485 © 2017 J. Cramer in Gebr. Borntraeger Verlagsbuchhandlung, Stuttgart, www.borntraeger-cramer.de Germany. DOI: 10.1127/nova_hedwigia/2017/0448 0029-5035/2017/0448 $ 3.25 Nova Hedwigia Vol. 106 (2018) Issue 3–4, 485–497 published online November 7, 2017; published in print May 2018 Article C Maximum temperature for growth and reproduction is similar in two soil isolates of Gaertneriomyces semiglobifer (Spizellomycetales, Chytridiomycetes) from different soil environments in north eastern New South Wales, Australia Linda Henderson*, Mai-Anh Ly, Katie Robinson, Frank H. Gleason and Osu Lilje University of Sydney, School of Life and Environmental Sciences, Macleay Building A12, University of Sydney, New South Wales 2006, Australia With 3 fgures and 2 tables Abstract: Two isolates of the zoosporic fungus, Gaertneriomyces semiglobifer (order Spizello-mycetales), one from a semi-arid region and one from a mild temperate region of New South Wales, Australia, had similar patterns of growth and sporulation in response to increased temperatures. Both strains of G. semiglobifer were able to grow in temperatures up to a maximum of 37°C and were able to recover growth after incubation on solid PYG media for 7 days at 40 but not 42°C. Both strains produced viable zoospores when incubated on solid PYG media for 7 days at up to 40 but not 42°C. The two strains grew at similar rates in liquid PYG media. Both strains increased in growth over time at 25°C and initially increased in growth at 37°C to 62 hours, but after that growth declined. Changes in rates of zoospore release for both strains were similar to changes in biomass as temperature increased, except for large increases in zoospore release for both isolates when incubated at 37°C. If temperature causes similar effects in the field it is expected that growth and reproduction of the fungus will be reduced in summer months when daytime air temperatures exceed 37°C. This may have implications for the geographical distribution and abundance of G. semiglobifer in the soils of NSW. Key words: Zoosporic fungi, Chytrids, Spizellomycetales, temperature, fungal growth rate. Introduction Although there have been many studies estimating the most likely responses of individual animal and plant species to large temperature increases predicted in the future due to global warming (Hochachka & Somero 2002, Atkin & Tjoelker 2003) there are only a few studies addressing the ability of soil fungi to adapt to similar temperature *Corresponding author: lhen2084@uni.sydney.edu.au eschweizerbart_xxx