Fasciation

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Wyethia helianthoides or mule's ear wildflower (on right) showing fasciation
A "crested" saguaro cactus (Carnegiea gigantea ), resulting from fasciation, located at Saguaro National Park (West), Arizona, U.S.

Fasciation (pronounced /ˌfæʃiˈʃən/, from the Latin root meaning "band" or "stripe"), also known as cresting, is a relatively rare condition of abnormal growth in vascular plants in which the apical meristem (growing tip), which normally is concentrated around a single point and produces approximately cylindrical tissue, instead becomes elongated perpendicularly to the direction of growth, thus producing flattened, ribbon-like, crested (or "cristate"), or elaborately contorted, tissue.[1] Fasciation may also cause plant parts to increase in weight and volume in some instances.[2] The phenomenon may occur in the stem, root, fruit, or flower head. Some plants are grown and prized aesthetically for their development of fasciation.[3] Any occurrence of fasciation has several possible causes, including hormonal, genetic, bacterial, fungal, viral and environmental causes.

Causation[edit]

Fasciation can be caused by hormonal imbalances in the meristematic cells of plants, which are cells where growth can occur.[4][5] Fasciation can also be caused by random genetic mutation.[6] Bacterial and viral infections can also cause fasciation.[4] The bacterial phytopathogen Rhodococcus fascians has been demonstrated as one cause of fasciation, such as in sweet pea (Lathyrus odoratus) plants,[7] but many fasciated plants have tested negative for the bacteria in studies,[8] hence bacterial infection is not an exclusive causation.

Additional environmental factors that can cause fasciation include fungi, mite or insect attack and exposure to chemicals.[8] General damage to a plant's growing tip[8] and exposure to cold and frost can also cause fasciation.[4][6] Some plants, such as peas and cockscomb Celosia, may inherit the trait.[8]

Fasciation is not contagious,[4] but bacteria that cause fasciation can be spread from infected plants to others from contact with wounds on infected plants and from water that carries the bacteria to other plants.[9]

Occurrence[edit]

Although fasciation is rare overall, it has been observed in over 100 plant species,[8] including members of the genera Acer, Aloe, Acanthosicyos, Cannabis, Celosia, Cycas, Delphinium, Digitalis, Euphorbia, Forsythia, Glycine max (specifically, soybean plants),[10] Primula, Prunus, Salix and many genera of the Cactaceae (cactus) family.[citation needed] Cresting results in undulating folds instead of the typical "arms" found on mature Saguaro cactus.[11]

Some varieties of Celosia are raised especially for their dependably fasciated flower heads, for which they are called "cockscomb".[4] The Japanese Fantail Willow (Salix sachalinensis 'Sekka') is another plant that is valued for its fasciations.[4][8]

Prevention[edit]

Fasciation that is caused by damage to genetic material and by bacteria can be controlled by not using fasciated plants and disposing of fasciated plants.[9] Avoiding injury to plant bases and keeping them dry can reduce the spread of bacteria.[9] Avoidance of grafting fasciated plants and the pruning of fasciated matter can also reduce the spread of bacteria.[9]

Examples[edit]

See also[edit]

References[edit]

  1. ^ White, Orland E. (1948). "Fasciation". The Botanical Review. 14 (6): 319–358. doi:10.1007/BF02861723.
  2. ^ Albertsen, Marc C.; Curry, Therese M.; Palmer, Reid G.; Lamotte, Clifford E. (1983). "Genetics and Comparative Growth Morphology of Fasciation in Soybeans (Glycine max [L.] Merr.)". Botanical Gazette. 144 (2): 263–275. doi:10.1086/337372. JSTOR 2474652.
  3. ^ Morris, Scott. "Fasciation in Flowers – What You Need To Know". Gardentoolbox. Archived from the original on 10 January 2014. Retrieved 10 January 2014.
  4. ^ a b c d e f Lerner, B. Rosie (September 2007). "Fascinating Fasciation". Purdue University Extension. Retrieved July 3, 2012.
  5. ^ Galun, Esra (2007). Plant Patterning: Structural and Molecular Genetic Aspects. World Scientific Publishing Company. p. 333. ISBN 9789812704085
  6. ^ a b "Fasciation in Vegetables and Fruits". University of Delaware Cooperative Extension. May 27, 2011. Retrieved July 6, 2012.
  7. ^ Tilford, P.E. (1936). "Fasciation of Sweet Peas caused by Phytomonas fascians n.sp". Journal of Agricultural Research. 53 (5): 383–394. Retrieved July 7, 2012.
  8. ^ a b c d e f Swift, Curtis E. (April 12, 1999). "Fasciation: Fascinating distortions of the plant world". Colorado State University Extension. Archived from the original on June 30, 2012. Retrieved July 3, 2012.
  9. ^ a b c d "Pests in Gardens and Landscapes". Statewide Integrated Pest Management Program, Agriculture and Natural Resources, University of California. October 13, 2008. Retrieved July 3, 2012.
  10. ^ Yamamoto, Etsuo; et al. (April 25, 2000). "Molecular characterization of two soybean homologs of Arabidopsis thaliana CLAVATA1 from the wild type and fasciation mutant". Biochimica et Biophysica Acta (BBA) - Gene Structure and Expression. 1491 (1–3): 333–340. doi:10.1016/S0167-4781(00)00061-0.
  11. ^ "Campus Arboretum". University of Arizona. 2008-08-20. Archived from the original on 2010-01-06. Retrieved 2010-01-14.

Further reading[edit]

External links[edit]