Sasanelli N, Vovlas N, Trisciuzzi N, Cantalapiedra-Navarrete C, Palomares-Rius J E, Castillo P
Istituto per la Protezione delle Piante, Sezione di Bari, Consiglio Nazionale delle Ricerche, 70126 Bari, Italy.
Centro Ricerca e Sperimentazione in Agricoltura "Basile Caramia", 70010 Locorotondo (BA), Italy.
Plant Dis. 2013 Mar;97(3):333-338. doi: 10.1094/PDIS-07-12-0699-RE.
Stunted cabbage ('Lupini') associated with severe soil infestations by a cyst-forming nematode were observed in large patches of open fields in Castellaneta, province of Taranto, southern Italy. Morphological traits based on mature cysts, males, and second-stage juveniles (J2s) and molecular analysis of ribosomal DNA (D2 to D3 expansion segments of 28S and internal transcribed spacer [ITS]1 region) were used to identify the species. ITS1 sequence information supported the identity of Heterodera cruciferae, also showing a high degree of similarity to other species of the Heterodera Goettingiana group, including H. goettingiana, H. carotae, and H. urticae. Nematodes successfully established permanent feeding sites in cabbage roots which caused cellular alterations in the root cortex, endodermis, pericycle, and vascular cylinder by inducing typical multinucleate syncytia. Syncytial cytoplasm was granular and dense, with variously sized vacuoles and hypertrophied nuclei with nucleoli. Cabbage plant growth was also reduced in pathogenicity tests. The relationship between the initial nematode population density in soil and shoot plant weight was well described by the Seinhorst's equation. Tolerance limits with respect to shoot plant weight of cabbage to H. cruciferae was estimated as 1.50 units of eggs plus J2s/cm of soil. The minimum relative value (m) for plant height was 0.71 at an initial nematode population density of (Pi) ≥ 64 units of eggs plus J2s/cm of soil. The maximum nematode reproduction rate (Pf/Pi) was 4.6 times that of the initial population density of 8 units of eggs plus J2s/cm of soil.
在意大利南部塔兰托省卡斯泰拉内塔的大片开阔田野中，观察到与一种孢囊线虫严重侵染土壤相关的发育不良的甘蓝（“羽扇豆”品种）。基于成熟孢囊、雄虫和二龄幼虫（J2）的形态特征以及核糖体DNA（28S的D2至D3扩展片段和内转录间隔区[ITS]1区域）的分子分析来鉴定该线虫种类。ITS1序列信息支持十字花科异皮线虫的鉴定，同时也显示出与异皮线虫戈廷组的其他物种，包括戈廷异皮线虫、胡萝卜异皮线虫和荨麻异皮线虫有高度相似性。线虫成功地在甘蓝根中建立了永久性取食位点，通过诱导典型的多核共质体，导致根皮层、内皮层、中柱鞘和维管束细胞发生改变。共质体细胞质颗粒状且致密，有大小各异的液泡和带有核仁的肥大细胞核。在致病性试验中，甘蓝植株的生长也受到了抑制。土壤中线虫初始种群密度与地上部植株重量之间的关系可用Seinhorst方程很好地描述。估计甘蓝地上部植株重量对十字花科异皮线虫的耐受极限为每厘米土壤1.50个卵加J2单位。在初始线虫种群密度（Pi）≥64个卵加J2单位/厘米土壤时，植株高度的最小相对值（m）为0.71。最大线虫繁殖率（Pf/Pi）是初始种群密度为8个卵加J2单位/厘米土壤时的4.6倍。
