Fasciation
Fasciation (pronounced /ˌfæʃiˈeɪʃən/, 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.
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![](../I/m/Crested_Saguaro_cactus.jpg)
Causation
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
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, Echinacea, Euphorbia, Forsythia, Glycine max (specifically, soybean plants),[10] Primula, Prunus, Salix and many genera of the cactus family, Cactaceae. 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
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
- Fasciation
- An example of fasciation, or "cresting," on a coneflower (Echinacea).
- Fasciation leading to two fully formed flower heads on a dandelion.
- Fasciation on Digitalis. Note the larger thickened stem compared to the normal-sized flowering spike on the left.
- Fasciation on a flowering cherry (Prunus) tree
- Asparagus (Asparagus officinalis) fasciation. Note the flattened state of the stem. Image published 1893.
- Common dandelion displaying both regular (upper right) and fasciated (center) flowers.
- Fasciation on a lilac shrub.
- Fasciation on a Phacelia campanularia or California bluebell wildflower.
- Fasciated showy daisy (Erigeron speciosus).
- Fasciated Crookneck Squash
See also
References
- White, Orland E. (1948). "Fasciation". The Botanical Review. 14 (6): 319–358. doi:10.1007/BF02861723.
- 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.
- Morris, Scott. "Fasciation in Flowers – What You Need To Know". Gardentoolbox. Archived from the original on 10 January 2014. Retrieved 10 January 2014.
- Lerner, B. Rosie (September 2007). "Fascinating Fasciation". Purdue University Extension. Retrieved July 3, 2012.
- Galun, Esra (2007). Plant Patterning: Structural and Molecular Genetic Aspects. World Scientific Publishing Company. p. 333. ISBN 9789812704085
- "Fasciation in Vegetables and Fruits". University of Delaware Cooperative Extension. May 27, 2011. Archived from the original on February 7, 2015. Retrieved July 6, 2012.
- 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.
- 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.
- "Pests in Gardens and Landscapes". Statewide Integrated Pest Management Program, Agriculture and Natural Resources, University of California. October 13, 2008. Retrieved July 3, 2012.
- 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. PMID 10760600.
- "Campus Arboretum". University of Arizona. 2008-08-20. Archived from the original on 2010-01-06. Retrieved 2010-01-14.
Further reading
- White, Orland E. (1945). "The Biology of Fasciation". Journal of Heredity. 36: 11–22. doi:10.1093/oxfordjournals.jhered.a105409.
- Crespi, M.; Messens, E.; Caplan, A.B.; Van Montagu, M.; Desomer, J. (1992). "Fasciation induction by the phytopathogen Rhodococcus fascians depends upon a linear plasmid encoding a cytokinin synthase gene". The EMBO Journal. 11 (3): 795–804. doi:10.1002/j.1460-2075.1992.tb05116.x. PMC 556518. PMID 1547783.
- Nilsson, O.; Moritz, T.; Sundberg, B.; Sandberg, G.; Olsson, O. (1996). "Expression of the Agrobacterium rhizogenes rolC Gene in a Deciduous Forest Tree Alters Growth and Development and Leads to Stem Fasciation". Plant Physiology. 112 (2): 493–502. doi:10.1104/pp.112.2.493. PMC 157972. PMID 12226405.
- Crespi, M.; Vereecke, D.; Temmerman, W.; Van Montagu, M.; Desomer, J. (1994). "The fas operon of Rhodococcus fascians encodes new genes required for efficient fasciation of host plants". Journal of Bacteriology. 176 (9): 2492–2501. doi:10.1128/jb.176.9.2492-2501.1994. hdl:1854/LU-322183. PMC 205384. PMID 8169198.
External links
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Look up fasciation in Wiktionary, the free dictionary. |
- Ombrello, T. (PhD). "Fascinating Fasciated Plants". Union County College, Cranford, NJ. Archived from the original on March 2, 2013. Retrieved July 6, 2012.
- "Definition of "Fasciation"". Merriam-Webster Dictionary. Retrieved July 6, 2012.