辣椒发生的一种类菌原体新病害

A NEW PEPPER DISEASE CAUSED BY MYCOPLASM ALIKE ORGANISM (MLO)

受害辣椒呈现丛枝小叶症状,叶柄变细伸长,花器变绿。严重时茎杆带化,花序聚生,花器萎落,鳞片发育成小叶片。经多年反复试验,该病原能通过大青叶蝉及嫁接顺利传播,而不能通过汁液摩擦和蚜虫传播。罹病辣椒的叶片中脉切片经甲苯胺兰(TBO)染色后,用荧光显微镜可在韧皮部观察到清晰的枯黄色萤光反应斑,整个维管束组织严重退化变小。用电子显微镜对超薄切片观察,在辣椒病株的筛管中观察到大量的172～311nm的MLO菌体。病株用土霉素(OTC)溶液灌根3周后症状开始缓解,而青霉素处理无效。据此,作者认为引起辣椒丛枝病的病原是一种类菌原体(MLO)。本文在国内首次报道了MLO对辣椒的为害。

Witches' broom and samll leaf appeared in diseased pepper plants (Capsicum frutescens). The petioles become long and thin, while flowers turned green, Severe infection of pepper showed stalkbanding, infloresence - clustering, flower - withering and scalephyllody. Many trials indicated that the causal agent can be transmitted by Tettigella virid is and graft, but not by aphides and sap inoculation. All of the vascular bandies were degenerated and orange fluorescence spots obvious were in discaled phloem of leaf midrid , when stained with 0. 25% toluidine blue o (TBO) solution observed under fluorescence microscopy. Spherical bodies, 172-311 nm in diameter in sieve tubes of the ultrathinsec-tions from infected pepper were seen in electron microscopy. Oxytetracycline (OTC) treatment made effectively more bright. It is demonstrated that the pepper witches broom was caused by mycoplasmalike organism (MLO) and is regarded as a first of such disease in China.