摘要
铁膜是水稻根系表面形成的铁(氢)氧化物胶膜。它不仅增强根系对水生环境的适应,而且显著影响植株养分吸收。但如何通过调控根表铁膜形成,提高水稻籽粒硒含量还有待进一步探索。本研究在弱酸性(pH 6.1)土壤盆栽条件下,对水稻植株进行不同水平的磷铁比、过氧化尿素及干湿交替处理,研究了上述3种铁膜调控技术对水稻根表铁膜形成及籽粒硒累积的影响。结果表明:与常规施肥处理相比,磷铁比1∶5处理的根表铁膜含量和籽粒硒含量均有显著提高。90 kg∙hm^(−2)过氧化尿素处理的根表铁膜含量和籽粒硒含量明显高于不施用过氧化尿素处理。另外,持续淹水处理的根表铁膜含量和籽粒硒含量显著高于对照和干湿交替处理。相关分析表明,磷铁比和过氧化尿素处理试验条件下,非结晶态和结晶态铁膜含量与籽粒硒含量都显著线性相关。正交试验当中,根表铁膜形成量最高且籽粒硒含量增加最显著的铁膜调控技术是磷铁比为1∶1、过氧化尿素用量为90 kg∙hm^(−2)、持续淹水组合处理,该条件下籽粒硒含量为0.116μg∙g^(−1),是对照的2.01倍。方差分析表明,3种调控技术对根表铁膜含量和水稻籽粒硒含量影响程度顺序为过氧化尿素处理>干湿交替处理>磷铁比处理。综上所述,铁膜调控技术能促进水稻根表铁膜形成及硒在根系累积,从而增加水稻籽粒硒累积,该研究结果对富硒水稻生产具有科学意义。
Iron plaque(IP)is a colloidal membrane consisting of iron(hydr)oxides formed on the root surface of rice(Oryza sativa),which not only enhances the adaptation of roots to the surrounding waterlogging but also affects nutrient uptake by rice.However,further exploration of methods to increase the Se accumulation in rice grains by regulating IP formation on the rice root surface is needed.Experiments on rice plants with different levels of phosphate-iron ratios(P/Fe),urea peroxide(UP),and alternation of wetting and drying(AWD)treatments were conducted under pot cultivation with mildly acidic(pH=6.1)soil conditions to investigate the effects of these three IP-controlling techniques on IP formation and Se accumulation in grains.The results indicated that the IP content on the root surface and the grain Se content after a 1∶5 P/Fe treatment were significantly higher than that after a 1∶0 P/Fe treatment.The IP content and grain Se content after 90 kg∙hm^(−2) UP treatment were significantly higher than that without UP.When P/Fe was less than 1∶3 or the UP dose was greater than 60 kg∙hm^(−2),the variation trend of the grain Se content became steady.In ad-dition,the IP content and grain Se content after long-term waterlogging treatment were remarkably higher than those of the control(irrigation to maintain a shallow water layer on the soil surface before naturally drying at the grain-filling stage)and AWD treatments.Although the IP content after one cycle of AWD treatment was lower than that after long-term waterlogging,the grain Se contents were similar.Correlation analysis suggested that both amorphous and crystalline IP contents presented a significant linear correlation with the grain Se content under the P/Fe and UP treatments,whereas this phenomenon did not occur under the AWD treatment.However,the linear coefficient of the correlation between the grain Se content and crystalline IP content was higher than that between the grain Se content and amorphous IP content under the P/Fe treatment,whereas the result was the opposite in the UP treatment.In orthogonal experiments,the IP controlling techniques harvesting the highest IP formation and the most remarkable increase in the grain Se content were the treatment combination of P/Fe of 1∶1,UP of 90 kg∙hm^(−2),and long-term waterlogging.The grain Se con-tent after this treatment combination was 0.116μg∙g^(−1),which was 2.01 times greater than that of the control(1∶0 P/Fe,no UP applic-ation,and conventional water management).The analysis of variation indicated that the effect sequence of the three controlling tech-niques on the IP content and grain Se content was UP>AWD>P/Fe.The effect of the P/Fe ratio on the IP content and grain Se content under this combination treatment could be neglected.In summary,IP controlling techniques,including regulating P/Fe,applying UP,and conducting AWD treatment,can promote IP formation on the root surface and Se accumulation in roots,thereby increasing Se ac-cumulation in rice grains.The results of this study are scientifically relevant for Se-enriched rice production.
作者
杨旭健
田宇豪
沈宏
YANG Xujian;TIAN Yuhao;SHEN Hong(College of Natural Resources and Environment,South China Agricultural University,Guangzhou 510642,China)
出处
《中国生态农业学报（中英文）》
CAS
CSCD
北大核心
2022年第7期1174-1185,共12页
Chinese Journal of Eco-Agriculture
基金
广东省自然科学基金项目(2021A1515012113)
广东省教育厅普通高校重点领域研究项目(2020ZDZX1002)资助。
关键词
水稻
硒
根表铁膜
过氧化尿素
磷铁比
干湿交替
Rice(Oryza sativa)
Selenium(Se)
Iron plaque on root surface
Urea peroxide
Phosphate iron ratio
Alternation of wetting and drying
作者简介
通信作者:沈宏,主要研究方向为生物激素与功能性肥料研制、作物根层调控与土壤植物健康诊断技术。E-mail:hshen@scau.edu.cn;杨旭健,主要研究方向为植物根际营养元素行为及养分吸收调控技术。E-mail:zh_yangxujian@scau.edu.cn。
