水杨酸诱导黄瓜抗黑星病抗性的部位差异和时效性

Cucumber leaves at 6 leaves phase, after treated with ρ (SA)/100 mg L -1 for 0, 1, 3, 6 d, were infected by Cladosporium cucumerinum . The results showed that the leaves presented the resistance to Cladosporium cucumerinum . The strongest resistance was found in the leaves pretreated for 3 d. But, the resistance then began to decrease obviously. Even in the same pretreatment time, the resistance reflected differently in different positions of the plant. The resistance was also found in the cucumber leaf from seed pretreated by ρ (SA)/20, 100 mg L -1 . When Cladosporium cucumerinum was cultured in the medium containing SA with different concentrations, no inhibition effect on Cladosporium cucumerinum was observed in the medium with ρ (SA)/ 20, 100 mg L -1 . Only in the medium with ρ (SA)/1000 mg L -1 inhibiting effect could be observed.