低磷水稻根表铁膜形成对养分吸收的影响

Effects of Phosphorus on Iron Plaque on Root Surface of Rice Seedlings and Nutritional Absorption

目的:分析水稻根表铁膜形成及其对水稻养分吸收的影响。为水稻施肥提供参考。方法:本试验以3种不同类型的水稻品种:磷敏感型水稻通粳981(TJ981)、耐低磷水稻郑旱6(ZH6)和根系扩展型水稻镇稻99(ZD99)为材料,采用营养液培养法,研究低磷(CK∶LP=25∶1)导致根表形成铁膜,营养元素(Fe、Cu、Mg、Ca、Zn、K等)在植株机体内的积累,以及根表铁膜对根系吸收营养元素的影响。结果:低磷处理水稻根系表面形成红棕色的铁膜,不同基因型水稻品种根表铁含量(以DCB-Fe含量计)存在差异,且铁膜的形成是不可逆的;水稻体内Fe含量显著增加;Cu在根部组织中含量显著增加,但地上部分变化不明显;其它元素(Mg、Ca、Zn、K)在不同水稻品种或同一品种的不同组织中的含量变化不一。结论:低磷导致根表铁膜的形成,且铁膜可促进水稻体内铁、铜含量的增加,但其对其它营养元素的吸收影响并未呈现一定的规律性。

Objective:To provide reference for the rational fertilization of rice growth in agricultural production,the formation and mechanism of iron membrane on the rice root surface by low phosphorus were studied,and effects of iron plaque on nutrient absorption in rice were analyzed.Methods:Three different types of rice varieties were used in this experiment,including Phosphorus sensitive rice Tongjing981(TJ981),Low phosphorus tolerant rice Zhenghan6(ZH6)and root extension type rice Zhendao99(ZD99)as testing materials.It used nutrient solution culture and studied the formation of root iron membrane caused by low phosphorus.The accumulation of nutrient elements(Fe,Cu,Mg,Ca,Zn,K,etc.)in plant body were collected,and the effects of iron surface film on root absorption of nutrient elements were studied.Results:It was showed that iron plaque was formed on the surface of rice root,and there were differences in the thickness of iron plaque in rice with different genotypes,and the formation of iron film was irreversible.In addition,Fe content in rice increased significantly,and Cu content in root increased significantly,but in leaves Cu did not change significantly.Other elements(Mg,Ca,Zn,K)vary in different rice varieties or in different tissues of the same variety.Conclusion:These indicated that low phosphorus resulted in the formation of root iron membrane,and iron membrane promoted the increase of Fe and Cu contents in rice,but the absorption of other nutrients did not express relationship by iron membrane.