供磷水平对不同磷效率玉米氮、钾素吸收和分配的影响

在砂培条件下,以磷高效利用型玉米(KH5)和磷低效利用型玉米(西502)为材料,研究了低磷(Pi25μmol/L,LP)和正常供磷(Pi2mmol/L,NP)2个供磷水平对其氮、钾素吸收和分配的影响。结果表明,磷高效利用型玉米氮钾素吸收和干物质积累受低磷处理的影响较小,表现出对氮、钾的高效吸收。正常供磷水平下,磷低效利用型玉米氮、钾素吸收量和干物质积累量显著高于磷高效利用型,但其氮、钾吸收和干物质生产能力远低于后者。低磷处理使玉米干物质和氮钾营养向根系分配的比例增加,磷低效利用型玉米这种趋势更为明显,反映其耐低磷能力较弱。

Effects of phosphorus supply on nitrogen and potassium absorption and distribution of maize with different phosphorus efficiency

A high phosphate efficient (HPE)maize (Zea Mays L.) variety (KH5)and a low phosphate efficient(LPE) maize variety (Xi 502) were planted in sand medium and supplied with low(Pi, 25(μmol/L), LP)and normal (Pi, 2(mmol/L), NP) phosphorus to study the effects of phosphate supply on nitrogen (N) and potassium (K) absorption and distribution. Result showed that HPE maize performed a higher N and K absorption efficiency in low P regiment, its N, K absorption and dry matter accumulation were less affected by low P supply. In low P condition, N and K absorption and dry matter production capability of LPE maize was much lower than that of HPE maize, despite its significantly higher N, K uptake and dry matter accumulation when growing in normal P condition. Low P supply caused an increase in the rate of dry matter and N, K distribution in root, and this kind of trend is more striking in LPE maize, reflects it's less tolerant to low P stress.