Study of Induction and Characteristics of Tetraploid Pumpkin(Cucurbita moschata D.)

Diploid pumpkin seeds of pumpkin(Cucurbita moschata D.) 'Shanghai Xiaozha Huanglang' were soaked in 4 concentrations of colchicine for 4 h to induce the tetraploid plants.The results indicated that the most efficient concentrations of colchicine were 0.2% and 0.3%.The chromosomes of tetraploid plants doubled(2n=4x=80).Comparison with diploid pumpkin,the tetraploid plant had less stoma in leave,larger and rounder leaves with deeper color,thicker stem,more deformed male flowers.The small cylinder-formed fruits of tetraploid pumpkin had shorter peduncle,longer neck and less seeds.The average seed number decreased from 340 to 68 per fruit.The proline content and SOD activity increased,but MDA content decreased.The bleeding intensity and root activity of tetraploid pumpkin were higher than those in diploid plant.