广西南宁巨峰葡萄果实溢糖性霉斑病病原菌鉴定

[目的]分离、鉴定广西南宁葡萄园中引发巨峰葡萄果实溢糖性霉斑的病原菌,为该病的防治提供参考依据.[方法]采用5点采样法在发病葡萄园区进行溢糖性霉斑发病情况调查和症状观察;随机选择100个具有典型形态特征的单一霉斑,挑取病原菌孢子进行菌株分离和纯化培养,根据柯赫氏法则分别验证其形成霉斑的致病力,并通过形态学观察及分子生物学手段对病原菌进行鉴定.[结果]被调查葡萄园中,2015年冬季果、2016年夏季和冬季果的葡萄果实溢糖性霉斑发病率分别达86.00%、87.32%和89.33%,发病指数分别为52.80、62.40和58.27.从100个霉斑样本中分离获得的优势菌株均具有相似的菌落形态,随机选取其中8株菌株进行验证,结果发现8株菌株均具有形成霉斑的致病力.根据形态学特征和分子生物学鉴定结果,确认分离所得的病原菌为橘青霉(Penicillium citrinum).[结论]橘青霉(P. citrinum)是引起广西南宁巨峰葡萄果实溢糖性霉斑的病原菌之一,当前应从栽培技术入手做好综合防控工作.

Identification of pathogenic bacteria causing Kyoho grape mildew disease in Nanning,Guangxi

[Objective]Pathogenic bacteria causing mildew disease on Kyoho grape berries surface in Nanning, Guangxi were isolated and identified to provide reference for controlling mildew disease.[Method]The morbidity and symptoms of mildew disease on grape berries was investigated by five-points sampling method in the infected vineyard. 100 single mildew spots with typical morphology characteristics were collected randomly.The spores of pathogenic strains were isolated and purified.Then their pathogenicities after forming mildew were tested by Koch's rule,and the pathogenic bacteria were identified by morphological observation and molecular methods.[Result]In the surveyed vineyard,the mor-bidity of mildew disease for winter berries in 2015,summer berries in 2016 and winter berries in 2016 were 86.00%、87.32% and 89.33%,and the corresponding disease index reached 52.80,62.40 and 58.27. From the 100 mildew sam-ples,the selected strains shared similar colony morphological characteristics,and pathogenicities after forming mildew of eight randomly selected strains were identified.According to morphological observation and molecular biology identifica-tion results,the isolated pathogenic bacteria was identified as Penicillium citrinum.[Conclusion]P.citrinum is one of the-pathogenic bacteria that causes mildew disease on Kyoho grape berries surface in Nanning,Guangxi.Comprehensive con-trol should be enhanced through cultivation techniques at present.