The effect of oxalic acid and ultraviolet radiation on rapeseed regenerants resistance to Sclerotinia sclerotiorum

Abstract

Sclerotinia sclerotiorum is an ubiquitous necrotrophic fungal pathogen capable of infecting a wide range of plants. In Brassica napus, the disease manifests itself as stem rot which, under weather conditions conducive to infection, results in severe yield losses. Oxalic acid and ultraviolet radiation were screened for the ability to induce resistance against Sclerotinia sclerotiorum in rapeseed (Brassica napus L.) regenerants cultured in vitro. Explants were cultured on the medium supplemented with different oxalic acid concentration or treated by UV light immediately after isolation. Combination of mentioned factors was investigated also. Exogenous oxalic acid in induction medium significantly increased resistance to S. sclerotiorum in regenerants of four from eight cultivars tested. Pretreatment of explants with ultraviolet radiation for 15 min caused an increase in the resistance to infection. However, UV radiation alone was less effective than the combination of 0.5 mM oxalic acid in induction medium and UV treatment for 15 min.