Eikemo H, Stensvand A, Tronsmo A M
The Norwegian Crop Research Institute, Plant Protection Center, Høgskoleveien 7, N-1432 Ås, Norway.
Plant Dis. 2003 Apr;87(4):345-350. doi: 10.1094/PDIS.2003.87.4.345.
Two putative elicitors of disease resistance (acibenzolar-S-methyl and chitosan) were tested for their effect on crown rot (Phytophthora cactorum) in strawberry. The effect of both compounds was enhanced when the time between treatment and inoculation was prolonged from 2 to 20 days. There were no significant differences between treatments when the concentration of acibenzolar-S-methyl was increased from 10 to 1,000 μg a.i./plant. The lowest tested concentrations of chitosan (10 and 50 μg a.i./plant) resulted in a lower disease score compared with the highest concentrations (250 or 1,000 μg a.i./plant). There were no differences in disease score between treatment with fosetyl-Al, acibenzolar-S-methyl, or chitosan when applied 5 or 15 days before inoculation. The effect of acibenzolar-S-methyl and chitosan also was tested against P. fragariae var. fragariae in alpine strawberry (Fragaria vesca var. alpina cv. Alexandria). Chitosan had no effect, whereas fosetyl-Al and all treatments with acibenzolar-S-methyl (50 or 250 μg a.i./plant; 5, 10, 20, or 40 days before inoculation) reduced the severity of the disease. There were no significant differences between acibenzolar-S-methyl and fosetyl-Al when applied at the same time. Acibenzolar-S-methyl and chitosan at concentrations of 0.5, 5, 50, and 500 μg a.i. ml in V8 juice agar were tested for possible effects on P. cactorum and P. fragariae var. fragariae in vitro. Only chitosan at concentrations of 50 and 500 μg a.i. ml had a growth-retarding effect on P. cactorum. Both acibenzolar-S-methyl and chitosan at a concentration of 500 μg a.i. ml reduced the growth rate of P. fragariae var. fragariae.
测试了两种假定的抗病激发子（烯丙苯噻唑和壳聚糖）对草莓冠腐病（恶疫霉）的影响。当处理与接种之间的时间从2天延长至20天时，两种化合物的效果均增强。当烯丙苯噻唑的浓度从10 μg a.i./株增加到1000 μg a.i./株时，各处理之间无显著差异。与最高浓度（250或1000 μg a.i./株）相比，壳聚糖的最低测试浓度（10和50 μg a.i./株）导致病害评分更低。在接种前5天或15天施用乙膦铝、烯丙苯噻唑或壳聚糖处理，病害评分无差异。还测试了烯丙苯噻唑和壳聚糖对高山草莓（麝香草莓变种亚历山大）中草莓疫霉草莓变种的作用。壳聚糖无作用，而乙膦铝和所有烯丙苯噻唑处理（50或250 μg a.i./株；接种前5、10、20或40天）均降低了病害严重程度。同时施用时，烯丙苯噻唑和乙膦铝之间无显著差异。测试了浓度为0.5、5、50和500 μg a.i./ml的烯丙苯噻唑和壳聚糖在V8汁琼脂中对恶疫霉和草莓疫霉草莓变种的可能影响。仅浓度为50和500 μg a.i./ml的壳聚糖对恶疫霉有生长抑制作用。浓度为500 μg a.i./ml的烯丙苯噻唑和壳聚糖均降低了草莓疫霉草莓变种的生长速率。
