Formation of panicles and hermaphroditic florets in wild-rice

Formation of panicles and flower primordia in wild-rice, Zizania palustris L., was investigated by scanning electron microscopy (SEM). Floral development involved the formation of both staminate and pistillate floral primordia in the wild-rice spikelet. The SEM study indicated that wild-rice shared a similar developmental process in panicle formation with that of cultivated white rice (Oryza sativa L.). Variations of hermaphroditic floret formation and sex expression were observed in the transition zone between the male and female portions of the panicles in several different wildrice populations. The frequencies of plants with hermaphroditic floret formation ranged from 27% in the Pistillate population (Z. palustris L.) to 70% in the Peterson Pond (Zizania aquatica L.) population. There was a high degree of phenotypic variation in sex expression in the transition zone of panicles from different wild-rice populations.