PDF(Sci-hub)
Abstract：
Adapting to specific hosts often involves trade-offs that limit performance on other hosts. These constraints may either lead to narrow host ranges (i.e. specialists, able to exploit only one host type) or wide host ranges often leading to lower performance on each host (i.e. generalists). Here, we combined laboratory experiments on field populations with experimental evolution to investigate the impact of adaptation to the host on host range evolution and associated performance over this range. We used the two-spotted spider mite, Tetranychus urticae, a model organism for studies on the evolution of specialization. Field mite populations were sampled on three host plant species: tomato, citrus tree and rosebay (Nerium oleander). Testing these populations in the laboratory revealed that tomato populations of mites could exploit tomato only, citrus populations could exploit citrus and tomato whereas Nerium populations could exploit all three hosts. Besides, the wider niche ranges of citrus and Nerium populations came at the cost of low performance on their non-native hosts. Experimental lines selected to live on the same three host species exhibited similar patterns of host range and relative performance. This result suggests that adaptation to a new host species may lead to wider host ranges but at the expense of decreased performance on other hosts. We conclude that experimental evolution may reliably inform on evolution in the field.
摘要：
适应特定主机通常涉及权衡，从而限制其他主机的性能。这些限制可能会导致宿主范围狭窄(即专家、能够仅利用一种主机类型）或宽主机范围，通常会导致每个主机（即通才）的性能降低。这里,我们将田间种群的实验室实验与实验进化相结合，以研究对宿主的适应性对宿主范围进化和该范围内相关性能的影响。我们用了两个斑点的蜘蛛螨，荨麻疹,研究专业化进化的模型生物。田间螨种群在三种寄主植物物种上采样：番茄，柑橘树和玫瑰（夹竹桃）。在实验室对这些种群进行测试后发现，螨虫的番茄种群只能利用番茄，柑橘种群可以利用柑橘和番茄，而Nerium种群可以利用所有三个宿主。此外,柑橘和Nerium种群的生态位范围更广，其代价是非本地宿主的低性能。选择生活在相同的三种宿主物种上的实验品系表现出相似的宿主范围和相对性能模式。该结果表明，适应新的宿主物种可能会导致更宽的宿主范围，但会损害其他宿主的性能。我们得出的结论是，实验进化可以可靠地告知该领域的进化。
