Results (
Thai) 1:
[Copy]Copied!
The vegetative mycelium of R. solani and other Rhizoctonia fungi are colorless when young but become brown colored as they grow and mature. The mycelium consists of hyphae partitioned into individual cells by a septum containing a dough-nut shaped pore. This septal pore allows for the movement of cytoplasm, mitochondria, and nuclei from cell to cell. The hyphae often branch at a 90o angles and usually possess more than three nuclei per hyphal cell. The anatomy of the septal pore and the cellular nuclear number (CNN) have been used extensively by researchers to differentiate R. solani from other Rhizoctonia fungi. R. solani [renamed Moniliopsis solani = Moniliopsis anderholdii (Moore, 1987)] is characterized by: CNN close to the tips in young hyphae greater than two, main runner hyphae usually wider than 7mm, mycelium buff-colored to dark brown, sclerotia (if present) irregular shape, light to dark brown, not differentiated into rind and medula and having Thanatephorus cucumeris its as teleomorph.Because R. solani and other Rhizoctonia fungi do not produce conidia and only rarely produce basidiospores, the classification of these fungi often has been difficult. Prior to the 1960’s, researchers relied mostly on differences in morphology observed by culturing the fungus on a nutrient medium in the laboratory and/or pathogenicity on various plant species to classify Rhizoctonia. In 1969, J. R. Parmeter and his colleagues at the University of California in Berkeley, reintroduced the concept of "hyphal anastomosis" to characterize and identify Rhizoctonia. The concept implies that isolates of Rhizoctonia that have the ability to recognize and fuse (i.e. "anastomose") with each other are genetically related, whereas isolates of Rhizoctonia that do not have this ability are genetically unrelated.
Being translated, please wait..
