Effect of hydropriming on physiological and biochemical activities of high and low vigour seed lots of a maize hybrid and its parental lines

Abstract

A study was conducted to evaluate the influence of hydropriming on high and low vigour seed lots of maize hybrid (VQPM 9) and its parental lines VQL 1 (female) and VQL 2 (male). Seeds were subjected to hydropriming (30h) followed by redrying to original moisture content. The primed and unprimed seeds were assessed for physiological and biochemical seed quality parameters. The results indicated that priming increased physiological performance in terms of increased germination percentage, shoot length, root length, dry matter production and vigour index in both high (I) and low (II) vigour seed lots of VQL 1, VQL 2 and VQPM 9. Increase in percentage of germination of VQL 1 (I) and (II) by 12.6% and 3.8%; that of VQL 2 (I) and (II) by 16.1% and 3.3% whereas in VQPM 9 (1) and (II) by 4.2% and 4.8% respectively. The increase in vigour indices paralleled that of seedling length and dry weight. The increase in vigour index I ranged from 5% to 11.3% and 14.4% to 54.8% in low and high vigour seed lots, respectively. Similarly, the increase in vigour index II ranged from 3.7% to 9.5% and 10.3% to 42.7 % in low and high vigour seed lots, respectively. The priming improved germination might be due to enhanced repair of membranes, which significantly reduced leakage of electrolytes. Water-soluble sugars content of leachate from primed seeds were found significantly low as compared to unprimed seeds. The activities of hydrolytic enzymes, amylase and dehydrogenase in high and low vigour lots were greater than unprimed controls and ranged from 1.0% to 11.7% and 1.4% to 8.4%, respectively. In hydro-primed seeds of both high and low vigour seeds lots of parental lines and their hybrid, significantly increased activities of antioxidant enzymes; superoxide dismutase, peroxidase and catalase, over control was recorded. From the present study, it was concluded that priming of VQPM 9 maize hybrid and its parental line seeds with water for 30h was found to improve the physiological seed quality parameters significantly which was supported by the pattern of increased enzymatic activities. It was also recorded that the seed priming effect was more pronounced in high vigour seeds than in low vigour seed lots.