水杨酸和壳聚糖诱导苹果叶片对斑点落叶病抗性的研究

摘要

采用喷雾接种的方法测定了不同浓度的水杨酸和壳聚糖对苹果斑点落叶病菌(Alternaria mali Roberts)的室内抑菌作用、诱导抗病效果及诱导苹果叶片后各种抗病性物质含量的变化.结果表明,不同浓度的水杨酸和壳聚糖对A.mali均无明显的抑制作用,其中100μ g/mL的水杨酸和500 μg/mL的壳聚糖对A.mali的抑制率较低,仅为5.33％和4.73％,但诱导抗病效果较显著,分别达到70.90％和77.77％.两种药剂诱导叶片后,叶片中POD、PAL活性以及木质素积累量明显高于对照,且随时间的增长,POD和PAL酶活性先升高后降低,在第3天,POD和PAL酶活性均达到峰值；而壳聚糖诱导后PPO活性随时间的增长呈升高的趋势,但水杨酸对PPO酶活性变化的影响较小.%The inhibitory and resistant effects of apple leaves against Alternaria mali Roberts,and the contents of disease-resistant substances were determined by induction using different concentrations of salicylic acid and chitosan through spraying method in this study.The results showed that different concentrations of salicylic acid and chitosan had no significant inhibitory effects against A.mali.The concentrations of 100 μ g/mL (salicylic acid) and 500 μg/mL (chitosan) had lower inhibition effects,and the inhibition rates were only 5.33％ and 4.73％,respectively.But the induced-resistance effects were stronger,which were 70.90％ and 77.77％,respectively.The activities of POD and PAL,and the content of lignin were significantly higher than the control,and with the increase of time,the POD and PAL activities increased at first and then decreased,and the maximum activities of the two enzymes were observed 3 days after induction.The activity of PPO had an increasing trend with the increase of induction time by chitosan,whereas the effect of salicylic acid on PPO activity was not significant.