Sun F, Miller S, Wood S, Côté M-J
Canadian Food Inspection Agency, Ottawa, Ontario K2H 8P9 Canada.
Canadian Food Inspection Agency, St. John's, Newfoundland, and Labrador, A1C 5X1 Canada.
Plant Dis. 2007 Jul;91(7):908. doi: 10.1094/PDIS-91-7-0908A.
Potato (Solanum tuberosum L. subsp. tuberosum) is one of the most important food crops in Canada. Potato cyst nematodes, Globodera rostochiensis (Wollenweber, 1923) Skarbilovich, 1959 and Globodera pallida (Stone, 1973) Behrens, 1975, are considered the most economically important nematode pests of potatoes worldwide and are the subject of strict quarantine regulations in many countries including Canada. In Canada, G. rostochiensis was found in the Saanich Peninsula of Vancouver Island, British Columbia and both G. rostochiensis and G. pallida are present on the island of Newfoundland (3). During August of 2006, soil and roots of potato plants collected from a 19.2-ha field in the Saint-Amable region, Quebec, were submitted to the Nematology Laboratory, Canadian Food Inspection Agency, Ottawa. Golden, spherical-shaped cysts were found associated with the roots and were also extracted from the soil. The nematodes recovered were identified by morphological and morphometric analysis and DNA analysis. Measurements and morphological observation of 60 second-stage juveniles were as follows: body length = 427.4 ± 22.0 (395 to 495) μm; stylet length = 21.3 ± 1.2 (18 to 23) μm; distance from stylet base to dorsal esophageal gland opening = 5.5 ± 0.9 (3.5 to 7.0) μm; tail length = 46.7 ± 3.7 (36 to 58) μm; hyaline tail terminus = 21.1 ± 3.1 (13 to 27) μm; and the shape of stylet basal knobs varied from rounded to lateral flattened. Observations for 35 mature cysts were: number of cuticular ridges between anus and vulval fenestra = 21 ± 6 (12 to 31); fenestral length = 18.4 ± 3.6 (11 to 30) μm; distance from anus to the edge of fenestra = 81.1 ± 30.4 (29 to 165) μm; Granek's ratio = 4.4 ± 1.6 (1.8 to 6.0), with parallel wavy cuticular ridges between anus and vulval fenestra. These observations conformed to the published description of G. rostochiensis (2). Additionally, the identification was supported by the PCR-restriction fragment length polymorphism pattern of the ITS-1 region amplified using primers 18S (5'-TTGATTACGTCCCTGCCCTTT-3') and rDNA1.58S (5'-ACGAGCCGAGTGATCCACCG-3') and digested with BstU I and a PCR product specific for G. rostochiensis (1). Sequence of a 1,190-bp PCR fragment of ribosomal DNA amplified using primers rDNA1 (5'-TTGATTACGTCCCTGCCCTTT-3') and rDNA2 (5'- TTTCACTCGCCGTTACTAAGG-3') showed 99.0 to 100% identity with published DNA sequences of the same genomic region for G. rostochiensis (4). The sequence is available from the authors upon request. The origin of the introduction of G. rostochiensis into Saint-Amable is unknown. An intensive soil survey is underway to define the infested area, and strict quarantine measures have been taken to prevent further spread of G. rostochiensis. To our knowledge, this is the first evidence of the occurrence of G. rostochiensis in Quebec, Canada. References: (1) A. Fullaondo et al. Nematology 1:157, 1999. (2) A. M. Golden et al. Proc. Helminthol. Soc. Wash. 39:64, 1972. (3) A. R. Stone et al. Plant Dis. Rep. 61:590, 1977. (4) S. A. Subbotin et al. Nematology 2:591, 2000.
马铃薯（Solanum tuberosum L. subsp. tuberosum）是加拿大最重要的粮食作物之一。马铃薯胞囊线虫，即罗氏马铃薯胞囊线虫（Globodera rostochiensis (Wollenweber, 1923) Skarbilovich, 1959）和马铃薯白线虫（Globodera pallida (Stone, 1973) Behrens, 1975），被认为是全球马铃薯最具经济重要性的线虫害虫，在包括加拿大在内的许多国家都受到严格的检疫规定限制。在加拿大，罗氏马铃薯胞囊线虫在不列颠哥伦比亚省温哥华岛的萨尼奇半岛被发现，而在纽芬兰岛同时存在罗氏马铃薯胞囊线虫和马铃薯白线虫（3）。2006年8月，从魁北克省圣阿马布尔地区一块19.2公顷田地采集的马铃薯植株土壤和根系被送交至渥太华的加拿大食品检验局线虫学实验室。在根系上发现了金色球形胞囊，同时也从土壤中提取到了胞囊。回收的线虫通过形态学、形态测量分析和DNA分析进行鉴定。对60条二龄幼虫的测量和形态观察结果如下：体长 = 427.4 ± 22.0（395至495）μm；口针长 = 21.3 ± 1.2（18至23）μm；口针基部到背食道腺开口的距离 = 5.5 ± 0.9（3.5至7.0）μm；尾长 = 46.7 ± 3.7（36至58）μm；透明尾端 = 21.1 ± 3.1（13至27）μm；口针基部瘤的形状从圆形到侧面扁平不等。对35个成熟胞囊的观察结果为：肛门与阴门裂孔之间的角质层脊数 = 21 ± 6（12至31）；裂孔长度 = 18.4 ± 3.6（1至30）μm；肛门到裂孔边缘的距离 = 81.1 ± 30.4（29至165）μm；格拉内克比率 = 4.4 ± 1.6（1.8至6.0），肛门与阴门裂孔之间有平行波浪状角质层脊。这些观察结果与已发表的罗氏马铃薯胞囊线虫描述相符（2）。此外，使用引物18S（5'-TTGATTACGTCCCTGCCCTTT-3'）和rDNA1.58S（5'-ACGAGCCGAGTGATCCACCG-3'）扩增并经BstU I酶切的ITS-1区域的PCR-限制性片段长度多态性图谱以及针对罗氏马铃薯胞囊线虫的PCR产物支持了该鉴定（1）。使用引物rDNA1（5'-TTGATTACGTCCCTGCCCTTT-3'）和rDNA2（5'- TTTCACTCGCCGTTACTAAGG-3'）扩增的核糖体DNA的1,190-bp PCR片段序列与已发表的罗氏马铃薯胞囊线虫相同基因组区域的DNA序列显示出99.0%至100%的同一性（4）。如有需要，该序列可向作者索取。罗氏马铃薯胞囊线虫传入圣阿马布尔的来源不明。正在进行密集的土壤调查以确定受侵染区域，并已采取严格检疫措施防止罗氏马铃薯胞囊线虫进一步传播。据我们所知，这是加拿大魁北克省出现罗氏马铃薯胞囊线虫的首个证据。参考文献：（1）A. Fullaondo等人，《线虫学》1:157，1999年。（2）A. M. Golden等人，《华盛顿蠕虫学协会学报》39:64，1972年。（3）A. R. Stone等人，《植物病害报告》61:590，1977年。（4）S. A. Subbotin等人，《线虫学》2:591，2000年。
