Phytopathology. 1999 Feb;89(2):136-40. doi: 10.1094/PHYTO.1999.89.2.136.
ABSTRACT In an earlier study, we demonstrated that isolates of apple stem grooving capillovirus (ASGV) from fruit trees comprise at least two to four sequence variants that differ considerably from each other in nucleotide sequence. In order to characterize the population of sequence variants within a single tree, we applied a combination of an immunocapture reverse transcription-polymerase chain reaction (IC-RT-PCR) and a single-strand conformation polymorphism (SSCP) analysis of a nested asymmetric PCR product. In the SSCP analysis of the PCR products from ASGV-infected apple, Japanese pear, or European pear trees, two to four bands were detected in samples from all trees, indicating that ASGV exists as a mixture of sequence variants. The composition of sequence variants (the number of bands and their relative quantity) differed among leaf samples from different branches, showing that each sequence variant is distributed unevenly within an individual tree. The SSCP analysis of isolates after serial passage in Chenopodium quinoa plants indicated that passages changed the composition of sequence variants originally contained in ASGV isolates; i.e., some sequence variants dominated and others decreased to undetectable levels.
摘要 在早期的研究中，我们证明了来自果树的苹果茎沟潜隐病毒（ASGV）分离株至少包含两到四个序列变体，它们在核苷酸序列上彼此差异很大。为了描述单个树内序列变体的群体，我们应用了免疫捕获反转录聚合酶链反应（IC-RT-PCR）和嵌套不对称 PCR 产物的单链构象多态性（SSCP）分析的组合。在来自感染 ASGV 的苹果树、日本梨树或欧洲梨树的 PCR 产物的 SSCP 分析中，从所有树木的样本中检测到 2 到 4 个条带，表明 ASGV 存在于序列变体的混合物中。序列变体的组成（条带的数量及其相对数量）在来自不同树枝的叶片样本之间存在差异，表明每个序列变体在个体树内分布不均匀。在藜麦植物中的连续传代后对分离株的 SSCP 分析表明，传代改变了 ASGV 分离株中原本包含的序列变体的组成；即，一些序列变体占主导地位，而其他序列变体减少到无法检测的水平。
