Vovlas N, Troccoli A, Minuto A, Bruzzone C, Sasanelli N, Castillo P
Istituto per la Protezione delle Piante (IPP), Sezione di Bari, Consiglio Nazionale delle Ricerche, (CNR), Via G. Amendola 122/D, 70126 Bari, Italy.
Centro regionale di Sperimentazione e Assistenza Agricola (Ce.R.S.A.A.) "Franco Ugo", Regione Liguria, Via Rollo, 98, Albenga (SV), Italy.
Plant Dis. 2008 Sep;92(9):1329-1335. doi: 10.1094/PDIS-92-9-1329.
Stunted growth of sweet basil (cv. Genovese) associated with large patches and severe soil infestations by the root-knot nematode Meloidogyne arenaria race 2 were observed in open fields at the end of the crop-growing season in Albenga, province of Savona, Northern Italy by early September 2007. Observed morphological traits of nematode life stages and results of analysis of isozyme electrophoretic patterns and differential host tests were used for nematode species and race identification. Nematode-induced mature galls (either in naturally infected plants or in artificially inoculated root tissues) were spherical or ellipsoidal and confluent along the root axis, containing usually several females, males, and egg-masses with eggs. Feeding sites were characterized by the development of giant cells that contained several hypertrophied nuclei and nucleoli. Giant cell cytoplasm was aggregated along the thickened cell walls. Vascular elements within galls appeared disorganized and disrupted. Due to the heavy damage observed, the relationships between the initial population density and growth of basil plants was also tested in a greenhouse experiment in which inoculum levels varied from 0 to 512 eggs and juveniles/cm of soil. Height and top fresh weight data of the inoculated and control plants was fitted to Seinhorst's model. Tolerance limits with respect to plant height and fresh top weight of basil cv. Genovese plants to M. arenaria race 2 were estimated as 0.15 eggs and juveniles/cm of soil. The minimum relative values (m) for plant height and top fresh weight were 0.39 and 0.19 at initial nematode population density (Pi) ≥16 eggs and juveniles/cm of soil, respectively. The maximum nematode reproduction rate (Pf/Pi) was 448.7 times at an initial population density of 4 eggs and second-stage juveniles/cm of soil.
2007年9月初，在意大利北部萨沃纳省阿尔本加的露天田地中，观察到甜罗勒（品种：热那亚）生长发育不良，伴有大片区域以及根结线虫南方根结线虫2号生理小种对土壤的严重侵染，这种情况出现在作物生长季节末期。利用观察到的线虫生活阶段的形态特征、同工酶电泳图谱分析结果以及鉴别寄主测试结果来鉴定线虫种类和生理小种。线虫诱导形成的成熟虫瘿（无论是在自然感染的植株中还是在人工接种的根组织中）呈球形或椭圆形，沿根轴融合，通常包含几只雌虫、雄虫以及带有卵的卵块。取食位点的特征是巨型细胞的发育，巨型细胞含有几个肥大的细胞核和核仁。巨型细胞的细胞质沿增厚的细胞壁聚集。虫瘿内的维管束元素显得紊乱且遭到破坏。由于观察到严重损害，还在温室试验中测试了初始种群密度与罗勒植株生长之间的关系，在该试验中接种体水平从0至512个卵和幼虫/厘米土壤不等。对接种和对照植株的株高和地上部鲜重数据进行了Seinhorst模型拟合。热那亚罗勒植株对南方根结线虫2号生理小种的株高和地上部鲜重的耐受限度估计为0.15个卵和幼虫/厘米土壤。在初始线虫种群密度（Pi）≥16个卵和幼虫/厘米土壤时，株高和地上部鲜重的最小相对值（m）分别为0.39和0.19。在初始种群密度为4个卵和二龄幼虫/厘米土壤时，最大线虫繁殖率（Pf/Pi）为448.7倍。
