1977年1月菲律宾北哥塔巴托(Cotabato)的当地农艺师M.G.Tirona报导发现一种新的水稻病害。同年2月国际水稻研究所亦观察到这一病害。随后在菲律宾的多个水稻产区都发现了这一病害。在病害严重的时候,田里90％以上的水稻受害,产量损失严重。此病害的症状与其他已知的水稻病毒病和类病毒病不同,我们将其命名为“水稻裂叶矮缩病”(Ragged stunt)。印度、印度尼西亚、斯里兰卡和泰国也曾报导发现同样症状的患病稻株。病害标本的电子显微图象显示出50—70nm的对称粒子,粒子大量存在于韧皮细胞和脉肿的细胞内。把病稻叶放在缓冲溶液中搅匀,离心后注射入褐稻飞虱体内,注射过的褐 January 1977 M.G.Tirona, a local agronomist in the Cotabato, Philippines, reported a new rice disease. In February the same year the International Rice Research Institute also observed the disease. This disease was subsequently found in several rice producing areas in the Philippines. When the disease is serious, more than 90% of the rice in the fields is harmed and the yield is seriously lost. The symptoms of this disease are different from those of other known rice virus and viroid viruses, which we named Ragged stunt. India, Indonesia, Sri Lanka and Thailand also reported the diseased rice plants that found the same symptoms. Electron microscopy images of diseased specimens show symmetrical particles of 50-70 nm, with large numbers of particles present in the cells of the bast and in the ventral telangiectasia. Put the sick rice leaves in buffer solution, stir, centrifuge injection into brown planthopper body, injected brown