甘薯块根形成和膨大对土壤紧实度的响应机制及与产量的关系

为探讨甘薯块根形成和膨大对土壤紧实度的响应机制及与产量的关系,以源库特征差异显著的食用型甘薯品种"北京553"和"龙薯9号"为试验材料,设置不同的土壤紧实度处理,研究土壤紧实度调控甘薯块根产量的生理生态原因。结果表明,降低土壤紧实度,全生育期耕作层土壤的非毛管孔隙度显著提高。在块根形成期(20～40 d),随土壤紧实度降低,耕作层土壤的最高温度提高、最低温度降低,温度日较差显著提高。在甘薯块根膨大期(45～165 d),与对照相比,疏松处理可以提高块根中蔗糖合酶(SS)和腺苷二磷酸葡萄糖焦磷酸化酶(ADPGPPase)活性,增加淀粉含量;提高块根中干物质积累初始势、干物质积累速率和功能叶13C同化物在块根中的分配比例。在收获时,疏松处理显著提高单薯重和收获指数,北京553和龙薯9号分别增产20.01%～24.25%和21.64%～27.78%。

Response mechanism of sweet potato storage root formation and bulking to soil compaction and its relationship with yield

Field experiments were performed using two sweet potato Ipomoea batatas L. (Lam.)].cultivars (‘Beijing 553’ and ‘Longshu 9’) with significant differences in source sink characteristics. The physiological and ecological mechanisms of regulation of soil compaction on storage root yield were studied under different soil compaction treatments. The non-capillary porosity of plough horizon increased significantly during the whole growth period with the decrease of soil compactness. During storage root formation (20-40 d), the minimum temperature was significantly decreased, the maximum temperature and diurnal temperature range of plough layer were significantly increased with the decrease of soil compactness. Compared with the control, the loose treatment could increase the activities of sucrose synthase (SS) and adenosine diphosphate glucose pyrophosphorylase (ADPGPPase) in storage roots, also the starch content, the initial dry matter accumulation potential, dry matter accumulation rate and the distribution ratio of ¹³C assimilates from functional leaf to storage root. At harvest period the average weight per storage root and harvest index were significantly increased in the loose treatment, Beijing 553 and Longshu 9 increased production by 20.01% to 24.25% and 21.64% to 27.78%, respectively.