Study On Botanical Characters,Nutritional Quality And Waterlogging Tolerance Of Baimi Series Pumpkin Varieties

In this study,10 pumpkin varieties of Baimi series were used as the research material.In order to reveal the characteristics of the different pumpkin varieties,and provide a theoretical basis for the promotion and utilization of high-quality varieties in the future.We had comparing the phenological stages,botanical characteristics,disease resistance,nutritional quality and the waterlogging tolerance.The specific research results are as follows:1.By measuring the phenological stage,disease resistance,nutritional quality and yield of 10 pumpkin varieties.We find that We found that 10 pumpkin varieties have different characteristics.Among them the yield and soluble sugars content of Baimi No.6,Baimi No.9 and Baimi No.10 were higher than others;Baimi No.3 and Baimi No.7 have high β-carotene content and can be used in food processing and production;Baimi No.2 and Baimi No.4 grew well,and Baimi No.4 had higher vitamin C content,and Baimi No.1,Baimi No.5 and Baimi No.8 had higher crude protein content.high resistance to virus disease,powdery mildew and downy mildew.2.The biomass and related physiological indexes of 10 pumpkin varieties of Baimi series were measured under waterlogging tolerance.The results showed that after flooding stress,the above-ground and underground fresh weight and dry weight of different pumpkin varieties have been significantly decreased;SPAD content;MDA content has increased in most varieties;SOD,POD and CAT activities showed different trends in different varieties.After comprehensive analysis and evaluation,it was found that 10 pumpkin varieties Baimi No.1,Baimi No.5,Baimi No.10,Baimi No.2,Baimi No.3 had strong waterlogging tolerance,Baimi No.6,Baimi No.9,and Baimi No.7 were moderately waterlogged,and Baimi No.4 and Baimi No.8 were weakly waterlogged.3.The selected Varieties of Baimi No.10（strong waterlogging tolerance）and Baimi No.8（weak waterlogging tolerance）were used as test materials,and the leaf phenotype changes,anaerobic respiration,antioxidant enzyme activity and related gene expression of pumpkin were studied for 7 days.The result showed that the normal growth of pumpkin was inhibited by flooding stress,mainly manifested in the yellowing,drying and drooping of leaves.The growth of Baimi No.10 was better than Baimi No.8.After waterlogging tolerance,there was most of no significant difference in the activities of alcohol dehydrogenase（ADH）and pyruvate dehydrogenase（PDC）in the roots of Baimi No.10 and Baimi No.8,this indicated that ADH and PDC may not be the reasons for the resistance to waterlogging.The accumulation of reactive oxygen species（ROS）in the leaves of pumpkin plants increases the enzyme activity by up-regulating the expression of SOD,POD,and CAT genes to resistance stress damage from 0 to 3 days.However,these enzyme activity were decreased,and the degree of membrane lipid peroxidation was aggravated after 3 days.