重庆试种期间绿玉树病害初报

A preliminary study on the diseases of Euphorbia tirucalli in Chongqing

绿玉树是一种集药用、观赏等多用途于一体的树种,病害的发生严重影响了绿玉树在重庆试种期间的健康生长。病害调查和病原鉴定结果表明:试种期间危害最严重的病害是灰霉病和根结线虫病。其中灰霉病由葡萄孢霉(Botrytissp.)危害所致,可使绿玉树的各个部位发生水渍状腐烂,上生灰色霉层,持续阴雨有利于病害的发生和流行。南方根结线虫(Meloidogyne incognita)为害引起根结线虫病,使绿玉树根部组织过度生长形成瘤状根结,发生严重可导致根部坏死腐烂。

Euphorbia tirucalli is most commonly used as medicinal and ornamental plant. But the occurrence ot diseases severely affected the health of the pencil tree during its planting period in Chongqing. The diseases of this plant introduced in Chongqing were identified in this paper. The results showed that the most severe diseases of this plant were gray mold and root knot. The gray mold was caused by Botrytis sp. , which could damage every part of E. tirucalli and made the tissue rotten. The infection firstly appeared as water-soaking, then a tan to gray fuzzy mold developing on the rotten tissues under humid conditions. The damage was more severe under overcast and rainy weather. The root-knot was caused by Meloidogyne incognita. The typical symptom of this disease was that there were a lot of knots on the roots. The infected roots became rotten and dead.