Andrew Loyd is originally from Baton Rouge, Louisiana, and is a PhD candidate at the University of Florida in Gainesville in the labs of Drs. Jason Smith and Brantlee Richter. He is the recipient of a 2017 MSA Clark T. Rogerson Award. Andrew’s research project focuses on the taxonomy, biology and physiology of the laccate (shiny or varnished) Ganoderma species in the United States. Ganoderma is a large and diverse, globally-distributed genus of basidiomycete wood decay fungi that includes species that cause white rot on a variety of tree species. In addition, Ganoderma species are considered “superior herbs” in traditional Asian medicine, where they are made into teas and tinctures and prescribed as anti-inflammatory and immune enhancing therapies. The taxonomy of the laccate Ganoderma species is confusing, but the lab is currently elucidating evolutionary relationships and biological differences between the laccate Ganoderma species present in the United States.
In addition, the lab has conducted surveys of Ganoderma species in commercially-available supplement products and grow-your-own Ganoderma kits that are labeled as containing G. lucidum sensu lato. Andrew and others in his lab are elucidating what species are actually being sold, because there are likely differences in the quantity and quality of pharmaceutical chemicals (e.g. triterpenes) produced. Furthermore, it is likely that non-native species are being introduced through the mushroom cultivation trade, which could lead to escapes into natural ecosystems. Currently, supplement products are not regulated by the the U.S. Food and Drug Administration and the medicinal fungus growing trade is often overlooked by the U.S. Animal and Plant Inspection Service.
For the past century, many studies of Ganoderma have used the name Ganoderma for any laccate Ganoderma species growing on hardwood trees. Molecular studies have established that G. lucidum sensu stricto (Curtis) Karst is not native to North America. The lab’s surveys of over 500 collections of Ganoderma species collected in the United States have revealed 12 putative native taxa, including: G. curtisii (Berk.) Murrill, G. martinicense Welti & Court., G. meredithiae Adask. & Gilb., G. oregonense Murrill, G. polychromum (Copel.) Murrill, G. ravenelii Steyaert, G. sessile Murrill, G. tsugae Murrill, G. tuberculosum Murrill, G. c.f. weberianum (Bres. & Henn.) Steyaert, G. zonatum Murrill, and Tomophagus colossus (Fr.) Murrill (syn. G. colossus). Andrew and others are investigating the geographic distributions and host preferences of the laccate Ganoderma species present in the United States to better understand the ecology of these important primary decay fungi. Furthermore, they have characterized the cultural characteristics to better understand the physiology of the laccate Ganoderma species in the U.S. For this Andrew and the lab characterized the optimal temperatures, average linear growth rates, and survival and resiliency to extreme temperatures.
There is some debate whether Ganoderma species are pathogens or early successional, opportunistic saprophytes, as many of these taxa are associated with the decline of living trees. Some Ganoderma species cause root and butt rot of living trees, but the pathogenicity and decay ability within the genus is understudied. Some, such as G. zonatum are considered aggressive pathogens, and have been associated with tree failure and mortality of mature palms, while others, are often saprophytic causing decay in old, weakened tress and can potentially be latent opportunistic saprophytes. Few studies have conducted pathogenicity tests in living trees, while many studies have associated Ganoderma species with a general decline of living trees. The lab is conducting pathogenicity assays with common Ganoderma species across several tree hosts in the southeastern U.S. to address these questions. Ganoderma species identification tools are being developed to make species diagnoses easier. Biological differences likely exist among the native North American Ganoderma species, and these results will be published in peer-reviewed journals soon.
Upon completion of his PhD, Andrew will step into a role as Plant Pathologist/Mycologist for the Bartlett Tree Research Laboratories based out of Charlotte, NC. He will continue to work on taxonomy and biology of wood decay fungi, especially species that are associated with living trees. Andrew would like to research different soil management and tree health enhancing cultural practices that can stimulate compartmentalization in living trees as management tactics to reduce the likelihood of tree failures due to decay. Other research interests involve surveys of mycorrhizal fungal species in urban forests relative to native forests, effects of fungicide injections on endophyte biodiversity, and sustainable management of tree diseases in the landscape.
What is your favorite fungus and why?
Obviously, Ganoderma species are the crème de la crème. I have thoroughly enjoyed studying this genus of fungi. Although the literature regarding the taxonomy of this genus is quite confusing, and at times frustrating, it has been very rewarding to unravel the chaos! Also, the cultural significance of Ganoderma species (reishi) in Asian culture is quite fascinating, where several Chinese deities are said to have lived for hundreds of years because of consumption of reishi.
My favorite fungus that I have eaten is the beef steak polypore (Fistulina c.f. hepatica). It is great on tacos or burritos, because it has a sweet and acidic flavor that is reminiscent of tomatoes.
What is your favorite fact/thing about fungi?
Fungi represent a fascinating Kingdom of life that is quite understudied and culturally significant. I think the use of fungi by indigenous people for medicine/religion all around the world is quite fascinating. The fact that indigenous peoples in different parts of the world, independently of each other, came to similar conclusions about the uses and spirituality surrounding fungi is so neat. I have learned a lot about this, especially involving wood decay fungi species, from reading and conversing with Bob Blanchette at the University of Minnesota.
Who is your mycology role model?
Personally: Larry Grand and Bob Blanchette; Academically: William Murrill
Any great stories from field work?
Working with citizen scientists has been quite rewarding in collecting a lot of fungi around the U.S. in a short amount of time. However, this has also has limited the amount of field work I have had to do for my current research. What stuck out to me though through using citizen scientists to aid in field work, was the knowledge and passion of SO many people who are truly dedicated to the study of fungi!
Although I didn’t get out in the field as much as I wanted, I did get the opportunity to go collect fungi in Wisconsin with the Blanchette lab. While collecting, I saw my first real, live porcupine! That was exciting.
What do you like to do in your free time? What are your hobbies?
In my free time, I enjoy cooking, eating Indian food, playing old-time music (fiddle, banjo, guitar), going to concerts, bird watching, camping, hiking, kayaking and of course collecting fungi!