香石竹立枯病菌的生物学特性与药剂筛选

Biological Characteristics and Screen of Chemical Fungicide of the Pathogen Causing Basal Stem Blight on Dianthus caryophyllus

香石竹立枯病是在香石竹上发生普遍,危害严重的主要病害。对病原菌立枯丝核菌（Rhizoctonia solaniK櫣hn）的生物学特性及5种杀菌剂对其的抑制作用进行了研究,结果表明：该菌在所供试的培养基上均能生长,能不同程度地利用多种碳、氮源。其中,可溶性淀粉和尿素分别为最佳碳源和氮源。病原菌在5～45℃,pH2.5～9.0条件下均能生长,适宜生长温度范围是20～30℃,最适生长温度为30℃,最适生长pH为5.5;12 h光照12 h黑暗有利于该菌营养体生长;菌丝致死温度为50℃,10 min。生物学特性分析结果表明：该菌是一类对营养需求不高,具有较强的适应性的病原菌。室内药效测定结果表明：灭菌星和广枯灵对该菌菌丝生长的抑制效果较好,其它杀菌剂对该菌的菌丝生长也具有抑制作用。

Basal stem blight is an important disease on carnation. Biological characteristics of Rhizoctonia solani Ktihn causing carnation basal stem blight were studied and effective fungicides for disease control were screened. The results showed that the pathogen of R. solani could grow on all kinds test media. The pathogen could use all kinds of carbon sources and nitrogen sources. The soluble starch was both the optimal carbon and nitrogen source. The fungus could grow at 5 -45℃with the optimum at 30℃ and it could grow at pH 2.5 - 9.0 with the optimum at pH 5.5. The mycclium grew well at light and dark in return with light for 12 h per day. The lethal temperature of the myeclium was 50℃ for 10 minutes. The biological characteristics of the pathogen showed that R. solani causing carnation basal stem blight was strong adaptive in environment. The fungicides for control of R. solani in lab were screened and the results showed that Miejunxing and Guangkuling were the most effective inhibitory ability for hypha growth. The other fungicides also showed some inhibitory ability.