Pánková Hana, Raabová Jana, Münzbergová Zuzana
Institute of Botany, Academy of Sciences of the Czech Republic, Průhonice, Czech Republic.
Department of Botany, National Museum, Prague, Czech Republic.
PLoS One. 2014 Apr 7;9(4):e93967. doi: 10.1371/journal.pone.0093967. eCollection 2014.
Many plant populations have adapted to local soil conditions. However, the role of arbuscular mycorrhizal fungi is often overlooked in this context. Only a few studies have used reciprocal transplant experiments to study the relationships between soil conditions, mycorrhizal colonisation and plant growth. Furthermore, most of the studies were conducted under controlled greenhouse conditions. However, long-term field experiments can provide more realistic insights into this issue. We conducted a five-year field reciprocal transplant experiment to study the relationships between soil conditions, arbuscular mycorrhizal fungi and plant growth in the obligate mycotrophic herb Aster amellus. We conducted this study in two regions in the Czech Republic that differ significantly in their soil nutrient content, namely Czech Karst (region K) and Ceske Stredohori (region S). Plants that originated from region S had significantly higher mycorrhizal colonisation than plants from region K, indicating that the percentage of mycorrhizal colonisation has a genetic basis. We found no evidence of local adaptation in Aster amellus. Instead, plants from region S outperformed the plants from region K in both target regions. Similarly, plants from region S showed more mycorrhizal colonisation in all cases, which was likely driven by the lower nutrient content in the soil from that region. Thus, plant aboveground biomass and mycorrhizal colonisation exhibited corresponding differences between the two target regions and regions of origin. Higher mycorrhizal colonisation in the plants from region with lower soil nutrient content (region S) in both target regions indicates that mycorrhizal colonisation is an adaptive trait. However, lower aboveground biomass in the plants with lower mycorrhizal colonisation suggests that the plants from region K are in fact maladapted by their low inherent mycorrhizal colonization. We conclude that including mycorrhizal symbiosis in local adaptation studies may increase our understanding of the mechanisms by which plants adapt to their environment.
许多植物种群已适应了当地的土壤条件。然而，在这种情况下，丛枝菌根真菌的作用常常被忽视。只有少数研究采用相互移栽实验来研究土壤条件、菌根定殖与植物生长之间的关系。此外，大多数研究是在可控的温室条件下进行的。然而，长期的田间实验能够为这个问题提供更实际的见解。我们进行了一项为期五年的田间相互移栽实验，以研究专性菌根营养草本植物紫菀（Aster amellus）的土壤条件、丛枝菌根真菌与植物生长之间的关系。我们在捷克共和国的两个地区开展了这项研究，这两个地区的土壤养分含量差异显著，分别是捷克喀斯特地区（K地区）和捷克中央山脉地区（S地区）。源自S地区的植物比源自K地区的植物具有显著更高的菌根定殖率，这表明菌根定殖率具有遗传基础。我们没有发现紫菀存在局部适应性的证据。相反，在两个目标地区，来自S地区的植物都比来自K地区的植物表现更好。同样，在所有情况下，来自S地区的植物都表现出更高的菌根定殖率，这可能是由该地区土壤中较低的养分含量所驱动的。因此，两个目标地区和植物来源地区之间，植物地上生物量和菌根定殖表现出相应的差异。在两个目标地区，土壤养分含量较低地区（S地区）的植物具有更高的菌根定殖率，这表明菌根定殖是一种适应性性状。然而，菌根定殖率较低的植物地上生物量也较低，这表明来自K地区的植物实际上因其低固有菌根定殖率而适应不良。我们得出结论，在局部适应性研究中纳入菌根共生关系，可能会增进我们对植物适应环境机制的理解。
