Genetic variation and population structure of an isolate of Citrus exocortis viroid (CEVd) and of the progenies of two infectious sequence variants
Genetic variation and population structure of an isolate of Citrus exocortis viroid (CEVd) and of the progenies of two infectious sequence variants
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DOI：
10.1007/s00705-005-0570-5
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发表时间：
2005-10-01
影响因子：
2.7
通讯作者：
Duran-Vila, N
中科院分区：
文献类型：
--
作者：
Gandía, M;Rubio, L;Duran-Vila, N
应用单链构象多态性（SSCP）和序列分析技术对柑桔裂皮病类病毒（CEVd）分离物的群体结构和多样性进行了研究。确定了占总人群52.8%的主要序列变异（V1）。V1和其他变体呈现CEVd严重菌株的P结构域特征的组合物。根据中性进化模型，该CEVd群体的核苷酸多样性低于预期，表明存在强烈的负选择。用九种序列变体的二聚体克隆接种香橼植物，其中两种导致感染性，诱导原始分离物的严重症状特征。从这些感染性变体中产生从头群体，并且与原始CEVd分离株相似，两个群体均呈现V1作为主要变体，但它们进化为更高的核苷酸多样性。
The population structure and diversity within a Citrus exocortis viroid (CEVd) isolate was estimated by single strand conformation polymorphism (SSCP) and sequence analysis. A predominant sequence variant (V1) representing 52.8% of the overall population was identified. V1 and other additional variants presented a composition of the P domain characteristic of severe strains of CEVd. The nucleotide diversity of this CEVd population was lower than expected according to a model of neutral evolution, suggesting a strong negative selection. Citron plants were inoculated with dimeric clones of nine sequence variants and two resulted infectious inducing the severe symptoms characteristic of the original isolate. De novo populations were generated from these infectious variants and like in the original CEVd isolate, both populations presented V1 as the predominant variant but they evolved to a higher nucleotide diversity.