摘要
由类菌原体(MLO)侵染引起的泡桐丛枝病曾采用各种细胞化学的方法进行检测。这些方法是报据MLO侵染的几个筛管分子群有特殊的染色反应或异常的荧光特征作为致病标志,并非在光镜下直接观察到MLO。本文报道了用泡桐病株嫩茎GMA切片,DAPI染色后能在光镜下直接观察到筛管分子中的MLO的特异DNA荧光光点。用PAS-TBO染色的切片和电镜切片观察证实了观察结果的可靠性。所有的健康植株所作的对照,筛管分子的DAPI染色都无MLO荧光。该方法不仅可以用于精确地检测各种MLO病害,同时也可以用来研究MLO在植株体内的分布、植株休眠期MLO的动态和MLO的传播方式,为MLO病害的防治提供理论依据。
Paulownia witches'-broom infected by mycopiasmalike organism (MLO) has been developed several cytochemical methods for diagnosis. These methods all based on the special stain reactions or abnormal fluorescence in groups of infected sieve elements as a diseased symptom, not really on the direct detection of MLO under light microscope. This paper deals with the demonstration of MLO specific white fluorescence after DAPI staining with GMA sections of diseased young stems. Such fluorescence was absent in sections from health plants. The results were confirmed by the ultrastructure of MLO and the structure of sieve elements showing from PAS-TBO stained GMA sections. The described method may not only be used in accurate diagnosis of MLO diseased in different plants, but is also worth in the studies of MLO distribution in plants, MLO dynamics ia plant resting stage and MLO transmission to support the theoretical basis for protection
关键词
泡桐
丛枝病
类菌原体
DAPI
MLO
Paulownia elongata Hu
Witches'-broom
DAPI
