摘要
柑橘链格孢褐斑病(Alternaria brown spot,ABS)是新近在我国局部地区新发现的病害,主要为害宽皮柑橘及某些杂交种柑橘,引起落叶、落果和枯梢,不仅影响产量,还影响果实的销售,造成严重损失,并且病害呈逐渐扩散和加重的趋势。药剂防治是目前防治ABS的最有效措施,然而目前尚无药剂被登记用于该病害的防治。本研究以来自我国各褐斑病发生区的54个代表菌株构成一个群体,应用刃天青(resazurin,RZ)显色法测定病菌群体对新烟酰胺类杀菌剂啶酰菌胺、氟酰胺和噻氟酰胺,以及吡啶类杀菌剂氟啶胺的敏感性。结果表明,该病菌种群孢子萌发对啶酰菌胺、氟酰胺、噻氟酰胺和氟啶胺而言都是野生的敏感群体,尚未发现抗药性菌株,平均EC50值分别为0.467 7μg/mL、0.010 3μg/mL、0.061 9μg/mL和0.010 0μg/mL。广东和浙江菌株对啶酰菌胺较不敏感,重庆菌株对噻氟酰胺更敏感,而对氟酰胺和氟啶胺的敏感性则与菌株的地理来源无关。柑橘褐斑病菌种群对这4种杀菌剂敏感性的确定,可为选择药剂防治ABS提供依据,并为这些药剂推广后的抗药性监测提供基础研究。
Alternaria brown spot（ABS）,an emerging disease in China,is caused by Alternaria alternate pv.citri（A.alternata pathotype tangerine）.The disease mainly affects tangerine and tangerine hybrid citrus,causing young leaf drop,fruit drop and dieback,and resulting in yield loss and affecting the commodity of fruits.ABS was first reported in Australia in 1962 and has become a serious problem in many citrus producing areas in South America,Florida,South Africa,Spain,Israel,Turkey and other countries in the Mediterranean area.ABS was first reported in China in 2010,affecting many important citrus varieties grown in Chongqing,Zhejiang,Yunnan,Hunan,Guangdong,Guangxi and Sichuan and causing significant yield losses.ABS can be controlled by fungicides;however,there is no existing fungicide that is currently registered for controlling ABS on citrus in China.In order to identify effective fungicides for controlling ABS,an in vitro sensitivity assay was conducted.In total,54 isolates of A.alternate pv.citri were single-spore collected from citrus-producing areas in Chongqing,Yunnan,Hunan,Zhejiang,Guangdong and Guangxi Provinces and were tested for sensitivity to fungicides,including boscalid,flutolanil,thifluzamide and fluazinam using a rapid Resazurin-based microtiterplate assay.Conidia were induced by growing fungal strains on V8 medium at 25 ℃ with 16hlight/8hdark cycle for 7to 10 days.The concentration for 50% of maximal effect（EC（50））of spore germination and mycelium was established for each isolate.All test isolates were sensitive to tested fungicides in varying degrees.In general,all isolates were highly sensitive to flutolanil,thifluzamide and fluazinam with an average EC（50） of 0.010 3μg/mL,0.061 9μg/mL and 0.010 0μg/mL,respectively.When tested with boscalid,isolates had EC（50） ranging from 0.238 3μg/mL（C（14）isolate collected from Chongqing）to 0.858 5μg/mL（Z（11）from Zhejiang）with an average of 0.467 7μg/mL.It was observed that fungal strains collected from Guangdong and Zhejiang were less sensitive to boscalid than other test isolates,and strains collected from Chongqing were more sensitive to thifluzamide than others.However,there was no correlation between the sensitivity to flutolanil and fluazinam and geographical origin of the isolates.Overall,our studies revealed that boscalid,flutolanil,thifluzamide and fluazinam were effective for suppressing A.alternate pv.citri in vitro.It will be imperative to conduct field experiments for controlling ABS.The EC（50） values obtained from this study could be used as baselines for monitoring the development of fungicide-resistant subpopulation in future.
出处
《浙江大学学报（农业与生命科学版）》
CAS
CSCD
北大核心
2016年第5期535-542,共8页
Journal of Zhejiang University:Agriculture and Life Sciences
基金
国家柑橘产业技术体系专项经费(CARS-27)
公益性行业(农业)科研专项经费(201303023)
浙江省公益性公益技术研究农业项目(2012C22100)
关键词
柑橘链格孢褐斑病
交链格孢菌
离体杀菌剂敏感性分析
Alternaria brown spot
Alternaria alternate pv
citri
in vitro fungicides sensitivity assay
