Maize Inbred Lines and Hybrid Analysis

Maize inbred lines B73, Zheng 58 and M6007 and hybrid Hi II were used in this study. B73 and M6007, corresponding to the WT lines of maize GMS mutants lob30 and ms7‐6007, respectively, were originally obtained from the Maize Genetics Cooperation Stock Center (http://maizecoop.cropsci.uiuc.edu). Zheng58 and Hi II are maintained in our laboratory. All plants were grown in the experimental stations of the University of Sciences and Technology Beijing (USTB) in Beijing and Sanya, excepting T₀ transgenic plants that were grown in a greenhouse under long‐day conditions (16 h/8 h (day/night) at 26 °C/22 °C). A Canon EOS 700D digital camera and an SZX2‐ILLB stereomicroscope (Olympus, Japan) were used to photograph the images of tassels and anthers, respectively. Pollen grains were stained with a 1% I₂‐KI solution and captured using an Olympus SZ51 microscope (Olympus, Japan) (Zhang et al., 2018a (link)).