Adverse temperature tolerance induction in cabbage seed at germination stage

To investigate adverse temperature tolerance induction in summer and autoumn cabbage, changes in adverse temperature tolerance of pretreated cabbage seeds with different degrees of temperature during germination were investigated. Results show that the optimum germination temperature of cabbage seeds is 20 ℃, and that germination vigor decreases remarkably when seeds germinate under above 35 ℃ or below 15 ℃. Mild pretreatment temperature can greatly improve the germination ability of cabbage seed in high temperatures (35 ℃). Minimum and maximum pretreatment temperatures are 10 ℃ and 30 ℃ respectively, optimal pretreatment time is 8 hours. Pretreatment lower temperatures of 5 ℃ and 10 ℃ improves seed vigor in high temperature (35 ℃)，while pretreatment higher temperatures of 25 ℃ and 30 ℃ adaptation to heat and chilling stress.