An Efficient Strategy for Developing Fusarium Wilt-Resistant Watermelon Germplasm Using EMS Mutagenesis and Toxin...

Fusarium wilt of watermelon (Citrullus lanatus), caused by Fusarium oxysporum f. sp. niveum, severely threatens watermelon production worldwide. This study, for the first time, explored a rapid and efficient method for creating disease-resistant watermelon germplasm by combining ethyl methanesulfonate (EMS) mutagenesis with crude toxin screening. Watermelon seeds treated with 1% EMS for 18 h achieved a germination rate of 52%, and resistant mutants were successfully identified using 50% crude toxin stock solution. The mutants exhibited enhanced stress tolerance, with significantly higher superoxide dismutase and catalase activities and lower malondialdehyde content compared with susceptible varieties. Artificial fungal inoculation confirmed the resistance of mutant plants, which exhibited a disease index comparable with that of the resistant varieties. This study demonstrated the effectiveness of a practical and innovative strategy combining chemical mutagenesis and toxin screening for developing Fusarium wilt-resistant watermelon germplasm.