3种杀线虫剂对香蕉土壤线虫群落结构的影响

摘要

In order to choose the best nematicides,it is significant to compare the effects of different nematicides on the community structure of plant-parasitic nematodes and total nematodes.The effects of three nematicides, 5×108 spores/g Paecilomyces lilacinus DP,1.8% abamectin EC and 10% fosthiazate GR,were investigated by the field experiment in this study.The results showed that the plant-parasitic nematodes were the dominant troph-ic groups in the continuous-cropping banana plantation.For plant-parasitic nematodes,1.8% abamectin EC treat-ment showed nematocidal ability in the seedling stage,while in budding stage all three treatments showed signifi-cant nematocidal ability,the number of which was significantly decreased by 49.3%,17.4% and 84.2% com-pared to the control.The number of Helicotylenchus and Rotylenchulus ,the dominant genera in plant-parasitic nematodes,was significantly reduced in 1.8% abamectin EC treatment in seedling stage,while the abundance of Rotylenchulus in 10% fosthiazate GR treatment was decreased by 20.3% compared to the control.In budding stage,the three treatments,5×108 spores/g Paecilomyces lilacinus DP,1.8% abamectin EC and 10% fosthiazate GR reduced the genera number of plant-parasitic nematodes and showed nematocidal ability to Helicotylenchus and Rotylenchulus ,the number of which was significantly reduced by 48.2%,40.6%,95.7% and 50.1%, 7.1%,84.5%,respectively,compared to the control.All treatments reduced the diversity and abundance of free-living nematodes in soil.In seedling stage,1.8% abamectin EC significantly increased the number of bacteri-a-feeding nematodes;the maturity index (MI )and Shannon index (H′)in 5×108 spores/g Paecilomyces lilacinus DP and 10% fosthiazate GR treatments were significantly decreased compared to the control.In budding stage, maturity index (MI )showed no significant difference among treatments while plant parasite index (PPI )in 10%fosthiazate GR treatment was significantly decreased compared to the control and the evenness (J′)significantly increased compared with other treatments.In conclusion,10% fosthiazate GR is the best nematicide with strong nematocidal effect on plant-parasitic nematodes and with long-lasting effect.Moreover,compared to the control, it showed no significant difference in the diversity and maturity index of soil nematodes.%比较不同杀线虫剂对植物寄生线虫的杀灭效果及其对土壤线虫群落的影响，对于杀线虫剂的选择具有指导意义。本研究比较了5亿活孢子／g 淡紫拟青霉粉剂、1．8％阿维菌素乳油和10％噻唑膦颗粒剂3种杀线剂对植食性线虫的防治效果及其对土壤线虫群落结构的影响。结果表明：植物寄生线虫是连作蕉园优势营养类群。苗期时只有阿维菌素表现出对植食性线虫的杀灭效果；蕾期3种杀线虫剂均表现出显著的杀灭效果，植食性线虫的数量较CK 分别减少49．3％、17．4％和84．2％；苗期时1．8％阿维菌素乳油表现出对螺旋线虫属和肾形线虫属的杀灭效果，10％噻唑膦颗粒剂处理中肾形属丰度较 CK 减少了20．3％；蕾期相比于 CK，5亿活孢子／g 淡紫拟青霉粉剂、1．8％阿维菌素乳油和10％噻唑膦颗粒剂处理中植物寄生线虫类群数均有所降低，各处理对优势属螺旋线虫属和肾形线虫属均有杀灭作用，减少的比例分别为48．2％、40．6％、95．7％和50．1％、7．1％、84．5％，差异显著。3种杀线剂处理均降低了土壤中的自由生活线虫种类和丰度。苗期1．8％阿维菌素乳油处理能显著增加食细菌线虫的数量，5亿活孢子／g 淡紫拟青霉粉剂和10％噻唑膦颗粒剂处理的自由生活线虫成熟指数 MI 和多样性指数 H′较 CK显著降低；香蕉蕾期处理间 MI 没有显著差异，10％噻唑膦颗粒剂处理的植物寄生线虫成熟指数 PPI 较 CK 显著减少，均匀度指数 J′显著高于其他处理。综上所述，10％噻唑膦颗粒剂的效果最好，持效期长，对植食性线虫有明显的杀灭效果，对土壤线虫类群多样性和线虫成熟指数无显著影响，适宜在香蕉种植园推广使用。