海藻多糖-纳米硒的结构及其促进水稻硒累积的机理  

Structure of alginate polysaccharide selenium-nanoparticles and the mechanism of promoting selenium accumulation in rice

作　　者：王潮鑫 杨春妹 张木 沈宏[1] WANG Chao-xin;YANG Chun-mei;ZHANG Mu;SHEN Hong(College of Resources and Environment,South China Agricultural University,Guangzhou,Guangdong 510642,China;Institute of Agricultural Resources and Environment,Guangdong Academy of Agricultural Sciences,Guangzhou,Guangdong 510640,China)

机构地区：[1]华南农业大学资源环境学院,广东广州510642 [2]广东省农业科学院农业资源与环境研究所,广东广州510642

出　　处：《植物营养与肥料学报》2023年第1期158-171,共14页Journal of Plant Nutrition and Fertilizers

基　　金：广东省基础与应用基础研究基金项目(2021A1515012113);广州市科技计划项目(202206010064);广东省普通高校重点领域研究项目(2020ZDZX1002);国家重点研发计划项目(2016YFD0200405-5)。

摘　　要：【目的】以海藻提取物和亚硒酸钠为原料,采用抗坏血酸还原法制备了海藻多糖–纳米硒(APS-SeNPs),以期为富硒大米生产提供高效的富硒肥料。【方法】采用单因素试验和响应面法优化APS-SeNPs的制备工艺;借助傅里叶红外光谱、透射电镜和表面张力仪对APS-SeNPs进行表征。通过开展大田试验,探究0、5、25 mg/L APS-SeNPs叶面喷施对粳稻‘洛稻998’和籼稻‘川香优2号’硒累积的影响。【结果】1)APS-SeNPs的最佳制备工艺:硒添加量2800 mg/L,亚硒酸钠与抗坏血酸的摩尔比19∶100,反应温度32℃,时间20 min。APSSeNPs粒径为38.94 nm,Zeta电位为–52.17 mV。红外分析结果表明,海藻多糖与纳米硒形成了新的Se—O化学键。APS-SeNPs的表面张力为46.23 mN/m,显著低于Na_(2)SeO_(3)。APS-SeNPs在水稻叶片上的持液量为6.28 mg/cm^(2),而Na_(2)SeO_(3)只有3.94 mg/cm^(2)。2)田间试验结果表明,随着APS-SeNPs喷施浓度增加,水稻叶片、稻壳和糙米的硒含量增加,各部位硒含量顺序为叶片>稻壳>糙米。与Na_(2)SeO_(3)处理相比,APS-SeNPs处理的糙米硒含量提高了2.2%~34.5%;两种硒源处理的糙米有机硒占糙米总硒比例为70.9%~85.3%,糙米有机硒比例均随叶面喷施硒浓度增加而下降,但值得一提的是,APS-SeNPs处理的稻米有机硒比例比Na2 SeO3处理高2.1~7.6个百分点。【结论】海藻糖与纳米硒的结合显著降低了Na_(2)SeO_(3)溶液的表面张力,喷施后在叶片上的持液量更多,因而提高了水稻硒的吸收,相应地提高了硒在籽粒中的累积量以及籽粒中的有机硒比例。在水稻灌浆期喷施浓度5 mg/L APS-SeNPs的效果最好,喷施后的稻米硒含量达到国家富硒标准(0.04~0.3 mg/kg),是富硒水稻生产的可行措施。【Objectives】The structure of alginate polysaccharide selenium-nanoparticles(APS-SeNPS)was characterized for explaining its efficiency in promoting Se absorption in rice.The optimum foliar spraying time and content of APS-SeNPS were studied for its efficient application.【Methods】The preparation process of APS-SeNPs was optimized by a single-factor experiment and response-surface methodology.Fourier transform infrared spectroscopy(FTIR),transmission electron microscopy(TEM)and surface tensiometer were used to characterize the APS-SeNPs.A field foliar spraying experiment was conducted on rice,with APS-SeNPs concentration of 0,5 or 25 mg/L,respectively.Se accumulation in japonica rice‘Luodao 998’and indica rice‘Chuanxiangyou 2’were investigated.【Results】1)The optimized preparation conditions of APS-SeNPs containing Se 2800 mg/L were as follows:molar ratio of Na_(2)SeO_(3)to ascorbic acid(Se∶Vc)was 19∶100,reaction temperature 32℃and reaction time 20 min.The produced particle size of APS-SeNPs was 38.94 nm,and the Zeta potential was−52.17 mV.The Se-O chemical bond was identified in APS-SeNPs by FTIR.The surface tension of APS-SeNPs is 46.23 mN/m,which is significantly lower than that of Na_(2)SeO_(3).The liquid holding capacity of APS-SeNPs on rice leaves was 6.28 mg/cm^(2),which was much higher than that of Na_(2)SeO_(3)(3.94 mg/cm^(2)).2)Field experiments revealed that Se contents in each organs of the two rice cultivars increased with the increase of spraying Se concentration.The Se content in both the rice cultivars was in order of leaf>rice husk>brown rice.The Se content of brown rice in APS-SeNPs treatment was 2.2%−34.5%higher than that in Na_(2)SeO_(3)treatments.The organic Se proportion in brown rice treated with two Se sources was 70.9%to 85.3%,and the organic Se proportion in brown rice was decreased with the increase of Se spray concentrations,but the organic Se proportion in brown rice treated with APS-SeNPs was 2.1−7.6 percentage points higher than that treated with Na_(2)Se

关 键 词：水稻 海藻多糖 纳米硒 响应面 喷施时期 喷施浓度 

分 类 号：S511[农业科学—作物学]