MORPHOLOGICAL AND MORPHOMETRIC CHARACTERIZATION OF PRATYLENCHUS SPECIES IN SUGARCANE CROPPING AREAS OF PERNAMBUCO STATE

ABSTRACT The root-lesion nematodes Pratylenchus spp. have a wide geographic distribution and a large number of host plants. These migratory endoparasites are found associated with sugarcane around the world causing diseases that induce permanent losses in productivity. Although this genus has ordinarily been reported in low-producing sugarcane areas in northeastern Brazil, studies of the species occurrence are few and restricted to a very low number of sites and samples. This study aimed to morphologically and morphometrically characterize Pratylenchus species from different sugarcane regions of Pernambuco state, where composite samples of soil and roots were collected on 30 farms from three sugarcane mills. The external morphological characters of the nematode body from different populations had a diagnostic value compatible with those obtained in the literature, showing the dominance of P. zeae (87%) in the region. Atypical populations of the genus Pratylenchus were also found.

摘要：根腐线虫属（Pratylenchus）线虫地理分布广泛，寄主植物种类繁多。该类迁移性内寄生线虫在全球范围内与甘蔗伴生，其所引发的病害会造成甘蔗生产性能的永久性损失。尽管该属线虫在巴西东北部低产甘蔗种植区已有常规报道，但针对其物种分布的相关研究仍较为匮乏，且仅局限于极少量采样位点与样本。本研究旨在通过形态学与形态测量学方法，对巴西伯南布哥州不同甘蔗种植区的根腐线虫属物种进行鉴定表征；研究期间从三家糖厂下辖的30个种植农场采集了土壤与根系混合样本。不同种群线虫的躯体外部形态特征具备与文献报道一致的诊断价值，结果显示该区域优势种群为玉米根腐线虫（P. zeae），占比达87%。本研究同时还发现了根腐线虫属的非典型种群。