Correlation Analysis On Starch, Sugars And Variation Trend Of β-amylase Activities Duirng Reproduction Stage And Storage Of Sweetpotato

The increasing numbers of researches have focused on the quality and application ofsweetpotatoes in recent years, and the storage roots of sweetpotato are the optimal material toproduce β-amylase. The study of β-amylase in sweetpotato roots during reproduction stageand storage stage may support the industrial application of sweetpotatoes. This research hasbeen divided into two parts:1. In order to investigate the correlation between β-amylase activities and starch contents,we assayed the starch contents and β-amylase activities in the roots of12genotypes ofsweetpotato that were provided by XuZhou Institute of Sweetpotato during regeneration stageto harvest. The results showed that the starch contents of most genotype sweetpotatoesincreased during the28-days period with the rate of1%~5%, The activities of β-amylase ofmost sweetpotato cultivars decreased significantly, and the activity of each cultivar wasremarkably differ from others. Correlation analysis indicated that the changes of the starchcontents were related to the changes of β-amylase activities during later regeneration stage,about6cultivars were significantly related to each other, and4cultivars were related to eachother. Different genotypes showed different plus-minus relativities and the significances.2. In order to investigate the effects that different postharvest treatments and differentstorage environments might impact on the β-amylase activities and the reducing sugars ofsweetpotato with different genotypes and colours,6sweetpotato cultivars from YangLingagricultural science and technology park were selected and put into three treatments,including greenhouse environment, low temperature storage after heat and low temperaturestorage. The results indicated that, compared with the sweetpotatoes white and purple flesh,the orange sweetpotato has lower starch content, but higher soluble sugar content andreducing sugar content. Appropriate treats like heat before storage could enhance the qualityand storage property of sweetpotato, β-amylase activities and the reducing sugar contents ofsweetpotatoes showed no significant difference between greenhouse treatment and lowtemperature treatment, and the storage properties were rather worse.