Combining Ability And Genetic Correlation Of Main Agronomic Characters In Seed Pumpkin(Cucurbita Maxima Duch.)

This experiment selected inbred lines of seed sqush(Cucurbita maxima Duch.): 10,H35-1-2, 37, H36-2-3, H11-1-1, H34-2-1, and the code name is 1, 2, 3, 4, 5, 6 respectively. The experiment copulation was designed with the complete diallel cross, through the methods of quantitative genetics, such as analysis of combining ability, analysis of heterosis and analysis of correlation , studies on combining ability of 18 agronomic characters on F1 of seed squash , and studies on heredity correlation of several main characters in relation to the economic characters. It offers materials and theoretical basis for seed squash breeding. The analysis of combining ability effect indicates, there are differences in different parents to every character on general combining ability effective value, and there are differences in same parents to different character on general combining ability effective value. This difference offer possibility to identify and choose fine inbred lines. The same character's special combining ability effective value vary with different crosses, and the same crosses vary with different characters. This difference offer possibility to identify and choose fine crosses.And cytoplasm effect is universal existence on seed squash. The analysis of heterosis indicates,seed squash main economic characters exist general heterosis,the amount of seeds per fruit,weight per 100 seeds,yield per fruit and seed width have bigger positive heterosis,seed longth has smaller positive heterosis and has negative heterosis trend.Heterosis for yield is geneally accompanied by heterosis for yield components.Four promising crosses were identified for developing high yielding F1 hybrids of seed squash with many desirable characters. The analysis of correlation indicates,weight per 100 seeds and amount of seed per fruit are main effective factors to yield per fruit.For developing amount of seeds per fruit, the weight per fruit and fruit traverse diameter should be developed because they have bigger positive straight effect,and the both characters have significant positive correlation,,but the fruit vertical diameter should be reduced.So,on seed squash yielding breeding, weight per fruit and fruit traverse diameter may regard as main characters choice indexes,and pay attention to fruit vertical diameter. Name:Xu Donghui Major:Vegetable breeding Supervisor:Cui Chongshi...