水杨酸诱导黄瓜生长及对白粉病的防效

Effect of salicylic acid on growth promotion of cucumber and control of powdery mildew

水杨酸是一种公认的系统获得抗性化学诱导剂。为明确其对黄瓜生长及黄瓜白粉病的控制作用,采用0.5~1.0 mmol·L^(-1)的水杨酸处理种子,结果发现其可显著提高黄瓜种子的萌发率和胚根胚芽长。叶面喷施4~5叶期黄瓜苗,以0.5~1.0 mmol·L^(-1)水杨酸液对黄瓜的促生效果最好,株高、根长、鲜质量、干质量和叶绿素值最高分别比对照提高了26.65%、5.70%、22.06%、18.87%和1.64%;高浓度(>0.5 mmol·L^(-1))水杨酸对黄瓜白粉病菌孢子萌发有抑制作用,当水杨酸浓度达到10 mmol·L^(-1)时,对孢子萌发的抑制率近50%;以1.0 mmol·L^(-1)水杨酸配合生物源物质或生防菌剂施用,对黄瓜白粉病的防效分别最高可达65.24%和71.92%。

Salicylic acid,an acknowledged chemical inducer for systemic acquisition resistance,can promote the growth of cucumber and shows better control effect on powdery mildew.When the cucumber seeds were treated with 0.5-1.0 mmol·L^(-1) of salicylic acid,the germination rate and elongation of the radicle and germ of them were improved.The plant height,root length,fresh weight,dry weight,and chlorophyll content increased after the cucumber plants,at 4-5 foliar stage,being sprayed with the same content of salicylic acid as above,and the rates of improvement were 26.65%,5.70%,22.06%,18.87%,and 1.64%,respectively,compared with the control group.Salicylic acid with concentration higher than 0.5 mmol·L^(-1) could inhibit the conidial germination of Sphaerotheca fuliginea,the pathogen of cucumber powdery mildew,and the inhibitory rate was nearly 50%when the concentration of salicylic acid reached 10 mmol·L^(-1).The better control effect on cucumber powdery mildew was found when 1.0 mmol·L^(-1) of salicylic acid combined with the biogenic materials or bio-control agents,and the best control effect was up to 65.24%and 71.92%,respectively.