涕灭威对大豆田土壤线虫生物多样性的影响

EFFECTS OF ALDICARB ON COMMUNITY STRUCTURE AND BIO-DIVERSITY OF SOIL NEMATODES IN SOYHEAN FIELD

利用涕灭威处理大豆田,研究土壤线虫群落结构和生物多样性的变化,共鉴定出7目12科17属的土壤线虫,其中植物寄生线虫是大豆根际土壤线虫的优势营养类群,短体属Pratylenchus,茎属Ditylenchus,小杆属Rhabditis和矛线属Dorylaimus是线虫优势属。与对照相比,除开花期因气候干旱外,涕灭威处理在大豆的各个生育期均抑制了土壤线虫总数和各营养类群的群体数量增长,尤其对植物寄生线虫抑制程度更为显著。应用多样性指数H′、成熟度指数MI、均匀度指数J′、丰富度指数SR、优势度指数l和植物寄生线虫成熟度指数PPI分析比较了处理区和对照区土壤线虫生物多样性变化规律,结果显示涕灭威处理显著降低了大豆田土壤线虫的多样性、增加了线虫的优势度指数,各生态指数较好地反映了涕灭威对大豆田土壤线虫生物多样性的干扰作用。

Soil nematodes played significant roles in the agroecosystems, except some plant parasitic nematodes can infest in crops. Aldicarb could control plant nematode diseases, such as soybean cyst nematode and root-knot nematode. Relationships between nematode community structure and bio-diversity with A1dicarb were examined in soybean plots on brown soil in Shenyang city, China. The result indicated：whether in the CK plots or treatment plots, plant parasites nematodes, being dominant trophic groups, were inhibited across the whole growing periods of soybean, while fungivores and omnivores-predators were the least abundant groups. The total numbers of nematode, trophic groups and diversity indices（H＇）were significantly different between sampling dates （P〈0.01）. Plant-parasites were decreased, but also community structure of free-living nematodes was reduced by aldicarb. The ecological balance and stability of soil nematodes was destroyed by chemical nematicide. Among the indices tested, H＇ and λ were effective in analyzing nematicide influenced soil nematodes.