PHENOTYPE MATCHING IN WILD PARSNIP AND PARSNIP WEBWORMS: CAUSES AND CONSEQUENCES
PHENOTYPE MATCHING IN WILD PARSNIP AND PARSNIP WEBWORMS: CAUSES AND CONSEQUENCES
复制标题
野生防风草和防风草网虫的表型匹配：原因和后果
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
M. Berenbaum
中科院分区：
文献类型：
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作者：
A. Zangerl;M. Berenbaum
摘要根据共同进化的地理镶嵌理论，选择强度的相互作用在不同的景观，形成一个选择镶嵌;相互作用的特点匹配在共同进化的热点，选择是互惠和不匹配的冷点，互惠不是一个因素。化学性状在野生欧防风与欧防风卷叶蛾的互作中起着重要作用。作为植物防御产生的呋喃香豆素通过细胞色素P450单加氧酶被蜘蛛解毒;植物中的呋喃香豆素生产和昆虫中的解毒都存在显著的加性遗传变异，使得这些性状可用于选择。为了检验这一假设，即选择强度的差异影响这种相互作用的共同进化的热点和冷点的分布，我们研究了20个人口的Webworms和野生防风草在伊利诺伊州和威斯康星州，不同的大小，范围的侵扰，接近树林（和潜在的脊椎动物捕食者），接近化学不同的替代宿主植物，Heracalanatum（欧洲防风草）。20个群体中有12个群体表现出植物防御和昆虫解毒谱之间的表型匹配。在8个不匹配的群体中，Logistic回归模型将匹配概率与两个预测因子相关：替代宿主的存在和黄毒素（由P. sativa产生的五种呋喃香豆素之一）的平均含量。错配的几率显着增加的存在下，替代主机（比值比= 15.4）和增加黄毒素含量（比值比= 6.053）。欧防风生长在牛欧防风附近显示出化学表型，化学中间牛欧防风和欧防风隔离生长。在这个系统中的快速表型匹配可能部分是由于每个季节的差异死亡率;幼虫转移到植物30米或更长的植物上，他们开发往往会遇到增加死亡率的幼虫转移到另一个伞形花序上同一植物上，他们已经开发，和植物种群，在2001年不匹配显示了化学表型分布的变化，从前一年。通过基因流的性状混合也是决定错配频率的一个可能因素。前一年消灭了网虫的种群全部被消灭;在这些种群中的七分之三，感染率超过90%。我们的研究结果，与地理镶嵌理论相一致，表明化学上不同的替代寄主植物的存在可以影响选择强度，以这样一种方式，以减少互惠的可能性野生防风草和防风草webworm之间的共同进化的相互作用。
Abstract According to the geographic mosaic theory of coevolution, selection intensity in interactions varies across a landscape, forming a selection mosaic; interaction traits match at coevolutionary hotspots where selection is reciprocal and mismatch at coldspots where reciprocity is not a factor. Chemical traits play an important role in the interaction between wild parsnip (Pastinaca sativa) and the parsnip webworm (Depressaria pastinacella). Furanocoumarins, produced as plant defenses, are detoxified by the webworms by cytochrome P450 monooxygenases; significant additive genetic variation exists for both furanocoumarin production in the plant and detoxification in the insect, making these traits available for selection. To test the hypothesis that differences in selection intensity affect the distribution of coevolutionary hotspots and coldspots in this interaction, we examined 20 populations of webworms and wild parsnips in Illinois and Wisconsin that varied in size, extent of infestation, proximity to woods (and potential vertebrate predators), and proximity to a chemically distinct alternate host plant, Heracleum lanatum (cow parsnip). Twelve of 20 populations displayed phenotype matching between plant defense and insect detoxification profiles. Of the eight mismatched populations, a logistic regression model related matching probability to two predictors: the presence of the alternate host and average content of xanthotoxin (one of the five furanocoumarins produced by P. sativa). The odds of mismatching were significantly increased by the presence of the alternate host (odds ratio = 15.4) and by increased xanthotoxin content (odds ratio = 6.053). Parsnips growing near cow parsnip displayed chemical phenotypes that were chemically intermediate between cow parsnip and parsnips growing in isolation. Rapid phenotype matching in this system is likely due in part to differential mortality every season; larvae transferred to a plant 30 m or more from the plant on which they developed tended to experience increased mortality over larvae transferred to another umbel on the same plant on which they had developed, and plant populations that mismatched in 2001 displayed a change in chemical phenotype distribution from the previous year. Trait mixing through gene flow is also a likely factor in determining mismatch frequency. Populations from which webworms were eradicated the previous year were all recolonized; in three of seven of these populations, infestation rates exceeded 90%. Our findings, consistent with the geographic mosaic theory, suggest that the presence of a chemically distinct alternate host plant can affect selection intensity in such a way as to reduce the likelihood of reciprocity in the coevolutionary interaction between wild parsnip and the parsnip webworm.