Effects of temperature, pH and carbon and nitrogen sources on growth of in vitro cultures of ectomycorrhizal isolates from Pinus heldreichii forest

Abstract

Aim of study: This study aims to provide basic information about physiological characteristics of isolates of Lactarius deliciosus (L.) Gray, Russula sanguinaria (Schumach.) Rauschert, Suillus collinitus (Fr) Kuntze, Suillus granulatus (L.) Rousell, Tricholoma batchii Gulden and Tricholoma imbricatum (Fr.) Kumm.Area of study: The isolates are obtained from Pinus heldreichii H. Christ forest in the south-eastern part of Montenegro.Material and methods: The isolates were molecularly characterised by internal transcribed spacer (ITS) sequencing and restriction fragment length polymorphism (RFLP) analysis. The effects of different temperatures (20, 22, 25°C), pHs (4, 4.5, 5.2, 5.8, 6.5, 7.5), and carbon (glucose, sucrose, dextrin, arabinose, xylose and starch) and nitrogen (NH4+, NO3- and protein) sources on their growth were examined under laboratory conditions.Main results: The studied factors established significant differences in the development of isolates. Isolates of R. sanguinaria, L. deliciosus and both Suillus, were characterised by faster growth at 22°C, while Tricholoma isolates grew faster at 25°C. S. granulatus, S. collinitus and T. imbticatum isolates grew well at lower pH values (4 - 5.2), while L. deliciosus, R. sanguinaria and T. bachii exhibited faster growth at pHs between 5.8 and 6.5. The examined isolates were able to utilize various carbohydrates as carbon sources. The biggest mycelial growth was characterised for sucrose, then glucose, dextrin, arabinose, starch and xylose. They grew on all examined nitrogen sources, while the biggest mycelia growth was achieved on ammonium, followed by nitrate and protein. Those characteristics varied amongst the species.Research highlights: Information about physiological characteristics of Tricholoma, Lactarius, Russula, as well as Suillus, are sparse. Hence, the data obtained in this study could contribute to the understanding of their function in ecosystems.