外源水杨酸(SA)对不结球白菜根肿病的抗性诱导效应

Effect of exogenous salicylic acid on seedling growth and clubroot resistance in pak-choi(Brassic campestris ssp. chinensis Makino)

以不结球白菜‘新矮青'为试材,在种子、子叶期、一叶一心期、三叶一心期灌施外源水杨酸(SA),研究0.2—0.8 mmol/LSA对不结球白菜植株根肿病发病和感病植株生长的影响,探讨外源SA防治不结球白菜根肿病的可行性。结果表明:适宜浓度的外源SA能够不同程度降低根肿病的发病率和病情指数,缓解感病不结球白菜生长的抑制作用。不同处理时期均存在剂量效应,种子、子叶期、一叶一心期、三叶一心期的最佳SA处理浓度分别为0.8 mmol/L、0.4 mmol/1、0.6 mmol/L、0.6 mmol/L。综合分析各处理组合下植株发病情况和感病植株生长情况,认为一叶一心期0.6 mmol/LSA对不结球白菜根肿病的抑制效果最好。

The seeds and plants of cotyledon, one-leaf stage, three-leaf stage were treated with 0.2--0. 8 mmol/L exogenous salicylic acid（SA） to study the effect of SA on the clubfoot incidence of pak-choi and thegrowth of infected plant, and evaluate the feasibility of exogenous SA on the prevention and control of clubroot,taking pak-choi variety ＇ Xin＇aiqin＇ as material. The results showed that the appropriate concentration ofexogenous SA can reduce the clubfoot incidence and disease index, and relieve the growth inhibition of pak-choi.There were dose effect of different treatment period, the optimal SA concentrations in seed, cotyledon, one-leafstage,three-leaf stage were 0.8 mmol/L, 0.4 mmol/L, 0.6 mmol/L, 0.6 mmol/L respectively. Comprehensiveanalysis of the clubfoot incidence and infected plants growth indicated that the best inhibitory effect on pak-choiclubfoot is 0.6 mmol/L SA at one-leaf stage.