几种化学物质诱导草莓抗根腐病的初步研究

利用叶圆片法对水杨酸(SA)、草酸(OAA)、磷酸氢二钾(K2HPO4)和壳聚糖(CTS)4种化学物质诱导草莓抗根腐病(Pestalotiopsis photiniae(Thuem)Y.X.Chen)的作用进行了研究,并对其机理进行了初步探讨。结果显示,SA在0.5 mmol/L浓度下诱导抗病效果达91.9%,OAA在20 mmol/L浓度下诱导抗病效果达96.4%,K2HPO4和CTS在供试浓度范围内均无诱导抗病作用;4种化学物质中只有CTS有直接抑菌作用,对根腐病菌丝生长的抑制中浓度为1.983 mg/mL,其余3种均无直接抑菌作用;用SA和OAA诱导处理后,草莓叶片中多酚氧化酶(PPO)、过氧化物酶(POD)和苯丙氨酸解氨酶(PAL)的活性变化表明,0.5 mmol/L SA诱导处理草莓叶片POD活性至第1天达到最大值,比对照增加了252.3%,而PPO和PAL活性变化不大;20 mmol/L OAA诱导处理草莓叶片PAL活性至第4天达到最大值,比对照增加了37.8%,而PPO和POD的活性变化不明显。

Effects of several chemicals on induced resistance to root rot of strawberry

Salicylic acid(SA),oxalic acid(OAA),K_2HPO_4 and chitosan(CTS) were used to induce the resistance of strawberry to root-rotting desease,and then the inhibition effect on the mycelium growth of Pestalotiopsis photiniae(Thuem)Y.X.Chen was measured and the activities of polyphenoloxidase(PPO),peroxidase(POD) and phenylalanine ammonialyase(PAL) were studied.Results showed that SA and OAA had no inhibition effect,but had remarkable induction efficiency. Protection efficiency of strawberry,which was treated with SA at 0.5 mmol/L or OAA at 20 mmol/L was 91.9% and 96.4%,respectively.K_2HPO_4 had no inhibition effect and induction efficiency.CTS didn't show induction efficiency,but had remarkable inhibition effect.Its EC_(50) was 1.983 mg/mL.POD activity which was treated with SA at 0.5 mmol/L increased by 252.3%,but PPO and PAL,compared with the control,didn't significantly change.PAL activity which was treated with OAA at 20 mmol/L increased by 37.8%,but POD and PPO had no difference from the control.