Hong J S, Masuta C, Nakano M, Abe J, Uyeda I
Graduate School of Agriculture, Hokkaido University, Kita-ku, kita 9, nishi 9, Sapporo 060-8589, Japan.
Theor Appl Genet. 2003 Jun;107(1):49-53. doi: 10.1007/s00122-003-1222-3. Epub 2003 Mar 25.
Cucumber mosaic virus soybean strains formerly called soybean stunt virus (SSV) were inoculated onto 23 wild soybeans collected from four Asian countries to investigate their infectivity in order to improve understanding of the co-evolution of SSVs and soybean. SSV inoculation resulted in systemic infection in most of the wild soybeans used. However, an SSV strain (SSV-In), which was isolated in Indonesia, did not result in systemic infection of many of the wild soybeans distributed in southern Japan. This exceptional infectivity of SSV-In may be due to its specific adaptation to the local soybean population(s) of Indonesia, which has rarely been affected by gene flows from wild soybean. In the present study, the nucleotide sequences of the 3a and CP genes of SSV were determined, and the data were used to classify seven SSV isolates among known Cucumber mosaic virus (CMV) strains. The phylogenetic analysis showed that the seven SSVs formed a distinct cluster separated from the other CMV strains despite their different geographical origins; SSV-In was the most divergent of the seven isolates. Comparison of the rates of synonymous and nonsynonymous substitutions revealed that the SSV group had evolved faster than subgroup IA. The implications of the findings are discussed in relation to the so-called Red Queen hypothesis.
将以前称为大豆矮化病毒（SSV）的黄瓜花叶病毒大豆株系接种到从四个亚洲国家收集的23份野生大豆上，以研究它们的感染性，从而增进对SSV与大豆共同进化的理解。接种SSV导致大多数所用野生大豆发生系统感染。然而，在印度尼西亚分离得到的一个SSV株系（SSV-In），并未使分布在日本南部的许多野生大豆发生系统感染。SSV-In这种特殊的感染性可能是由于其对印度尼西亚当地大豆群体的特异性适应，而当地大豆群体很少受到来自野生大豆的基因流影响。在本研究中，测定了SSV的3a和CP基因的核苷酸序列，并将这些数据用于在已知黄瓜花叶病毒（CMV）株系中对七个SSV分离物进行分类。系统发育分析表明，尽管这七个SSV地理来源不同，但它们形成了一个与其他CMV株系分开的独特聚类；SSV-In是这七个分离物中差异最大的。同义替换率和非同义替换率的比较表明，SSV组的进化速度比IA亚组快。结合所谓的红皇后假说对这些发现的意义进行了讨论。
