（1College of Horticulture，Anhui Agricultural University，Hefei 230036，Anhui，China；2Institute of Horticulture，Anhui Academy of Agricultural Sciences，Hefei 230031，Anhui，China；3Key Laboratory of Genetic Improvement and Eco-physiology of Horticultural Crop，Hefei 230031，Anhui，China）
Abstract：This paper took the highly inbred line‘W-17-FGFB’as test material；set 4 EMS concentration（0.5%，1.0%，1.5%，2.0%）combined with 3 mutation times（12 h，16 h，24 h）treatments；and studied the effects of different mutated conditions on germination rate，seedling emergence rate，and field agronomic characters of watermelon．The results showed that the germination rates of watermelon seeds were all above 68% when treated with the low concentration（0.5%-1.5%）of EMS with 3 time treatments．The lethality was closest to the semi-lethal dose when treated with 2.0% EMS for 24 h．The plants performed rich phenotypic variations in leaf shape，leaf color，flower and fruit．According to the results of comprehensive evaluation，2.0% EMS concentration with seed soaking for 24 h was selected as the most suitable condition for watermelon seeds mutation．Thus，materials with abundant phenotypic variation could be obtained．
