RAPD analysis of genetic variation within a collection of Monascus spp. isolated from red rice (ang-kak) and sofu

Genetic variation within a collection of 25 isolates of Monascus from red r ice and sofu was assessed with RAPD markers using genetic distances (1-Jacc ard's coefficient) calculated for all combinations of isolates. Cluster ana lysis based on genetic distance was performed using the Ward's minimum vari ance method. Five distinct clusters were revealed based on genetic distance s between and among clusters. The robustness (reproducibility) of the clust er assignments was tested by resampling (bootstrap) analysis. Cluster distr ibution was visualized as a three-dimensional graph based on multiple corre spondence analysis. A dendrogram, based on the clusters, was constructed to examine the relationships. Three clusters accounted for 21 isolates; the f ourth cluster consisted of three isolates which were quite distinct from ea ch other and all other isolates. The fifth cluster, a single isolate from J apan, was very different from all others in RAPD patterns and was used as a n outgroup. Resampling analysis indicated that the 25 isolates represented four genetic lineages of red rice fungi, suggesting that a relatively narro w genetic source of Monascus isolates is used in food products in Asia.