Genetic diversity of the endemic gourmet mushroom Thelephora ganbajun from south-western China

Abstract

The ectomycorrhizal fungus Thelephora ganbajun is an endemic gourmet mushroom in Yunnan province, south-western China. However, despite its widespread consumer appeal, nutritional value and potential ecological role in natural forests, very little is known about its genetics, diversity and ecology. In this study, we investigated DNA sequence variation at the internal transcribed spacer (ITS) regions among 156 specimens collected from 23 sites of nine regions in Yunnan Province. Our analysis identified a total of 34 ITS haplotypes and these haplotypes were clustered into five distinct phylogenetic groups. The evolutionary divergences among these clades are similar to or greater than many known sister species pairs within the genus Thelephora and the closely related genus Tomentella. Among the 34 ITS haplotypes, 22 were represented by one specimen each and the remaining 12 were each shared by two or more specimens. The most common haplotype contained 68 specimens distributed in 21 of the 23 sites, a result consistent with gene flow among geographical populations. However, analysis of molecular variance (AMOVA) revealed low but significant genetic differentiation among local and regional populations. Interestingly, the Mantel test identified that the extent of genetic differentiation was not significantly correlated with geographical distance. Our study revealed significant genetic divergence within Th. ganbajun and limited but detectable gene flow among geographical populations of this endemic ectomycorrhizal gourmet mushroom.

Fungal DNA barcoding

“…As DNA barcode sequences increase, barcode-based species identification is becoming increasingly common and the barcode sequences are generating many new species hypotheses. For example, ITS sequences helped reveal divergent lineages within the commercially important wild edible mushrooms Thelephora ganbajun (Sha et al 2008), Russula vinosa , and Boletus (Feng et al 2012). Similar findings have been reported for other organisms such as the root-knot nematodes where DNA barcoding information at four loci identified limitations in species identification based on a single barcode and the usefulness of multiple loci in revealing several new lineages within quarantine root-knot nematodes (Meloidogyne spp.)…”

Frequent heteroplasmy and recombination in the mitochondrial genomes of the basidiomycete mushroom Thelephora ganbajun

“…These samples included 134 isolates previously analyzed in the Sha et al . 17 study and 242 new isolates collected from 2008–2012. Our samples were obtained from two sources, our own field collections from public lands and local mushroom hunters.…”

“…The species is economically very important for the locals and has been heavily harvested to meet both local and regional needs as a food delicacy. A previous study showed abundant sequence variations at the inter-transcribed spacer (ITS) regions of the nuclear ribosomal RNA gene cluster, both within and among local populations of this mushroom 17 . The abundant genetic variations, coupled with the availability of a large number of samples from a relatively small geographic area suggest that this mushroom may represent an excellent system from which to examine the potential for mitochondrial genetic variations in nature.…”

Extraction of Natural Antioxidants from the Thelephora ganbajun Mushroom by an Ultrasound-Assisted Extraction Technique and Evaluation of Antiproliferative Activity of the Extract against Human Cancer Cells

“…The mushroom Thelephora ganbajun , known as ‘‘Gan-Ba-Jun’’ in Chinese, is an ectomycorrhizal fungus that grows in symbiosis with pine trees in Yunnan Province of China [7,8,9]. It is a delicious and popular food for its unique flavor.…”