Symbiotic germination and development of the myco‐heterotrophic orchid Neottia nidus‐avis in nature and its requirement for locally distributed Sebacina spp.

Abstract

Summary• Symbiotic germination and development of the fully myco-heterotrophic orchid Neottia nidus-avis were studied in 'packets' of seed placed adjacent to, or at varying distances from, adult plants in a Fagus sylvatica woodland.• The distribution and identity of the fungal partner(s) of N. nidus-avis were investigated by internal transcribed spacer (ITS)-restriction fragment length polymorphism (RFLP) and sequence analysis of part of the 28S gene in fungal DNA extracted from adult plants from the UK and Germany, and from seedlings germinated in situ .• Germination commenced in the spring, but only in the presence of a specific fungus, and occurred most frequently in plots containing adults of N. nidus-avis . Seedlings grew best in packets in which a large number of seeds germinated. Adults and seedlings of UK origin contained the same fungal partner whose 28S sequence most closely matched Sebacina dimitica. Plants of German origin contained a closely related, but distinct, fungus.• The results provide the first definitive chronology of the development of N. nidus-avis and establish its critical dependence upon, and specificity for, the locally distributed Sebacina -like fungus that is required for germination and growth.

Germinação de sementes e desenvolvimento de protocormos de Epidendrum secundum Jacq. (Orchidaceae) em associação com fungos micorrízicos do gênero Epulorhiza

“…1; Pereira et al 2009). Outros trabalhos buscaram isolar fungos presentes em protocormos e plântulas coletadas no campo ou a partir de protocormos obtidos após incubação de sementes das orquídeas de interesse no seu habitat natural (McKendrick et al 2002;Pereira et al 2005a).…”

“…A associação da planta com o fungo adequado é indispensável para a germinação das sementes, para o desenvolvimento do protocórmio e da plântula, de forma que a presença do parceiro fúngico é um fator importante na distribuição e desenvolvimento das orquídeas na natureza (Mckendrick et al 2002;Peterson et al 2004). Deste modo, a melhor compreensão da especifi cidade nesta associação é necessária para propagação simbiótica de mudas, tanto em programas para a reintrodução de espécies ameaçadas de extinção, como também para produção de mudas de orquídeas de interesse comercial (Pereira et al 2002).…”

Enigmatic Sebacinales

“…The requirement for locally distributed Sebacina spp., necessary for symbiotic germination and development of the European N. nidusavis, has been shown under natural conditions by McKendrick et al (2002), while at the same time the sebacinoid mycobionts were detected by Selosse et al (2002a, b) in roots of adult Neottia nidus-avis. These were demonstrated as ectomycorrhizae on closely growing Picea abies, Pinus sylvestris, Fagus sylvatica, Carpinus betulus, Corylus avellana, Tilia sp., and Populus nigra.…”

Pollinator limitation and inbreeding depression in orchid species with and without nectar rewards

“…Laboratory and glasshouse studies of progeny growth can over-or under-estimate true field estimates of inbreeding depression (Dudash, 1990;Wolfe, 1993). Therefore I incorporate here a novel field technique (Rasmussen & Whigham, 1993;McKendrick et al ., 2000McKendrick et al ., , 2002 to compare germination and growth under both laboratory and field conditions.…”