Simplified and efficient DNA extraction protocol for Meliolaceae specimens

Abstract

Meliolaceae is an obligate biotrophic fungal family which cannot be cultured in artificial media. This has resulted in a lack of DNA sequence data in public databases to better resolve species taxonomy. The main criterion for specific classification, therefore, relied heavily on host association. Fresh collections from living leaves of Croton persimilis and Tamarindus indica with black colonies in Mae Fah Luang University, Thailand yielded a new species, Irenopsis crotonicola sp. nov., and a new record of Meliola tamarindi. These taxa are described and phenotypic comparisons are made with known species. To better classify the putative novel species that cannot be cultivated, we outline the protocol to extract DNA from fruiting bodies and generate new phylogenetic data. The results indicate that this direct DNA extraction method is suitable to yield quality DNA sufficient for polymerase chain reaction (PCR) amplifications of several commonly used DNA regions in fungal systematics. The 28S rDNA phylogram generated confirms the position of our taxa within Meliolaceae and indicate a close relationship of I. crotonicola sp. nov. to I. walsurae. Sequences of tef, β-tubulin, and GPDH regions of Meliolaceae are provided as well.