| 摘要: |
| 【目的】探究栾树枝枯病病原菌及其生物学特性，为栾树枝枯病的防治提供参考。【方法】采用组织分离法分离纯化栾树枝枯病病原菌，通过柯赫氏法则验证病原菌；采用形态学和分子生物学分析对病原菌进行鉴定；采用平板测定法探讨不同培养基、碳源、氮源、pH、光照和温度条件对病原菌菌丝生长及产孢量的影响，以及菌丝和孢子的致死条件，初步明确该病原菌的生物学特性。【结果】发病栾树枝干皮层出现多个灰白色圆形斑块，斑块边缘洁白不规则，皮层干枯坏死，分离得4种类型微生物;利用柯赫氏法则，结合形态学鉴定和分子生物学分析结果，确定引起栾树枝枯病的病原菌是小新壳梭孢（Neofusicoccum parvum），分离频率为72%。该病原菌在胡萝卜培养基上菌丝生长最好，直径达6.20 cm，产孢量最多，为100.95×107 /mL；碳源以葡萄糖、D-果糖和麦芽糖最佳，氮源以牛肉膏最好；菌丝和产孢适合在偏碱性、25 ℃环境中生长，完全黑暗条件下菌丝生长速度慢、产孢量少，光照12 h及以上培养效果好，产孢量最大可达77.55×107 /mL；菌丝和分生孢子致死条件分别为50 ℃处理30 min和60 ℃处理15 min。【结论】小新壳梭孢（Neofusicoccum parvum）能引起栾树枝枯病，其对环境适应性好，生长繁殖能力强，有很强的致病性。 |
| 关键词: 栾树 枝枯病 病原菌鉴定 小新壳梭孢 生物学特性 |
| DOI： |
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| 基金项目:国家自然科学基金项目（31700568）；四川农业大学科研兴趣培养项目（2019249） |
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| Identification and biological characteristics of branch withered disease causing pathogen to Koelreuteria paniculata Laxm. |
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LI Zhaojia,LI Wenjin,MAO Yueyan,et al
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| Abstract: |
| 【Objective】This study explored the pathogenic bacteria of Koelreuteria paniculata Laxm. branch withered disease and its biological characteristics to help control the disease.【Method】The pathogenic fungus was separated and purified by tissue separation method,and was verified by Koch’s rule.The pathogen was identified by the morphology and polygene analysis methods.The effects of different media,carbon source,nitrogen source,pH,light and temperature on colony diameter and sporulation of pathogenic fungus,as well as the lethal temperature of hyphae and spores were studied by plate method.Based on above items,the biological characteristics of this pathogen was preliminarily clarified.【Result】Several gray white round plaques appeared in the dried cortex of the diseased branches.The plaque edges were white and irregular,and the cortex was dry and necrotic.Four types of microorganisms were isolated and determined by Koch’s rule,the morphology and polygene analysis result that the pathogen causing branch withered disease was Neofusicoccum parvum with the separation frequency of 72%.The pathogen had the best hyphae growth with the diameter of 6.20 cm and the highest sporulation of 100.95×107 /mL on the carrot medium.The best carbon source was glucose,fructose and maltose,and the best nitrogen source was beef extract.Hyphae and sporulation were suitable for alkaline at 25 ℃.The rate of colony growth and the number of spores were low under complete dark conditions,and the effect of light more than 12 hours was good with the maximum spore numbers of 77.55×107 /mL.The lethal condition of hyphae and conidia were 30 min under 50 ℃ and 15 min under 60 ℃,respectively.【Conclusion】Neofusicoccum parvum can cause branch blight,and it is good in adapting to the environment with strong growth and reproduction ability as well as pathogenicity. |
| Key words: Koelreuteria paniculata Laxm. branch withered disease pathogens identification Neofusicoccum parvum biological characteristics |
