杭白菊枯萎病的病原菌分离鉴定及淀粉酶产色链霉菌对其防治效果

杭白菊枯萎病是杭白菊重要病害之一，枯萎病的爆发对杭白菊产量造成了巨大的影响。为了明确杭白菊枯萎病的病原菌及其生防菌的防治效果，本文通过形态学和ITS序列分析方法，初步鉴定杭白菊枯萎病病原菌为半裸镰刀菌Fusarium incarnatum。进一步采用菌丝生长速率法和孢子萌发法，测定了淀粉酶产色链霉菌Streptomyces diastatochramogenes 1628代谢产物对该病原菌的抑制效果。结果发现，链霉菌1628代谢产物对菌丝生长和孢子萌发的EC₅₀分别为2.22%和4.70%（体积浓度）。盆栽试验结果表明，施用淀粉酶产色链霉菌代谢产物原液14和28 d后，其对杭白菊枯萎病的保护效果、治疗效果分别为52.84%和42.85%、19.23%和30.16%。说明淀粉酶产色链霉菌1628的代谢产物对杭白菊枯萎病具有明显的保护和治疗作用。

Identification of the Pathogens Causing Fusarium Wilt Disease in Chrysanthemum morifolium Ramat and Control Effect of Streptomyces diastatochramogenes

Fusarium wilt disease is one of the important diseases of Chrysanthemum morifolium Ramat. The outbreak of Fusarium wilt caused huge yield loss of C. morifolium. Based on morphological and ITS sequence analysis, the pathogen of C. morifolium Fusarium wilt was preliminarily identified as Fusarium incarnatum. The inhibition effect of metabolites of Streptomyces diastatochramogenes 1628 on F. incarnatum was determined by mycelial growth inhibition and spore germination method. The EC₅₀ values of the metabolites against mycelial growth and spore germination were 2.22% and 4.70% (the ratio of volume), respectively. Pot experiment showed that after irrigating metabolites of S. diastatochramogenes 1628 for 14 d and 28 d, the therapeutic effect and protective effect were 42.85% and 30.16%, 19.23% and 30.16%, respectively. The above results showed that the metabolites of S. diastatochramogenes 1628 have strong biocontrol effects on Fusarium wilt of C. morifolium.