Potassium phosphite affects growth, antioxidant enzymes activity and alleviates disease damage in cucumber plants inoculated with Pythium ultimum

Abstract

In the present study, the impact of potassium phosphite on response of cucumber plants inoculated with Pythium ultimum var. ultimum was assessed. Variations in the accumulation of both antioxidant enzymes and growth parameters were investigated. The results revealed that fresh and dry weights of shoot and root exhibited up to 2 fold increase in potassium phosphite-treated plants. The concentrations of peroxidase, superoxide dismutase and catalase were significantly higher in the plants treated with 4 g L⁻¹ of potassium phosphite compared to other treatments, at 48 h after inoculation. It was demonstrated that both 2 and 4 g L⁻¹ treatments could alleviate the disease damage to a high extent, while control plants were severely damaged by the pathogen. The results of this study suggest that the increased induction of antioxidant enzymes (2.2, 2.8 and 4 fold increase for superoxide dismutase, catalase and peroxidase, respectively) might have alleviated damping-off symptoms leading to increased plant growth and yield.

Keywords:

• Cucumber
• damping off
• antioxidant enzymes
• plant growth, potassium phosphite
• Pythium ultimum

Acknowledgment

We would like to thank Dr A. Sarpelleh (Iranian Research Institute of Plant Protection, Tehran) for the kind provision of Pythium ultimum Inoculum.

Funding

The research was supported by the Genetics and Agricultural Biotechnology Institute of Tabarestan, Sari, Iran [grant number 1].