Fig. 4

Phenotypic comparison of different flowers. a The stamens of maintainer line SP2, CMS SP2-A, TMS SP2S-under low temperature, TMS SP2S-under high temperature, CMS SP2-A + CIMS, and TMS SP2S + CIMS. The flowers of maintainer line SP2 (b, fertile), CMS SP2-A (c, partially sterile), and CMS SP2-A + CIMS (d, sterile). Pollen grains in the anthers of maintainer line SP2 (e, fertile), CMS SP2-A (f, partially sterile), and CMS SP2-A + CIMS (g, sterile). Scale bar = 50 μm