Fig. 1. Comparison of pollen grains using different viability assays. A. Viable, germinated pollen grain assessed by the B & K method and phase contrast microscopy. B. Viable and nonviable pollen (partially stained, arrows) assessed by Alexander's stain method. C. Viable, fluorescing pollen assessed by FCR method. D. Irregularly stained, nonviable pollen grain from glyphosate-treated DP 5415RR plant assessed by FCR method. Scale bars are 50 µm.