甘蓝型油菜幼苗体内磷组分差异与磷高效关系的研究

利用盆栽土培和营养液培养的方法，研究了甘蓝型油菜磷高效品种97081和磷低效品种97009在正常磷和低磷胁迫下幼苗植株生长、磷的吸收累积、植物磷组分以及酸性磷酸酶活性的差异。结果表明，缺磷条件下，97081品种的干物质重和磷累积量分别比97009高85.7%和50.0%，并且单位磷含量可以生产较多的干物质，具有较强的磷的吸收和利用效率。两品种中不可溶性有机磷、可溶性有机磷和无机磷含量都随着营养液磷水平的增加而提高。低磷胁迫时，根部不可溶性有机磷含量97009显著下降。两品种可溶性有机磷占总磷的比例均表现为下部叶＞上部叶；97081根和下部叶可溶性有机磷含量及其比例均高于97009。97081根部无机磷含量高于97009，但其所占全磷比例却较低。缺磷处理，上部叶酸性磷酸酶（APase）活性两品种无显著差异；但根中和下部叶APase活性97081显著高于97009。这与甘蓝型油菜高效品种具有较强的磷吸收和再利用能力密切相关。

Genotypic variation in phosphorus fractions and its relation to phosphorus efficiency in seedlings of Brassica napus L.

Rapeseed (Brassica napus) needs enough phosphorous (P) in its early growth stage and thus is very sensitive to P deficiency. Two genotypes of rapeseed, i.e., a P-efficient cv. 97081, and a P-inefficient cv.97009, were used to study the growth, P uptake and utilization, plant P fractions and the activity of acid phosphatase (APase) under normal and low P nutrient status using soil pot and hydroponic experiments. The results showed that cv. 97081 possessed high effiency of P uptake and utilization since its dry biomass and P accumulation increased by 85.7% and 50.0%, respectively, in comparison with cv. 97009 under P deficient condition. In both rape cultivars, all the P fractions, including insoluble organic P, soluble organic P and inorganic P, increased with P levels in the medium. Low P stress reduced the concentrations of insoluble organic P in the roots of cv. 97009, but not cv. 97081. The ratio of soluble organic P (ester-P) in total P was higher in bottom leaves than upper leaves. Both the concentration and ratio of ester-P of cv. 97081 were higher than that of cv. 97009. The concentration of inorganic P in the roots of cv. 97081 was higher than that of cv. 97009; however, the ratio was much lower compared with cv. 97009. P-efficent cv. 97081 had greater activity of APase in roots and bottom leaves under low P stress than P-inefficient cv. 97009 although there was no significant difference in upperleaves between the two cultivars. The results suggested that the concentrations and distributions of P fractions and the activity of APase were closely related to P uptake and utilization efficiency of Brassica napus.