Heterosis Potential of Triple Hybrid and Double Hybrid of No-heading Chinese Cabbage

Heterosis of no-heading Chinese cabbage were compared for triple and doube hybrid with single hybrid.The results showed that the heterosis in single plant weight were different between triple,double and single hybrid of no-heading Chinese cabbage.Based on average,the leaf-stalk weight and single plant weight of triple hybrid were higher than which of single hybrid,while other indices in yield traits were similar for both.The performances of plant height,leaf-stalk length,leaf-stalk weight,and single plant weight were better in single than in double cross hybrid.The growth regularity was the best in single hybrid but the worst in double hybrid.The heat-tolerance of plant was the best in triple hybrid,and that of the double hybrid and single hybrid was similar;The capacity in disease resistance of three hybrid was ranked in order as double cross hybrid,triple hybrid,and then single cross hybrid,while the spread of disease was quicker in double cross hybrid and triple hybrid than in single hybrid.