The hydrolysis dynamic of storage reserves in maize seed germination helps to explain differences in inbred lines and hybrid seed vigor

Abstract

Storage reserves composition is directly related to the manifestation of seed vigor. However, the physiological potential expression in inbred lines, as well as hybrids from the storage reserves hydrolysis, is not clear. Thus, the aim of this study was focused on verifying if there are differences in the hydrolysis of seed storage reserve of maize inbred lines or hybrids during germination, and also checking if the changes in hydrolysis are associated with seed vigor. The seeds of inbred lines and hybrids were submitted to germination test, vigor by accelerated aging and cold tolerance. Biochemical profiling (total protein content, soluble proteins, phytate, inorganic phosphorus, starch, and soluble sugars), was temporally determined at 0 h (quiescent seeds), 12 h, 24 h, 30 h, and 48 h after imbibition. The seeds of inbred lines showed a longer time for root protrusion and less vigor when compared to hybrids. The highest hydrolysis rates in inbred lines were observed in phase I and at the end of phase II of germination. In hybrids, the rates remained, on average, constant throughout germination. The greatest differences in the hydrolysis of reserve compounds occur in phase II of germination and differentiate the germination metabolism of hybrids and inbred lines.