Gao Xuebiao, Yin Bei, Borneman James, Becker J Ole
Department of Nematology and Department of Plant Pathology and Microbiology, University of California, Riverside, CA 92521, USA.
J Nematol. 2008 Mar;40(1):1-6.
This study assessed the potential impact of various Fusarium strains on the population development of sugarbeet cyst nematodes. Fungi were isolated from cysts or eggs of Heterodera schachtii Schmidt that were obtained from a field suppressive to that nematode. Twenty-six strains of Fusarium spp. were subjected to a phylogenic analysis of their rRNA-ITS nucleotide sequences. Seven genetically distinct Fusarium strains were evaluated for their ability to influence population development of H. schachtii and crop performance in greenhouse trials. Swiss chard (Beta vulgaris) seedlings were transplanted into fumigated field soil amended with a single fungal strain at 1,000 propagules/g soil. One week later, the soil was infested with 250 H. schachtii J2/100 cm(3) soil. Parasitized eggs were present in all seven Fusarium treatments at 1,180 degree-days after fungal infestation. The percentage of parasitism ranged from 17 to 34%. Although the most efficacious F. oxysporum strain 471 produced as many parasitized eggs as occurred in the original suppressive soil, none of the Fusarium strains reduced the population density of H. schachtii compared to the conducive check. This supports prior results that Fusarium spp. were not the primary cause of the population suppression of sugarbeet cyst nematodes at this location.
本研究评估了各种镰刀菌菌株对甜菜孢囊线虫种群发展的潜在影响。从对该线虫具有抑制作用的田间获得的甜菜孢囊线虫（Heterodera schachtii Schmidt）的孢囊或卵中分离出真菌。对26株镰刀菌进行了rRNA-ITS核苷酸序列的系统发育分析。在温室试验中，评估了7种遗传上不同的镰刀菌菌株影响甜菜孢囊线虫种群发展和作物表现的能力。将瑞士甜菜（Beta vulgaris）幼苗移植到用单一真菌菌株以1000个繁殖体/克土壤改良的熏蒸田间土壤中。一周后，在每100立方厘米土壤中接种250条甜菜孢囊线虫J2。在接种真菌后1180度日时，所有7种镰刀菌处理中均存在被寄生的卵。寄生率在17%至34%之间。尽管最有效的尖孢镰刀菌菌株471产生的被寄生卵数量与原始抑制性土壤中的一样多，但与对照相比，没有一种镰刀菌菌株降低了甜菜孢囊线虫的种群密度。这支持了先前的结果，即镰刀菌不是该地点甜菜孢囊线虫种群受抑制的主要原因。
