Effects Of Salicylic Acid On Resistance To Rhizomania In Sugarbeet

The resistant and susceptible to Rhizomania varieties of sugar beet were treated with different concentration of salicylic acid (SA), including soaking seeds and spraying on leaves. From the point of view of defence enzymes activities and related physiological characteristics, the effects of salicylic acid on the resistance to Rhizomania in sugar beet were studied in this research. The results showed that treatments with SA increased the peroxidase(POD),polyphenol oxidase(PPO), phenylalanine ammonia lyase( PAL) and superoxide dismutase (SOD) activities and soluble protein, soluble sugar contents, and reduced contents of superoxide anion radical and malondialdehyde(MDA). Moreover, the disease index of Rhizomania fell and yield,percentage of sugar and sugar yield increased. It is also showed that treatments with SA had a role in resistance to Rhizomania in sugar beet. By comparison, following conclusions were come to that the effects of treatments with SA on the susceptible variety were better than on the resistant one. Treatments of soaking seeds excelled spraying on leaves, and within the limit of the concentration, the optimum concentration to the resistant variety was 3mmol?L-1 and to the susceptible one was 5mmol?L-1.