Effects of Exogenous Hydrogen Peroxide 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
NaHCO
₃
; (3) H
₁
+ Na: 0.001 mmol·L
^-1
H
₂
O
₂
+ 70 mmol·L
^-1
NaHCO
₃
; (4) H
₂
+ Na: 0.01 mmol·L
^-1
H
₂
O
₂
+ 70 mmol·L
^-1
NaHCO
₃
. 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 NaHCO
₃
stress were decreased significantly, while these above indexes were markedly improved when exogenous H
₂
O
₂
was added, compared to those under NaHCO
₃
stress, which suggested that exogenous H
₂
O
₂
enhanced cucumber seeds salinity tolerance. The result of subordination function showed that exogenous H
₂
O
₂
had promoted the seeds germination under NaHCO
₃
stress and the 0.001 mmol·L
^-1
H
₂
O
₂
concentration was the better treatment concentration in this study.