叶面喷施硒对紫甘薯硒吸收、分配及品质的影响

摘要

In order to clarify the absorption characteristics of selenium (Se),root yield,Se utilization,content of amino acids and mineral elements in purple sweet potato,a field experiment of foliage spraying with three treatments of 0,30,and 60 g ha-1 pure Se application were carried out in 2015 and 2016 respectively.The root yield of purple sweet potato received no significantly effect from Se foliage spray,the Se content,organic Se content and the Se accumulation in root were improved,with a root Se content of 311.3 μtg kg 1 (DW),8.54 times as high as that of the control under 60 g ha-1 Se application.Se content and accumulation amount in root increased and the utilization rate of Se decreased significantly with the increase of Se application,while the content of organic Se in root received no significantly effect from Se foliage spray.With increasing Se application,the content of crude protein in root of purple sweet potato was significantly increased,which was 11.67％ and 29.71％ higher than that of CK under Se treatment of 30 g ha1 and 60 g ha-1 respectively.Under 60 g ha-1 Se application treatment,seven essential amino acids for human body contained in roots increased significantly except Threonine,and the other six nonessential amino acids in roots also increased significantly such as Asparagine,Serine,Glutamic acid,but the content of Cysteine decreased.Se application treatments increased the contents of K,Na,Mg,Fe,Cu and decreased the contents of Ca,Mn in roots of purple sweet potato,but had no effect on content of Zn.The results of this study are of significance guiding production of Se-enriched purple sweet potato.%为研究叶面施硒条件下紫甘薯对硒的吸收利用特征及其品质效应,于2015年和2016年分别布置紫甘薯叶面施硒田间试验,设纯硒施用量0、30和60 g hm-2 3个水平,研究了叶面喷施外源硒对紫甘薯块根产量、不同器官硒含量、块根硒累积量与硒利用率的影响,并分析了块根中粗蛋白、氨基酸和矿质元素含量随施硒量的变化.结果表明,施硒对紫甘薯块根产量的影响不显著,但可提高块根中的总硒含量、有机硒含量和硒累积量,60 g hm-2施硒量下,块根中的硒含量可达311.3 μg kg-1(干重),是对照处理的8.54倍;随施硒量增加,块根中硒含量和硒累积量显著增加,块根对硒的利用率下降,但施硒对块根中有机硒占总硒的比例无显著影响;紫甘薯块根中的粗蛋白含量随施硒量增加而显著提高,两个施硒量下分别比对照增加11.67％和29.71％;60 g hm-2施硒量下,块根中除苏氨酸外的其他7种人体必需氨基酸含量显著增加,天冬氨酸、丝氨酸、谷氨酸等6种人体非必需氨基酸含量显著增加,胱氨酸含量降低;施硒还可提高紫甘薯块根中K、Na、Mg、Fe、Cu等元素的含量,使块根中Ca、Mn等元素含量降低,两个施硒量对块根中的Zn元素含量均未产生显著影响.本研究结果对富硒紫甘薯生产具有指导意义.