Genetic analysis and substrate utilization of fungal isolates from the standing dead material of the moss Schistidium apocarpum from a High Arctic site

• Main Author: Leung, Garwai
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2011
• Subjects: ascomycete; soil; Schistidium apocarpum; fungi; Svalbard; moss; Arctic
• Online Access: https://research.manchester.ac.uk/en/studentTheses/ba29ca57-209e-4107-aba4-dd5e8a5b170b; https://pure.manchester.ac.uk/ws/files/54510078/FULL_TEXT.PDF

Fungi isolated from the litter of the moss Schistidium apocarpum, from a site in Svalbard, Norway (78°56 N, 11°50 E), were placed into 12 different groups using culture morphology. Representative isolates from each group were then subcultured and identified by sequencing the Internal Transcribed Spacer region (ITS1-5.8S-ITS2) of the ribosomal DNA. Sequences were compared to species from the BLASTn database and were aligned using CLUSTALW. A phylogenetic tree was constructed using MEGA 5 and bootstrapped 1000 times. Subcultured isolates were tested to see if they could degrade several pure carbon sources (casein, cellulose, lignin, pectin, starch, tannic acid, and xylan) as analogues of carbon substrate, found in plant litter, at 6oC. Isolates were also grown at three different temperatures (4, 10 and 25oC) and mycelia extension rates were measured. The majority of isolates were identified as Phoma sclerotioides, a known cause of brown root rot in alfalfa in temperate regions with harsh winters. Other isolates identified included Debaryomyces hansenii, Fimetariella rabenhorstii, Hypocrea viridescens, Monodictys arctica, Penicillium camemberti and Phoma herbarum. Isolate identities and enzyme activity were similar to mid-late stage of decomposition although isolates were from standing-dead material and it is possible to be at the start of decomposition. This study shows a variety of fungi have the potential to utilize carbon sources from Schistidium apocarpum litter at low temperatures, therefore they are likely to be contributing to the mineralization of carbon in the arctic environment.