黄瓜幼苗内生真菌诱导植株对南方根结线虫的抗性

在2007-2008年的一项温室测验中,10株黄瓜幼苗内生真菌表现出了对南方根结线虫较好的防效,为了阐明其作用方式,用裂根试验设计研究了10个菌株诱导黄瓜产生根结线虫抗性的能力.同一植株的根系被分为彼此隔离的挑战根系和应答根系,镰刀菌Fusarium spp.菌株Fu234和Fu654、毛壳菌Chaetomium sp.菌株Ch1001、叶点霉Phyllosticta sp.菌株Ph511在挑战根系中接种后,应答根系中的线虫入侵总数显著降低,较对照分别降低了42.4％、35.7％、38.4％、23.6％(第1次测定)和63.6％、45.2％、51.0％、37.0％(重复测定),这4个菌株诱导了黄瓜对根结线虫入侵的抗性.同时,Fu234、Fu654、Ch1001和拟青霉Paecilomyces sp.菌株Pa972接种后应答根系中的卵与雌虫的比值显著减少,相比对照其比值分别降低了24.3％、37.7％、48.3％、21.2％(第1次测定)和21.6％、39.8％、30.0％、46.2％(重复测定),这4个菌株诱导了黄瓜对根结线虫繁殖的抗性.

Induced systemic resistance by cucumber endophytic fungi to root-knot nematode Meloidogyne incognita

In a greenhouse test conducted in 2007-2008, ten strain endophytic fungi isolated from cucumber seedlings have demonstrated good control efficacy to root-knot nematode Meloidogyne incognita. In order to elucidate their modes of action, split-root experiment design was used to investigate their ability to induce systemic resistance in cucumber against M.incognita. The roots of the same cucumber plant were divided into two isolated parts, one part was defined as challenging roots and another was defined as responding roots. With the inoculation of the Fusarium strains Fu234 and Fu654, Chaetomium sp. Ch1001 and Phyllosticta sp. Ph511 in the challenging roots, the nematodes penetration in the responding roots were significantly reduced, the reduction rate reached 42.4%, 35.7%, 38.4%, 23.6% in the first trail and 63.6%, 45.2%, 51.0%, 37.0% in the repeat trial, indicating that the four strains have induced resistance against invasion of M.incognita. With the inoculation of Fu234, Fu654, Ch1001 and Paecilomyces strain Pa972 in the challenging roots the ratio of eggs to females in the responding roots have significantly decreased, the reduction rate were 24.3%, 37.7%, 48.3%, 21.1% in the first trial and 21.6%, 39.8%, 30.0%, 46.2% in the second trial, indicating that these four strains endophytic fungi have induced resistance to nematode reproduction.