内蒙古中部地区苜蓿根腐病病原研究

摘要

To identify the major pathogen,317 alfalfa root rot isolates sampled from Huhhot,Inner Mongolia of China,were determined.The results showed that:root rot of alfalfa was caused by several pathogens,where predominant pathogen was Fusarium spp.Pathogenicity analysis indicated that F.solani had the strongest virulence with infected rate of 90.0%,whereas in fected rate of F.culmorum and F.oxysporum was 81.7% and 61.7%,respecti vely.When F.solani was coinoculated with other isolated pathogens,the infected rate of the host were higher than individual infection of F.culmorum and F.oxysporum.F.solani was the major pathogen of root rot of alfalfa,F.culmorum and F.oxysporum played an accessory role in alfalfa.%为了查明内蒙古中部地区苜蓿根腐病的主要致病菌,按照柯赫氏法则对呼和浩特地区感染苜蓿根腐病的317个样品进行病原物分离鉴定.结果表明:呼和浩特地区的苜蓿根腐病是由多种病原菌混合侵染所致,从发病部位分离到的菌株以镰孢霉(Fusarium spp.)为优势病原,经致病性测定和接种试验证明,茄病镰刀菌(F.solani)致病性最强,接种后发病率达90.0%,其次是尖孢镰刀菌(F.oxysporum)和黄色镰刀菌(F.culmorum),发病率分别为61.7%和81.7%.茄病镰刀菌是苜蓿根腐病的主要病原菌,与黄色镰刀菌或尖孢镰刀菌复合侵染后,发病率高于黄色镰刀菌或尖孢镰刀菌单独接种的发病率.