Tolerancia à salinidade em sementes de Senna macranthera (DC. ex Collad.) H. S. Irwin & Barneby com nitroprussiato de sódio (SNP) promovida pelo cianeto

摘要

Studies show the positive effect of the nitric oxide donor in the seed germination process. However, there are no precise reports about which compound present in sodium nitroprusside would cause these effects in seeds under salt stress. The aim of this study was to evaluate the effects of SNP on germination of Senna macranthera seeds under salt stress. The osmotic potentials of -0.3, -0.4, and -0.5 MPa of NaCl were used, as well as the concentration of 100 μM of sodium nitroprusside, inactive sodium nitroprusside, and ferrocyanide. The sodium nitroprusside in germination was applied before, during, and after salt stress. Germination rate, germination speed index, percentage of normal seedlings, and seedling development components were evaluated. The treatments that proved to be more promising in recovery of germination under salt stress are -0.4 MPa together with SNP; -0.4 MPa together with inactive SNP; -0.5 MPa together with SNP and -0.5 MPa together with inactive SNP. Effects similar to those brought about by the sodium nitroprusside treatment were also observed in the treatments with inactive sodium nitroprusside and ferrocyanide, indicating that the effects observed were related to release of the cyanide present in the sodium nitroprusside.