Bateson Marion F, Lines Rosemarie E, Revill Peter, Chaleeprom Worawan, Ha Cuong V, Gibbs Adrian J, Dale James L
School of Life Sciences, Queensland University of Technology, GPO Box 2434, Brisbane, Queensland 4000, Australia1.
Hanoi Agricultural University, Gia Lam, Vietnam2.
J Gen Virol. 2002 Oct;83(Pt 10):2575-2585. doi: 10.1099/0022-1317-83-10-2575.
The potyvirus Papaya ringspot virus (PRSV) is found throughout the tropics and subtropics. Its P biotype is a devastating pathogen of papaya crops and its W biotype of cucurbits. PRSV-P is thought to arise by mutation from PRSV-W. However, the relative impact of mutation and movement on the structure of PRSV populations is not well characterized. To investigate this, we have determined the coat protein sequences of isolates of both biotypes of PRSV from Vietnam (50), Thailand (13), India (1) and the Philippines (1), and analysed them together with 28 PRSV sequences already published, so that we can better understand the molecular epidemiology and evolution of PRSV. In Thailand, variation was greater among PRSV-W isolates (mean nucleotide divergence 7.6%) than PRSV-P isolates (mean 2.6%), but in Vietnamese populations the P and W biotypes were more but similarly diverse. Phylogenetic analyses of PRSV also involving its closest known relative, Moroccan watermelon mosaic virus, indicate that PRSV may have originated in Asia, particularly in the Indian subcontinent, as PRSV populations there are most diverse and hence have probably been present longest. Our analyses show that mutation, together with local and long-distance movement, contributes to population variation, and also confirms an earlier conclusion that populations of the PRSV-P biotype have evolved on several occasions from PRSV-W populations.
番木瓜环斑病毒（PRSV）是一种马铃薯Y病毒，在热带和亚热带地区均有发现。其P生物型是番木瓜作物的毁灭性病原体，W生物型则危害葫芦科作物。人们认为PRSV-P是由PRSV-W突变产生的。然而，突变和病毒传播对PRSV群体结构的相对影响尚未得到充分描述。为了研究这一问题，我们测定了来自越南（50个）、泰国（13个）、印度（1个）和菲律宾（1个）的PRSV两种生物型分离株的外壳蛋白序列，并将其与已发表的28个PRSV序列一起进行分析，以便更好地了解PRSV的分子流行病学和进化情况。在泰国，PRSV-W分离株之间的变异（平均核苷酸差异7.6%）大于PRSV-P分离株（平均2.6%），但在越南群体中，P和W生物型的多样性更高且相似。对PRSV及其已知关系最近的病毒——摩洛哥西瓜花叶病毒进行的系统发育分析表明，PRSV可能起源于亚洲，特别是印度次大陆，因为那里的PRSV群体最为多样，因此可能存在的时间最长。我们的分析表明，突变以及本地和远距离传播共同导致了群体变异，同时也证实了先前的一个结论，即PRSV-P生物型群体曾多次从PRSV-W群体进化而来。
