磷高效转基因水稻全生育期根际土壤磷组分特征差异

为了解磷高效转基因水稻对土壤无机磷和有机磷形态特征及磷酸酶活性的影响,以两种磷高效转基因水稻OsPT4(磷高效吸收材料)和PHO2(磷高效突变体材料)及其非转基因亲本水稻日本晴为供试材料,采用盆栽试验研究磷高效水稻的种植对根际土壤磷素形态及其有效性的影响.结果表明,水稻OsPT4和PHO2的根干重、生物量和磷素积累量均有不同程度的增加,磷高效转基因水稻OsPT4分蘖期和扬花期根际土壤的有效磷浓度与亲本差异显著;在四个生育期内,磷高效转基因水稻OsPT4和磷高效突变体PHO2根际土壤各个磷形态的含量变化趋势与其亲本日本晴基本一致,OsPT4和PHO2水稻根际土壤无机磷组分含量表现为Ca₁₀-P >O-P >Ca₈-P >Fe-P >Al-P >Ca₂-P,有机磷浓度表现为中活性有机磷 >中稳性有机磷 >高稳性有机磷 >活性有机磷,且各时期根际土壤的不同磷形态含量和同期日本晴相比均差异不显著.磷高效转基因水稻材料OsPT4、磷高效突变体水稻材料PHO2根际土壤磷酸酶活性和同期日本晴相比均差异不显著.研究表明磷高效转基因水稻材料OsPT4和磷高效突变体材料PHO2一年期种植对根际土壤的磷素形态和磷酸酶活性的影响不显著.

Phosphorus Fractions in Rhizospheric Soil of High-Phosphorus Efficiency Transgenic Rice During Its Growth Period

High-phosphorus(P) efficiency rice has great potential to take up phosphorus from soil, which may influence the status of soil phosphorus fractions. We designed an experiment to identify the characteristics of phosphorus fractions in rhizospheric soil of a high-P efficiency transgenic rice during its growth period using japonica rice cultivar Nipponbare(CK) and its high-P efficiency transgenic rice(OsPT4) and high-P efficiency mutant(PHO2) as model plants. Alkaline phosphatase activity in rhizospheric soil was also examined. Significant higher root dry weight, biomass and P accumulation were observed in OsPT4 and PHO2 than in CK. PHO2 also had higher phosphorus use efficiency than Nipponbare did. Compared with the control, available phosphorus concentrations in rhizospheric soil of OsPT4 was significantly higher at tillering stage, whereas it was significantly lower at heading stage. Phosphorus fractions in OsPT4 and PHO2 rhizospheric soils had no significant difference from those of Nipponbare during their growth period. Inorganic P fractions were in order:Ca₁₀-P >O-P >Ca₈-P >Fe-P >Al-P >Ca₂-P. Of organic P fractions, moderate labile organic phosphorus was dominant, followed by resistant organic phosphorus and moderate-resistant organic phosphorus, while labile organic phosphorus was the lowest. No significant difference was observed in the activity of soil alkaline phosphatase between OsPT4 and PHO2 and Nipponbare during their growth period. High-P efficiency rice OsPT4 and PHO2 had no significant effects on phosphorus fractions and alkaline phosphatase activity in rhizospheric soil in the first year.