Departamento de Biología Vegetal y Ecología, Facultad de Ciencia y Tecnología, Universidad del País Vasco, UPV/EHU, Apdo. 644, E-48080, Bilbao, Spain.
Departamento de Biología Vegetal y Ecología, Facultad de Farmacia, Universidad del País Vasco, UPV/EHU, Pº de la Universidad 7, 01006, Vitoria-Gasteiz, Spain.
J Plant Physiol. 2020 Nov;254:153284. doi: 10.1016/j.jplph.2020.153284. Epub 2020 Sep 19.
The response of plant species to external factors depends partly on the interaction with the environment and with the other species that coexist in the same ecosystem. Several studies have investigated the main traits that determine the competitive capacity of plant species, and although the relevance of the traits is not clear, traits both from belowground and aboveground have been observed. In this paper, we grew Trifolium pratense and Agrostis capillaris in intra- and interspecific competition, analyzing the photosynthetic metabolism and nitrogen uptake, among other variables. The results indicated that T. pratense possesses better competition ability due to the higher competitive performance for soil resources compared to A. capillaris, explained by a higher root biomass and a higher nitrogen uptake rate in the former than in the latter. These traits permitted T. pratense to show higher photosynthetic rate than A. capillaris when both species were grown in mixture. Furthermore, the interspecific competition provoked A. capillaris to activate its antioxidant metabolism, through SOD activity, to detoxify the reactive oxygen species generated due to its lower capacity for using the photochemical energy absorbed. In this experiment, we conclude that the competitiveness seems to be more related with soil resources competition than with light competition, and that the photosynthetic rate decline in A. capillaris is more a secondary effect as a consequence of nitrogen limitation.
植物物种对外部因素的反应部分取决于与环境的相互作用以及与同一生态系统中共存的其他物种的相互作用。有几项研究调查了决定植物物种竞争能力的主要特征，尽管特征的相关性尚不清楚，但已经观察到来自地下和地上的特征。在本文中，我们在种内和种间竞争中种植了三叶草和羊茅，分析了光合作用代谢和氮吸收等变量。结果表明，由于与羊茅相比，三叶草对土壤资源具有更高的竞争能力，因此具有更好的竞争能力，这可以通过前者的根生物量和氮吸收速率高于后者来解释。这些特征使得三叶草在两种物种混合生长时表现出比羊茅更高的光合速率。此外，种间竞争促使羊茅通过 SOD 活性激活其抗氧化代谢，以清除由于其利用吸收的光化学能的能力较低而产生的活性氧。在这个实验中，我们得出结论，竞争力似乎与土壤资源竞争有关，而不是与光竞争有关，羊茅的光合速率下降更多是氮限制的次生效应。
