湖北省桑萎缩病研究初报

通过对症状和病原的形态观察,证明了2003年湖北省远安县发生的桑萎缩病为黄化型,发病率多在10%～60%,个别田块高达90%以上;根据远安县桑种植和桑萎缩病发生的历史及其分布现状推断病源属本地原有病源,非1998年调运桑苗所致;桑萎缩病的发生与桑树品种、病源积累、媒介昆虫的密度、采伐有关;对桑萎缩病的桑叶进行超薄切片的电镜观察发现,细胞内有少量的MLO病原体,病原体为圆形,50～160nm.

Primary Study on Mulberry Dwarf in Hubei

Mulberry dwarf had been discovered in Yuanan, Hubei province in 2003.And The symptom type was yellowing caused by mycoplasma-like organism (MLO). Incidence of the disease was from 10% to 60% generally. Few got to more than 90%. According to the situation of Mulberry cultivation and accorance of Mulberry dwarf in Yuanan , it could be concluded that the source of infection was native but not by importing mulberry seedlings in1998. The occurrence of mulberry dwarf was related to the kind of variety, quantity of pathogen , the population of vector insect, time of deforestation. The pathogen causing Mulberry dwarf was investigated on transmission electronic microscopy of the leaf of diseased plant collected in the field. A mycoplasma-like organism was identified in the leaf. The organism was spheric in shape, ranging from 50 to 160nm in diameter.