McDonald, Geral I.; Martin, Neil E. ^988. Armillaria in the Northern Rockies: delinea- 

 tion of isolates into clones. Res. Pap. INT-385. Ogden, UT: U.S. Department of 

 Agriculture, Forest Service, Intermountain Research Station. 13 p. 



Isolates derived from Armillaria spp. rhizomorphs and fans collected within a 

 300-mile radius of Moscow, ID, were delineated into clones. The 394 isolates taken 

 from 87 randomly located 0.04-ha plots were assigned to 177 clones. Multiple blind 

 assessments of isolates among clones produced an overall reading error of about 5 

 percent. An average of 5.4 isolates per plot yielded two to three clones per plot, 

 leading to the conclusion that most plots supported two or three species of Armillaria. 

 The clones seemed to fall into four groups with regard to host affinities, pathogenicity, 

 and rhizomorph production. This suggests that the Northern Rocky Mountains are 

 home to four Armillaria spp. 



KEYWORDS: isolate compatibility, Armillaria specification, statistical analysis of clone 

 definitions 



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 Logan, Utah (in cooperation with Utah State University) 

 Missoula, Montana (in cooperation with the University of Montana) 

 Moscow, Idaho (in cooperation with the University of Idaho) 

 Ogden, Utah 



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 Reno, Nevada (in cooperation with the University of Nevada) 



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