中文摘要：

本研究开展生防放线菌对尖镰孢西瓜专化型的皿内防效初筛,在此基础上进行多菌复配,变单一菌剂为放线菌混合菌剂使用,以期提高生防菌剂对西瓜枯萎病的防效.采用皿内抑菌试验、单一菌株的盆栽促生及定殖试验等筛选出对尖镰孢西瓜专化型防效较好的生防菌;制成混合菌剂并探究其对西瓜枯萎病的防治效果和对西瓜幼苗的促生效果.单一菌株SC11、153、SF6及其混合菌剂对西瓜枯萎病均有防治效果,其防效分别为25.87％、20.61％、16.72％和47.50％,且对西瓜幼苗有较好的促生效果,对植株鲜重的提升幅度分别达99.26％、124.44％、144.44％和162.22％,无论是防病方面还是促生方面,均以组合SC11＋153＋SF6效果最为理想.生防放线菌混合菌剂的防病促生作用明显优于单个菌株,混合菌剂各菌株间通过协同作用达到优势互补,充分发挥生防效果.

英文摘要：

Abstract： This study was based on the primary screening ofbiocontrol actinomycetes against Fusarium oxysporium f. sp. niveum, then combined 3 strains （153, SC11 and SF6） into a multi-complex mixture, in order to improve the biocontrol effect on watermelon wilt disease. Actinomycetes strains with antagonistic activity in vitro were screened through petri dish test and pot examination. Three of them were mixed into a multi-complex to explore the biocontrol efficacy on watermelon wilt disease and the growth promotion on watermelon seedlings. Three single strains including SC 11, 153, SF6 and the combined strain had inhibiting effect on F. oxysporium f. sp. niveum, the control efficacy was 25.87%, 20.61%, 16.72% and 47.50%, respectively, while the combined strain had the most remarkable effect, significantly higher than that of the single strain. On the other hand, the effect on the plant growth by the strains showed significant promoting, the increase of the fresh weight of plant by them were 99.26%, 124.44%, 144.44% and 162.22%, respectively. The increase of plant height, leaf area and chlorophyll content by the combined strain was 84.93%, 35.60% and 226.83%, respectively. The efficacy was remarkably higher than single agent. Regardless of the prevention or promoting aspects, the effect of the combined strain was the most ideal. The combined actinomycetes mixture had an improved biocontrol efficacy and growth promotion than the single strains; the traits could be achieved through the synergy of complementary advantages, and make the full use of their biocontrol effects.