Pollen is essential for seed production and serves as the primary means of gene fl ow in outcrossing species like switchgrass (Panicum virgatum L.). There is a lack of information on basic pollen biology in switchgrass. This study
investigated pollen viability, pollen longevity, and pollen size using different materials, including the tetraploid cultivar Alamo, the octoploid cultivar Cave-in-Rock, and transgenic Alamo plants. Pollen grains were collected from fi eldgrown Alamo and Cave-in-Rock plants, and greenhouse-grown transgenics.