Jacobs Helen, Gray Simon N, Crump David H
Division of Biology, University of Luton, Park Square, Luton, Beds, LU1 3JU, UK.
Mycol Res. 2003 Jan;107(Pt 1):47-56. doi: 10.1017/s0953756202007098.
The efficacies of three nematophagous fungi, Paecilomyces lilacinus, Plectosphaerella cucumerina and Pochonia chlamydosporia, for controlling potato cyst nematodes (PCN) as part of an Integrated Pest Management (IPM) regime were studied. The compatibility of the nematophagous fungi with commonly used chemical pesticides and their ability to compete with the soil fungi Rhizoctonia solani, Chaetomium globosum, Fusarium oxysporum, Penicillium bilaii and Trichoderma harzianum were tested in vitro. Paecilomyces lilacinus was the most successful competitor when the ability to grow and inhibit growth of an opposing colony at both 10 and 20 degrees C was considered. P. lilacinus also showed potential for control of the soil-borne fungal pathogen R. solani, releasing a diffusable substance in vitro which inhibited its growth and caused morphological abnormalities in its hyphae. Pochonia chlamydosporia was least susceptible to growth inhibition by other fungi at 20 degrees in vitro, but the isolate tested did not grow at 10 degrees. Plectosphaerella cucumerina was a poor saprophytic competitor. Radial growth of Paecilomyces lilacinus and Plectosphaerella cucumerina was slowed, but not prevented, when grown on potato dextrose agar incorporating the fungicides fenpiclonil and tolclofos-methyl, and was not inhibited by the addition of pencycuron or the nematicide oxamyl. Radial growth of Pochonia chlamydosporia was partially inhibited by all the chemical pesticides tested. The efficacy of Paecilomyces lilacinus as a control agent for R. solani was further investigated in situ. Treatment with P. lilacinus significantly reduced the symptoms of Rhizoctonia disease on potato stems in a pot trial. The effectiveness of P. lilacinus and P. cucumerina against PCN was also tested in situ. Three application methods were compared; incorporating the fungi into alginate pellets, Terra-Green inoculated with the fungi and applying conidia directly to the tubers. Both formulations containing P. lilacinus and formulation mixtures alone, particularly alginate pellets, significantly reduced multiplication of PCN in soil. We conclude that P. lilacinus showed the greatest potential for use in combination with selected fungicides and nematicides as part of an IPM programme for the control of PCN, but further work is required to confirm whether it is effective against PCN in soil.
研究了三种食线虫真菌，即淡紫拟青霉、黄瓜拟茎点霉和厚垣孢普可尼亚菌作为综合虫害管理（IPM）体系一部分用于防治马铃薯胞囊线虫（PCN）的效果。在体外测试了食线虫真菌与常用化学农药的相容性，以及它们与土壤真菌立枯丝核菌、球毛壳菌、尖孢镰刀菌、拜莱青霉和哈茨木霉竞争的能力。当考虑在10℃和20℃下生长以及抑制对立菌落生长的能力时，淡紫拟青霉是最成功的竞争者。淡紫拟青霉还显示出控制土壤传播真菌病原体立枯丝核菌的潜力，它在体外释放一种可扩散物质，抑制其生长并导致其菌丝出现形态异常。厚垣孢普可尼亚菌在体外20℃时对其他真菌的生长抑制最不敏感，但所测试的分离株在10℃时不生长。黄瓜拟茎点霉是一种较差的腐生竞争者。当在添加了拌种咯和甲基立枯磷的马铃薯葡萄糖琼脂上生长时，淡紫拟青霉和黄瓜拟茎点霉的径向生长减缓，但未被阻止，并且添加戊菌隆或杀线虫剂草氨酰对其生长没有抑制作用。所测试的所有化学农药均部分抑制了厚垣孢普可尼亚菌的径向生长。在原位进一步研究了淡紫拟青霉作为立枯丝核菌防治剂的效果。在盆栽试验中，用淡紫拟青霉处理显著减轻了马铃薯茎上立枯丝核菌病的症状。还在原位测试了淡紫拟青霉和黄瓜拟茎点霉对PCN的防治效果。比较了三种施用方法；将真菌掺入藻酸盐颗粒中、用真菌接种Terra-Green以及将分生孢子直接施用于块茎上。含有淡紫拟青霉的两种制剂以及单独的制剂混合物，特别是藻酸盐颗粒，均显著减少了土壤中PCN的繁殖。我们得出结论，淡紫拟青霉作为IPM计划中防治PCN的一部分，与选定的杀菌剂和杀线虫剂联合使用显示出最大潜力，但需要进一步研究以确认其在土壤中对PCN是否有效。
