Seed dispersal and realized gene flow of two forest orchids in a fragmented landscape

Abstract

Species with vast production of dust-like windborne seeds, such as orchids, should not be limited by seed dispersal. This paradigm, however, does not fit recent studies showing that many sites suitable for orchids are unoccupied and most seeds land close to their maternal plant. To explore this issue, we studied seed dispersal and gene flow of two forest orchid species, Epipactis atrorubens and Cephalanthera rubra, growing in a fragmented landscape of forested limestone hills in southwest Bohemia, Czech Republic.• We used a combination of seed trapping and plant genotyping methods (microsatellite DNA markers) to quantify short-and long-distance dispersal, respectively. In addition, seed production of both species was estimated.• We found that most seeds landed very close to maternal plants (95% of captured seeds were within 7.2 m) in both species, and dispersal distance was influenced by forest type in E. atrorubens. In addition, C. rubra showed clonal reproduction (20% of plants were of clonal origin) and very low fruiting success (only 1.6% of plants were fruiting) in comparison with E. atrorubens (25.7%). Gene flow was frequent up to 2 km in C. rubra and up to 125 km in E. atrorubens, and we detected a relatively high dispersal rate among regions in both species.• Although both species occupy similar habitats and have similar seed dispersal abilities, C. rubra is notably rarer in the study area. Considerably low fruiting success in this species likely limits its gene flow to longer distances and designates it more sensitive to habitat loss and fragmentation.Plant Biology 22 (2020) 522-532

Genetic diversity based on SSR markers of 30 Aeridinae sub-tribe orchid genetic resources of Indonesian Ornamental Crop Research Institute, Cianjur, Indonesia

“…Hybridization between AJS and ALG is known to produce viable seedlings. Such observation aligns with earlier reports that accessions showing high similarity based on their genetic distance also share similar plant phenotypes (Kotilinek et al 2020) and are cross-compatible (Hartati et al 2017;Hartati et al 2019).…”

Transcriptome data reveals the conservation genetics of Cypripedium forrestii, a plant species with extremely small populations endemic to Yunnan, China

“…Currently, four particularly rare Cypripedium species are considered as PSESP for priority protection ( Sun, 2021 ). The distribution patterns and population genetics of Cypripedium orchids are, as is the case for many orchids, limited by their relatively short seed dispersal distance ( Brzosko et al., 2017 ; Kotilínek et al., 2020 ), low fruiting rate ( Suetsugu and Fukushima, 2014 ; Gargiulo et al., 2021 ) and the heterogeneity of available microhabitats ( Diez, 2007 ; Hollick et al., 2007 ; Jacquemyn et al., 2012 ; McCormick et al., 2012 ). Human activities, including over-collection for folk medicine and horticultural use, habitat destruction and disturbance also contribute to the decline of wild orchid populations ( Brundrett, 2007 ; Brundrett, 2019 ).…”

Fine‐scale genetic structure in the orchidGymnadenia conopseais not associated with local density of flowering plants

“…Orchid populations frequently have significant within‐population genetic structure, typically at very local scales (<5–10 m; Chung et al, 2004, 2005; Jacquemyn et al, 2006, 2009). Such fine‐scale genetic structure has been attributed to both restricted pollen and seed dispersal, where especially the latter has been documented to be surprisingly local (Machon et al, 2003; Jacquemyn et al, 2007; Jersákova and Malinová, 2007; Brzosko et al, 2017; Kotilínek et al, 2020), despite minute, wind‐dispersed orchid seeds. In addition, orchid germination success has been found to be higher in proximity of established plants (Diez, 2007; Jacquemyn et al, 2012), perhaps because orchids need a mycorrhizal partner to germinate and progress into the seedling stage and sharing the parental fungal strain could potentially favor the establishment of seedlings.…”