Physiological basis of potato drought tolerance induced by azoxystrobin

In this study, three potato cultivars with different drought resistance were used as the testing materials in potted-experiments. Azoxystrobin was used as the ditch treatment chemicals (A) before planting. The group with full irrigation was the control (CK, soil volume water content θ_w: 60%-70%). The drought group was the one with water stress treatment (D, θ_w: 30%-40%). The group (A-D) was treated by both drought and azoxystrobin. The physiological basis of the potato drought tolerance improvement induced by azoxystrobin was investigated by measuring leaf photosynthetic parameters, antioxidant enzyme activities, malondialdehyde (MDA) and proline content, potato yield per plant and tuber quality. The results showed that azoxystrobin could effectively enhance the photosynthetic rate and stomatal conductance of potato leaves. Under full irrigation conditions, application of azoxystrobin could increase the activities of CAT and APX, which played a role in the delay of the senescence of plants. Under drought stress conditions, the accumulation of MDA and proline content in leaves was reduced, resulting in an increase in drought tolerance of plants. Azoxystrobin respectively increased the yields of Qingshu No.9, Longshu No.6 and Atlantic by 30.74%, 59.87% and 5.90%, compared to those of the CK. And A-D treatment respectively increased the yields of Qingshu No.9, Longshu No.6 and Atlantic by 15.17%, 43.43% and 16.49%, compared to those of the D group. In addition, the comprehensive quality scores of A Qingshu No.9, Longshu No.6 and Atlantic respectively were 1.184, 2.856, 0.621, and A-D respectively were −1.112, −0.240, −0.349. It can be seen that azoxystrobin was beneficial to the improvement of potato tubers quality under drought stress.