Abstract Detail

Mycology

Caiafa Sepulveda, Marcos Vinicius [1], Smith, Matthew [2].

Disentangling the ecology and evolution of Buchwaldoboletus (Boletaceae).

Boletaceae is a diverse family with >50 genera worldwide. Most Boletaceae form ectomycorrhizal associations with plants but two sister groups (subfamily Chalciporoideae and the Pseudoboletus lineage) appear to be non-ectomycorrhizal and putatively mycoparasitic. Chalciporoidae is the earliest diverging lineage and includes the genera Chalciporus and Buchwaldoboletus. Chalciporus piperatus is considered mycoparasitic because it is routinely found in association with Amanita muscaria. Similarly, Buchwaldoboletus species fruit directly on wood and B. lignicola can parasitize Phaeolus schwenitzii in pure culture assays. In the southeastern USA, three Buchwaldoboletus species have been reported: B. lignicola, B. hemichrysus and B. sphaerocephalus. Although B. lignicola acts as mycoparasite in the lab, the nutritional mode and host range of other Buchwaldoboletus species remain unexplored. Our objectives were: 1) examine phylogenetic relationships among taxa in Chalciporoideae; 2) test the mycoparasitic ability of Buchwaldoboletus species on a wide range of wood-decay fungi and 3) test the effect that Buchwaldoboletus species have on the decay potential of wood decay fungi on wood blocks. We constructed a maximum likelihood phylogeny using 28S, tef1, rpb1 and rpb2. To examine the ability of Buchwaldoboletus to parasitize diverse fungi we challenged the three Buchwaldoboletus species against 22 different wood-decay fungi from seven orders, including both brown rot and white rot taxa. Confrontation experiments were performed on Petri dishes of MMN agar. To determine whether parasitism by Buchwaldoboletus species could impact the decay potential of wood decay fungi, we performed confrontation assays on wood blocks using a subset of wood decay fungi. In agreement with previously results, our multi-gene phylogeny indicated that the Chalciporus lineage is the sister group of all other Boletaceae. However, Buchwaldoboletus was not monophyletic in our phylogeny. We identified new features of these fungi in pure culture; B. hemichrysus and B. sphaerocephalus produce abundant conidia whereas B. lignicola produces sclerotia. Confrontation experiments on agar found that Buchwaldoboletus species can parasitize a wide range of wood-decay fungi from three orders (B. lignicola: 5 species, B. hemichrysus: 10 species, B. sphaerocephalus: 9 species). When the Buchwaldoboletus species and wood decay fungi were inoculated at the same time, the presence of Buchwaldoboletus species did not significantly impact the rate of wood decay. When B. lignicola or B. hemichrysus were inoculated alone, the results were highly variable but both species decayed wood using a brown rot strategy and caused 35–65% of mass loss.

1 - University of Florida, Department of Plant Pathology, PO Box 110680, Gainesville, FL, 32611, USA
2 - University of Florida, Department of Plant Pathology, PO Box 110680, , Gainesville, FL, 32611, USA

Keywords:
Boletes
mycoparasitism
Wood-decay
Chalciporoideae
Mycology.

Presentation Type: Oral Paper
Session: MY1, Mycology: Ecology and Conservation
Location: /
Date: Monday, July 19th, 2021
Time: 11:15 AM(EDT)
Number: MY1002
Abstract ID:810
Candidate for Awards:None