壳聚糖与水杨酸复配对小白菜霜霉病与盐胁迫复合逆境的诱抗作用

Role of chitosan and salicylic acid application in induction of Brassica chinensis resistance to dual stress of downy mildew and salt stress

为探明壳聚糖(CTS)和水杨酸(SA)复配处理对小白菜(Brassica chinensis L.)复合逆境的诱抗作用和效果,采用根际施用结合叶面喷洒的方法,研究了CTS与SA复配对小白菜盐和霜霉病胁迫复合逆境的诱抗作用。结果表明:SA、CTS单一与复配施用均能显著降低复合逆境下小白菜的盐害指数和病情指数,提高复合逆境下小白菜的株高、展开叶数、最大叶片面积和单株干质量等形态指标,促进小白菜在复合逆境下的正常生长,降低小白菜叶片的丙二醛(MDA)含量,增强过氧化物酶(POD)、多酚氧化酶(PPO)等保护酶的活性。在复合逆境下,SA、CTS复配施用对小白菜的诱导抗病和抗盐效果显著,盐害指数和病情指数均低于SA、CTS单一处理,且抗病和抗盐的共效系数均分别为-14.76和1.72,均表现为相加作用。

The role of chitosan（CTS） and salicylic acid（SA） compound application in induction of pakchoi（Brassica chinensis L.） resistance to dual stress of downy mildew and salt stress was studied by the method of rhizosphere application with foliar spray.The results showed that both separate and joint application of SA and CTS significantly reduced salt injury index and disease index of pakchoi under the dual stress,increased the plant height,the number of expanding leaves,maximum leaf area,plant dry weight and other morphological indicators,and promoted the normal growth of pakchoi under dual stress,reduced malondialdehyde（MDA） content of leaves,and enhanced peroxidase（POD） and polyphenol oxidase（PPO） activities.The effects of CTS and SA joint application on the induction of resistance against downy mildew or salt stress in pakchoi were significant under the dual stress,with the salt injury index and disease index lower than those of single CTS or SA application.In the treatment of CTS and SA joint application,the coefficients of disease resistance and salt tolerance were-14.76 and 1.72,respectively,indicating additive effect.