In Vitro Evaluation of the Inhibitory Activity of Different Selenium Chemical Forms on the Growth of a Fusarium proliferatum Strain Isolated from Rice Seedlings

In this study, the in vitro effects of different Se concentrations (5, 10, 15, 20, and 100 mg kg(-1)) from different Se forms (sodium selenite, sodium selenate, selenomethionine, and selenocystine) on the development of a Fusarium proliferatum strain isolated from rice were investigated. A concentration-dependent effect was detected. Se reduced fungal growth starting from 10 mg kg(-1) and increasing the concentration (15, 20, and 100 mg kg(-1)) enhanced the inhibitory effect. Se bioactivity was also chemical form dependent. Selenocystine was found to be the most effective at the lowest concentration (5 mg kg(-1)). Complete growth inhibition was observed at 20 mg kg(-1) of Se from selenite, selenomethionine, and selenocystine. Se speciation analysis revealed that fungus was able to change the Se speciation when the lowest Se concentration was applied. Scanning Electron Microscopy showed an alteration of the fungal morphology induced by Se. Considering that the inorganic forms have a higher solubility in water and are cheaper than organic forms, 20 mg kg(-1) of Se from selenite can be suggested as the best combination suitable to inhibit F. proliferatum strain. The addition of low concentrations of Se from selenite to conventional fungicides may be a promising alternative approach for the control of Fusarium species.

Automated summary

This study investigated the in vitro effects of different selenium concentrations and forms on Fusarium proliferatum strain isolated from rice. The results showed that selenium had a concentration-dependent effect on fungal growth, with selenocystine being the most effective at the lowest concentration. Selenium from selenite at 20 mg kg(-1) was found to be the best combination for inhibiting F. proliferatum strain, and adding low concentrations of selenium from selenite to conventional fungicides may be a promising alternative approach for controlling Fusarium species.