安徽省草莓黄萎病病原的鉴定及主栽草莓品种的抗性评价

摘要

在安徽省主要草莓种植区随机采集的18个草莓黄萎病株进行病原菌的分离与鉴定,结果共分离出15个菌株,病原菌的形态特征基本一致。根据病原菌的形态学分析,初步确定分离到的菌株均为镰刀菌( Fusari-um)；选取真菌通用引物ITS1/ITS4对菌株基因组DNA进行PCR扩增并将扩增出的条带进行克隆、测序和序列比对,同时根据分子鉴定与形态学鉴定结果最终确定该病原菌为尖孢镰刀菌( Fusarium oxysporum)；根据序列比对的结果显示该病原菌可能来源于橡胶、木薯、棉花等木本植物。研制出可用于该病原菌的孢子悬浮液大量制备的优化液体培养基配方,解决了该病原菌由于菌丝生长过旺而产孢量很少的难题,同时申请了发明专利。通过人工伤根接种的方法将该病原菌的孢子悬浮液回接到健康草莓幼苗上,2周后植株表现出明显发病的症状。从发病植株中重新分离获得出该病原物。基于形态学、分子生物学鉴定及人工接种鉴定的结果,最终确定安徽省草莓黄萎病的病原菌主要为尖孢镰刀菌。对我国主栽的几个草莓品种进行黄萎病病圃鉴定,结果显示：枥木少女和红颜发病最重,其中红颜病株率最高,为17.79%；章姬、丰香和佐贺清香次之,而欧系和宁玉2个品种的黄萎病抗性较强。%Verticilium wilt in strawberry was observed in the main production area in Anhui Province and 18 samples from affected plants were collected at random. Fifteen strains were isolated at the colony edge for subculture and purification.It was found that all the isolated strains isolates were similar in morphology and col-ony.The purified isolates were preminary determined as Fusarium based on morphological and colony charac-teristics.The rDNA-ITS sequence of genomic DNA was amplificated,cloned,sequenced and aligned by the uni-versal primers of ITS1/ITS4.It was confirmed that these strains were identified as Fusarium oxysporum by mor-phological and molecular identification.Meanwhile,this pathogen maybe originated from such woody plants as rubber,cassava and cotton according to the result of alignment of ITS sequence.A new optimized medium formula was developed for large-scale preparation of spore suspension of this pathogen,which solved the problem of low sporulation capacity as a result of rapid growth of hyphae on the growth medium.The authors applied for a patent of invention according to aboved-mentioned result.Healthy strawberries were used for fungal pathogenicity test by artificial root inoculation.Symptoms became to appear 2 weeks after inoculation and began to die gradually.The pathogen was recovered from strawberry roots.Based on the morphological characteristics,molecular bioassay and pathogencity test,the pathogen of Verticilium wilt in strawberry from Changfeng County was identified as Fusari-um oxysporum.The resistance evaluation of some widely cultivated strawberry varieties was conducted in the dis-ease nursery.The result showed that strawberry varieties‘Tochiotome’ and‘Benihoppe’ were most susceptible to this disease,the incidence rate was 17.79%,the highest among them;followed by ‘Akihime’,‘Toyonoka’ and‘Sagahonoka’;Ningyu and the varieties from European countries were most resistant to this disease.