We tested whether root exudation confers high P acquisition efficiency (PAE) in rice by quantifying ¹³C allocation and rhizosphere phosphatase activity for three contrasting genotypes. Phosphatase activity per root surface was similar for all genotypes, indicating that it is not conferring PAE in rice. DJ123 allocated more ¹³C from shoots to roots compared to Nerica4 and Chomrong Dhan in accordance to increased root biomass of this genotype. The allocation of ¹³C from roots to the soil was similar between genotypes indicating no difference of root exudation. However, DJ123 showed lower PAE compared to the other two genotypes. We conclude that in the tested genotypes, root systems size rather than root exudation confers PAE.

我们通过量化三种相反基因型的¹³ C分配和根际磷酸酶活性，测试了根系分泌物是否赋予水稻高P吸收效率（PAE）。对于所有基因型，每个根表面的磷酸酶活性都相似，表明它不赋予水稻PAE。DJ123分配更多¹³ C来自芽于根据本基因型的根生物量相比增加Nerica4和Chomrong香谷根。基因型之间从根到土壤的¹³ C分配相似，表明根系渗出没有差异。然而，与其他两种基因型相比，DJ123显示出较低的PAE。我们得出结论，在测试的基因型中，根系大小而不是根系分泌物赋予PAE。