Variaciones espacio-temporales en la composición y/o abundancia de hongos micorrízicos arbusculares (hma) en táxones vegetales de interés para la reconstrucción dunar

Résumé

Successful arbuscular mycorrhizal fungi (AMF) symbiosis in sand dunes is a key factor for the maintenance of stable vegetation. Therefore, the main goal of this work was to study the AMF species associated with sand dunes in the Gulf of Valencia (Spain), as well as the effects of environmental and temporal factors on these AMF communities. In order to achieve these, soil samples from the rhizosphere of four plant species were seasonally collected at 6 sites during 2 years in three habitats. Frequency and relative abundance of AMF among these samples were examined. Among the ten AMF species identified, only Corymbiglomus corymbiforme and Diversispora aurantia (Diversisporaceae) had been previously described. Populations of these species in these sandy ecosystems displayed higher morphological variability than those originally described having the same macro- and micro-structure of spores. Moreover, regarding the other eight species, D. valentina (Diversisporaceae), Cetraspora sucrosa, Racocetra papillosa and R. sicanica (Gigasporaceae) displayed a phylogenetically unknown position, although all were related to some species of their respective genus. In respect to Scutellospora deformata (Gigasporaceae), it was molecularly related with a strain of Sc. calospora (GenBank FJ461865.1), however, it was less related with the type material of this species (GenBank AJ510231.1). Consequently, we suggest that material of this strain (GenBank FJ461865.1) should be revised. On the other hand, Funneliformis pillosus (Glomeraceae) was related, morphological and molecularly, to F. coronatus. Glomus ibericum (Glomeraceae) was related morphological and molecularly with G. aggregatum and G. macrocarpum. Finally, Septoglomus mediterraneum (Glomeraceae) was molecularly related with S. jasnowskae and morphologically related to S. turnauae, S. constrictum, S. furcatum and S. titan. Furthermore, pure cultures of F. pillosus, S. mediterraneum, Co. corymbiforme, D. aurantia and D. valentina were obtained at the greenhouse. Overall, the distribution of all AMF species found was mainly correlated to the anthropogenic disturbance of the site. Meanwhile, Gigasporaceae C. sucrosa and R. sicanica preferred undisturbed soil; Diversisporaceae, Glomeraceae and the others Gigasporaceae identified were associated to recently restored sand dunes. Although all AMF species were found in all plant species analyzed, interestingly, Co. corymbiforme was mainly associated to Echinophora spinosa. Our results might contribute to improve Mediterranean sand dunes restoration.