%A CUI Peng,ZHAO YiRen,YAO ZhiPeng,PANG LinJiang,LU GuoQuan %T Starch Physicochemical Properties and Expression Levels of Anabolism Key Genes in Sweetpotato Under Low Temperature %0 Journal Article %D 2022 %J Scientia Agricultura Sinica %R 10.3864/j.issn.0578-1752.2022.19.012 %P 3831-3840 %V 55 %N 19 %U {https://www.chinaagrisci.com/CN/abstract/article_22538.shtml} %8 2022-10-01 %X

【Objective】Starch is the main component of sweetpotatoe, and the main use of tuberous roots is directly determined by the physicochemical properties of starch. Sweetpotato is a typical temperature-preferred tropical crop and sensitive to the storage temperature. Therefore, it is very important to study the effects of low temperature on starch physicochemical properties for the safe storage of sweetpotato. 【Method】 The starch average granule size and distribution, heat enthalpy, gelatinization properties, moisture absorption and swelling power were investigated in an experiment conducted by using Yanshu 25 and Shangshu 19 with storage of 13℃ (CK) and 4℃ (Low temperature, LT) for 14 days. 【Result】 The results demonstrated that the significant differences were observed in amylose/amylopectin content between the two sweetpotato varieties. The amylose content of Shangshu 19 (31.47%) was significantly higher than that of Yanshu 25 (25.86%), while the amylopectin content showed an opposite trend. The average particle size, volume and surface area of Yanshu 25 and Shangshu 19 ranged from ≤2.50 μm, 2.50-5.00 μm to 5.00-25.00 μm, respectively. The average particle size, volume and surface area of starch particles, moisture absorption and swelling power were decreased under LT stress. The starch initial temperature (T0), peak temperature (Tp) and heat thermal value (△H) of Yanshu 25 and Shangshu 19 during gelatinization process were decreased significantly as compared with CK. The change in starch △H of Yanshu 25 was higher than that of Shangshu 19, which indicated that the effect of low temperature on thermal properties of Yanshu 25 starch was more serious than that of Shangshu 19. Under low temperature storage conditions, the peak viscosity (PKV), disintegration value (BDV) and recovery value (CSV) of Yanshu 25 and Shangshu 19 were decreased significantly, while the gelatinization temperature (PT) was not significantly affected by temperature. The differences between the two varieties were significant. The expression levels of IbAGPa, IbAGPb, IbSBEI and bSBEII genes were decreased significantly under LT condition, while Ibα-amylase and Ibβ-amylase increased significantly. 【Conclusion】 In conclusion, the temperature played an important role in the starch physicochemical properties of sweetpotato, and the change of which was closely related to the storage temperature.