水稻瘤矮病—广东湛江新发生的一种水稻病毒病

 广东新发生的水稻瘤矮病于1981~1982年在广东湛江地区的信宜、高州和化州县发生流行。室内用叶蝉接种2叶龄的稻苗,在10~11月广州温室温度约为土9~23℃下,潜育期为13~28天,主要症状为病苗矮缩,叶片浓绿色,叶背及叶鞘上长有若干个淡黄绿色近圆形小瘤(0.1~1.2毫米直径)。病毒粒子球状,直径约60毫微米。昆虫介体为电光叶蝉(Recilia dorsalis Motsch.)和黑尾叶蝉(Nephotettix cinticeps Uhler.)。褐稻虱(Nilaparvata lugens Stal.)和白背飞虱(Sagatella furcifera Horvath.)不能传病。二点黑尾叶蝉(N.virescence Distant.)和大斑黑尾叶蝉(N.apicalis Motsch)还有待进一步研究决定。电光叶蝉的最短获毒饲育期少于24小时。潜育期在平均室温22~23℃下为13~24天。保毒虫能终生传毒。根据上述实验结果,初步认为本病与泰国和马来西亚报道的水稻瘤矮病相同。

RICE GALL DWARF——A NEW VIRUS DISEASE EPIDEMIC IN THE WEST OF GUANGDONG PROVINCE OF SOUTH CHINA

A new rice virus disease identified as rice gall dwarf which was first reported in Thailand(1980) and Peninsular Malaysia(1982) broke out in the western part of Guangdong Province in South China in 1981~1982.The affected acreage was estimated to be about 7000 ha in 1981 and about 30000 ha in 1982.The loss of yields in the most seriowsly affected fields was reported to be as great as 4500 kg/ha.
The main symptoms of the disease at the seedling stage consisted of severe dwarfing,dark greening of leaves and small gall formations on the underside of the leaves and on the leaf-sheaths.The galls were light yellowish-green in color and nearly spherical in shape and some of them seemed to be extending longitudinally along the veins.The incubation period of the disease at the two-leaf seedling stage under 19~23℃ in green house was 13~28 days.
The virus particles,prepared by leaf dip method with 3% PTA(pH6.7) as a negative stain and examined under electron microscope(EM400),were spherical in shape with a diameter of about 60nm.The ultrathin sections(LKB 5) showed that the virus particles existed in the phloem cells of diseased plants.
The insect vectors of the virus were found to be the Recilia dorsalis Motsch,and Nephotettix cincticeps Uhler.The former was much more efficient than the latter.N.virescence Distant and N.apicalis Motsch re-main to be further confirmed.Nilaparvata lugens Stal.and Sagatella furcifera Horvath,however,were unable to transmit the disease.
In R.dorsalis the incubation period of the virus was 13~24 days under 22~23℃.The transmission was persistent.There is evidence that the virus can overwinter in the insect vectors in the west of Guandong province.