Genetic diversity analysis of Monascus strains using SRAP and ISSR markers

In this study, sequence-related amplification polymorphism (SRAP) and inter-simple sequence repeat (ISSR) were analyzed for accessing the genetic diversity of 37 Monascus isolates and 14 control strains. According to the dendrogram produced by SRAP data, all the tested strains were grouped into four clusters at a 78% similarity level. Comparatively, 51 tested strains were divided into four major groups at a similarity level of 74% based on the dendrogram generated via ISSR marker analysis. Based on the two sets of dendrograms, Monascus aurantiacus, M. purpureus, M. serorubescens, M. anka, and M. ruber were clustered in the same clade; M. albidus, M. fuliginosus, and M. barkeri were clustered with M. pilosus in a second clade; and M. lunisporas and M. argentinensis occurred together in a third cluster distinct from the other Monascus species. The cluster result produced by SRAP data shared great similarity with that by ISSR data with minor differences in the subgroups, which is basically in agreement with morphological observations. In general, SRAP and ISSR are more simple, rapid, and efficient, which may provide alternative molecular approaches to studying genetic diversity, classification, and identification of Monascus strains.