Alvaro Peix¹, Laura Martín-Martín¹, Eustoquio Martínez-Molina¹, Pedro F. Mateos¹, Claudino Rodríguez-Barrueco², Encarna Velázquez¹

Bacteria from Genus Mesorhizobium form symbiosis with legumes, and specifically, M. mediterraneum nodulates chickpea plants. All the bacterial species nodulating plants have been studied for their nitrogen fixing potential, however, some of them are also phosphorous mobilizers in plants. Among all the species that nodulate legumes, species from Mesorhizobium, specially those nodulating chickpea, are the best phosphate solubilizers in vitro. A strain of M. mediterraneum (PECA21) is able to mobilize phosphorous to its natural host(Cicer arietinum), as well as to barley (Hordeum vulgare). Nevertheless, plants with coloured fruits are the most sensitive to P content, and, among them, strawberry has a great commercial importance. In this work strawberry plants were inoculated with strain PECA21 under growth chamber conditions . A sandy soil was used fertilized previously (2 months before) with NPK. Treatments were: Control, soil inoculated with strain PECA21 and soil inoculated with strain PECA21 added with insoluble phosphate. According to the results obtained, an increase in %N was observed, though differences were not statistically significant. However, a statistically significant increase in %P as well as in fruit production was observed in plants inoculated with strain PECA21 added with insoluble phosphate with respect to uninoculated plants. These results are in agreement with those observed in barley and chickpea crops and suggest new ways for the use of rhizobia as biofertilizers in non-legume plants.