LGEI, Ecole des Mines d'Alès, Institut Mines-Telecom et Université de Montpellier Sud de France, 6 Avenue de Clavières, 30319 Alès, France.
Natural Plant Protection, Arysta LifeScience group, Avenue Léon Blum, 64000 Pau, France.
Viruses. 2019 Jul 5;11(7):621. doi: 10.3390/v11070621.
To test the importance of the host genotype in maintaining virus genetic diversity, five experimental populations were constructed by mixing two granulovirus isolates, the Mexican isolate CpGV-M and the CpGV-R5, in ratios of 99% M + 1% R, 95% M + 5% R, 90% M + 10% R, 50% M + 50% R, and 10% M + 90% R. CpGV-M and CpGV-R5 differ in their ability to replicate in codling moth larvae carrying the type I resistance. This ability is associated with a genetic marker located in the virus gene. Six successive cycles of replication were carried out with each virus population on a fully-permissive codling moth colony (CpNPP), as well as on a host colony (R) that carries the type I resistance, and thus blocks CpGV-M replication. The infectivity of offspring viruses was tested on both hosts. Replication on the CpNPP leads to virus lineages preserving the markers characteristic of both isolates, while replication on the R colony drastically reduces the frequency of the CpGV-M marker. Virus progeny obtained after replication on CpNPP show consistently higher pathogenicity than that of progeny viruses obtained by replication on R, independently of the host used for testing.
为了检验宿主基因型在维持病毒遗传多样性方面的重要性，我们构建了五个实验种群，方法是按 99% M+1% R、95% M+5% R、90% M+10% R、50% M+50% R 和 10% M+90% R 的比例混合两种颗粒体病毒分离株，即墨西哥分离株 CpGV-M 和 CpGV-R5。CpGV-M 和 CpGV-R5 在携带 I 型抗性的天幕毛虫幼虫体内的复制能力存在差异，这种能力与位于病毒基因中的一个遗传标记有关。我们在一个完全允许天幕毛虫取食的天幕毛虫种群（CpNPP）和一个携带 I 型抗性的宿主种群（R）上，对每个病毒种群进行了六轮连续复制实验，R 种群能够阻止 CpGV-M 的复制。我们对亲代病毒的后代在两种宿主上的感染性进行了测试。在 CpNPP 上的复制会导致病毒谱系保留两个分离株各自特有的标记，而在 R 种群上的复制则会大大降低 CpGV-M 标记的频率。在 CpNPP 上复制得到的病毒后代，其致病性始终高于在 R 上复制得到的后代病毒，而与用于测试的宿主无关。
