Data_Sheet_1_The Effect of Strain Level Diversity on Robust Inference of Virus-Induced Mortality of Phytoplankton.PDF

Infection and lysis of phytoplankton by viruses affects population dynamics and nutrient cycles within oceanic microbial communities. However, estimating the quantitative rates of viral-induced lysis remains challenging in situ. The modified dilution method is the most commonly utilized empirical approach to estimate virus-induced killing rates of phytoplankton. The lysis rate estimates of the modified dilution method are based on models which assume virus-host interactions can be represented by a single virus and a single host population with homogeneous life-history traits. Here, using modeling approaches, we examine the robustness of the modified dilution method in multi-strain, complex communities. We assume that strains differ in their life history traits, including growth rates (of hosts) and lysis rates (by viruses). We show that trait differences affect resulting experimental dynamics such that lysis rates measured using the modified dilution method may be driven by the fastest replicating strains; which are not necessarily the most abundant in situ. We discuss the implications of using the modified dilution method and alternative dilution-based approaches for estimating viral-induced lysis rates in marine microbial communities.

病毒侵染并裂解浮游植物的过程，会对海洋微生物群落内的种群动态与营养循环产生影响。然而，原位定量估算病毒诱导的浮游植物裂解速率仍面临诸多挑战。改良稀释法（modified dilution method）是当前估算浮游植物病毒诱导致死速率最常用的经验性研究手段。该方法的裂解速率估算基于一类模型，这类模型假设病毒-宿主相互作用可通过单一病毒与单一宿主种群进行表征，且二者具备均一的生活史特征。本研究借助建模方法，探究了多菌株复杂群落环境下改良稀释法的稳健性。研究假设不同菌株的生活史特征存在差异，具体包括宿主的生长速率与病毒介导的裂解速率。研究结果表明，生活史特征的差异会改变实验动态，使得通过改良稀释法测得的裂解速率可能由复制速率最快的菌株主导，而此类菌株未必是原位丰度最高的种群。我们还探讨了在海洋微生物群落中，采用改良稀释法及其他基于稀释的替代方法估算病毒诱导裂解速率的相关应用意义。