Arbuscular mycorrhizal fungi alter plant interspecific interaction under nitrogen fertilization

Abstract

Plant symbionts, such as arbuscular mycorrhizal fungi (AMF), serve as an effective substitute for root surface. As mycorrhizal benefits are related to plant nutrient uptake and are therefore likely to influence plant competition. In this study, the competitive interactions between mycorrhizal (+AMF) and non-mycorrhizal (–AMF) individuals of legume Vicia faba L. and grass Hordeum vulgare L. were studied by conducting a glasshouse experiment. Two fertilization treatments (N0 and N15) were used to simulate nutritional differences over the competitive interactions. Plant biomass, nutrient acquisition and competitive strength of legume and grass were assessed in the different AMF inoculation and N fertilization treatments. The results showed that AMF altered the competitive interactions between the investigated plant species. The growth performance of V. faba, increased when grown with H. vulgare in the presence of +AMF treatment than –AMF. Both plant species showed differential responses to competition in the presence of AMF. Although the V. faba and H. vulgare both benefitted from AMF inoculation when grown solitary, but in competition AMF favored the V. faba. Negative performance was observed in H. vulgare when grew in competition with V. faba under N fertilization, corresponded to more biomass and N uptake in V. faba. These findings help support the idea, that presence of AMF can influence plant competition interaction between co-occurring plant species thus representing the key role of mycorrhizal symbionts to be taken into account for sustainable crop management strategies.