Quick n’ Cheap – a simplified workflow to barcode plasmodial slime molds(Myxomycetes)

We present a workflow for efficient barcoding of myxomycete fructifications, which (i) requires less than 1000 spores, (ii) allows to collect spores with only a needle, (iii) works without any commercial kits, and (iv) is optimized for the use of 96-well PCR plates throughout the process. Specimens of 291 dark-spored nivicolous myxomycetes and 121 bright-spored members of the Trichiaceae were sequenced for the barcode marker 18S rDNA (SSU) with a low rate of failure and no detectable cross-contamination. Crude DNA extracts can be stored for further analyses: the elongation factor 1 alpha gene (EF1A), a single-copy marker, was successfully amplified after four weeks of storage.As such our procedure will allow a time- and cost-efficient barcoding of large series of specimens.

Records of corticolous myxomycetes from selected trees in Angat Watershed Forest Reserve, Bulacan, Philippines

Corticolous myxomycetes are a specialized guild of myxomycetes thriving on the bark of living trees. In this study, we explored the bark-inhabiting myxomycetes from selected trees in the Angat Watershed Forest Reserve, Bulacan, Philippines. Pieces of dead tree barks were carefully removed from selected mature trees — Gmelina arborea (“gmelina” or “yemane”), Mangifera indica (“mango”), Parkia timoriana (“kupang”), Pinus sp. (“pine tree”), Pterocarpus indicus (“narra”), Samanea saman (“acacia” or “rain tree”), and Shorea contorta (“white lauan”), within the accessible forest area and used for the preparation of moist chamber culture. Following incubation for 8–12 weeks, fruiting bodies from the moist chambers were identified. Results showed a total of 17 species belonging to 10 genera from five orders. The identified corticolous myxomycetes were Arcyria cinerea, A. denudata, Comatricha pulchella, C. tenerrima, Cribraria microcarpa, C. violacea, Diderma effusum, D. hemisphaericum, Hemitrichia pardina, Lamproderma scintillans, Licea operculata, Licea sp.1, Perichaena chrysosperma, P. pedata, Physarum album, P. leucophaeum, and Trichia decipiens. This is the first report of corticolous myxomycetes in the Angat Watershed Forest Reserve. KEYWORDS: bark, moist chamber culture, Paleotropics, plasmodial slime molds, species list

Myxomycetes associated with canopy organic matter in temperate rainforests of southern New Zealand

The dead plant material (canopy organic matter) associated with the mats of vascular plants and bryophytes found on tree branches in temperate rainforests along the southwestern coast of New Zealand was investigated for the presence of myxomycetes (plasmodial slime molds or myxogastrids). Samples of both the superficial litter layer (canopy litter) on the surface of the mat and the humus-like layer (canopy soil) beneath the mat were collected and used to prepare a series of moist chamber cultures. Canopy soil yielded more positive cultures (57%) but only three species of myxomycetes, whereas eight species were recovered from canopy litter (40% positive cultures). The higher percentage of positive cultures for canopy soil was the result of the appearance of plasmodia that could not be induced to form fruiting bodies. In contrast, fruiting bodies represented 67% of the positive cultures recorded from canopy litter.

Mechanism of signal propagation inPhysarum polycephalum

Complex behaviors are typically associated with animals, but the capacity to integrate information and function as a coordinated individual is also a ubiquitous but poorly understood feature of organisms such as slime molds and fungi. Plasmodial slime molds grow as networks and use flexible, undifferentiated body plans to forage for food. How an individual communicates across its network remains a puzzle, butPhysarum polycephalumhas emerged as a novel model used to explore emergent dynamics. WithinP. polycephalum, cytoplasm is shuttled in a peristaltic wave driven by cross-sectional contractions of tubes. We first trackP. polycephalum’s response to a localized nutrient stimulus and observe a front of increased contraction. The front propagates with a velocity comparable to the flow-driven dispersion of particles. We build a mathematical model based on these data and in the aggregate experiments and model identify the mechanism of signal propagation across a body: The nutrient stimulus triggers the release of a signaling molecule. The molecule is advected by fluid flows but simultaneously hijacks flow generation by causing local increases in contraction amplitude as it travels. The molecule is initiating a feedback loop to enable its own movement. This mechanism explains previously puzzling phenomena, including the adaptation of the peristaltic wave to organism size andP. polycephalum’s ability to find the shortest route between food sources. A simple feedback seems to give rise toP. polycephalum’s complex behaviors, and the same mechanism is likely to function in the thousands of additional species with similar behaviors.

The occurrence of myxomycetes from a lowland montane forest and agricultural plantations of Negros Occidental, Western Visayas, Philippines

Higher floral and faunal biodiversity is expected in multi-species-covered mountainous forests than in mono-typic agricultural plantations. To verify this supposition for cryptogamic species like the plasmodial slime molds, a rapid field survey was conducted for myxomycetes and substrates in forest floor litter and agricultural plantation were collected in Negros Occidental, Philippines. Morphological characterization identified a total of 28 species belonging to the genera Arcyria, Ceratiomyxa, Collaria, Comatricha, Craterium, Cribraria, Diderma, Didymium, Hemitrichia, Lamproderma, Physarum, Stemonitis, Trichia and Tubifera. The myxomycete species Arcyria cinerea was the only abundant species found both in the agricultural and forested areas. The majority of collected species were rarely occurring. In terms of species composition, more myxomycetes were recorded in the mountainous forest (27) compared to agricultural sites. Furthermore, aerial leaf litter collected in the forests had the highest number of records for fruiting bodies but in terms of species diversity, twigs yielded higher value based on Shannon index. Findings in this study verify that a habitat with more heterogenous plant communities yields higher species of myxomycete assemblages. This research is the first study to report myxomycetes from Negros Occidental.