南京毛刺线虫对山定子的直接致病性研究

北京南口农场山定子砧苹果树受线虫侵害严重。田间树势调查结果表明:病树长势衰退,产量降低,品质下降;补植的幼树表现出再植病症状。田间根系症状调查结果表明:病树根系生长异常,表现出典型的短粗根病症状,即受害幼根不呈延伸生长,而是在生长中不断分枝,以致最后形成须状丛簇根,每年只在新根旺长期长出一小段具有吸收功能的白色、毛笔尖状的新根。盆栽幼苗接种试验表明:南京毛刺线虫的侵染严重影响了山定子幼苗的形态建成,且使根系表现出短粗根病症状,从而证明南京毛刺线虫(Trichodorus nanjingensis Liu＆Chen)是导致该场苹果树势衰退、再植病和短粗根病的主要病原。

Study on the Pathogenesis of Trichodorus nanjingensis to Mains baccata

Serious nematode disease was found in apple orchard in Nankou, Beijing. The results of investigation showed that, after apple tree was infected with nematode, the vigor of the tree was declined, the yield was decreased and the fruit quality was bad. What's more, replanted seedlings showed replant disease. The results of root symptom investigation in the field showed that root in-fected with nematode displayed symptoms of stubby-root disease, namely, young root infected with nematode couldn't grow extensively,but finaly formed fibrous stubby root. The results of seedling inoculation test showed that the Trichodorus nanjingensis affected the morphogenesis of Malus baccata and caused stubby-root and replant desease.