Castillo Pablo, Vovlas Nicola, Azpilicueta Andrea, Landa Blanca B, Jiménez-Díaz Rafael M
Institute of Sustainable Agriculture (IAS), Spanish Council for Scientific Research (CSIC), P.O. Box 4084, 14080 Córdoba, Spain.
Istituto per la Protezione delle Piante, Sezione di Bari, Consiglio Nazionale delle Ricerche (C.N.R), 70126 Bari, Italy.
Plant Dis. 2007 Jan;91(1):71-79. doi: 10.1094/PD-91-0071.
Stunted growth of fall-sown sugar beets (Beta vulgaris) associated with high incidence of crownroot infections and large soil infestations by Ditylenchus dipsaci were observed at the end of the crop growing season in southern Spain by early June 2005. The largest proportion (75%) of the nematode life-stages in plant and soil was the fourth-stage juvenile. The large number (up to 3,750 nematodes per gram of fresh tissue) of D. dipsaci individuals and severe anatomical alterations observed in storage sugar beet roots suggest that the stem and bulb nematode is the causal agent of the impaired growth of sugar beets observed in commercial fields. Observed morphological traits of nematode specimens and results of specific polymerase chain reaction (PCR) and phylogenetic analyses confirmed that the population of D. dipsaci infecting sugar beet belongs to the normal (nongiant) biological type of the nematode. Results of host-range bioassays indicated that the population of D. dipsaci infecting sugar beet in southern Spain reproduces on pea (including seeds and pods), onion, potato, spinach, and tomato, but not on bean, cotton, maize, and tobacco. These results indicate that D. dipsaci may be an important constraint for sugar beet crops in the affected area, but also for other important crops commonly used in rotation with them.
2005年6月初，在西班牙南部作物生长季结束时，观察到秋播甜菜（Beta vulgaris）生长发育迟缓，伴有严重的冠根感染，且土壤中茎线虫（Ditylenchus dipsaci）大量滋生。植物和土壤中线虫生命周期阶段的最大比例（75%）为第四阶段幼虫。在贮藏甜菜根中观察到大量的茎线虫个体（每克新鲜组织中多达3750条线虫）以及严重的解剖学改变，这表明茎线虫是在商业田地中观察到的甜菜生长受损的致病因素。观察到的线虫标本形态特征以及特异性聚合酶链反应（PCR）和系统发育分析结果证实，感染甜菜的茎线虫种群属于该线虫的正常（非巨型）生物型。寄主范围生物测定结果表明，在西班牙南部感染甜菜的茎线虫种群可在豌豆（包括种子和豆荚）、洋葱、马铃薯、菠菜和番茄上繁殖，但不能在豆类、棉花、玉米和烟草上繁殖。这些结果表明，茎线虫可能是受影响地区甜菜作物的一个重要限制因素，对于与之轮作的其他重要作物也是如此。
