Pollen sterility calculation Collect pollen from at least ten florets at anthesis, fix in 70% alcohol. Place 2-3 anthers from each of five florets on a glass slide, and squeeze the pollen out in a drop of 1% iodine potassium iodide (I2-KI) solution with a spear-shaped needle. Fertile pollen grains will be round and well stained, sterile pollen grains will be unstained or partially stained, and withered or round. Using a microscope at magnification 10x10, count fertile and sterile grains in at least three microscopic fields, calculate the proportion that are sterile attribute entity variable_of acronym scale_of method_of