Comparison of starch granule sizes of maize seeds between parental lines and derived hybrids suggests a maternal inheritance trend

Abstract

Maize (Zea mays) starch is an important agricultural commodity that serves as food, feed, and a raw material for industrial purposes. It is organized into starch granules (SG) inside amyloplasts and is highly accumulated in endosperms. Maize hybrids, which exhibits heterosis over their parents, are globally grown due to higher vigor of the F1 plants. However, the parental effect on the size of SG in F1 hybrid seeds remains unclear. Here we compared the seed SG sizes among two parental inbred lines (Chang7-2 and Zheng58) as well as their reciprocal hybrids. SG was observed in situ and in vitro with SEM. The size of seed SG in hybrids was more like that of female parents, especially for large SG population. Thus, the control of SG size exhibits a maternal inheritance trend in the context of plastid (amyloplast) inheritance. Our results provide some insight on selecting parental inbred lines for breeding maize hybrids with different SG sizes.