Antibiosis of metabolites from Xenorhabdus nematophilus against Phytophthora infestans was studied by using agar plate, detached potato plant and pot trail. The results showed that the growth rate of hyphae was inhibited 70% at 1.5～3 mL*L-1 of fermentation filtrate and 100% at 50～12 mL*L-1 of fermentation filtrate. 100% disease reduction could obtained at 100 mL*L-1 of fermentation filtrate and 93.08% at 50 mL*L-1 of supernatant. In potted plant tests, disease reduction reached 75.9% and 69.8% at 50 mL*L-1 and 25 mL*L-1 in 7 days after inoculation, which was a little lower than that of chemical fungicide Metalaxy (86.2%). Curing effect was lower than protective efficacy. At 50 mL*L-1 dilution, only 52.4% of curing effect was obtained whereas about 80% of protective effect. When lower dose metabolites combination with Metalaxy, about 50%～60% disease reduction obtained, which is correspond to chemical fungicide (Metalaxy) alone. There were synergism between biocontrol agent and Metalaxy.%报道了嗜线虫致病杆菌发酵液对马铃薯晚疫病的平板抑制作用以及对离体叶片和盆载植株的防病效果.嗜线虫致病杆菌发酵液对致病疫霉菌丝生长有强烈的抑制作用,50～12 mL*L-1 发酵液能完全抑制疫霉菌丝的生长;100～50 mL*L-1发酵液对离体马铃薯叶片晚疫病的发病和病害发展有较强的控制作用,其病害控制率分别达100%和93.08%;在盆载试验中,50 mL*L-1的发酵液作为保护剂对晚疫病害控制率平均达75.9%,与20 mL*L-1 的25%甲霜灵效果差异不显著(P=0.05), 作为治疗剂对病害的控制率达52.4%,当低剂量的甲霜灵与发酵液混合时,其防病效果相当于二者单独使用的效果,说明发酵液与甲霜灵之间有增效作用.
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