Diversity and evolution of Lactarius & Lactifluus (Russulales) in West Africa and the socio-economic value of useful wild mushrooms in Guinea.
Gbamon Konomou
gbamon.konomou@ugent.be
Promotor: Prof. dr. Mieke Verbeken (UGent)
Copromotor: Prof. Nourou Soulemane Yorou (University of Parakou, Benin)
Project duration: 2023-2027
The Russulaceae family includes agaricoid and pleurotoid species, gastroid forms with closed or partially closed fruiting bodies and crust-like corticioid forms (Buyck et al.; 2008). The largest genera are predominantly agaricoid: Lactarius Pers, Lactifluus (Pers.) Roussel and Russula Pers (Miller et al., 2006). Within the Russulaceae, the genera Lactarius, Lactifluus and Russula are the best documented in tropical Africa (Verbeken 1995 ; Verbeken & Walleyn 2010 ; De Crop et al., 2012). However, there are still major gaps in our knowledge, including incomplete sampling in West Africa (Piepenbring et al 2020), which hampers our understanding of their evolutionary history.
Mushrooms belonging to the genera Lactarius and Lactifluus, also known as milkcaps, are easily recognized as such and often very striking in the field due to the presence of milk (latex) that exudes once the fungus is bruised or touched. However, in the tropics, certain macromorphological characters do not correspond to the traditional circumscription of the genus (e.g. the presence of a ring), and some characters can present a great deal of intraspecific variation, making it very difficult to recognize separate and numerous species. Species complexes occur especially in the genus Lactifluus (De Crop et al., 2014). The total number of known tropical African milkcap species is around 113 taxa (39 species of Lactarius and 74 species of Lactifluus). All are strictly endemic to the continent, most of them described in the Zambezi and Guineo-Congolese ecozones.
Lactarius is a predominantly temperate genus, but is represented with a few isolated and presumably basal clades in tropical Africa (Lagaet, Nuytinck & Verbeken, in prep.), while Lactifluus has its main distribution in tropical Africa.
Although there is an increased number of now-Lactarioidean taxa described recently from West Africa (Maba et al. 2015), the exact phylogenetic positions of Lactarius relative to Lactifluus in the global phylogeny are still lacking. At present, no clear picture can be drawn concerning the specific contribution of African species to the global evolution of Lactarius and Lactifluus. For a better assessment of the evolutionary contribution of taxa from tropical Africa, we need to generate a critical amount of DNA sequences compared to what is currently available in Genbanks (2021). Similarly, many recently described taxa (Maba et al, 2017) appear as species complexes, requiring critical anatomo-morphological and phylogenetic re-evaluation for other species.
On the other hand, although wild mushrooms are invaluable resources for local populations as a source of food and cash income (Yorou et al. 2014 ; Boni & Yorou 2015), very little attention is paid to them by scientists and large public. As a result, decision-makers and forest managers do not integrate wild edible mushrooms into their forest management strategies. Russulaceae species are among the most widely consumed edible wild mushrooms in rural communities in tropical Africa (Degreef et al., 2016).
Yet there is not enough documentation on the use of wild edible mushrooms by local populations in Guinea, although mycophagy is common in rural villages.
In the present project, we aim to fill important gaps : sampling in West Africa has been incomplete. An exploration of Guinea's wealth and biodiversity revealed the presence of undescribed taxa. For species described from West Africa, molecular sampling is absent or incomplete. These data will also enable us to understand the diversity of the genera Lactarius and Lactifluus in West Africa, and to complete their phylogeny in order to reconstruct the evolutionary history of both genera. The latter is impossible without completing this African part of the fungus. We also intend to study the socio-economic potential of edible wild mushrooms in Guinea, particularly in the Guinée Forestière region where mycophagy is more common.
Some critical fungal fruiting bodies from the natural habitats of Guinea:
(click the first picture to see the slideshow)
