摘要:
运用媒介昆虫的研究方法和电镜技术,研究柑桔木虱传播黄龙病的规律和病原在虫体内的分布。结果表明,单只成虫会传病,其指示柑桔苗的发病率高达80%。带“毒”成虫在柑桔苗上传“毒”1～3小时不会传病,5小时以上会传病。1～3龄若虫不会传病,成虫体内携带的病原也不会经卵传到后代。4～5龄若虫会传病,高龄带“毒”若虫羽化的成虫不经再饲“毒”也会传病,高龄若虫携带的病原会跨龄传到成虫。应用电镜除在木虱的唾液腺细胞内观察到病原外,还发现黄龙病的病原体广泛地分布在成虫消化道的滤室、中肠和后肠的细胞内。由于木虱具有选择寄主嫩梢产卵的习性和黄龙病树梢期紊乱,因此,田间病树不但是黄龙病的“毒”源树,而且是其介体昆虫柑桔木虱的虫源树。这些残留的病树和从病树扩散的木虱是黄龙病在田间流行的根源。
Abstract:
The law of transmission of Citrus Huanglungbin by psylla and the distribution of pathegen in psylla have been studied since 1984. The results show that Huanglungbin agent can be transmitted by a single adult after feeding on the diseased citrus plant. It will infect tested seedlings at a high efficiency of 80%.The pathogen cannot be transmitted by a single adult after a 1-3-hour acquisition feeding on the diseased citrus plant,nor by a nymph of the 1st to 3rd instar. The infected adult is unable to transmit pathogen through its egg. But the pathoren can be transmitted by a single adult after an acquisition feeding of more than 5 hours on the diseased citrus plant and also by a nymph of the 4th to 5th instar. A freshly emerged adult from an infected old nymph is able to transmit the pathogen to the tested citrus seedlings and the pathogen in an old nymph can be transmitted to an adult emerging from the nymph, It is able to transmit the pathogen by striding instar. Since psyliid needs fresh shoots to lay eggs on, and the shoots of dissased citrus plant grow in a disorderly way, the Huanglunbin diseased tree in an orchaned is not only a tree of the pathogen source, but also tree of the vector source. On condition of psyliid transmitting pathogen by striding instar, psyliid growing on and spreading from diseased plant is the epidemic source of Huanglungbin disease in orchards. It is an important law on transmission of pathogen by psyliid.
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