Fig. 1. Anther culture process of Yongyou 1540 (YY1540) and Hanyou 73 (HY73). A, Anthers on induction culture medium. Scale bar, 2 cm. B, Anthers producing calli at approximately 40 d post-culture. Scale bar, 1 mm. C, Calli showing green spots. Scale bar, 1 mm. D, Green shoots differentiated from calli. Scale bar, 2 mm. E, Albino shoots formed from calli. Scale bar, 1 cm. F, Effect of temperatures on shoot regeneration. Data represent mean ± SD (n > 100). Different lowercase letters in the same column for the same variety indicate significant differences between treatments (P < 0.05). G, Green plantlets regenerated from calli. Scale bar, 2 cm. H, Adventitious root formation. Scale bar, 1 cm. I, Acclimatization of regenerated plantlets in a greenhouse. Scale bar, 2 cm. J, Regenerated plants in the field. Scale bar, 10 cm. K, PCR screening using insertion/deletion (InDel) markers spanning 12 chromosomes (Chr.). Y, YY1540 F1 plants; Lanes 1-19, Regenerated doubled haploid plants. L and M, Ploidy analysis of diploid (seedling #35, L) and haploid (seedling #55, M) regenerated plants by flow cytometry. Histograms show relative nuclear DNA content.