Using the ectomycorrhizal symbiosis between Coccoloba uvifera L. and Scleroderma bermudense Coker to restore a degraded coastal sand dune in Cuba

Key message

Scleroderma bermudense improves growth and physiological traits of seagrape exposed to salt stress in planting.

Abstract

In Cuba (The Greater Antilles), Coccoloba uvifera L., (Polygonaceae), an ectomycorrhizal (ECM) fruit tree also called seagrape, is among the earliest plant colonizers of sandy and rocky shores within its natural range, and often grows near the tidal swing zone subject to salinity. Here, we assessed the persistence of pre-inoculation beneficial effects on seagrape seedlings in nursery and planting with Scleroderma bermudense Coker to restore a degraded sand dune of Cuba. While growth of ECM plants versus non-ECM plants was not significant at 2 months in nursery, differences in the growth promotion of ECM seagrape seedlings were improved at 3, 6, 9, and 12 months after planting. Using morphological and molecular analysis of ITS from ectomycorrhizae, it was found that S. bermudense successfully colonized and established in the absence of native ECM fungi on seagrape roots in nursery and field conditions. Consequently, the beneficial effects of the ECM symbiosis on growth and functional traits, such as photosynthetic and transpiration rates, chlorophyll fluorescence and content, stomatal conductance, sub-stomatal CO_2, and water status, resulted in improved growth performance of seagrape exposed to salt stress in planting. This study provided first insight on the use of ECM seagrape to restore degraded coastal ecosystems subject to salty, sandy, nutrient-poor soils in Cuba.