Maternal inbred line is a decisive factor determining the vigour of F1 hybrid maize seeds

The underlying mechanisms and patterns of seed vigour differences in reciprocal cross F1 hybrids have remained an unsolved problem. In this study, about 70% of maize F1 lines generated in reciprocal cross combinations showed significant differences in seed vigour. Correlation analysis showed that seed vigour index (VI), germination index (GI) and dry weight per seedling (DWS) of hybrids derived from reciprocal crosses could be attributed to significant maternal effects. It was also observed that there were significant positive correlations between VI of reciprocal cross hybrids and DWS ( R 2 = 0.83), and between DWS and dry weight of seed embryo (DWE). Therefore, DWE is a key factor determining the maternal effects on seed vigour of F1 hybrid seeds. α‐amylase activity showed significant differences in crosses showing differences in DWS and non-significant differences in crosses without difference in DWS. In conclusion, the maternal inbred line is the decisive factor affecting the vigour of F1 hybrid seeds by influencing DWE and starch metabolism. Selecting high vigour inbred lines as the maternal parent is key to high vigour seed breeding and production.