Influence of Different ORYZALIN Treatments on Tetraploid Mutagenic Effect of Watermelon

The inbred lines of diploid watermelon were used for experiment material.Mutagenic effect of tetraploid were compared by using herbicide ORYZALIN as mutagen in different treatment methods(dropping seedling treated by ORYZALIN at 25 mg/L,40 mg/L and 55 mg/L;smearing treated by ORYZALIN at 25 mg/L,40 mg/L and 55 mg/L;seed soaking,germinated seeds were immersed into 40 mg/L ORYZALIN solution) and different ways of stem training.The results showed that the mutagenic effect of tetraploid were best with 40 mg/L ORYZALIN for 6 d in drop seedling and with 125 mg/L in smearing growing point,the mutation rate was up to 17.39% and 36.36%;and it was up to 3.33% the highest mutation rate after treatment with soaking seed.There was no significant variation in the treatment of dry seed with soaking.Mutagenic effect of tetraploid was different in various diploid inbred lines.