부산대학교 도서관

Isolates of Rhizoctonia solani AG 2 from tobacco (Ntisolates) were reported to anastomose with isolates of AG-BI in high frequency (fusion frequency [FF] ≥ 50%) compared to isolates of AG 2-1 (FF < 50%), even though mature culture and thiamine requirement of the isolates were closely similar to AG 2-1. In this study, whole-cell fatty acid compositions of Nt-isolates (four isolates), isolates of AG 2-1 (eight isolates) and AG-BI (two isolates) were compared by gas-liquid chromatography analysis. Four isolates of AG 2 from tulip (AG 2-t) were also included. Palmitic (16:0), oleic (18: 1 cis9) and linoleic (18 : 2 cis9,12) acids were the three major fatty acids identified which constituted 89.6-93.4% of whole-cell fatty acid content. Myristic (14 : 0), pentadecanoic (15 : 0), palmitoleic (16 : 1 cis9), stearic (18 : 0) and linolenic (18 : 3 cis9,12) acids were present at low levels. Heptadecanoic (17 : 0) and 9-heptadecenoic (17 : 1 cis9) acids were also present in Nt-isolates and isolates of AG 2-1 but not in isolates of AG 2-t and AG-BI. With the exception of oleic acid, percentage composition of fatty acids of Nt-isolates were similar with those of isolates of AG 2-1 and AG 2-t but were different from isolates of AG-BI. Although fatty acid compositions of Nt-isolates and isolates of AG 2-1 were qualitatively and quantitatively similar, principal component and cluster analyses based on all detected fatty acids showed separation of the former from the latter groups indicating that Nt-isolates are a homogenous population in AG 2-1. Additionally, isolates of AG 2-t were closely related to isolates of AG 2-1. Isolates of AG-BI were distinctly separated from isolates of AG 2-1, AG 2-t and Nt-isolates. Results of fatty acid analysis support the designation of Nt-isolates as a member of AG 2-1 based on sequence similarity of rDNA-ITS. [ABSTRACT FROM AUTHOR]