Population structure and genetic variation in Nectria fuckeliana

Abstract

Population structure and genetic variation in Nectria fuckeliana Booth isolated from Picea abies (L.) Karst. in Sweden and Lithuania was studied using somatic incompatibility tests and DNA fingerprinting. All incompatibility pairings between different isolates of N. fuckeliana resulted in demarcation zones; thus, no vegetative compatibility groups were detected. Each isolate was distinguishable from all other isolates on the basis of banding patterns produced by amplification of DNA using the M13 primer. No country-specific markers were observed. Principal component analysis of amplified banding patterns separated the isolates from Sweden and Lithuania into two clusters, showing genetic differentiation between the geographical populations across the Baltic sea. An analysis of similarity matrix, calculated by the program SIMQUAL from the numerical taxonomy package NTSYS-pc, confirmed the separation of the isolates into the two groups. Low genetic differentiation was revealed within both the Swedish and Lithuanian geographical populations of the fungus. Local distances in the forest stand (100 m) had no influence on the genetic similarity of the N. fuckeliana isolates (R2 = 0.003). Key words: Nectria fuckeliana, DNA fingerprinting, genetic variation, somatic incompatibility, population structure.