Growth of fraxinus uhdei inoculated with two ectomicorrhyzic strains in two substrates, one polluted with mercury

Abstract

Mining is one of the most important industrial activities in many countries; however, environmental damages associated with this activity are severely detrimental. These effects are a consequence, among other things, of heavy metals originated by mineral extraction methods. To reduce the environmental impact of this activity, it is important to develop remediation technologies, including the symbiotic relationships between species that allow high survival and proper development of plants. Therefore, a me-socosm assay was carried out to document the response of Fraxinus uhdei (Wenz.) Lingelsh (ash) inoculated with ectomycorrhizal fungi on two different substrates: a mine-derived substrate from the municipality of Tlalpujahua de Rayón, Michoacán, and an organic one. The study consisted in the inoculation of F. uhdei plants with two fungi strains, Laccaria laccata and Lactarius deliciosus, on two doses: 2.5 × 105 and 1 × 106 spores per plant. Ectomycorrhizal fungi favored the development and survival in both substrates; however, the performance of the plants was higher with the organic substrate. Height, cover, and fresh weight of plants inoculated with Laccaria laccata were the highest (66 cm, 1186 cm2, and 92 g, respectively). Mercury was lower in plants inoculated with Lactarius deliciosus (F(1, 28) = 12.22; P = 0.002) with respect to those inoculated with Laccaria laccata. Our results indicate that inoculation has a positive effect on ash growth both in an organic rich substrate and a substrate produced by mining activities, also the potential use of the tree species for remediation of mining dumps.