Fig. 1

A Individual stages of flower (1F–10F) development in yellow lupine. After completing the dehiscence (1F–3F), anther opening occurred at approximately the fourth phase of flower development (4F) when the flower was completely closed. Then, pollination, fertilization, and pod setting and development occurred (5F–10F). The first and second stages of flower development correspond to the first stage of late anther development (LAD); the third and fourth stages of flower development correspond to the second stage of LAD; the fifth stage of flower development is parallel to the third stage of LAD; and the sixth and seventh stages of flower development correspond to the fourth stage of LAD. B-I The anatomical structure of yellow lupine anthers in different stages of late development. Cross-sections were stained with toluidine blue, and anthers were photographed by light microscopy. C – connective, VB – vascular bundle, Se – septum, StR – stomium region, P – pollen grain, En – endothecium, E – epidermis, T – tapetum. Scale bars = 1 cm (A); 50 μm (B-I)