Andromonoecy is a breeding system of plant species in which

male Male (Planet symbols, symbol: ♂) is the sex of an organism that produces the gamete (sex cell) known as sperm, which fuses with the larger female gamete, or Egg cell, ovum, in the process of fertilisation. A male organism cannot sexual repro ...

and

hermaphrodite A hermaphrodite () is a sexually reproducing organism that produces both male and female gametes. Animal species in which individuals are either male or female are gonochoric, which is the opposite of hermaphroditic. The individuals of many ...

flowers are on the same plant. It is a monomorphic

sexual system A sexual system is a distribution of male and female functions across organisms in a species. The terms reproductive system and mating system have also been used as synonyms. Sexual systems play a key role in genetic variation and reproductive ...

comparable with

monoecy Monoecy (; adj. monoecious ) is a sexual system in seed plants where separate male and female cones or flowers are present on the same plant. It is a monomorphic sexual system comparable with gynomonoecy, andromonoecy and trimonoecy, and con ...

, gynomonoecy and trimonoecy. Andromonoecy is frequent among

genera Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...

with zygomorphic flowers, however it is overall rare and occurs in less than 2% of plant species. Nonetheless the breeding system has gained interest among biologists in the study of sex expression.

Etymology

The word andromonoecious is a combination of andr- (meaning male) and monoecious and was first used in 1877.

Prevalence

Andromonoecy is uncommon and has been estimated to occur in less than 2% of plant species. In angiosperms, it occurs in 1.7% of angiosperms making up around 4000 species in 33 families. It is common in the grass subfamily

Panicoideae Panicoideae is the second-largest subfamily of the grasses with over 3,500 species, mainly distributed in warm temperate and tropical regions. It comprises some important agricultural crops, including sugarcane, maize (or corn), sorghum, and s ...

Andromonoecious species

* ''Cucumis melo'' subsp * ''

Cucumis melo ''Cucumis melo'', also known as melon, is a species of ''Cucumis'' that has been developed into many cultivated varieties. The fruit is a pepo. The flesh is either sweet or bland, with or without an aroma, and the rind can be smooth (such as ho ...

'' * '' Chaerophyllum bulbosum'' * '' Erophaca baetica'' * '' Silene tibetica''

''
Solanum ''Solanum'' is a large and diverse genus of flowering plants, which include three food crops of high economic importance: the potato, the tomato and the eggplant (aubergine, brinjal). It is the largest genus in the nightshade family Solana ...
''

* '' Solanum agnewiorum'' * '' Solanum aureitomentosum'' * '' Solanum campylacanthum'' * '' Solanum carolinense'' * '' Solanum cerasiferum'' * '' Solanum incanum'' * '' Solanum insanum'' * '' Solanum lichtensteinii'' * '' Solanum linnaeanum'' * '' Solanum melongena'' * '' Solanum rigidum'' * '' Solanum umtuma'' * '' Solanum usambarsense''

Evolution

Some authors view andromonoecy as a transitional state from hermaphroditism to monoecy. It has been suggested that andromonoecy evolved from hermaphroditism due to the loss of female structures. Andromonoecy is also considered an evolutionary step towards

dioecy Dioecy ( ; ; adj. dioecious, ) is a characteristic of certain species that have distinct unisexual individuals, each producing either male or female gametes, either directly (in animals) or indirectly (in seed plants). Dioecious reproduction is ...

. If

female An organism's sex is female ( symbol: ♀) if it produces the ovum (egg cell), the type of gamete (sex cell) that fuses with the male gamete (sperm cell) during sexual reproduction. A female has larger gametes than a male. Females and ...

flowers are better at producing seeds than hermaphroditic ones, andromonoecy could evolve towards monoecy.

References