Phytochrome-Dependent Regulation of Melon Resistance to Fusarium Wilt

Abstract

The effect of pre-sowing seed treatment with light in the red spectral region on the resistance of melon plants (Cucumis melo) of the cultivar Kichkintoy to Fusarium wilt damage caused by Fusarium oxysporum f. sp. melonis was investigated. The directly-opposite effects of red and far red light on the degree of plant damage by the pathogen, which was determined by the special symptoms of the disease on the leaves and stems of plants, were revealed. When alternating seed treatment with red and far red light, the final effect was determined by the type of irradiation that acted last. The results of photobiological testing made it possible to establish the participation of the phytochrome system in the control of the resistance of melon plants of the cv. Kichkintoy to Fusarium wilt. It is shown that there is a high positive correlation between the parameters of chlorophyll fluorescence induction of leaves reflecting the functional activity of the photosynthetic apparatus and the degree of damage to plants grown from non-irradiated seeds and seeds irradiated with red light. The results of the conducted studies establish the possibility of effective regulation of the resistance of the melon cv. Kichkintoy to the defeat of F. oxysporum f. sp. melonis through photoactivation of the phytochrome system of seeds before sowing.