葱兰黄化病病原类菌原体的研究

A STUDY ON MYCOPLASMA-LIKE ORGANISMS CAUSING YELLOW DISEASE ON AUTUMN ZEPHYRLILY

葱兰为石蒜科(Amaryllidaceae)草本植物,是一种在我国各地普遍栽培的多年生观赏花卉.葱兰黄化病是1992年在杭州发现的一种新病害,该病对葱兰的生长和观赏价值有严重影响.罹病株(丛)最初表现为深红色斑点,逐渐扩大为鲜红色条斑或斑块并转为亮黄色,最后整株叶片大部分转为鲜艳的黄色,呈现典型的系统侵染.发病1—2月后整株(丛)地上部分枯死.发病一般始于早春(3月上旬),春末夏初有一个发病高峰期;秋末有另一个发病期,但病状较轻;感染株有恢复现象,即在下一个生长季能从地下部分重新生长出叶片,但病株叶片明显细小,有丛簇现象,病株开花少且花期短.作者从1992年春起,对该病害进行了病原分离、生物学测定和病组织超薄切片电镜检查,发现该病害可能与类菌原体有关,现将研究结果报告如下.1 材料和方法1.1 样品感病植株分别于1992年4月采自浙江农业大学校园和1992年6月采自杭州花圃,用盆栽保存于防虫温室中,同时采取健株作为对照.1.2

A yellow disease of Zephyranthes Candida is discribed, which has so far been reported only in Hangzhou, China. Isolating of pathogenic fungi and bacteria and efforts of finding saptransmited agents causing this new disease were failed. No virus particles was detected under electron microscope after negative staining of diseased leaf sap. Mycoplasma-Like Organisms (MLOs) were observed in phloem cells of infected leaves by examing ultrastruture under electron microscope. Those oval bodies with trine membranes measuring about 45-1200nm in diameter were mostly located alongside cell membrane. No such structures were found in cells of heathy plants. MLOs was considered as the causing pathogens of this yellow disease of Z. Candida. This is the first report of MLOs happened in this genus.