甘薯茎线虫主要侵入途径分析

Invasion Route Bioassays of Potato Rot Nematode in Sweetpotato

[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。

[ Objective] The aim was illustrate the mechanisms underlying the severely yield reduction of sweetpotato caused by potato rot nem- atodes （PRNs）. [ Method] Greenhouse and field exprements were can＇ied 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 l g 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 cuhivars. 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 treat- ment. Compare to burying stern treatment, the yield of ten plants in pressing stern treatment was increased by 56. 1% , and the number of stor- age root was increased by 115.8%. [ Conclusion] Sealing off the wounds on the underground stem wouhl be the key of PRNs control.