田间大棚西瓜枯萎病病原菌的分离与鉴定  

Identification and characterization of pathogens causing fusarium wilt of watermelon from field greenhouses

作　　者：王小慧[1] 朱震[1] 马雪莲[1] 卢颖林[2] 李奇伟[2] 冉炜[1] 沈其荣[1] 

机构地区：[1]南京农业大学江苏省固体有机废弃物资源化高技术研究重点实验室,江苏南京210095 [2]广州甘蔗糖业研究所,广东广州510316

出　　处：《南京农业大学学报》2012年第6期61-67,共7页Journal of Nanjing Agricultural University

基　　金：江苏省科技支撑项目(BE2009347;BE2010351);国家973计划项目(2011CB100503);广东省教育厅产学研结合项目(2010B090400431)

摘　　要：采用室内分离和盆栽致病性试验相结合的方法,分别从田间大棚西瓜枯萎病病株的根部、茎部和叶片分离纯化获得34株疑似病原菌的菌株,并从中挑选出6株形态差异明显的菌株用于盆栽回接试验。结果表明:菌株LD和LB回接7 d后植株开始出现轻微萎焉症状,到第14天时发病率分别达到100%和72%,病情指数分别为2.00和1.14;菌株LA、LC和XB在回接30 d后西瓜植株发病率和病情指数均为14%和0.29;而菌株XA在回接30 d后植株未出现发病症状。对西瓜植株的生物量统计表明,在接种病原菌30 d后,接种菌株XA和XB的处理植株的株高和地上部干质量与对照差异不显著。接种菌株LA和LC的处理西瓜植株的株高比对照分别降低29.1%和15.9%。经形态学鉴定和28S rDNA D1/D2区序列分析表明:菌株LD和LB为尖孢镰刀霉菌,菌株LC是腐皮镰刀霉菌,菌株LA属于层出镰刀霉菌,菌株XA与XB属于轮枝镰刀霉菌;菌株LD和LB皆为强致病力病原菌,菌株XB、LA和LC是弱致病力病原菌,而菌株XA可能是无致病力菌株。Through lab-screening and pot experiment,thirty-four suspected pathogens were isolated from root,stem and leaf of the diseased watermelon plants grown in field greenhouse.Pathogenic pot inoculation tests of 6 strains with obvious morphological variations showed that strains LD and LB could cause slight wilt symptom after transplanting for 7 days,and the disease incidences reached 100% and 72% with the disease indexes at 2.00 and 1.14 on 14 days,respectively.After inoculation for 30 days,the disease incidence and disease index of the three treatments with strains LA,LC and XB all were 14% and 0.29,respectively.However,there was no diseased watermelon plant in the treatment with strain XA.After 30 days inoculation,the height and dry weight of the watermelon plants in the treatments of XA and XB had no significant difference as compared with control,while the height of the plants in the treatments with strains LA and LC reduced by 29.1% and 15.9%,respectively.Based on morphological identification and molecular analysis of 28S rDNA D1/D2 sequence,strains LD and LB were identified as Fusarium oxysporum,strain LC was F.solani,strains LA was F.proliferatum,and strain XA and XB were F.verticillioides.The result indicated that strains LD and LB had stronger pathogencity than strain XB,LA,LC in watermelon,while XA might be nonpathogenic strain.

关 键 词：西瓜枯萎病 病原菌分离 28SrDNAD1 D2区 形态鉴定 镰刀菌 

分 类 号：S432.4[农业科学—植物病理学]