徐振 孙厚俊 杨冬静

摘要[目的]明确甘薯茎线虫造成甘薯严重减产的机制。[方法]通过室内及田间试验分析了茎线虫侵入甘薯的主要途径。[结果]苗期茎线虫主要从薯苗基部伤口侵入。在地下部无伤口条件下，薯苗1 g组织内茎线虫数量仅为9.2头，显著低于对照处理的165.2头。薯块表皮对抵御茎线虫侵入具有重要作用，且不同品种薯块表皮对茎线虫的侵入抗性水平不同。田间试验结果表明，压茎处理组薯拐及薯块病情指数均显著低于埋茎处理组。与传统的埋茎处理组相比，通过压茎法种植的薯苗由于地下部没有伤口存在，平均10株薯苗产量增加56.1%，结薯数增加115.8%。[结论]封闭薯苗基部伤口是防治茎线虫病的关键。

关键词 甘薯茎线虫；侵入途径；产量

中图分类号 S435.315 文献标识码 A 文章编号 0517-6611（2017）02-0164-03

Abstract[Objective] The aim was illustrate the mechanisms underlying the severely yield reduction of sweetpotato caused by potato rot nematodes （PRNs）.[Method] Greenhouse and field exprements were carried out to explore the main invasion route of PRNs.[Result]During seedling stage， PRNs enter seedlings mainly through the wounds at the base of underground stems. In average， there were only 9.2 PRNs in 1g tissue of seedlings without wounds on underground stems， which is significantly lower than control treatment（165.2 PRNs）. Storage root cuticle play important role in preventing PRNs invasion， with the resistant level changing as cultivars. Field exprement results showed that the disease incidences both of underground stem and storage root were significantly lower in pressing stem treatment than that in burying stem treatment. Compare to burying stem treatment， the yield of ten plants in pressing stem treatment was increased by 56.1%， and the number of storage root was increased by 115.8%.[Conclusion] Sealing off the wounds on the underground stem would be the key of PRNs control.

Key words Potato rot nematode；Invasion route；Yield

甘薯茎线虫病是我国北方薯区较严重的病害之一。国家甘薯产业技术体系2010年对甘薯病虫害普查报告显示，甘薯茎线虫病在河北、河南、安徽和山东省都是危害甘薯最严重的病害，发病面积达133.2万hm2。甘薯茎线虫病的病原为马铃薯腐烂茎线虫（Ditylenchus destructor Thorne），又称甘薯茎线虫，属垫刃目茎线虫属[1]。该线虫普通发生可导致甘薯减产20%～50%，严重年份甚至绝收[2]。甘薯茎线虫为迁移性内寄生线虫，其寄主非常广泛，包括多种重要农作物和杂草[3]，同时具有食真菌性[4]，所以采用传统的作物轮作方法很难防治。采用化学农药防治，除不可避免的残留和抗药性问题外，由于茎线虫的生活习性，很少有药剂能够达到理想的防治效果。……