Hymenocallis littoralis growing in southern China has been recently extensively damaged by virus-like symptoms of necrosis, chlorosis, and ringspot. Of 44 plant samples collected from Yunnan, Guangxi, Guangdong, and Fujian provinces in southern China, 32 were infected with hippeastrum chlorotic ringspot virus (HCRV). Phylogenetic analysis based on the N gene divided the virus samples into two branches suggesting a geographic distribution attributed to the initial stage of a founder effect. The N gene was under purifying selection pressure and most of the deleterious mutants had been removed. Both the population dynamics and genetic analyses suggested that populations of HCRV in southern China are spreading.
Keywords: Hymenocallis littoralis; hippeastrum chlorotic ringspot virus (HCRV); nucleocapsid protein; population expansion; purifying selection pressure; population dynamics..