Gynodioecy

Gynodioecy is a dimorphic breeding system in which male-sterile individuals (i.e. females) coexist with hermaphroditic individuals in populations. For example, populations of Lobelia siphilitica and Lobelia spicata in Massachusetts are gynodioecious; the hermaphrodites within both populations were found to be self-compatible; and mixed mating occurred (Miller and Stanton-Geddes 2007). Consequently, reproduction in gynodioecious species might occur within the hermaphrodite (i.e. for self-compatible hermaphrodites) or involve a hermaphrodite and a female. The genetic basis of gynodioecy involves both cytoplasmic and nuclear control (Delph et al. 2007), with ecological and genetic factors suggested to be important in regulating the frequency of females in populations.