我国水稻黄矮病,是六十年代以来新发现的一种病毒病,目前分布范围广,一般发病损失产量2-3成,是南方稻区的一个重要病害。本病的症状特征是:始病叶位,在水稻生长前期,从顶叶以下一、二叶开始;病斑先从叶尖端开始向叶基扩展,全叶形成叶肉黄化、叶脉绿色的条状或斑驳状花叶,以后向上纵卷枯黄;病叶与茎杆夹角增大。病原为弹状病毒,在病叶超薄切片中大小为50-90×100-180nm,在分离提纯过程中容易发生变化。介体昆虫有三种黑尾叶蝉,病毒在虫体内属非经卵传染。黑尾叶蝉(Nepho-teffix cincticeps)获毒的最短时间为5-10分钟,多数12小时以上,循回期7-39天(随自然气温的上升而缩拉),传毒时间至少3-5分钟,开始传毒虫态最早是4龄,多数在成虫期,无毒虫时病毒的亲和性个体在半数以下,保毒虫传毒多数是不连续的,有效的传毒天率(传毒天数与昆虫自开始传毒到死亡的天数之比)在30-60%。单个虫体可以同时获得本病和普通矮缩病或黄萎病(类菌质体)两种病原,并能先后或同叶在一株水稻上传病。病毒寄主目前仅知水稻(Oriza sativa)一种。水稻对病毒的反应因品种、生育期和环境条件不同而异。抗性品种主要表现为感病率低,潜育期长,病情较轻,病株恢复率高等。水稻在分蘖末期以前为感病期,分蘖初期至盛期最感病,拔节以后不易感病。发病生育期迟,生长条件好时病株恢复率高,产量损失少。浙江省双季稻区,病毒主要在黑尾叶蝉体内越冬,春季随介体昆虫的迁飞传播到水稻上,成为初次侵染源。早稻发病主要由初次侵染源引起,晚稻发病则主要由早稻收获期迁移的介体昆虫侵染所致。早稻后期发病率与苗期迁入的越冬代黑尾叶蝉虫量成正相关,晚稻后期发病率与本田初期(约15天内)迁入的第二、三代虫量成正相关。 Yellow dwarf disease in our country is a newly discovered virus disease since the 1960s. At present, it has a wide range of distribution and generally produces 2-3% of the disease loss, which is an important disease in the southern rice area. Symptoms of the disease are characterized by: diseased leaf position, in the early rice growth, from the parietal lobe, the second leaf began; lesions from the tip of the leaf began to expand to the leaf base, the whole leaf formation of yellow leaves, veins green stripes Shaped or mottled mosaic, after the upward kerzy yellow; sick leaves and stem angle increases. The pathogen is Rhabdovirus, which is 50-90 × 100-180nm in the ultrathin section of the diseased leaves, which is prone to change during the isolation and purification. Mediator insects have three kinds of black leafhopper, the virus is non-oestrus in the parasites. Nepho-teffix cincticeps has a minimum of 5-10 minutes of poisoning, most of them for more than 12 hours, with a recovery period of 7-39 days (with the natural temperature rise and contraction), the transmission time of at least 3- 5 minutes, the beginning of the first toothache state is 4 instar, most in the adult stage, non-toxic insects when virus affinity in less than half of the majority of poisoning insecticide is not continuous, effective virus poisoning rate To the number of days since the insecticide began to transmit to death) ranged from 30-60%. A single insect can get both the pathogen and the common dwarf disease or Verticillium wilt (mycoplasma) two pathogens, and can successively or in the same leaf in a rice disease. Currently, the virus host only knows about Oriza sativa. The response of rice to the virus varies by species, growth period and environmental conditions. The resistant varieties mainly showed low susceptibility, long incubation period, mild disease and higher disease recovery rate. Rice at the end of tillering for the susceptible period, the early tillering to the most susceptible period, not susceptible to disease after jointing. Disease onset late, good growth conditions when the plant recovery rate, yield loss less. Zhejiang double cropping rice area, the virus is mainly in the black tail leafhopper winter, with the migrant insect in spring fly spread to rice, becoming the primary source of infection. The incidence of early rice was mainly caused by the primary source of infection. The incidence of late rice was mainly caused by the infection of the mediator insects that migrated during the harvesting period of early rice. The incidence of late rice was positively correlated with the number of overwintering black-leafed cicadas in the seedling stage. The incidence of late rice was positively correlated with the second and third generations of migratory plants in the early stage of Honda (about 15 days).