Effect of cytokinins on P. granatum cuttings inoculated with Glomus intraradices on drought stress.

BOMPADRE, M.J.; DIVO DE SESAR, M.; RODRÍGUEZ, M.A.; BIDONDO, L.; SILVANI, V.; PÉRGOLA, M.; NAVARRO, L.; GODEAS, A.M.

Rosario, Sante Fe, Argentina

Congreso; XLII Reunión anual. 42th annual meeting; 2006

Socieda Argentina de Investigación en Bioquímica y Biología Molecular

Arbuscular mycorrhizas are mutualistic fungi that colonize roots of mostly plants. In general, this association produces a nutritional improvement (P2, N2 and H2O from microagregates where roots can’t take them) of the host and they exchange photosintates. Cytokinins are vegetal hormones that characteristically retard senescence. Our objective was to evaluate the effect of mycorrhiza in combination with cytokinins and drought stress. Cuttings of Punica granatum were inoculated with Glomus intraradices; half of them received 3 applications from aspersion with a solution of cytokinins (5 mg/ml), each cutting received 0,5 ml per application. A half was well watered whereas the other was watered stressed for 10 days. We measured root colonization, chlorophylls “a”, “b” and totals, total poliphenols, soluble proteins, catalase, ascorbate peroxidase and superoxide dismutase activities. We observed an improvement on the phenolic content, on the chlorophylls “a” and “b” and protein contents in presence of drought stress (independently of the presence or absence of cytokinins) between inoculated and non inoculated cuttings. Inoculated cuttings presented low levels of catalase, superoxide dismutase and ascorbate peroxidase levels on drought stress, whereas the non inoculated ones didn’t. In conclusion, mycorrhizas are important protectors of drought stress in comparisons with cytokinins.