Study On Fruit Storage Tolerance Of Baimi Series Pumpkin Varieties

Five pumpkin cultivars of Baimi series were studied in this experiment.The nutritional quality,physiological indexes,cell wall components,cell wall enzyme activity and fruit texture of five pumpkin cultivars were studied during storage for 10 days,20 days,30 days,40 days,50 days and 60 days The fruit appearance and cellular structure of five pumpkin cultivars of Baimi series were observed in the early(10d),middle(35 d)and late(60 d)storage period,and the storability of five pumpkin cultivars of Baimi series was comprehensively evaluated In order to reveal the changes of nutritional quality and cellular structure of pumpkin fruits during storage period and select pumpkin varieties with good storage tolerance The specific research results are as follows:1.The physiological indexes of nutritional quality and fruit appearance of five pumpkin varieties in Baimi series were measured and observed The results showed that with the extension of storage time,the vitamin C content of five pumpkin varieties decreased;The weight loss rate and malondialdehyde content showed an upward trend.Soluble sugar and respiration rate increased at first and then decreased The fruit appearance of Baimi No.2,Baimi No.3 and Baimi No.5 changed obviously in the middle and late storage period During the whole storage period,the content of nutrient components(starch,soluble sugar and soluble solids)of fruits of Baimi No.3 and Baimi No.5 was higher than that of fruits of Baimi No.5 and Baimi No.3 Baimi No.10 has the advantage of storage resistance from physiological indexes and fruit appearance.2.The enzyme activity of cell wall components and fruit texture of five pumpkin varieties in Baimi series were determined The results showed that with the prolongation of storage time,the content of protopectin of five pumpkin varieties decreased and the soluble pectin increased The content of cellulose and hemicellulose showed a downward trend The contents of protopectin and cellulose of Baimi 10 were higher than those of the other four varieties after 60 days of storage The PG activity of five pumpkin varieties in Baimi series showed an overall upward trend and the β-Gal、Cx、PE activity showed an overall downward trend After 30 days of storage,the PG activity of five pumpkin varieties increased obviously,and the Cx activity decreased obviously TPA hardness,brittleness and elasticity of five pumpkin varieties in Baimi series showed a downward trend.The adhesion,cohesion,recovery and chewiness of fruit increased at first and then decreased The fruit firmness and elasticity of Baimi No.5 and Baimi X1 decreased faster with the extension of storage time,and the fruit firmness and elasticity of Baimi No.10 decreased more than that of Baimi No.10.3.After storage for 10 days,35 days and 60 days,the cellular structure of pericarp and pulp of five pumpkin cultivars were observed by electron microscope,and the cell area of pulp was calculated by Image J software The results showed that with the prolongation of storage time,there was a large gap between exocarp cells of Baimi No.3 and Baimi No.5,and there was a bulge at the junction between epidermal cells and exocarp cells of Baimi No.5 and Baimi X1 The pulp cells of Baimi No.2 and Baimi No.10 were nearly round.The pulp cells of Baimi No.3,Baimi No.5 and Baimi X1 were elliptical Starch granules appeared in pulp cells of Baimi No.2,Baimi No.3,Baimi No.10 and Baimi X1 after storage for 10 days The starch grains disappeared after 35 days of storage The pulp cell area of five pumpkin varieties increased obviously with the extension of storage time,and the pulp cell area of Baimi X1 was the largest during the whole storage period After 60 days of storage,there was a large gap between the pulp cells of Baimi No.2,Baimi No.3 and Baimi No.5 The pulp cells of Baimi No.10 are closely arranged and the intercellular space is small.4.Comprehensive evaluation of storability of five pumpkin varieties in Baimi series was carried out by principal component and membership function method The results showed that after 60 days of storage,the order of comprehensive scores from high to low was: Baimi No.10,Baimi No.5,Baimi No.3,Baimi X1,Baimi No.2 Baimi No.10 has good storability and Baimi No.2 has poor storability.