Characterization of Morel (Morchella spp.) Diversity in Indiana

Nicolette Albright, Purdue University

Abstract

Characterizing morel (Morchella spp.) diversity is challenging due to the limitations in both morphological species recognition (MSR) and the single-locus internal transcribed spacer (ITS) barcoding methods for this genus. The lack of both micro- and macrophenotypically informative characters makes species identification difficult with morphological data alone, while the ITS locus underestimates Morchella diversity. As a result, the current standard for Morchella delimitation is through the phylogenetic species recognition (PSR) criteria using a multilocus molecular dataset. There are, however, many locations in which morel collections have not been assessed with the current recognition methods and criteria. To begin evaluating Morchella in Indiana, we collected 132 morels from six counties in 2013, 2014 and 2015. The PSR criteria were applied using loci previously identified as phylogenetically informative in combination with each other for this genus: partial elongation factor 1-alpha ( EF1-α); the second-largest RNA polymerase subunit ( RPB2); and nuclear ribosomal large subunit (LSU) 28S rDNA. Color variation was quantified for 78 of these morels by calculating the average Pantone color values of sporocarp pits and ridges in Photoshop. Our morel collections displayed tremendous color variability. Particularly, the color variability of M. americana sporocarp ridges ranged from (P–6–11–C) to (P–178–16–C) and pits ranged from (P–12–16–C) to (> P–179–16–C). Visual color descriptions of this species are congruent with current reports; however, we have begun to improve the precision of numerically characterizing sporocarp colors. Phylogenetic analyses identified 98% of these morels (77/78) as M. americana, and one isolate as M. diminutiva . Over 94% (124/132) of our total collections were also identified as M. americana when analyzed with PSR criteria; the remaining morels were identified as M. diminutiva (n = 3) and M. punctipes (n = 5). Of the three loci evaluated, a partial fragment of EF1-α was the only locus to provide bootstrap support ≥ 72% for all but one node when used alone in phylogenetic reconstructions of the Morchella spp. known to this region. As a result, the EF1-α fragment was used as a single locus to expedite phylogenetic reconstructions for species identification in the later years of our collections. Our results describe the color variability among M. americana in a region where morel diversity has not been assessed, as well as methodologies to expedite phylogenetic species identification in our region using by using the EF1-α fragment as a sole locus.

Degree

M.S.

Advisors

Beckerman, Purdue University.

Subject Area

Botany|Plant Pathology

COinS