Seed Priming with PEG Improves the Growth, Photosynthesis, and Recovery Capacity of SUB1DRO1 and DRO1 Near-Isogenic Lines Under Drought

This study evaluated the effects of polyethylene glycol concentrations in enhancing the physiological performance of the rice varieties and their recovery ability after drought stress. The experiment comprised of IR64, NIL-SUB1DRO1, and NILDRO1. Seed priming was conducted by submerging 5 g of samples in petri dishes containing 100 mL of 5% and 10% PEG solutions. Drought stress significantly reduced all the growth traits, with the susceptible genotypes IR64 recorded highest reduction of shoot length 36%, tiller number 41.3%, shoot dry weight 77%, and root dry weight 72% compared to non-primed NILDRO1 and NIL-SUB1DRO1 with reduction in shoot length 34–35%, tiller number 34–45%, root dry weight 60–66%, and shoot dry weight (70–71%). Similar results were recorded for IR64, Pn, 63%, gs 78% E 66%, and RWC 66%, respectively, compared with NILDRO1 (55%, 60%, and 58%), while NIL-SUB1DRO1 showed reductions of 55%, 50%, and 54%. PEG 5% and 10% significantly enhanced primed IR64 Pn (29–57%), gs (70%), E (56–64%), and RWC 65%. During the recovery phase, primed seedlings showed a more rapid restoration of growth and photosynthetic efficiency than the non-primed seedlings. PEG 5% and 10% were effective in mitigating drought stress and enhanced recovery ability of rice.