柑桔衰退病病毒是佛罗里达柑桔最严重的一种病毒,柑桔衰退病病毒有许多株系,这些株系在发病症状的程度方面有很大的差別。从前在佛罗里达通常观察到的最熟悉的症状是:以酸橙(Cjtrus anrantjum L)为砧木嫁接的甜橙(C.si—nensis〈L〉Osb.)、葡萄柚(C.patadisi Maf)和桔子(C.reticnla—ta Blanco)表现缓慢的衰败。近年来,在佛罗里达中部和南部地区有大量柑桔树、在印第安河流域有许多柑桔却表现很快地衰败,常常在第一个症状出现后几星期内就枯死了。苗田中许多用酸橙作砧木嫁接的苗木也不能保持正常 Citrus recession virus is one of the most serious viruses in Florida citrus and there are many lines of citrus recession virus that vary greatly in the degree of onset of symptoms. The most familiar symptoms that were commonly observed in Florida before were: sweet orange (C. si-nensis Osb.) Grafted with Cjtrus anrantjum L, C. patadisi Maf and orange (C.reticnla-ta Blanco) slow decline. In recent years, there have been numerous citrus trees in central and southern Florida, many oranges in the Indian River basin have declined rapidly, and often die within a few weeks of the first symptoms. Many nursery stock with lime as rootstock grafted seedlings can not be maintained