火龙果溃疡病的症状观察和病原菌鉴定  

Symptom observation and pathogen identification on canker disease of pitaya

作　　者：张荣[1] 刘爱媛[1] 白成艳[1] 刘成明[1] 罗笑容 姜峰[3] 梁瑞伟 郑红莉[1] 

机构地区：[1]华南农业大学园艺学院,广州510642 [2]清远市大丰果业有限公司,广东清远511500 [3]华南农业大学发展规划处,广州510642

出　　处：《果树学报》2013年第5期854-856,I0002,共4页Journal of Fruit Science

摘　　要：【目的】2012年广东省清远市火龙果种植区爆发一种病害，株发病率高达60％，对火龙果茎和果实造成极大危害，为识别和控制该病害的发生，进行了该项研究。【方法】采用常规植物病理学方法观察病害症状，鉴定病害的病原菌。【结果】发病初期，受侵染的肉质茎和果实出现圆形凹陷褪绿病斑，病斑逐渐变成橘黄色；发病后期，受侵染部位呈灰白色突起，产生黑色分生孢子器，病斑直径可扩展到0．5cm。从病组织中分离出的病原菌，在PDA培养基上生长的菌落由白色逐渐转为黑绿色，产生具0—2个隔膜的节孢子，节孢子无色到浅褐色，杆状、柱状或腰鼓状：节孢子细胞壁加厚，形成深褐色，球形厚垣孢子；在马尾松（Casuarina equisetifolia）水琼脂培养基中．可产生黑色分生孢子器，分生孢子器遇水喷射出分生孢子，产孢细胞无色桶形，分生孢子卵圆形，无色单孢，大小（13．31±1．42）μm×（5．4±0．35）μm。【结论】经鉴定该病原菌为Neoscytalidium dimidiatum，导致火龙果肉质茎和果实溃疡。[Objective] Canker disease of pitaya expanded quickly in most commercial planting areas of Qingyuan city in Guangdong, where incidence rate of the disease reached as high as 60% in 2012. The objective of the study was to identify and control the disease. [Method] The symptoms were described, the pathogen was identified by using phytopathological research methods. [Result]The results showed that symptoms on the stem and fruit were small, circular, sunken, chlorotic spots at early infection and then developed into cankers. In late infection period, black pycnidia were erumpent from the surface of the cankers. Disease spots enlarged as they matured to a maximum of 0.5 cm in diameter. Colony changes from white, sparse, radial expansion to black-green with long and sparse aerial mycelium on PDA. Hyphae disarticulated into cylindrical-truncate, oblong-obtuse to dolioform, 0-to-2-septate arthrospores, which developed from hyaline to brown. Brown and globose chlamydospores were produced. Subconical and black pycnidia were induced by culturing on sterile horsetail tree （Casuarina equisetifolia） leaves. Conidiogenous cells were dolioform. Conidia （13.31±1.42μm×5.4±0.35）μmm） ejected from pycnidium in water droplets were one-celled, hyaline, and ovate. [Conclusion] The pathogen causing canker disease of pitaya was identified as Neoscytalidium dimidiatum based on pathogenicity and morphological observation.

关 键 词：火龙果 溃疡病 Neoscytalidium dimidiatum 

分 类 号：S667.9[农业科学—果树学]