**5. Conclusions**

It is evident from previous literature that phosphorus fertilizer will significantly increase the whole plant growth, leaf photosynthesis, dinitrogen fixation of nodules, and yield of seed. In this study, we further found no significant di fferences in these physiological parameters between the low-phytate line and normal-phytate cultivar under any fertilization conditions. While seed crude protein and lipid concentrations were found to be higher in the higher levels of P application in both the low-phytate line and normal-phytate cultivar, seed crude protein concentration was higher in the low-phytate line than in the normal-phytate cultivar. These results sugges<sup>t</sup> that reducing phytic acid in seeds does not a ffect growth after leaf photosynthesis, dinitrogen fixation of nodules, or final yield of plants following germination and stand establishment. P application had little e ffect on seed Zn, Fe, and Mn, but increasing P fertilization increased seed Cu by 1.7-fold regardless of genotype or cultivar background. The lower molar ratios of phytic acid to Zn, Fe, Cu, and Mn in seed of the

low-phytate soybean lines as compared with the normal-phytate soybean cultivars should enhance the bioavailability of these microelements.

**Author Contributions:** Conceived and designed the experiments, N.A.T., H.S.; breeded and selected the low phytate soybean lines, H.S.; performed experiments, N.A.T., Q.D. and K.E.; wrote the paper, N.A.T. and H.S.; data analysis, writing and editing, V.R.

**Funding:** This research was funded by Grans-in-Aid for Scientific Research, KAKEN, from Japan Society for the Promotion of Science: Grant Number 15K14678 and 18K05948 to Saneoka H.

**Conflicts of Interest:** The authors declare no conflict of interest.
