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期 刊 ：植物保护学报 2006年

关键词：黄瓜白粉病菌；接种；涂抹子叶法；杀菌剂；敏感性；

Keywords:Sphaerotheca fuliginea, inoculation, cotyledon-brushing with conidial suspension, fungicide, susceptivity,

摘 要 ：建立了孢子悬浮液接种黄瓜子叶测定黄瓜白粉病菌杀菌剂敏感性的简便方法。比较了白粉病菌分生孢子悬浮液涂抹法和喷雾法接种黄瓜幼苗子叶的效果,结果表明,涂抹法发病率高,均匀度更好;测定了接菌后不同时间施药,白粉病菌对己唑醇、腈菌唑、三唑酮、甲基硫菌灵和百菌清等5种杀菌剂的敏感性,结果表明,接菌后96 h施药较为敏感,测得的EC₅₀较小。最后确定接种及毒力测定方法为:接种时白粉病菌分生孢子悬浮液使用十二烷基硫酸钠水溶液分散悬浮,孢子浓度为15×10倍显微镜下每视野30~40个,接种后96 h施药,发病后直接利用病斑数来计算毒力测定结果。该方法可用于黄瓜白粉病菌抗药性监测和对杀菌剂敏感性测定。

Abstract:In this paper a new inoculation method, cotyledon-brushing with conidial suspension in the assay of sensitivity of Sphaerotheca fuliginea on cucumber to fungicide, was introduced. The comparison test of this new method with spray inoculation method was conducted. The results showed the former method could increase the incidence of disease and uniformity than the latter one. Used cotyledon-brushing with conidial suspension and fungicide foliar spraying method, the EC₅₀ values of hexaconazole, myclobutanil, triadimefon, thiophanate-methyl and chlorothalonil to Sphaerotheca fuliginea treated in different time after inoculation were determined; the results showed that 96 h was better time for disease severity evaluating. In the preparation of inoculums, sodium dodecyl sulfate was used to make sure the consistency of conidial suspension. And when the density of condial was 30-40 per visual field (microscope, 15×10 times), the cotyledon suffered the disease uniformity. Using the numbers of powdery mildew colony replaced the disease index in calculating the toxicities could reduce the artificial errors. This method could be used in fungicide sensitivity test and screening resistance level of fungicide against cucumber powdery mildew.

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