Genetic variability and molecular phylogeny of Pleurotus eryngii species-complex isolates from Iran, and notes on the systematics of Asiatic populations

Abstract

The Pleurotus eryngii species-complex includes taxa of the northern hemisphere growing in association with plants of the family Apiaceae (umbellifers). In this study, 45 Pleurotus strains were isolated from five different hostplants: Ferula ovina, F. assa-foetida, Smyrniopsis aucheri, Kellusia odoratissima, and Cachrys ferulacea; all plant species, with the exception of C. ferulacea, are reported for the first time as hosts for this fungal group. Random amplified polymorphic DNA-PCR (RAPD) analysis and nucleotide sequence data from the internal transcribed spacer of the nuclear rRNA genes (ITS1, 5.8S and ITS2) were used for assessing genetic diversity and for determining phylogenetic relationships among the populations studied. Results permitted the grouping of the strains studied into three major clusters corresponding mainly to the nature of the host-plant: the first included isolates collected from Ferula spp. only, the second included isolates originating from C. ferulacea only but from various sampling locations, and the third included all K. odoratissima and S. aucheri associated strains plus a few isolates collected from F. ovina and C. ferulacea. The grouping of the Iranian material, in conjunction with the position in the resulting phylograms of other previously obtained P. eryngii complex sequences, revealed that the first cluster is related to the asiatic 'P. nebrodensis' (or to the asiatic Ferula spp. associated Pleuroti), the second forms a rather distinct lineage which is linked with reference strains originally classified as P. fossulatus, whereas the third cluster falls within the main part (or the "core") of this complex, i.e., P. eryngii. Pleurotus populations growing on umbellifers in Iran seem either to have recently diverged through a sympatric speciation process based mainly on ecological factors (e.g., P. fossulatus), or they form part of a rather wide agglomerate associated with various host-plants where exchange of genetic material is still in progress (i.e., P. eryngii).

Rapid strain classification and taxa delimitation within the edible mushroom genus Pleurotus through the use of diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy

“…Pleurotus nebrodensis is the fourth taxon with the same absorbance pattern; however, it presented minor differences in the exact wavenumber of some peaks. More importantly, it was clearly distinguished from the closely related P. eryngii (Zervakis et al 2001;Ravash et al 2010;Rodriguez-Estrada et al 2010) by lacking two absorbance peaks at 1742 cm À1 and 1105 cm À1 . Pleurotus citrinopileatus (the fifth taxon with identical absorbance pattern, again with slight different peaks within the same absorbance regions) and Pleurotus cornucopiae are closely related taxa (Ohira 1990;Zervakis 2004); their FT-IR spectra demonstrated high similarity (ten out of 11 peaks were common), and only a peak at the amide III region exhibited by P. cornucopiae differentiated them.…”

“…(mainly due to the significant influence exerted by environmental factors on macroscopic characters). Furthermore, mating compatibility tests are laborious and in some cases inconclusive, while molecular techniques are known to be expensive and require a rather high level of expertise (Vilgalys & Sun 1994;Zervakis & Balis 1996;Petersen & Hughes 2003;Zervakis et al 2004;Ravash et al 2010).…”

The Edible Mushroom Pleurotus spp.: I. Biodiversity and Nutritional Values

“…In recent decades, various biochemical and molecular techniques applied for investigation of phylogenetic relationship and strain identification of Pleurotus population. Isozyme electrophoresis [21], sequence analysis of ribosomal DNA [30], internal transcribed spacer region (ITS) [22,31], random amplified polymorphic DNA (RAPD) [31][32][33], amplified fragment length polymorphism (AFLP) [28], restriction fragment length polymorphism (RFLP) [28] and mating compatibility test [27,29,33,34] are among these techniques. Although extensive research conducted to clarify the obscure taxonomy of genus Pleurotus, still many questions is not fully addressed in the literature.…”

“…Despite precious information obtain form interfertility tests, but the need for more accurate comprehension of phylogenic relationship among species and specification mechanism of this genus increase the importance of precise means of species identification, especially for the strain which their geographical locations are in ambiguity [21]. Therefore, various molecular and biochemical techniques applied for this reason [27,31]. One of the approaches is enzymes electrophoresis, which is subjected to 11 Pleurotus species [18], as eleven enzymatic activities were investigated regarding the number of genes and alleles involved in their production.…”

Taxonomic relationships among non-macrocystidiate taxa of Lactarius subg. Russularia from Europe with special reference to species from Greece

“…Genomic DNA was extracted from dried material as previously described (Ravash et al 2010;Zervakis et al 2014).…”