Diversity and Ecological Characterization of Sporulating Higher Filamentous Marine Fungi Associated with Spartina maritima (Curtis) Fernald in Two Portuguese Salt Marshes

Abstract

Fungal communities associated with early stages of decomposition of Spartina maritima (Curtis) Fernald were assessed in two geographically distinct salt marshes in Portugal by direct observation of fungal sporulating structures. Twenty-three fungal taxa were identified from 390 plant samples, 11 of which were common to both study sites. Natantispora retorquens, Byssothecium obiones, Phaeosphaeria spartinicola, Phoma sp. 1 and Stagonospora sp. were the most frequent fungal taxa in the studied communities. The fungal species Anthostomella spissitecta, Camarosporium roumeguerii, Coniothyrium obiones, Decorospora gaudefroyi, Halosarpheia trullifera, Leptosphaeria marina and Stagonospora haliclysta were recorded for the first time on S. maritima plants; with the exception of C. roumeguerii and L. marina, all of these species were also new records for Portugal. The differences between species composition of the communities associated with S. maritima were attributed to differences in abiotic conditions of the salt marshes. Although the fungal taxa were distributed differently along the host plants, common species to both fungal communities were found on the same relative position, e.g. B. obiones, Lulworthia sp. and N. retorquens occurred on the basal plant portions, Buergenerula spartinae, Dictyosporium pelagicum and Phoma sp. 1 on the middle plant portions and P. spartinicola and Stagonospora sp. on the top plant portions. The distinct vertical distribution patterns reflected species-specific salinity requirements and flooding tolerance, but specially substrate preferences. The most frequent fungi in both communities also exhibited wider distribution ranges and produced a higher number of fruiting structures, suggesting a more active key role in the decay process of S. maritima.

Revealing the hidden diversity of marine fungi in Portugal with the description of two novel species, Neoascochyta fuci sp. nov. and Paraconiothyrium salinum sp. nov.

“…belonging to the order Lulworthiales that comprises marine ascomycetes [63] which are commonly associated with wood substrates [64]. Previous studies in Portuguese waters have also shown the presence of Lulworthiales species in standing plants and baits of Spartina maritima [65] and wood of Pinus pinaster and Fagus sylvatica [64].…”

Molecular data reveals a new holomorphic marine fungus, Halobyssothecium estuariae, and the asexual morph of Keissleriella phragmiticola

“…However, Halobyssothecium estuariae is distinct from H. obiones in having longer and narrow papilla (65–85 × 55–85 vs. 25–35 × 130–145 μm) and ascospores with smaller dimensions (20–44 × 4–9 vs. 28–47 × 10–18 μm). Further, the asexual morph of Halobyssothecium estuariae is hyphomycetous characterised by xylomyces-like chlamydospores, whereas in H. obiones the asexual morph produces phoma-like conidia (Kohlmeyer and Kohlmeyer 1979 ; Calado et al 2015 ).…”

“…Halobyssothecium obiones is frequently reported on Spartina stems, which plays a major role in the breakdown of lignocellulosic secondary walls of plant cells and nutrient recycling (Gessner and Goos 1973 ; Newell et al 1995 ; Barata 2002 ; Calado et al 2015 , 2019 ). Our collection of Halobyssothecium obiones on Spartina sp.…”

“…and sea grass species of Halodule, Thalassia and Zostera occur (Teal 1962 ; Christian et al 1990; Newell et al 1995 ; Van Ryckegem et al 2006 ; Calado and Barata 2012 ; Dayarathne et al 2019 ). Salt marshes are distributed worldwide and are recognised as a most productive costal ecosystem, with a vital role in nutrient recycling and shoreline protection (Gessner and Kohlmeyer 1976 ; Newell et al 1995 ; Newell 1996 ; Calado et al 2015 , 2019 ). Studies on salt marsh plants, such as Spartina alterniflora, Juncus roemerianus and Phragmites australis , have been shown to support a great diversity of marine fungi akin to many mangrove plants (Fell and Hunter 1979 ; Cuomo et al 1982 , 1985 ; Poon and Hyde 1998 ; Barata 2002 ; Kohlmeyer and Volkmann-Kohlmeyer 2002 ; Wong and Hyde 2002 ; Van Ryckegem and Verbeken 2005 ; Calado and Barata 2012 ; Jones et al 2019 ).…”

“…The genus Phragmites includes predominant perennial grasses found in marine coastal environments worldwide, throughout temperate and tropical regions and Phragmites australis has been widely studied for marine fungi (Poon and Hyde 1998 ; Wong and Hyde 2002 ; Van Ryckegem and Verbeken 2005 ). More than 300 fungi have been reported in association with this plant (Wong and Hyde 2001 , 2002 ; Calado et al 2015 ; Goonasekara et al 2019 ), of which 109 species were recorded from intertidal marshes in Hong Kong. Poon and Hyde ( 1998 ) described three new species Massarina phragmiticola, Phomatospora phragmiticola and Cytoplacosphaeria phragmiticola from this plant and Wong et al ( 1998 ) introduced the novel genus Phragmitensis typified by P. marina .…”