mannitol as solely carbon resource, and use methionine, unrea, potassium nitrate, ammonium sulfate and peptone as solely nitrogen. The test of pathogenicity to Konjac reavealed that the pathway to widely spread was by soil and infection
13、 was through cutting of plants. The analysis of ITS sequences of strains showed that they belonged to Sclerotium rolfsii Sacc. , Agonomycetales, Hyphomycetes and Deuteromycotina.The pathogenic bacteria that cause sclerotium rolfsii disease have been determind by the ITS sequence analysis method. The
14、 results of this experiment will provide a theoretical basis for disease prevention.Prevention and control methods in biological research, mainly used to do 10 kinds of antibiotics susceptibility test, ampicillin was the best, followed by penicillin, chloramphenicol and Jinggangmycin.Screening of an
15、tagonistic bacteria in which the antagonistic effect of J-1 the most significant antagonistic mechanism requires further in-depth research, to provide biological control of konjac soft rot damage theory.【关键词】魔芋 软腐病 白绢病 分离鉴定 生物防控【英文关键词】Konjac Soft rot Southern Blight Isolation and Identification Biol
16、ogical control【目录】岚皋县魔芋软腐病和白绢病病原菌的分离鉴定和生物防控初探 摘要 5-6 ABSTRACT 6-7 第一章 文献综述 10-20 1.1 引言 10-11 1.2 魔芋研究进展 11-12 1.3 魔芋病害研究进展 12-15 1.3.1 魔芋软腐病研究进展 12-14 1.3.2 魔芋白绢病的研究进展 14-15 1.3.3 魔芋其他病害的研究进展 15 1.4 软腐病和白绢病综合防控措施的研究进展 15-18 1.4.1 农业防控措施 15-16 1.4.2 生物防控措施 16-17 1.4.3 药剂防控措施 17-18 1.5 研究内容 18 1.6 立题
17、依据及研究意义 18-20 第二章 魔芋软腐病病原菌的分离鉴定与生物学特性研究 20-32 2.1 采样地概况 20 2.2 材料 20-21 2.2.1 主要试剂 20 2.2.2 主要培养基 20-21 2.3 方法 21-25 2.3.1 样品采集 21-22 2.3.2 目的菌分离纯化 22 2.3.3 目的菌的形态观察与生物学特性的研究 22-23 2.3.4 目的菌的致病性研究 23 2.3.5 病原菌的 16S rDNA 序列研究 23-25 2.4 结果与分析 25-30 2.4.1 分离株与致病性检测结果 25-26 2.4.2 病原菌形态观察结果与生物学特性 26-28 2
18、.4.3 分子鉴定 28-30 2.5 讨论 30-32 第三章 魔芋白绢病病原菌的分离鉴定与生物学特性研究 32-41 3.1 材料与方法 32-36 3.1.1 采样 32-34 3.1.2 病原菌的分离与纯化 34 3.1.3 致病性的测定 34 3.1.4 病原菌丝体的形态观察及生物学特性测定 34-35 3.1.5 病原菌的 ITS 序列分析 35-36 3.2 结果与分析 36-39 3.2.1 病原菌分离与纯化与致病性 36 3.2.2 病原菌形态观察与部分生物学特性 36-39 3.3 讨论 39 3.4 结论 39-41 第四章 魔芋软腐病生物防控研究初探 41-46 4.1 材料与方法 41-43 4.1.1 试验材料 41 4.1.2 试验方法 41-43 4.2 结果与分析 43-45 4.2.1 分离菌 43 4.2.2 拮抗菌的抑菌率 43-44 4.2.3 药敏性实验 44-45 4.3 小结 45-46 参考文献 46-50 缩略词 50-51 附录 51-53 致谢 53-54 作者简介 54
