Morphology and life cycle of a new species ofDidymium(Myxomycetes) from arid areas of Mexico

Abstract

A new species of myxomycete, Didymium umbilicatum, isolated from the bark of Agavaceae, is described from arid zones of Mexico. This species was obtained from moist chamber cultures of Yucca spp. bark, collected in four different years from two states (Puebla and Querétaro) in central Mexico and found in the field from Hidalgo, Oaxaca and Puebla on the dead remains of Agave sp. The new species has small, flat, white sporocarps or short plasmodiocarps, 0.2-1.3 mm diam, and 0.15-0.4 mm tall. They are sessile on a reduced base or have a short, calcareous pale stalk and warted spores, warts fused in an irregular subreticulum by SEM. It is the sixth species of Didymium recently described from arid areas. The stability of the taxonomic characters of the species was confirmed by spore-to-spore culture on agar. Life cycle events are described from germination to sporulation. The morphology of the myxomycete specimens was examined with scanning electron microscopy and light microscopy, and micrographs of relevant details are included.

The Life Cycle of Didymium laxifilum and Physarum album on Oat Agar Culture

“…; Wrigley de Basanta et al. , , , ). Phylogenetic relationships confirmed that Columellidia is composed of the paraphyletic Stemonitales and the monophyletic Physarales, with Echinosteliales as a sister group of both (Fiore‐Donno et al.…”

“…), 51 d for Didymium umbilicatum D. Wrigley, Lado & Estrada (Wrigley de Basanta et al. ), 40 d for Didymium operculatum D. Wrigley, Lado & Estrada (Wrigley de Basanta et al. ), 6 d for Didymium annulisporum H.W.…”

“…; Wrigley de Basanta et al. , , , ). In most of previous studies, plasmodia were fed with living bacteria or yeast which induced serious difficulty in culturing and purification.…”

“…In connection with the pivotal role of life cycle, agar culture makes it possible for researchers to observe each stage of life cycle. Spore-to-spore culture is also an important addition to the description of new species (Haskins and Wrigley de Basanta 2008;Lado et al 2007;Wrigley de Basanta et al 2008, 2011.…”

Myxomycete diversity in the coastal desert of Peru with emphasis on the lomas formations

“…Research carried out in the Patagonian steppe registered 133 different species (Lado & al., 2014), almost the 15% of the total number of species known worldwide. These arid regions have become even more interesting because of the number of new species that have been discovered and described from them (Lado & al., 1999(Lado & al., , 2007(Lado & al., , 2013(Lado & al., , 2014Estrada-Torres & al., 2001, 2009Wrigley de Basanta & al., 2008b, 2009, 2010a, 2015. These new species represent four different orders, and the genera Cribraria, Didymium, Licea, Macbrideola, Perichaena and Physarum. Since the publication of the first records by Rudolphi (1829), only 31 species of myxomycete had been published from Peru, until a recent paper increased the number to 80 (Rojas & al., 2011), but almost all of these records were from the tropical forests of the Amazon basin, to the East of the Peruvian Andes.…”