Department of Biology, University of British Columbia, Okanagan Campus, Kelowna, BC, V1V 1V7, Canada.
Department of Biology, Algoma University, Sault Ste. Marie, ON, P6B 2G4, Canada.
New Phytol. 2017 May;214(3):1330-1337. doi: 10.1111/nph.14465. Epub 2017 Feb 10.
Although arbuscular mycorrhizal (AM) fungi are obligate symbionts that can influence plant growth, the magnitude and direction of these effects are highly variable within fungal genera and even among isolates within species, as well as among plant taxa. To determine whether variability in AM fungal morphology and growth is correlated with AM fungal effects on plant growth, we established a common garden experiment with 56 AM fungal isolates comprising 17 genera and six families growing with three plant host species. Arbuscular mycorrhizal fungal morphology and growth was highly conserved among isolates of the same species and among species within a family. By contrast, plant growth response to fungal inoculation was highly variable, with the majority of variation occurring among different isolates of the same AM fungal species. Our findings show that host performance cannot be predicted from AM fungal morphology and growth traits. Divergent effects on plant growth among isolates within an AM fungal species may be caused by coevolution between co-occurring fungal and plant populations.
尽管丛枝菌根（AM）真菌是专性共生体，可以影响植物生长，但在真菌属内甚至在种内的分离株之间，以及在植物类群之间，这些效应的大小和方向都具有高度的可变性。为了确定 AM 真菌形态和生长的变异性是否与 AM 真菌对植物生长的影响有关，我们用 56 种 AM 真菌分离物进行了一个共同的花园实验，这些分离物包括 17 个属和 6 个科，与三种植物宿主物种一起生长。同种分离物和同一科内的种间的丛枝菌根真菌形态和生长具有高度的保守性。相比之下，植物对真菌接种的生长反应变化很大，大多数变化发生在同一 AM 真菌种的不同分离物之间。我们的研究结果表明，不能根据 AM 真菌形态和生长特征来预测宿主的表现。同一 AM 真菌种内的分离株对植物生长的不同影响可能是由共存的真菌和植物种群之间的共同进化引起的。
