Cytological observations in abortion formation and morphological character of pollen in seedless chestnut rose (Rosa sterilis)

•As compared with chestnut rose, the flowers produced by seedless chestnut rose was normal, but the pollen development was abnormal.•Pollen studies revealed that pollen grains were deformed, uneven in size, low in yield and low in vigor.•Abnormal chromosome behavior during meiosis may be the main cause of pollen abortion in seedless chestnut rose.