Population structure of Monilinia fructicola in Prunus persica var. nucipersica tree canopies

Monilinia fructicola was collected from lesions on 74 nectarine ( Prunus persica var. nucipersica ) fruits within a 10 tree by 10 tree area of a commercial orchard in Dinuba, California. Only members of one M. fructicola vegetative compatibility group (VCG) were detected in an individual lesion. However, in separate lesions on fruit in three tree canopies, there were seven, 10 and 18 M. fructicola VCG, respectively, among 19, 16, and 19 fruit lesions sampled from each canopy. Only one M. fructicola VCG was common to samples from all three tree canopies. There were 16 VCG in a random sample of one lesion from one fruit on each of 20 other trees. There were 38 different M. fructicola VCG among the 74 isolates collected.