Effects of Exogenous Silicon on Germination Characteristics of Cucumber Seeds under NaHCO3 Stress

The germination characteristics of cucumber seeds were determined after treatments of as follows: (1) the control (CK): distilled water; (2) Na: 70 mmol•L-1 NaHCO3; (3) S1 + Na: 0.01 mmol•L-1 silicon + 70 mmol•L-1 NaHCO3; (4) S2 + Na: 0.1 mmol•L-1 silicon + 70 mmol•L-1 NaHCO3. The results showed that the germination rate, germination potential, germination index, growing vigor index, the length of taproot, number of fist later root, the length of hypocotyledonary axis and fresh weight of cucumber under NaHCO3 stress were decreased significantly, while those above indexes were markedly improved when the right exogenous silicon concentration was added, compared to those under NaHCO3 stress, which suggested that exogenous silicon enhanced cucumber seeds salinity tolerance. The result of subordination function showed that exogenous silicon had promoted the seeds germination under NaHCO3 stress and the 0.01 mmol•L-1 silicon concentration was the better treatment concentration in this study.