食用木薯天然富硒品种筛选及外源硒强化技术研究

Selection of Natural Selenium-rich Edible-cassava Varieties and Strengthening Technology of Exogenous Selenium

【目的】通过田间试验,筛选出天然富硒品种和高效外源硒强化技术,为食用木薯的富硒生产提供技术支撑。【方法】在硒背景值分别为1.45和0.63 mg/kg^2个土壤环境下常规种植,测定7个木薯品种天然富硒能力大小,然后在食用木薯块根膨大期通过叶面喷施、根施和"叶面喷施+根施"3种方式施入不同量的外源硒,研究不同强化方式和强化量下食用木薯的块根硒含量和外源硒利用率的差异。【结果】在自然条件下,7个食用木薯品种块根的硒含量在0.017~0.109 mg/kg之间波动,其中NK-10和NZ199两个品种的块根硒含量和硒吸收系数皆大于其它5个品种,然而两者向地上的转运系数却低于其他5个品种;外源硒强化条件下的食用木薯块根的硒含量均大于对照,且随着外源强化量的增加呈先增大后减小的趋势;叶面喷施、根施和"叶面喷施+根施"3种外源硒强化方式的外源硒利用率的变化范围分别为0.55%~1.62%、0.16%~0.61%和0.06%~0.32%。【结论】不同食用木薯品种的天然富硒能力差别较大,其中NK-10和NZ199两个木薯品种的天然富硒能力较强;在外源强化条件下,适量的外源硒能有效提高木薯块根的硒含量,其中叶面喷施方式下的外源硒利用率最高。

【Objective】To provide technical support for the selenium-rich production of edible cassava,natural selenium-rich varieties and high efficient exogenous selenium strengthening technology were screened out through field experiments.【Method】The natural selenium enrichment capacity of 7 cassava varieties was measured under two soil environments with background selenium values of 1.45 mg/kg and 0.63 mg/kg respectively.Then,different amounts of exogenous selenium were applied by spraying,root fertilization,leaf spraying+root fertilization during the tuber swelling period of cassava to study the differences in the content of root selenium and the utilization rate of exogenous selenium in cassava under different strengthening methods and amounts.【Result】Under natural conditions,the selenium content in the root tuber of 7 edible cassava varieties fluctuated between 0.017 and 0.109 mg/kg.The selenium content and absorption efficiency of the root tuber of NK-10 and NZ199 were higher than those of the other 5 varieties,while the transfer efficiency of the two varieties to the ground was lower than that of the other 5 varieties.The root selenium content of cassava root under the condition of exogenous selenium strengthening was all higher than that of the control,and the selenium content of the roots increased at first and then decreased as the amount of exogenous strengthening increased.The utilization rates of exogenous selenium by foliar spraying,root fertilization and leaf spraying+root fertilization were 0.55%-1.62%,0.16%-0.61%and 0.06%-0.32%.【Conclusion】The natural selenium enrichment capacity of different cassava varieties varied greatly,among which NK-10 and NZ199 had strong natural selenium enrichment capacity.Under the condition of exogenous selenium,proper amount of exogenous selenium could effectively improve the selenium content of cassava root,and the utilization rate of exogenous selenium was the highest under foliar spraying.