Diversity of root-associated culturable fungi ofCephalanthera rubra(Orchidaceae) in relation to soil characteristics

Abstract

Cephalanthera rubra (L.) Rich., Red Helleborine, is a widespread orchid in Europe but known only from three very small populations in England. These populations are in decline with no natural seed setting for more than a decade. The species may become extinct in the UK soon unless viable strategies are in place for ex situ conservation, especially the use of symbiotic propagation. Because of the fragile nature of the populations in England mycorrhizal fungal diversity study is not feasible. Therefore, to understand the factors needed for healthy Red Helleborine populations, soil characteristics and diversity of culturable root-derived fungi of the populations from a small area in the Loire Valley in France were studied. The main objectives of the study were: (1) Which culturable mycorrhizal fungi associated with C. rubra roots and (2) To what extent is variation in fungal communities related to variation in soil characteristics? Here, we report a significant difference in diversity of culturable mycorrhizal and non-mycorrhizal fungi depending on soil pH and phosphorus content. Mycorrhizal associations were favoured by plants in locations with low soil nutrient availability and comparatively higher pH. Our study shows that mycorrhizal fungi, both ecto and endo, can be cultured from roots of plants at different maturity stages.

Progress and Prospects of Mycorrhizal Fungal Diversity in Orchids

“…Previous studies have demonstrated the importance of in vitro fungal isolation in the understanding and experimenting on OM. Moreover, the identifications of some relatively easy-toisolate strains and biological effect detection have been reported in recent years (Meng et al, 2019a,b,c;Bell et al, 2020;Gao et al, 2020b;Zhang et al, 2020). Isolation methods mainly include isolation from whole tissue or tissue section, in situ seeding and trapping isolation, and single peloton isolation; of these, single peloton isolation (i.e., the isolation of pelotons from host cells by micromanipulation) is considered as the most reliable and accurate method (Zettler et al, 2005;Batty et al, 2006;Zi et al, 2014;Zettler and Corey, 2018).…”

“…Currently, in vitro investigations on the functions of ONF during the life cycle of orchids are limited, even though at least 65 ONF genera have been successfully isolated and cultured (Novotná et al, 2018;Meng et al, 2019a,b,c;Sarsaiya et al, 2019;Shah et al, 2019;Bell et al, 2020). It is crucial to further investigate the ONF that frequently occurs in orchids roots, in order to determine their potential physiological and ecological advantages.…”

Fungal Diversity of Selected Habitat Specific Cynorkis Species (Orchidaceae) in the Central Highlands of Madagascar

“…had high diversity (H and D indices) for non-mycorrhizal fungi when P content was high and K content was low. As Bell et al [ 40 ] reported with Cephalanthera rubra , members of Cynorkis also recruited more non-mycorrhizal fungi when soil P values were comparatively high. The Central Highlands landscape is prone to eutrophication due to burning and grazing.…”

“…Therefore, for the purpose of understanding specific requirements for reintroduction, targeted environmental analysis is required. Previous studies indicate that low P content may be linked to higher mycorrhizal diversity in Cephalanthera rubra [ 40 ] and several orchids from Madagascar [ 11 ]. Likewise, Van der Ent et al [ 41 ] found that the rhizosphere soil concentrations of P and K was low in soil in the study site where Paphiopedilum rothschildianum was growing.…”

Taxonomic, phylogenetic and functional diversity of root‐associated fungi in bromeliads: effects of host identity, life forms and nutritional modes

“…Talaromyces , Alternaria , Exophiala , Cyphellophora , Cladosporium , Phialophora , Xylaria ) have also been isolated and identified in numerous other plants (e.g. Bonfim et al ., 2016; Liu et al ., 2017; Bell et al ., 2020). In addition, Alternaria sp., Cyphellophora sp., Exophiala dermatitis and Paraconiothyrium sp.…”