Phenotypic characterization of WT lettuce and Lsfancm-1mutant. A, Seedlings of WT and Lsfancm-1 before bolting. B, Mature plants of WT and Lsfancm-1 at flowering. C, Capitula of WT and Lsfancm-1. D, Florets of WT and Lsfancm-1. E and F, Alexander-red staining of pollen grains from WT and Lsfancm-1. The arrowheads indicate the aborted pollen grains, which are light-colored and smaller in size than the viable ones. G and H, Comparison of the fractions of viable pollen grains and seed set in WT and Lsfancm-1, respectively. Error bars indicate SD. n =21 for WT and Lsfancm-1 (G), n =45 for WT and Lsfancm-1 (H).**P ≤ 0.01. Two-tailed Mann–Whitney test. I, Example showing normal seed (left) versus aborted seed (right). Bars =10 cm (A and B), 1 mm (C and D), 50 µm (E and F), 1 mm (I).