组织化学技术快速检测泡桐丛枝病研究

 迪纳氏染色和萤光显微镜技术——苯胺蓝染色法,和DAPI染色法,可从感染泡桐丛枝病的嫩茎和叶柄及将MLO转接到长春花上,表现典型症状的嫩茎和叶柄中诊断MLO的侵染。病株切片的迪纳氏染色阳性,健株切片阴性。苯胺蓝染色病株韧皮部产生的特异性萤光区域比健株大。DAPI染色可直接检测韧皮部组织中的MLO,而且韧皮部萤光强度与MLO的密度和外部症状严重度呈正相关。三种染色方法比较结果说明,DAPI染色法是一种灵敏度高,特异性更强的泡桐丛枝病类菌原体检测方法。

HISTOCHEMICAL DIAGNOSIS OF PAULOWNIA WITCHES' BROOM

Dienes' stain and fluorescence microscopy including aniline blue stain and 4',6'-diamidino-2-pbenylindole-2HC1 (DAPI) stain can detect MLO infection from paulownia and periwinkle inoculated with paulownia witches' broom agent.The result of Dienes' stain on cross section of young internode regions and petiole tissue of diseased plant was positive,while that on the healthy one was negative.Fluorescence microscopy of cross section of the tissue,stained with aniline blue,showed a marked difference in fluorescence in the phloem area of healthy and diseased plants.MLO-specific fluorescence after staining with DAPI was shown in the diseased plant,but such fluorescence was absent in sections from healthy plants.This is a more specific and sensitive method to detect MLO infection as compared with Dienes' stain and aniline blue stain.MLO infection was further comfirmed by electron micoscopy.