Dichogamy


Also found in: Dictionary, Medical, Wikipedia.
Related to Dichogamy: heterostyly

dichogamy

[dī′käg·ə·mē]
(biology)
Producing mature male and female reproductive structures at different times.

Dichogamy

 

the maturation of the anthers and stigmas of flowers at different times. The importance of dichogamy for cross-pollination was first noted by A. T. Bolotov in 1780. In some flowers the anthers are the first to mature (protandry), and in others it is the stigma (protogyny). Dichogamy occurs not only in bisexual flowers but also in the unisexual flowers of monoecious and dioecious plants. Dichogamy is termed complete if the stigmas mature after the wilting of the stamens (or vice versa). More often dichogamy is incomplete, that is, the later maturing organs attain sexual maturity while the organs of the opposite sex have not lost their function. Protandry occurs in almost all the plants of the families Compositae and Umbelliferae. Protogyny is encountered more rarely, for example, in plants of the families Cruciferae, Rosaceae, and Ranunculaceae (anemones). The maturation of organs of different sexes at different times in cryptogams is also termed dichogamy.

References in periodicals archive ?
New (evolutionary) aspects are also expected by comparison of symmetry types with other features, such as genetics of breeding systems via dichogamy (Kalisz et al.
Because field studies of the floral biology are particularly meager, data on such characteristics as dichogamy and herkogamy are very limited.
The lower rate of autogamy on the Juan Fernandez Islands may be attributable to the significant percentage of species that have temporal separation of the sexes through dichogamy (mostly protandry).
Elisens (1985) found that seed set from self-pollinations in species of subtribe Maurandyinae (Antirrhineae) varied at the intra-individual and interspecific levels; he characterized this subtribe as facultatively autogamous/xenogamous, with mostly showy flowers having a prevalence of dichogamy and herkogamy.
Despite the existence of these alternative mechanisms for IA, there is one group of dioecious plants whose ancestors appear to lack alternative outbreeding devices: the majority of dioecious and gynodioecious zoophilous (animal-pollinated) species do not have self-incompatible ancestors (Baker, 1959), nor do such species exhibit dichogamy (Cruden, 1988), i.
Thus, some species (those prone to self-clogging) may evolve dichogamy even after self-incompatibility has evolved.