Antioxidants from maize seeds and accelerated ageing

Abstract

Seed deterioration is expressed as the loss of viability, vigour and quality during ageing. The major causes of seed deterioration refer to free radical-mediated lipid peroxidation, enzyme inactivation or protein degradation, disruption of cellular membranes and damage to genetic integrity. Accelerated ageing (AA) is a simple method for studying the mechanisms of deterioration over short periods. In order to estimate the deterioration rate, seeds of four maize genotypes were exposed to accelerated ageing for different time points (three and six days of AA). In parallel, the same genotypes were evaluated regarding the content of total phenolics, phenolic acids, flavonoids and anthocyanins, as well as regarding total antioxidant capacity. Compared to non-stressed seeds, ageing was evidenced by decreased germination energy (48 .9%), a total number of seedlings (40 .8%) and seedlings growth (70 .0% for root length, 44 .0% and 10 .5% for root and shoot fresh weight, 5 .0% for seed rest fresh weight, 12 .0% and 11 .5% for root and shoot dry weight, 15 .3% for seed rest dry weight, respectively), as well as by an increased number of abnormal seedlings (22 .0%). Correlation analysis revealed that higher content of total phenolics, flavonoids and anthocyanins contributed to a higher radical scavenging activity, which was reflected through a lower level of deterioration rate, both regarding the energy of germination and overall seedling performance.