Orchid Mycorrhiza: Vitamin Production and Requirements by the Symbionts

Abstract

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Root-associated Fungi in Orchidaceae: Diversity, Phylogeny, Ecology, and Outstanding Questions

“…Green orchids can provide photosynthetic C resources for mycorrhizal fungi to achieve a temporal symbiotic mutualism within orchid lifecycles (Cameron et al 2006). Although C supply from mycoheterotrophic orchids is limited or not possible, several pioneering studies have already provided evidence that fungi receive other resources (vitamins and ammonia) from orchids (Hijner & Arditti 1973; Cameron et al 2008), even at early mycoheterotrophic developmental stages of orchids (Fochi et al 2017). In addition, endophytism (residing in orchid roots) may help to expand the ecological niches of mycorrhizal fungi (Selosse et al 2018).…”

Comparative seed germination and seedling development of the ghost orchid,Dendrophylax lindenii(Orchidaceae), and molecular identification of its mycorrhizal fungus from South Florida

“…However, sugar and starch deposits have been documented in a few orchid species ( Manning and Van, 1987 ; Yeung and Law, 1992 ). Fungal mycobionts supply water and nutrients, such as minerals, sugar, thiamine and folic acid, which promote germination and protocorm development ( Arditti, 1967 ; Hijner and Arditti, 1973 ; Rasmussen, 1995 ; Bougoure et al , 2014 ). Numerous symbiotic and asymbiotic studies have been conducted to investigate orchid seeds’ germination requirements (reviewed by Arditti, 2009 ).…”