Cleistogamy is a type of automatic self-pollination of certain plants that can propagate by using non-opening,
self-pollinating flowers. Especially well known in
peanut
The peanut (''Arachis hypogaea''), also known as the groundnut, goober (US), pindar (US) or monkey nut (UK), is a legume crop grown mainly for its edible Seed, seeds. It is widely grown in the tropics and subtropics, important to both small ...
s,
peas, and
pansies, this behavior is most widespread in the grass family. However, the largest genus of cleistogamous plants is ''
Viola''.
The more common opposite of cleistogamy, or "closed marriage", is called
chasmogamy, or "open marriage". Virtually all plants that produce cleistogamous flowers also produce chasmogamous ones.
[Meeuse, Bastiaan and Sean Morris. 1984. The sex life of flowers. New York, NY: Facts on File Publishers. pp 110-111.] The principal advantage of cleistogamy is that it requires fewer plant resources to produce seeds than does chasmogamy, because development of petals, nectar and large amounts of pollen is not required. This efficiency makes cleistogamy particularly useful for seed production on unfavorable sites or adverse conditions. ''
Impatiens capensis,'' for example, has been observed to produce only cleistogamous flowers after being severely damaged by grazing and to maintain populations on unfavorable sites with only cleistogamous flowers. The obvious disadvantage of cleistogamy is that
self-fertilization occurs, which may suppress the creation of genetically superior plants.
[ Another disadvantage of self-fertilization is that it leads to the expression in progeny of deleterious recessive ]mutation
In biology, a mutation is an alteration in the nucleic acid sequence of the genome of an organism, virus, or extrachromosomal DNA. Viral genomes contain either DNA or RNA. Mutations result from errors during DNA or viral replication, m ...
s.
For genetically modified (GM) rapeseed
Rapeseed (''Brassica napus ''subsp.'' napus''), also known as rape, or oilseed rape, is a bright-yellow flowering member of the family Brassicaceae (mustard or cabbage family), cultivated mainly for its oil-rich seed, which naturally contains a ...
, researchers hoping to minimise the admixture of GM and non-GM crops are attempting to use cleistogamy to prevent gene flow
In population genetics, gene flow (also known as gene migration or geneflow and allele flow) is the transfer of genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalen ...
. However, preliminary results from Co-Extra, a current project within the EU research program, show that although cleistogamy reduces gene flow, it is not at the moment a consistently reliable tool for biocontainment; due to a certain instability of the cleistogamous trait, some flowers may open and release genetically modified pollen.
See also
* Co-existence of genetically modified, conventional, and organic crops
References
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Plant reproduction
Pollination
Plant sexuality