【摘要】 【目的】通过取样调查和田间叶喷硒肥试验,研究中国不同麦区小麦籽粒硒含量状况、硒含量的影响因素以及提高硒含量的农艺措施。【方法】分别于2008—2009、2009—2010、2010—2011年小麦季收集中国不同麦区73份春小麦和582份冬小麦共计655份田间小麦样品,调查籽粒产量并测定籽粒硒含量。于2010—2011年在14个省（市）的30个国家小麦产业技术体系综合试验站开展叶面喷施硒肥试验,设叶面喷施清水或0.017%亚硒酸钠2个处理,于拔节中、末期各喷施1次,完全随机区组设计,重复3次,测定拔节前植株样品的硒含量和收获后籽粒产量和硒含量。【结果】655份小麦籽粒样品平均硒含量为64.6μg·kg^-1,远不能满足以小麦为主食人群对硒的营养需求,变幅为0—821.0μg·kg^-1,春、冬小麦平均分别为67.5和64.2μg·kg^-1。有63%缺硒,19%偏低,仅有8%富硒,未发现有小麦籽粒硒含量达到中毒水平。小麦籽粒硒含量在不同区域表现为北部高于南部、西部高于东部。各地的田间试验表明,叶面喷施亚硒酸钠对小麦籽粒产量没有显著影响,不喷硒和喷硒平均产量分别为6 650和6 649 kg·hm-2。叶喷硒肥使籽粒硒含量显著提高,不喷硒时,籽粒硒含量平均为31.0μg·kg^-1,喷硒116 g·hm-2使籽粒硒含量平均增加到647.8μg·kg^-1,达到了富硒水平,但没有达到中毒水平。每施用1.0 g Se·hm^-2,籽粒硒含量平均提高5.3μg·kg^-1,施用51 g Se·hm-2可将小麦籽粒硒含量从平均31.0μg·kg^-1提高到300μg·kg^-1以上。小麦籽粒硒含量不受产量的影响,但不喷硒时籽粒硒含量与0—20 cm土层土壤有效硒含量和拔节前植株硒含量分别呈显著和极显著正相关。土壤有效硒含量在6.3—30.7μg·kg^-1每增加1.0μg·kg^-1,不喷硒时籽粒硒含量平均增加2.1μg·kg^-1,拔节前植株硒含量在0—147.2μg·kg^-1每增加1.0μg·kg^-1,不喷硒籽粒硒含量平均增加0.7μg·kg^-1。喷硒后籽粒硒含量和硒强化指数均与拔节前植株硒含量极显著正相关。拔节前植株硒含量每增加1.0μg·kg^-1,喷硒籽粒硒含量平均增加5.7μg·kg^-1,籽粒硒强化指数平均增加0.043μg·kg^-1（g·hm-2）-1。【结论】在农业生产中,通过拔节前土壤施硒提高土壤有效硒水平、在拔节中期或末期叶面喷施硒肥等,均可使植株累积较多的硒,并在灌浆期向籽粒转移,从而提高籽粒硒含量。更多还原

【Abstract】 【Objective】 In order to determine wheat grain selenium content in different wheat production regions in China, and to investigate factors that influence grain selenium content and agronomic measures that could increase selenium content, a wheat grain sampling and investigation and then a field experiment of foliar-selenium application on wheat were conducted.【Method】A total of 655 field wheat grain samples including 73 spring wheat and 582 winter wheat samples from different wheat production regions in China were collected from 2008-2009, 2009-2010, and 2010-2011 wheat seasons, and grain yield was investigated and grain selenium content was measured. The field experiment was conducted in 30 comprehensive experimental stations of China Agricultural Research System on Wheat in 14 provinces（municipalities） from 2010 to 2011, including two treatments of foliar applied with water and 0.017% sodium selenite solution at the middle and late jointing stages in a randomized complete block design with 3 replicates, and selenium content of plant before jointing and grain yield and selenium content at harvest were measured. 【Result】Over the 655 wheat grain samples, the average selenium content was 64.6 μg·kg^-1, which was too low to meet the selenium requirement of populations who rely primarily on wheat-derived foods, and grain selenium content ranged from 0 to 821.0 μg·kg^-1, with the average of spring and winter wheat of 67.5 and 64.2 μg·kg^-1. Of these samples, 63%, 19% and 8% had selenium content be deficient, low and enriched, no sample was found to have selenium content reach the toxic level. Selenium of wheat grain in different regions exhibited higher content in northern regions than that in southern regions, while it was higher in western regions than in eastern regions. Results from the field experiments showed that foliar application of sodium selenite did not significantly affect wheat grain yield, with yield for no selenium application and foliar selenium application averaged 6 650 and 6 649 kg·hm^-2. Foliar selenium application significantly increased grain selenium content, when no selenium was applied, grain selenium content averaged 31.0 μg·kg^-1, applying selenium at 116 g·hm^-2 increased the grain selenium content to an average of 647.8 μg·kg^-1, which reached selenium-enriched level, but still below toxic level. For 1.0 g Se·hm^-2 applied, grain selenium content was increased by an average of 5.3 μg·kg^-1, and applying 51 g Se·hm^-2 could increase the selenium content of wheat grain from the average of 31.0 μg·kg^-1 to above 300 μg·kg^-1. Grain selenium content was not influenced by yield, but under no selenium applied it was significantly correlated with the available soil selenium content in 0-20 cm soil layer and with selenium content of plant before jointing. For each 1.0 μg·kg^-1increment of available soil selenium content from 6.3 to 30.7 μg·kg^-1, the grain selenium content without selenium applied increased by an average of 2.1 μg·kg^-1, and for each 1.0 μg·kg^-1 increment of selenium content of plant before jointing from 0 to 147.2 μg·kg^-1, the grain selenium content without selenium applied increased by an average of 0.7 μg·kg^-1. Grain selenium content with selenium applied as well as selenium biofortification index were both significantly correlated with selenium content of plant before jointing. For each 1.0 μg·kg^-1 increment of selenium content of plant before jointing, the grain selenium content with selenium applied increased by an average of 5.7 μg·kg^-1, and selenium biofortification index increased by an average of 0.043 μg·kg^-1(g·hm^-2)^-1. 【Conclusion】In agriculture production, applying selenium in soil before wheat jointing to increase the available soil selenium level, or applying foliar selenium fertilizer at the middle or the late jointing stage etc., are all effective measures to make the plant accumulate more selenium and to transfer it into grain at filling stage, and therefore increase the grain selenium content.更多还原