The flux rate of Ca2+ into embryo can be used to evaluate the vigour level of maize seeds

Seed vigour is an important trait and is often used to evaluate seed quality. A rapid and accurate evaluation of seed vigour is very important for agricultural production. Ca2+ is an important secondary messenger in plants, responding to various biotic and abiotic stimuli by Ca2+ flux into cytoplasm. To the best of our knowledge, however, no report has been published about seed vigour and Ca2+ influx. In this study, we used two hybrid maize (Zea mays L.) lines and their corresponding female parent lines as materials, and performed ageing and 'ageing + priming' treatments to obtain seeds with different vigour levels. After seeds were imbibed for 24 h, the intact seeds or embryos were used as materials for determining the Ca2+ influx rate using non-invasive micro-test technique (NMT). Results showed that, with the intact embryos as materials, the Ca2+ influx rate showed higher stability and higher values. Correlation analysis indicated that there was a significant, positive linear correlation between the shoot dry weight vigour index and Ca2+ flux rate into embryo. The results demonstrated that the Ca2+ influx rate can be used to evaluate the vigour levels of maize seeds.