Bolin Lana G, Benning John W, Moeller David A
Department of Plant and Microbial Biology University of Minnesota St. Paul Minnesota.
Ecol Evol. 2018 Oct 26;8(22):10743-10753. doi: 10.1002/ece3.4523. eCollection 2018 Nov.
Multispecies interactions can be important to the expression of phenotypes and in determining patterns of individual fitness in nature. Many plants engage in symbiosis with arbuscular mycorrhizal fungi (AMF), but the extent to which AMF modulate other species interactions remains poorly understood. We examined multispecies interactions among plants, AMF, and insect herbivores under drought stress using a greenhouse experiment and herbivore choice assays. The experiment included six populations of (Onagraceae), which span a complex environmental gradient in the Southern Sierra Nevada of California. 's developing fruits are commonly attacked by grasshoppers at the end of the growing season, and the frequency of attack is more common in populations from the range center than range margin. We found that AMF negatively influenced all metrics of plant growth and reproduction across all populations, presumably because plants supplied carbon to AMF but did not benefit substantially from resources potentially supplied by the AMF. The fruits of plants infected with AMF did not differ from those without AMF in their resistance to grasshoppers. There was significant variation among populations in damage from herbivores but did not reflect the center-to-margin pattern of herbivory observed in the field. In sum, our results do not support the view that AMF interactions modulate plant-herbivore interactions in this system.
多物种间的相互作用对于表型的表达以及自然界中个体适合度模式的决定可能具有重要意义。许多植物与丛枝菌根真菌（AMF）形成共生关系，但AMF调节其他物种间相互作用的程度仍知之甚少。我们通过温室实验和食草动物选择试验，研究了干旱胁迫下植物、AMF和食草昆虫之间的多物种相互作用。该实验包括六种柳叶菜科植物的种群，它们分布在加利福尼亚州内华达山脉南部一个复杂的环境梯度中。柳叶菜正在发育的果实通常在生长季节末期受到蚱蜢的攻击，且攻击频率在分布区中心的种群比边缘种群更为常见。我们发现，AMF对所有种群的植物生长和繁殖的各项指标均产生负面影响，推测是因为植物向AMF提供碳，但未从AMF可能提供的资源中获得实质性益处。感染AMF的植物果实与未感染AMF的植物果实在对蚱蜢的抗性方面没有差异。食草动物造成的损害在种群间存在显著差异，但并未反映出在野外观察到的食草作用从中心到边缘的模式。总之，我们的结果不支持AMF相互作用调节该系统中植物 - 食草动物相互作用的观点。
