Species diversity ofEpichloësymbiotic with two grasses from southern Argentinean Patagonia

Abstract

In this work we performed morphological and molecular phylogenetic analyses (based on sequences of calmodulin M [calM], translation-elongation factor 1-α [tefA] and β-tubulin [tubB] genes) to characterize the diversity of Epichloë endophytes in Bromus setifolius and Phleum alpinum. The phylogenies obtained from the three genes were congruent and allowed differentiation of three lineages of endophytes that also presented morphological differences. One lineage corresponds to the previously described species Epichloë tembladerae, which is present in a wide range of native grasses from Argentina including B. setifolius and P. alpinum. Another genotype isolated only from B. setifolius is a non-hybrid endophyte, a rare condition for the South American Epichloë endophytes. Isolates of this genotype, described herein as a new variety, Epichloë typhina var. aonikenkana, presented waxy colonies at maturity and a low production of conidia. The third lineage, exclusively found in isolates from P. alpinum, is a hybrid between E. typhina and a common ancestor of E. amarillans and E. baconii. Isolates of this lineage produce abundant conidia that are variable in shape and size. Based on its unique phylogenetic position and morphology, we propose the new species, Epichloë cabralii for this lineage. The new combinations Epichloë tembladerae and E. pampeana also are proposed for the previously described Neotyphodium tembladerae and Neotyphodium pampeanum species.

Interspecific hybridization and bioactive alkaloid variation increases diversity in endophyticEpichloëspecies ofBromus laevipes

“…The 36 isolates representing BlaTG‐2, the most common endophyte genotype, showed similar allele grouping with a recently named hybrid endophyte Epichloë cabralii from Phleum alpinum (McCargo et al ., ). In both the tefA and tubB trees, allele 1 grouped with E. typhina ssp.…”

“…Phylogenetic placement of asexual vertically transmitted Epichloë species is either congruent with their sexual nonhybrid relatives, or heteroploid containing genomes from more than one progenitor, suggesting they arose from interspecific hybridization events. Such analyses coupled with estimations of host specificity suggest that hybridization among Epichloë species is a strikingly regular phenomenon (Moon et al ., ; Leuchtmann & Oberhofer, ; Leuchtmann et al ., ; McCargo et al ., ). Current data strongly suggest that interspecific hybridization occurs via somatic cell fusion or anastomosis followed by karyogamy (Schardl & Craven, ), as fertility barriers are strong between sexual Epichloë species and they lack a demonstrable vegetative incompatibility system (Chung & Schardl, ).…”

Occurrence of Epichloë fungal endophytes in the sheep-preferred grass Hordeum comosum from Patagonia

“…The evolutionary model for ML was K2 þ G (gamma ¼ 0.37) for tubB and K2 for tefA, established with Mega 6 (Tamura et al, 2013). Reference sequences from other endophytes from Argentina, published by Iannone et al (2009) and Mc Cargo et al (2014, and from sexual and asexual Epichlo€ e species and isolates from other Hordeum and close related species, published in Moon et al (2004) were included in the analyses. …”

“…Sequences of these two genes have been extensively used to establish the phylogenic relationships between Epichlo€ e species (Moon et al, 2004;Iannone et al, 2009). DNA isolation and PCR reactions were performed as described by Moon et al (2004) andMc Cargo et al (2014). To establish the possibility of a hybrid origin, both genes were firstly amplified using non selective primers.…”

Advances in Research on Epichloë endophytes in Chinese Native Grasses

“…Epichloë endophytes are typically analyzed using β-tubulin ( tubB ) (Tsai et al, 1994), translation elongation factor 1-α ( tefA ) (Moon et al, 2002), actin ( actG ) (Moon et al, 2007; Zhang et al, 2009), simple sequence repeats (SSR) (Moon et al, 1999; Schirrmann et al, 2015), amplified fragment length polymorphisms (AFLP) (Karimi et al, 2012), internal transcribed spacers of the nuclear ribosomal RNA (ITS) (Moon et al, 2000), calmodulin M ( calM ) (McCargo et al, 2014), and so on. The most common markers for taxon identification and determining phylogenetic relationships are tubB, tefA , and actG (Clay and Schardl, 2002).…”