Effect of Nitric Oxide on Seed Germination and Seedlings Development of Carrot under Water Deficit

Seed germination is strongly influenced by water deficit. Reduction of the osmotic potential and, consequently, of the water availability decreases the percentage of normal seedlings. It has been reported that nitric oxide (NO) is efficient in stimulating germination under both normal and stress conditions. The present work aims to evaluate the effect of exogenous application of NO, through a donor (SNP), on seed germination and on the development of carrot seedlings under water stress. Seeds of carrot cv. "Brasília" were submitted to water stress by PEG 6000, -0.3 MPa, and to SNP applications in the following concentrations: 100, 200 and 300 μM. The germinative assay was conducted at 20°C in germinator for 14 days. The first germination count (FGC), total germination (G), germination speed index (GSI), and dry matter of normal seedlings were evaluated. The SNP positively affected the germination and development of carrot seedlings under water stress. The most efficient concentration was observed at 100 μM.