摘要:
应用指示植物测定、电子显微镜学检查以及间接ELISA方法,对采自福建、广东、江西、海南、浙江、湖南、云南、四川、贵州等九个省表现各种田间病状类型的332份柑桔类样本进行了带毒情况的检测。田间病状包括全株性的矮缩、青枯,叶片褪绿黄斑、斑驳、均匀黄化、缺素状黄化、卷叶、船形叶、小叶,叶脉黄化、木栓化,木质部陷点、陷槽(病情指数为6.7～71.1),树干痂斑、瘤状增生,红鼻子果、不定期开花,畸形花、果,砧木裂皮,嫁接口离层等。鉴定结果表明:我国至少已发生四种柑桔病毒病和类似病毒病:碎叶——积橙矮化病,衰退病、黄龙病、裂皮病。福建、广东等地的福桔、蕉柑、芦柑、百年桔、滑身仔、北京柠檬等品种已感染碎叶——积橙矮化病毒(TL-CSV),田间表现隐症或褪绿黄斑、卷叶、嫁接口离层等。病原可能包括能侵染豇豆的700～850×9～15nm和不侵染豇豆的400～500×6～10nm二个病毒组分。衰退病毒(CTV)分布极为广泛,且同时存在茎陷点毒系和苗黄毒系,田间隐症或表现木质部陷点、陷槽,叶脉黄化、木栓化,常与TL-CSV、黄龙病类细菌(CYS)、裂皮病类病毒(CEV)混合侵染。CTV在枳壳实生苗上逐渐被过滤掉。福建的一个柑桔无病母本国已有1.9～28.8%的母树重新感染CTV。田间根据斑驳病状诊断CYS相当可靠。单一的汁液摩擦方法不适用于CEV的草本植物鉴定。初步证明福建、湖南等地发生的温州蜜柑接缩、青枯病状无传染性。本文还就今后培育无病苗的途径进行了讨论。
Abstract:
332 multisymptomatic or symptomless citrus samples, collected from 9 provinces,i.e. Fujian,Guangdong, Guangxi,Hainan,Zhejiang,Hunan,Yunnan, Sichuan and Guizhou, were identified for virus or virus-like agents with the help of indicator plants, electron microscopy and indirect-ELlSA.In the field conditions, citrus trees show symptoms such as green-withering or dwarfing of a whole plant, chlorotic yellow spots, mottling, uniform yellowing or nutrition-deficiency yellowing on lea-res, leaf rolling, boat-shaped or samller leaves, yellowing and corking of vein, pitting and grooving of xylem. (with a disease index of 6.7-71.1),scabious spots and tumorous proliferation of stem or trunk,"red-nose" fruit, irregular flowering, distorted flower or fruit, bark shelling of rootstock and separated bud-union, etc.The results of the identification indicate that at least 4 kinds of virus or virus-like diseases, namely, tatter leaf-citran gestunt, tris-teza, "Huanglongbin"(CYS) and exocortis,have occurred in citrus Orchards in China. In Fujian and Guangdong, tangerine cvs., Fuju, Bainianju, mandarin cvs.,Tankan,Ponkan,Sweet orange cv., Xinhui orange and Meyer lemon have been infected by TL-CSV that show chlorotic yellow spots, leaf rolling, separated budunion or show no visible symptoms The agent probably contains two components, 1. 700-850?6-15 nm infecting cowpea (Vigna sinensis (Tomer, Savi, and 2. 400-500?6-10 nm, uninfective, CTy, consisting of two strains, i. e. stem pitting strain and seedling yellow strain, has had a widespread distribution in citrus producing areas in China and grooving of xylem,yellowing and corking of vein or shows no visible symptoms on terminal branches. It usually attacks citrus trees in the existence of TL-CSV, CYS and CEV on the infected plants, but its agent can be filtered away gradually by incubation on trifoliate orange (Poncirus trifoliata (L.) Raf.) seedlings. In Fujian, 1.9-28.8% of mothet trees of a disease-free foundatioe garden have been reinfected by CTV. It has been proven rather reliable to diagnose "Huanglongbin" according to the mottling symptom in the field. A single inoculation method of sap-rub has been unsuitable for CEV detection on herbaceous indicators. The primary data imply that dwarfing and green-withering of Satsuma in Fujian and Hunan are uninfective.An approach to produce disease-free seedling in the future has been discussed in the paper.
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