Cleistogamy
Encyclopedia
Cleistogamy or automatic self-pollination describes the trait of certain plants to propagate by using non-opening, self-pollinating
flowers. Especially in peanut
s, pea
s, and bean
s, this behaviour is most widespread in the grass family, though the largest genus of cleistogamous plants is actually Viola.
The more common opposite of cleistogamy: "Closed-marriage", is called chasmogamy
: "Open-marriage". Virtually all plants that produce cleistogamous flowers also produce chasmogamous ones. The principal advantage of cleistogamy is that it requires less plant resources to produce seeds than by chasmogamy, because development of petals, nectar and large amounts of pollen are 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.
For genetically modified
(GM) rapeseed, researchers hoping to minimise the admixture of GM and non-GM crops are attempting to use cleistogamy to prevent gene flow
. However, preliminary results from Co-Extra
, a current project within the EU research programme, 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.
Self-pollination
Self-pollination is a form of pollination that can occur when a flower has both stamen and a carpel in which the cultivar or species is self fertile and the stamens and the sticky stigma of the carpel contact each other in order to accomplish pollination...
flowers. Especially in peanut
Peanut
The peanut, or groundnut , is a species in the legume or "bean" family , so it is not a nut. The peanut was probably first cultivated in the valleys of Peru. It is an annual herbaceous plant growing tall...
s, pea
Pea
A pea is most commonly the small spherical seed or the seed-pod of the pod fruit Pisum sativum. Each pod contains several peas. Peapods are botanically a fruit, since they contain seeds developed from the ovary of a flower. However, peas are considered to be a vegetable in cooking...
s, and bean
Bean
Bean is a common name for large plant seeds of several genera of the family Fabaceae used for human food or animal feed....
s, this behaviour is most widespread in the grass family, though the largest genus of cleistogamous plants is actually Viola.
The more common opposite of cleistogamy: "Closed-marriage", is called chasmogamy
Chasmogamy
Chasmogamy is a botanical term describing a type of flower. A flower which is chasmogamous opens and exposes the stamens and styles to the environment. This potentially allows the flower to be cross-pollinated by another individual. This is the opposite of cleistogamy.- External links :*...
: "Open-marriage". Virtually all plants that produce cleistogamous flowers also produce chasmogamous ones. The principal advantage of cleistogamy is that it requires less plant resources to produce seeds than by chasmogamy, because development of petals, nectar and large amounts of pollen are not required. This efficiency makes cleistogamy particularly useful for seed production on unfavorable sites or adverse conditions. Impatiens capensis
Impatiens capensis
Impatiens capensis, the Orange Jewelweed, Common Jewelweed, Spotted Jewelweed, Spotted Touch-me-not, or Orange Balsam, is an annual plant native to North America. It is common in bottomland soils, ditches, and along creeks, often growing side-by-side with its less common relative, Yellow Jewelweed...
, 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.
For genetically modified
Genetically modified organism
A genetically modified organism or genetically engineered organism is an organism whose genetic material has been altered using genetic engineering techniques. These techniques, generally known as recombinant DNA technology, use DNA molecules from different sources, which are combined into one...
(GM) rapeseed, researchers hoping to minimise the admixture of GM and non-GM crops are attempting to use cleistogamy to prevent gene flow
Gene flow
In population genetics, gene flow is the transfer of alleles of genes from one population to another.Migration into or out of a population may be responsible for a marked change in allele frequencies...
. However, preliminary results from Co-Extra
Co-Extra
Co-Extra is an EU-funded research programme on co-existence and traceability of genetically modified crops and their edible derivatives. It has been granted €13.5 million under the Sixth Framework Programme of the European Union, and is conducted by more than 200 scientists in 52 organisations in...
, a current project within the EU research programme, show that although cleistogamy reduces gene flow, it is not at the moment a consistently reliable tool for biocontainment
Biological containment
Biological containment describes measures aimed at preventing genetically modified organisms and their transgenes from spreading into the environment ....
: 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 cropsCo-existence of genetically modified and conventional crops and derived food and feedIn the context of agriculture and food and feed production, co-existence means using cropping systems with and without genetically modified organisms in parallel. For co-existence to be assured, the separation and the identity of the respective food and feed products must be maintained at all...