Testing spore amyloidity in Agaricales under light microscope: the case study of Tricholoma
- PDF / 16,113,896 Bytes
- 20 Pages / 595.276 x 790.866 pts Page_size
- 0 Downloads / 207 Views
IMA Fungus
RESEARCH
Open Access
Testing spore amyloidity in Agaricales under light microscope: the case study of Tricholoma Alfredo Vizzini1*, Giovanni Consiglio2 and Ledo Setti3
Abstract Although species of the genus Tricholoma are currently considered to produce inamyloid spores, a novel standardized method to test sporal amyloidity (which involves heating the sample in Melzer’s reagent) showed evidence that in the tested species of this genus, which belong in all 10 sections currently recognized from Europe, the spores are amyloid. In two species, T. josserandii and T. terreum, the spores are also partly dextrinoid. This result provides strong indication that a positive reaction of the spores in Melzer’s reagent could be a character shared by all genera in Tricholomataceae s. str. Keywords: Agaricomycetes, Basidiomycota, Iodine, Melzer’s reagent, nrITS sequences, Pre-heating, Taxonomy of Tricholomataceae
Introduction It has been known for about 150 years that some ascomycete and basidiomycete sporomata may contain elements which stain grey to blue-black with iodinecontaining solutions. Such a staining was termed amyloid reaction, sometimes written as I+ or J+ (the term “amyloid” being derived from the Latin amyloideus, i.e. starch-like), because plant starch gives a similar reaction with iodine (starch-reaction) (Bailey and Whelan 1961; Locquin and Langeron 1978; Immel and Lichtenthaler 2000). The blue colour of the stain is due to the amylose component of plant starch (Takahashi and Ono 1972; Bluhm and Zugenmaier 1981; Moulik and Gupta 1984; Murdoch 1992; Immel and Lichtenthaler 2000). The amylose chain forms a helix shape, and iodine (as triiodide anion I3−) can be bound inside the helix channel. The other component, amylopectin, gives a red-purple colour which is much less intense than the amylose stain (Bailey and Whelan 1961; Shen et al. 2013). The nature * Correspondence: [email protected] 1 Department of Life Sciences and Systems Biology, University of Torino and Institute for Sustainable Plant Protection (IPSP-SS Turin), C.N.R, Viale P.A. Mattioli, 25, I-10125 Torino, Italy Full list of author information is available at the end of the article
of the starch–iodine interaction is extremely complex and still remains imperfectly known (Bluhm and Zugenmaier 1981; Immel and Lichtenthaler 2000; Shen et al. 2013; Du et al. 2014; Okuda et al. 2020). An overview of the historical use of Melzer’s was provided by Leonard (2006). Iodine was used in Mycology in the mid-1800s (as alcoholic solutions) mainly for studying lichens and asci (entire ascus wall or apical apparatus). The earliest reference to the use of such a bluing reaction in fungi as a character having a systematic significance is a report of the bluing of a cleistothecial marine ascomycete, Amylocarpus encephaloides by Currey (1859). Then the Tulasne brothers (1865), Nylander (1865) and Rolland (1887) noted and described iodine bluing in lichens and Ascomycetes at ascus and ascospore level. Boudier (1885, 1905–1910) was the first to describ
Data Loading...
