磷高效转基因水稻对潮土无机磷形态的影响

为探究磷高效转基因水稻种植对潮土不同形态无机磷的影响,采用完全随机设计的方法分析了在施磷和不施磷条件下,磷高效转基因水稻OsPT4、磷高效突变体水稻 PHO_2及非转基因亲本日本晴(Nipponbare)在分蘖期、孕穗期、灌浆期、成熟期的种植土壤中无机磷组分特征差异。结果表明:在两种施肥处理下,同一生长期Os PT4和 PHO_2的土壤全磷含量与日本晴无显著差异,同一生长期的 PHO_2土壤有效磷含量、无机磷总量、Ca8-P、Al-P含量均显著低于日本晴,OsPT4的土壤Ca8-P、Al-P含量在灌浆期和成熟期均显著低于日本晴。不施磷条件下,Os PT4土壤Ca_2-P含量在灌浆期、成熟期显著低于日本晴,在施磷和不施磷条件下,同一生长期的Os PT4土壤Ca10-P含量与日本晴无显著差异。与对照相比,磷高效转基因水稻Os PT4强化了对Ca_2-P、Ca8-P、Al-P、Fe-P这4种植物有效性高的无机磷形态的吸收利用,但未对土壤全磷含量造成显著影响。由于仅分析了第一年的种植土壤,水稻磷高效基因的表达对土壤不同无机磷形态以及全磷含量产生的效应还有待于进一步调查研究。

Effects of P-efficient transgenic rice (OsPT4) on inorganic phosphorus fractions of fluvo-aquic soil

High phosphorus(P)-efficiency rice has great potential to take up phosphorus from soil, which may influence soil inorganic phosphorus fractions. We designed an experiment with a completely random design and two phosphorous application rates(0 and 15 g·m^-2) to identify the variation characteristics of inorganic phosphorus fractions in the soil of high P-efficiency transgenic rice(OsPT4), P-efficient mutant rice(PHO2), and non-transgenic parental OsPT4(Nipponbare) in different growing seasons. Under the two phosphorous application rates, no significant difference was observed in total soil phosphorus among OsPT4, PHO2, and Nipponbare during the same growing periods. However, the contents of available phosphorus, inorganic phosphorus, Ca₈-P, and Al-P of PHO2 were significantly lower than those of Nipponbare during the corresponding growing period(P<0.05). At the filling stage and maturing stage, the contents of Ca₈-P and Al-P of OsPT4 were significantly lower than those of Nipponbare under the same P application rate, and the content of Ca₂-P in the soil of OsPT4 was significantly lower than that of Nipponbare under no P application(P<0.05). Under the two treatments, the contents of Ca₁₀-P for OsPT4 showed no significant difference from that of the soil of Nipponbare at the same growing stage(P<0.05). The absorptive capacities for plant-available P fractions(i.e. Ca₂-P, Ca₈-P, Al-P, and Fe-P) in the soil of high P-efficiency rice were higher than those in the soil of Nipponbare. Planting high P-efficient transgenic rice exerted no significant effect on total soil phosphorus. However, the effects of P-efficient transgenic rice on soil inorganic phosphorus fractions and total phosphorus should be surveyed further, on a longer time scale.