Hydropriming associated physiological and biochemical changes responsible for the enhanced planting value of maize hybrid and its parental line seeds

Authors: HEENA RASOOL MIR, SHIV YADAV, SANGITA YADAV

Abstract: Hydropriming has the potential to ameliorate the stress-induced ill effects on yields of the crop plants and quality of seed produced. In the present study, half of the fresh seeds of maize hybrid, PEHM 5 and its parental lines (Female - CM 150, Male - CM 151) were subjected to accelerated aging test for bringing down the viability and vigour, thereby creating low vigour lots while high vigour lots consisted of fresh seeds, which were hydroprimed (30 h at 25 °C). Half of the hydroprimed seeds were surface dried while the other half were redried back to the original moisture contents. All the seed lots after treatments were evaluated for performance of physiological and biochemical parameters viz.: germination test, vigour index, electrical conductivity of seed leachates, and antioxidant enzyme activities. Results divulged significant improvement of germination and the seedling growth parameters in both the treatments: surface dried and redried after hydropriming over untreated seeds. Significant improvement was observed in root and shoot lengths, dry weight of seedlings, and vigour indices of surface dried maize seeds, and this treatment also resulted in earlier and synchronized germination. A steady increase was also noted in the activities of four key antioxidant enzyme systems: peroxidase (POX), superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR) in both high and low vigour seed lots of hybrid and its parental lines upon hydropriming irrespective of surface dried or redried strategies. It is, therefore, suggested that hydro priming could improve the seed vigour by protecting the seed from oxidative damage by reactive oxygen species by the increasing activities of antioxidant enzymes. The surface dried seed showed all the benefits of seed priming in terms of seed quality parameters and enhanced antioxidant defense mechanism as compared to redried seeds. Therefore, surface drying could be promulgated as an effective and simple technique to mitigate the ill effects while sowing maize seeds under unfavorable growing conditions.

Keywords: Antioxidant enzymes, hydration, maize, MGT, priming, redried, ROS, surface dried, viability, vigour

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