Significance of mycorrhizal associations for the performance of N2-fixing Black Locust (Robinia pseudoacacia L.)

Black Locust (Robinia pseudoacacia L.) is a woody legume with a worldwide distribution. Its ecological and economical importance is largely due to fast growth and dinitrogen (N-2)-fixation ability with rhizobia. These features make Black Locust suitable as a model species for other woody legumes as well. However, its symbiotic association with mycorrhizal fungi has not gained much attention. The small body of literature published indicates that this mycorrhizal association interacts with symbiotic N-2-fixation, greatly enhancing the ecological and physiological performance of Black Locust by improving its rate of growth, nutrition status and resistance to stress conditions, such as drought and salt and heavy metal accumulation. Here we summarize the current knowledge on the benefits of the association of Black Locust with arbuscular mycorrhizal fungi with the aim of providing future research directions on how this symbiotic partnership is involved in a tripartite symbiotic association including rhizobia. This association is of particular importance considering both the invasive nature of Black Locust, its economic and cultural importance and its use in restoration of degraded or contaminated landscapes.