广西鹿寨水稻及其种植土壤中硒含量分布特征分析

摘要

【目的】研究广西鹿寨水稻及其种植土壤硒含量的分布特征，为广西富硒有机稻的产业化、规模化和科学化生产提供理论依据。【方法】采集广西鹿寨具有代表性的28套水稻植株及其对应的根系土样品，采用氢化物原子荧光光谱法分析水稻植株各部位的硒含量，并与其对应根系土中的硒含量进行对比，考查水稻生长过程中的富硒能力。【结果】28个水稻根系土样品的足硒率、富硒率及硒中毒率分别占样品总数的3.57%、92.86%和3.57%；28个水稻籽实样品中有26个样品达富硒标准值，富硒率达92.86%，剩余的2个样品硒含量低于标准值（占7.14%）。水稻植株不同部位及对应根系土硒含量的分布规律为：根系土>根须>茎叶>籽实；水稻籽实、茎叶、根须硒含量与对应根系土硒含量间均存在极显著正相关（P<0.01），且随着根须、茎叶、籽实与对应根系土距离的增加，其相关性随之依次减弱。【结论】广西鹿寨水稻田土壤富硒率高，其平均值(1.002 mg/kg）远高于全国平均水平（0.29 mg/kg），产出的水稻有92.86%达国家富硒水稻标准，具备生产天然富硒水稻的条件。%Objective]The present study was conducted to study distribution characteristics of rice and rhizosphere soil in Luzhai,Guangxi,in order to provide a theoretical basis for industrialized,large-scale and scientific production of se-lenium-enriched rice in Guangxi. [Method]Twenty-eight sets of representative rice plants and corresponding rhizosphere soil samples were collected from Luzhai,Guangxi,and the selenium content in different parts of rice plants was determined by hydride atomic fluorescence spectrometry,compared with selenium content of corresponding rhizosphere soil,so as to investigate ability of rice to enrich selenium during growth process. [Result]Results showed that,enough-selenium rate,se-lenium-enriched rate and selenium poisoning rate of 28 rice rhizosphere soil samples accounted for 3.57%,92.86% and 3.57% of total samples. Twenty-six of twenty-eight seed samples were up to standard of selenium enrichment,selenium-enriched rate was 92.86%,but two of which were lower than standard,accounting for 7.14%. Distributions of selenium con-tents in different parts of rice plant and rhizosphere soil were ranked as follows:rhizosphere soil>root hair>cauline leaf>seed. Selenium content of corresponding rhizosphere soil was extremely significantly positively correlated with selenium content of seeds,cauline leaf and root hair,respectively(P<0.01),however,this correlation was attenuated with the increase of distance between rhizosphere soil and each of root,cauline leaf and seed. [Conclusion]Paddy soil of Luzhai,Guangxi is rich in selenium,with an average selenium content of 1.002 mg/kg,which is much higher than national average(0.29 mg/kg), 92.9%of total rice reach up to national standard of selenium-enriched rice,therefore,Luzhai of Guangxi has natural condi-tion for production of selenium-enriched rice.