A male- and female-sterile mutant of Kentucky bluegrass (Poa pratensis L.) induced by space radiation

► A mutant from 'Nassau' Kentucky bluegrass induced by outer space lost seed producing ability. ► Embryo sac development was investigated at morphology, organ, and tissue levels. ► The results showed that the mutant is likely both male and female sterile. ► The mutant is potentially a useful material for studying seed production in apomictic species.