Phosphorus Uptake Relates to Vegetative Growth, Grain Yield and Grain Quality in Phosphorus Deprived Rice Genotypes

The response of rice towards phosphorus (P) deficiency, from vegetative growth to crop maturity, grain yield, and grain quality, has been less studied. Importance of acid phosphatases (ACP) under P-deficiency is not well understood. In this study, P-non-application (P0) was compared to P application (P30) at a rate of 30 kg ha-1 in seven rice genotypes grown under field conditions. Biomass, P-uptake, and ACP activity of shoots and roots were measured at 30 and 60 days after transplantation (DAT), while grain yield, grain size and grain-P content were measured at harvest, and grain quality after six months of storage following harvest. At 30 DAT, the biomass of shoots was most affected in Pusa44, but by 60 DAT, biomass of shoots and roots improved in CSR10/IET28816 compared to other genotypes under P0. P-uptake was most affected in Pusa44, while it improved by 60 DAT in CSR10/IET28816 compared to the other genotypes under P0. P-uptake was positively related to root growth, and ACP activity in roots under P0. At harvest, grain yield reduced in Pusa44/IET28075, and grain length reduced in Pusa44. In addition, the total P content of grains reduced in IET28066/IET28061/IET27641 under P0. In stored grains, total antioxidant capacity decreased, and oxidative stress increased to a high extent in Pusa44, while it increased to a low extent in CSR10/IET28816 compared to other genotypes under P0. The results concluded that P-uptake determined plant growth, grain yield and grain quality under P0. CSR10/IET28816 showed greater adaptation to P0 compared to the other genotypes.