Analysis of Whole-Cellular Fatty Acids for Binucleate Rhizoctonia Species Associated with AG-A

Abstract

Previous researches have demonstrated that whole-cellular fatty acid analysis is a useful tool for identifying and establishing taxonomic relationships between the anastomosis groups (AGs) and the species related to the Rhizoctonia. In this experiment, the composition of fatty acid of 20 isolates belonging to the binucleate of AG-A, consisting of R. candida, R. endophytica var. endophytica, R. fragariae and R. ramicola were evaluated using the gas chromatography based fatty acid analysis. The detected fatty acids identified were myristic, pentadecanoic, palmitic, palmitoleic, stearic, oleic, linoleic and linolenic acids in all isolates. The major fatty acids, palmitic, oleic and linoleic acids were presented in the all isolates, constituting 94-96% of the whole-cellular fatty acids. Principal component analysis based on the composition of total cellular fatty acids revealed that isolates of R. candida, R. endophytica and R. fragariae showed similar fatty acid compositions but isolates of R. ramicola differed from the other AG-A isolates. Average linkage cluster analysis also showed that isolates of AG-A were distinguishable between R. ramicola and the other anamorphs of AG-A, representing to R. candida, R. endophytica and R. fragariae, according to the composition of detected whole-cellular fatty acids.