Morphological and physiological responses of Coccoloba uvifera (L.) L. seedlings of different origin to salt stress

The salinity of soils and water for irrigation is a limitation that influences the productivity of crops that has increased worldwide and affects the morphology and physiology of plants since it causes osmotic stress and ionic toxicity and impairs the absorption of water and nutrients. The effect of salt stress on some morphological and physiological traits in Coccoloba uvifera (L.) L. (sea grape) seedlings from different origins was evaluated and the traits whose behavior under salt stress could be used as an effective criterion of tolerance to salinity were determined. A completely randomized design experiment with ten repetitions was performed. The factors under study were salinity (0, 5, 15, and 25 dS m-1), which was maintained for a period of sixteen weeks, and the second factor was the origin of the plant material. The salinity level and the seedlings’ origin significantly influenced the morphological and physiological variables controlled. However, it is necessary to carry out in situ experiments to obtain more information related to the mechanisms used by sea grape to tolerate salinity conditions, because in the consulted sources no research focused on evaluating the effect of salinity and the origin on the morphology and physiology of C. uvifera seedlings in Cuba has been found. The results of the research provide preliminary information to understand the negative effect of salt stress on this type of plant. The behavior of some controlled traits under salt stress can be used as an effective criterion of tolerance to salinity

Mycorrhiza in Tropical and Neotropical Ecosystems

Mycorrhizal symbiosis is a mutualistic association of plant roots and fungi that plays a major role in ecosystem function and diversification, as well as its stability and productivity. It also plays a key role in the biology and ecology of forest trees, affecting growth, water and nutrient absorption and protection against soil-borne pathogens. However, the mycorrhizal research in tropical and neotropical ecosystems remains largely unexplored despite its importance in tropical and neotropical ecosystems. These ecosystems represent more than 0.6% of the total land ecosystems and they have a crucial role in the Earth’s biogeochemical cycling and climate. Threats to tropical forest biodiversity should therefore encourage investigations and inventories of mycorrhizal diversity, function and ecology in tropical latitudes because they concern ecologically and economically important plant species. This Research Topic aims to provide an overview of the knowledge of mycorrhizal symbioses in tropical and neotropical ecosystems. For this Research Topic, we welcome articles that address the diversity, ecology and function of mycorrhiza associated with plants, the impacts of mycorrhiza on plant diversity and composition, the regeneration and dynamics of ecosystems, and biomass production in ecosystems

Genetic diversity and functional traits of <em>Pterocarpus officinalis</em> Jacq. associated with symbiotic microbial communities in Caribbean swamp forests in relation to insular distribution, salinity and flooding

International audiencePterocarpus officinalis is a significant component of the Caribbean wetland plant community. Currently, stands are growing near their physiological extreme, thus it is very important to understand the biology of the species to develop effective conservation strategies and plans. The intra-specific diversity of P. officinalis has been analyzed at different spatial scales, from the continental to the insular Caribbean areas, by using AFLP, chloroplast and nuclear microsatellites, cpDNA, and nrITS markers. The genetic diversity of P. officinalis was higher from continental than from island populations. A similar pattern of genetic diversity resulted from Bradyrhizobial strains isolated from P. officinalis nodules. Bradyrhizobial strains associated with P. officinalis have positive effects on nodulation, N-acquisition, and plant growth. Pterocarpus officinalis is not a halophyte plant. However, it grew better in flooding due to the lenticels, adventitious roots, and aerenchyma that promote root colonization by arbuscular mycorrhizal fungi (AMF) and N-fixing root-nodular bacteria. Furthermore, arbuscular mycorrhizal colonization and nodulation improve flooding tolerance in P. officinalis seedlings. The ecological, demographic, genetic, and physiological data that have been collected through the Caribbean populations of P. officinalis in combination with data from its associated microorganisms are providing the framework to develop better restoration efforts for the species