Inducement and Identification of Yellow Flesh Tetraploid Watermelon

We induced tetraploid watermelon by treating the seedling growingpoints of yellow flesh diploid watermelon with 0.3% and 0.4% solution of colchicines.Autotetraploid plants were selected and identified on morphology,flow cytometry,hybridization and quality.After 3 successive quarters cultivation and observation,we gained a stable tetraploid.The results showed that the most effective treatment was extirpating interior-leaf at the 8th day after sowing,then treating the seedling growing points with 0.3% colchicine for 6 days.The survival rate of seedlings could reach over 80% and the induction frequency of tetraploid watermelon could be stabled above 16%.The treatment can improve the accuracy of selection high-quality tetraploid material combined with other identification methods.