多效唑对食用甘薯北京553块根淀粉积累及相关酶活性的影响

【目的】揭示多效唑促进食用甘薯北京553块根膨大、提高块根产量的生理基础。【方法】试验于2008-2009年2 个生长季在山东农业大学农学试验站进行。以北京553 为试验材料，设置0、100、200 mg?kg-1 3个浓度的多效唑处理，每个处理重复3次。采用块根膨大过程中定期取样的方法，研究块根膨大过程中淀粉积累特性及淀粉合成相关酶活性的变化。【结果】喷施多效唑显著提高了蔗糖合成酶（SS）和腺苷二磷酸葡萄糖焦磷酸化酶（ADPGase）活性，降低了块根中蔗糖含量，从而显著提高了淀粉含量和淀粉积累速率，增加淀粉产量。喷施多效唑也显著增加了单薯重和鲜薯产量。相关分析表明，腺苷二磷酸葡萄糖焦磷酸化酶（ADPGase）活性与淀粉含量和淀粉积累速率呈显著正相关（相关系数分别为0.69 和0.71）；蔗糖合成酶（SS）活性与淀粉含量和淀粉积累量呈显著正相关（相关系数分别为0.58 和0.81）。【结论】喷施多效唑显著提高了块根蔗糖合成酶（SS）和腺苷二磷酸葡萄糖焦磷酸化酶（ADPGase）活性，使得块根淀粉含量和淀粉积累速率显著提高，块根产量得以提高。

Effect of Paclobutrazol on Starch Accumulation and Related Enzyme Activity of Storage Root in Edible Sweet Potato cv.Beijing 553

【Objective】 The objective of this study was to discuss the effects of paclobutrazol on the physiological mechanism of promotion of the storage root growth rate and increase of storage root yield in edible sweet potato cv. Beijing 553.【Method】Field plot experiments with paclobutrazol at M0, 100 mg?kg-1 (M1), and 200 mg?kg-1 (M2) were conducted in a field at agricultural experiment station of Shandong Agricultural University in summer crop seasons of 2008 and 2009, using the typical varieties of edible sweet potato Beijing 553. There were three replicates for each treatment. The changes of starch accumulating characteristics and activities of enzymes involved in starch synthesis were determined by using periodic sampling during storage root development.【Result】Paclobutrazol significantly improved the activities of sucrose synthesis (SS) and adenosine diphosphorate glucose pyrophosphorylase (ADPGase), reduced the sucrose content in storage root. As a result, the starch accumulating rate and starch content were improved, and the starch production increased. Increase of the concentrations of paclobutrazol significantly increased the fresh weight per lump and fresh yield. Correlation analysis showed that ADPGase activity was positively correlated with starch content and starch accumulation rate and the correlation coefficients were 0.688 and 0.714, respectively (P＜0.05). The correlation analysis also showed that SS activity was significantly positively correlated with starch content as well as the starch accumulating quantity and the correlated coefficients were 0.58 and 0.81 respectively (P＜0.05).【Conclusion】The results suggested that spraying paclobutrazol increased yield of storage root, which resulted from the increased starch content and the improved starch accumulating rate. The higher activities of SS and ADPGase were found in resulting in higher yield of storage root in sweet potato.