Retention of Rice dwarf virus by descendants of pairs of viruliferous vector insects after rearing for 6 years
Retention of Rice dwarf virus by descendants of pairs of viruliferous vector insects after rearing for 6 years
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DOI：
10.1094/phyto-97-6-0712
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发表时间：
2007-06-01
期刊：
影响因子：
3.2
通讯作者：
Omura, Toshihiro
中科院分区：
文献类型：
--
作者：
Honda, Kazuto;Wei, Taiyun;Omura, Toshihiro
水稻矮缩病毒（RDV）是一种能在植物和叶蝉媒介昆虫中大量繁殖的病毒，其传播方式是跨卵传播。黑尾叶蝉的菌落，最初来自对叶蝉感染RDV的普通菌株，在实验室中保持6年，并发现，在这段时间结束时，仍然窝藏RDV。而且。从这些菌落获得的RDV分离物，命名为RDV-I，保留了感染水稻植物的能力。当我们将叶蝉与单独放置在浸水滤纸上的卵分开饲养，并在健康的水稻幼苗中饲养时，我们发现所有这些叶蝉都携带RDV。这一观察结果表明，RDV-I已保持在叶蝉的跨卵传播。进一步的两个观察结果，即，在其上饲养了含病毒昆虫的无病毒植物上，无病毒昆虫对RDV的获得率低，以及当通过RDV-I-含病毒昆虫接种水稻幼苗时，只有2 - 5%的植物有症状的事实，证实了通过植物和昆虫的任何其他传播方式维持RDV-I是不可能的。这种有效的和长期的维持RDV在一个人口的病毒昆虫可能解释了水稻矮缩病在田间的持续时间长，一旦有一个严重的爆发。
Rice dwarf virus (RDV) is characterized by its unusual ability to multiply in both plants and leafhopper vector insects and by its transovarial mode of transmission. Colonies of Nephotettix cincticeps, derived originally from pairs of leafhoppers infected with an ordinary strain of RDV,, were maintained for 6 years in the laboratory and were found, at the end of this time, still to harbor RDV. Moreover. the isolate of RDV, designated RDV-I, obtained from these colonies retained the ability to infect rice plants. When we raised leafhoppers separately from eggs that had been placed individually on pieces of water-soaked filter paper and reared them in the presence of healthy rice seedlings, we found that all of these leafhoppers harbored RDV. This observation suggested that RDV-I had been maintained in the leafhoppers by transovarial transmission. Two further observations, namely, the low rate of acquisition of RDV by virus-free insect nymphs on symptomless plants on which viruliferous insects had been reared, and the fact that only 2 to 5% of plants had symptoms when rice seedlings were inoculated via RDV-I-viruliferous insects, confirmed that the maintenance of RDV-I by any other mode of transmission through plants and insects was unlikely. This efficient and long-term maintenance of RDV in a population of viruliferous insects might explain the prolonged duration of rice dwarf disease in the field, once there has been a serious outbreak.