柑桔裂皮病发生情况鉴定

 柑桔裂皮病(exocortis)是以枳、枳橙和檫檬作砧木的柑桔树的严重病害,它的病原是一种类病毒^4]。有的毒系引起砧木部树皮纵向开裂或翘裂,植株矮化,树势衰退;有的毒系仅引起植株矮化。此病除了嫁接传播外,亦通过修枝剪等与韧皮部接触传播。病害的鉴定,以利用指示植物为主。敏感的指示植物是Etrog香橼的USDCS 60-13选系和亚利桑那861选系^1、2]。此外,亚利桑那861-S-1选系更为敏感^3]。它不仅适用于鉴定一般毒系,亦适用于鉴定弱毒系。防治措施以通过茎尖嫁接脱毒或鉴定选择无病母树繁殖无毒苗木为主,亦要注意防止通过工具等的田间传播。

INDEXING FOR THE INFECTION OF CITRUS EXOCORTIS VIROID(CEV)

The bark symptom of exocortis has been found in Sichuan,Guangxi,Hunan and Guangdong provinces.The shoots from citrus trees with or without symptoms were collected and indexed for the infection of CEV by using the Etrog citron Arizona 861 or 861-S-1 as indicators.
Seventeen of the 19 cultivars imported from U.S.A.,Morocco,Albania,Cuba were infected with CEV.Seedling propagations of three of these cultivars and the satsuma imported from Japan were free of CEV.Six of the 27 native cultivars of sweet orange and mandarin were infected.Native sweet orange,Anliucheng of six sources were all infected.