不同叶面肥及水稻品种对水稻糙米重金属累积的影响

Heavy Metal Accumulation in Husk-removed Grains as Affected by Foliar Fertilizer Application and Rice Variety

【目的】研究不同水稻品种和叶面肥对水稻糙米富集多种重金属的影响。【方法】采用田间试验的方法,选用10个广西当地主要种植的晚稻品种,每个品种设置喷施硒肥(Se)、硅肥(Si)和CK施肥处理。测定和分析水稻糙米重金属As、Cd、Pb、Cr含量差异,比较不同晚稻品种As、Cd、Pb、Cr累积特性,筛选出适合广西当地种植的重金属低累积晚稻品种,同时分析出两种叶面肥对水稻糙米累积重金属的影响。【结果】不同水稻品种糙米对As、Cd、Pb、Cr的累积存在明显差异。其中桂育12糙米Cd含量最低,裕丰优158糙米As含量最低,荃香优822糙米Cr含量最低;10个水稻品种中,仅有华浙优1号检测出Pb含量。4种重金属在水稻糙米中富集能力大小依次为:Cd>As>Cr>Pb。喷洒硒肥(Se)和硅肥(Si)后水稻糙米Cd含量分别下降了44.8%和44.2%。富集系数分别降低了47.2%和47.4%。喷洒硅肥(Si)后,水稻糙米As含量及富集系数相较于对照处理分别降低了30.0%和19.0%。喷洒叶面肥后对水稻糙米Pb含量影响较小。【结论】选用品种桂育12在广西当地种植可以很好地降低糙米重金属中Cd的累积,选用裕丰优158可以很好地降低糙米中重金属As的累积,施用硅肥(Si)可显著降低As在水稻糙米中的累积,叶面喷施硒肥(Se)和硅肥(Si)均可以很好地阻控在水稻糙米中Cd的富集。

【Objective】Effects of rice variety and applied foliar fertilizers on the accumulation of heavy metals in the huskremoved grains were studied.【Method】In a field experimentation,10 major local late-season rice cultivars in Guangxi Province were sprayed with selenium(Se),silicon(Si),or water as CK.Contents of As,Cd,Pb,and Cr in the husk-removed grains were determined to identify the rice varieties with lower potential to retain heavy metals.【Result】Significant differences were found in the pollutants accumulation of rice grains.Among the 10 cultivars,Guiyu 12 was the lowest on Cd,Yufengyou 158 the lowest on As,Quanxiangyou 822 the lowest on Cr,and only Huazheyou No.1 detected with Pb.The greatest to the least heavy metal accumulated was in the order of Cd>As>Cr>Pb.On average,the application of Se foliar fertilizer reduced the Cd accumulation in grains by 44.8%,and that of Si by 44.2%with the enrichment coefficients decreased by 47.2%and 47.4%,respectively.Si application lowered the As content by 30.0%with an enrichment coefficient by 19.0%over CK,but less effective on Pb reduction.【Conclusion】The accumulation of Cd in the grains of Guiyu 12 could be significantly minimized,and also that of As in Yufengyou 158 rice,for the cultivation in Guangxi.Application of Si fertilizer on the leaves of a rice plant could decrease As accumulation and that of either Se or Si reduce Cd in the grains.