Meloidogyne Species Associated with Weeds in Rio Grande do Sul

ABSTRACT: The frequency of species of root-knot nematodes (Meloidogyne spp.) was evaluated in weeds collected in different fallow farms in the State of Rio Grande do Sul, Brazil. In the samples where the nematode was found, the species of the root-knot nematode was identified by electrophoresis using the isozyme esterase. They were obtained from weeds belonging to 24 weed species from 13 different botanical families: Amaranthaceae, Asteraceae, Commelinaceae, Convovulaceae, Cyperaceae, Euphorbiaceae, Lamiaceae, Malvaceae, Oxalidaceae, Poaceae, Portulacaceae, Solanaceae, Verbenaceae. Meloidogyne javanica Est J3 (Rm: 1.0, 1.25, 1.40) was the most frequent species and occurred in 53.3% of the samples. M. arenaria with phenotype Est. A2 (Rm: 1.20, 1.30) was detected in 15.6% of the samples. M. incognita Est. I2 (Rm: 1.0, 1.1), M. ethiopica Est. E3 (Rm: 0.9, 1.15, 1.30), M. enterolobii Est. M2 (Rm: 0.7, 0.75, 0.9, 0.95) and M. hapla Est. H1 (Rm: 1.17) in 13.3%, 8.9%, 6.7% and 2.2% of the samples, respectively. Therefore, knowledge of the range of host plants to different species of the root-knot nematode can positively contribute to the adoption of management practices that allow the reduction of their populations in the soil.

摘要：本研究评估了巴西南里奥格兰德州不同休闲农场采集杂草中根结线虫属（Meloidogyne spp.）各物种的发生频率。在检出线虫的样本中，研究人员通过酯酶同工酶电泳技术对根结线虫的种类进行了鉴定。本次研究的杂草样本采自隶属于13个不同植物科的24种杂草，涵盖苋科（Amaranthaceae）、菊科（Asteraceae）、鸭跖草科（Commelinaceae）、旋花科（Convovulaceae）、莎草科（Cyperaceae）、大戟科（Euphorbiaceae）、唇形科（Lamiaceae）、锦葵科（Malvaceae）、酢浆草科（Oxalidaceae）、禾本科（Poaceae）、马齿苋科（Portulacaceae）、茄科（Solanaceae）、马鞭草科（Verbenaceae）。爪哇根结线虫（Meloidogyne javanica）酯酶同工酶型Est J3（迁移率Rm：1.0、1.25、1.40）是检出频率最高的种类，在53.3%的样本中均有发现。花生根结线虫（Meloidogyne arenaria）酯酶同工酶型Est A2（Rm：1.20、1.30）的检出率为15.6%；南方根结线虫（Meloidogyne incognita）酯酶同工酶型Est I2（Rm：1.0、1.1）、埃塞俄比亚根结线虫（Meloidogyne ethiopica）酯酶同工酶型Est E3（Rm：0.9、1.15、1.30）、象耳豆根结线虫（Meloidogyne enterolobii）酯酶同工酶型Est M2（Rm：0.7、0.75、0.9、0.95）以及北方根结线虫（Meloidogyne hapla）酯酶同工酶型Est H1（Rm：1.17）的检出率分别为13.3%、8.9%、6.7%和2.2%。综上，明确不同根结线虫种类的寄主植物范围，可为制定土壤根结线虫种群防控措施提供科学支撑，从而有效降低土壤中的线虫种群数量。