木虱传播柑桔黄龙病及电镜检验报告

 本试验在福建省福州市及广东省侥平县两地进行。1978年以来,在福州市以蕉柑、福桔和新会甜橙病树为毒源树,以柑桔实生健苗为指示植物,进行木虱传试验。结果在329株指示苗中,发病40株,发病率12.2%,潜育期短的半年,长的5年。对照指示苗72株均未见发病。1982~1984年,在饶平县以蕉柑病树为毒源树,以椪柑实生健苗为指示植物,共试验70株,发病33株,发病率47.1%,潜育期短的2个月,长的8个月。对照指示苗9株未见发病。木虱传染病苗的病状与毒源树的病状相同,均表现黄梢和叶片斑驳。获"毒"木虱的唾液腺和脂肪体的超薄切片样本在电镜下均观察到原核细胞微生物(称为类立次克体或类细菌)。唾液腺内的病原体分布在外皮层细胞,内皮层细胞和腺腔内。其菌体的形状大小和膜壁结构等特征均与毒源树及木虱传染病苗的筛管细胞内的相同,木虱获得和传递柑桔黄龙病病原的方式与蚜虫传播病毒中的持久性类型十分相似。

ON THE TRANSMISSION OF CITRUS YELLOW SHOOT BY PSYLLA AND OBSERVATIONS WITH ELECTRON MICROSCOPY

The transmission studies were conducted in both districts of Fuzhou city,Fujian and Rao Ping county,Guangdong province.Since 1978 using the diseased citrus plant as the inoculum source plant,the pathogen of citrus yellow shoot was successfully transmitted by psylla(Diaphorina cirri) from diseased citrus plant to heathy citrus seedlings.Of 329 plants tested,40 plants showed symptoms at 0.5-5 years after test feeding.72 plants of check treatment showed no symptoms.In transmission made in Raoping county during the year of 1982-1984,33 of 70 plants tested showed symptoms at 2-8 months after test feeding.19 check plants showed no symptoms.The diseased seedlings inoculated by the citrus psylla showed yellow shoot and mottled leaf symptoms,same as that of inoculum source plant.On the ultra-thin sections of salivary glands from the pathogen carrier 9 psylla under electron microscope,the particles of the procaryote called rlckettsia-like organism-or bacteria-like organism were found in the outer and inner layer cells and cavity of salivary gland,and sometimes in the outside fat tissue.Its shape,size and the structure of membranous wall are the same to that found in the seive cell of inoculum source-plant and in seedling inoculated by psylla.The status of acquisition and transmission of yellow shoot pathogen by citrus psyllais quite similar to those of persistent vectors such as aphids.