Rhizoctonia
Rhizoctonia is a type of fungi. They have long filaments called mycelia and a root like structure consisting of food reserves, called sclerotia. Rhizoctonia species eat through a process called saprotrophic nutrition, as the filaments (mycelia) absorb decayed organic matter through the cell wall. The species may resort to plant pathogeny, meaning that it can sometimes cause crop diseases. Some Rhizoctonia species live on the roots of orchid plants[1] and exhibit a mutually beneficial relationship with them during orchid germination.
| Rhizoctonia | |
|---|---|
| |
| Disease of cucumber caused by Rhizoctonia solani | |
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Fungi |
| Division: | Basidiomycota |
| Class: | Agaricomycetes |
| Order: | Cantharellales |
| Family: | Ceratobasidiaceae |
| Genus: | Rhizoctonia DC. (1815) |
| Type species | |
| Rhizoctonia solani J.G. Kühn (1858)
| |
| Synonyms | |
|
Moniliopsis Ruhland (1908) | |
The term Rhizoctonia (meaning “root killer”) was first used by Augustin Pyramus de Candolle to describe the species Rhizoctonia crocorum, which causes violet root rot in carrots.[2] It was found that Rhizoctonia solani also causes significant plant diseases, affecting grass, seeds, potatoes, cereals, sugar beet, cucumber, rice and many others.[3]
Disease
changeWhen this type of fungus begins to grow on a plant the infected area decays rapidly, leading to brown and red lesions below the soil-line. If the disease develops, these lesions enlarge to form sunken cankers that can cut through the plant root and stem.[4] Other symptoms include plants wilting in the middle of the day and damping off.
Characterisation
changeSince Rhizoctonia don't produce many spores, they are characterised by their hyphae. The hyphae are responsible for producing branch filaments at right and acute angles. Some hyphae are specialised with compact cells called miliolid cells. These cells form strong structures called sclerotia, this strength allows these fungi to survive extreme conditions.
There are two groups of classification based on the number of nuclei (cell compartment storing genetic material) within the hyphae cells. The two groups are binucleate (two nuclei) and multinucleate (more than two nuclei) Rhizoctonia.
A further classification into groups is based on the ability of hyphae to fuse together, by a process called Anastomosis.[4]
References
change- ↑ Wu, Jianrong; Ma, Huancheng; Lü, Mei; Han, Sufen; Zhu, Youyong; Jin, Hui; Liang, Junfeng; Liu, Li; Xu, Jianping (January 2010). "Rhizoctonia fungi enhance the growth of the endangered orchid Cymbidium goeringii". Botany. 88 (1): 20–29. doi:10.1139/B09-092. ISSN 1916-2790.
- ↑ "Pests and Diseases Quick Reference : Violet root rot". 2006-09-25. Archived from the original on 2006-09-25. Retrieved 2022-07-21.
{{cite web}}: CS1 maint: bot: original URL status unknown (link) - ↑ Roberts, Peter (1999). Rhizoctonia-forming fungi : a taxonomic guide. Kew [England]: Herbarium, Royal Botanic Gardens. ISBN 1-900347-69-5. OCLC 42331663.
- ↑ 4.0 4.1 "Rhizoctonia diseases of turfgrass". Rhizoctonia diseases of turfgrass. Retrieved 2022-07-26.