磷和不同价态硒对小麦硒吸收转运的影响

【目的】 研究小麦在施磷情况下对不同价态外源硒的吸收及转运规律,阐明小麦对硒吸收与转运的影响,分析不同价态硒在小麦体内的转运与分配。【方法】 采用盆栽试验,研究在施磷条件下硒酸盐和亚硒酸盐处理对小麦硒的吸收与转运。【结果】 低量硒酸盐处理中,低磷和高磷处理较不施磷处理的小麦硒肥利用率分别提高了96%和128%;高量硒酸盐处理中,低磷和高磷处理较不施磷处理的小麦硒肥利用率分别提高了78%和123%。低量亚硒酸盐和高量亚硒酸盐处理中,高磷处理较不施磷处理小麦硒肥利用率降低了50.7%和55.6%。施用硒酸盐时,高磷处理较不施磷处理小麦根、茎、叶及穗的硒含量分别增加了23.0%、17.0%、64.6%和62.1%;施亚硒酸盐时,高磷处理较不施磷处理小麦根、茎、叶及穗的硒含量分别降低了71.3%、72.1%、80.6%和73.8%。施用硒酸盐时,在不施硒、低硒及高硒条件下,高磷处理小麦植株硒富集系数较不施磷处理分别增加28.9%、60.6%和50.5%;施用亚硒酸盐时,在低硒及高硒条件下,高磷处理小麦植株硒富集系数较不施磷处理分别降低65.3%、72.3%。【结论】 磷素可以活化土壤中稳定态硒,提高了硒酸盐的生物有效性。施磷降低了土壤pH值,促使土壤中可溶态硒和可交换态硒转化成铁氧化物态硒和有机态硒,而铁氧化物态硒与有机态硒很难被作物吸收利用,造成当磷肥与亚硒酸盐配施时降低了作物对亚硒酸盐的吸收。

Effects of Phosphorus and Different Valence Selenium on the Absorption and Transport of Selenium in Wheat

【Objective】 The project aims to study the absorption and translocation of exogenous selenium under different phosphorus levels in wheat, and to elucidate the effects of wheat on selenium absorption and translocation and to analyze the translocation and distribution of different selenium in wheat.【Method】 Pot experiments were conducted to study the uptake and translocation of selenium by selenate and selenite in wheat with phosphorus application. 【Result】 In the treatment of low amount of selenate, the utilization rate of selenium fertilizer in wheat treated with low phosphorus and high phosphorus was increased by 96% and 128% respectively compared with that of the treatment without phosphorus; In the treatment of high content of selenate, the utilization rate of selenium fertilizer in wheat with low phosphorus and high phosphorus treatment was increased by 78% and 123%, respectively compared with that of the treatment without phosphorus. In low amount of selenite and high Liangya selenate treatment, the wheat utilization rate of Se fertilizer of high phosphorus treatment was decreased by 50.7% and 55.6% compared with that of treatment without phosphorus. When applying selenate, the selenium contents in the roots, stems, leaves and panicles of high phosphorus treatment were increased by 23%, 17%, 64.6% and 62.1% compared with those of treatments without phosphorus; When applying selenite, the selenium contents in the roots, stems, leaves and panicles of high phosphorus treatment were decreased by 71.3%, 72.1% 80.6% and 73.8% compared with those of treatment without phosphorus. When applying selenate, wheat plant selenium enrichment coefficient of high selenium treatment increased by 28.9%, 60.6% and 50.5% respectively compared with those of treatments without selenium, with low selenium and with high selenium. When applying selenite, under the condition of low selenium and high selenium, wheat plant selenium enrichment coefficient of high phosphorus treatment decreased by 65.3% and 72.3% compared with that of the treatment without P fertilizer.【Conclusion】 Phosphorus can activate the stable selenium in soil, thus improving the bioavailability of selenate. The application of phosphorus reduces the pH value of the soil and promotes the transformation of soluble selenium and exchangeable selenium in soil into iron oxide state selenium and organic selenium. But the iron oxide selenium and organic selenium are difficult to be absorbed by crops, which reduce the absorption of selenite when phosphorus fertilizer is used together with selenite.