The Ability of Spontaneous Autogamy in Four Orchid Species: Cephalanthera Rubra, Neottia Ovata, Gymnadenia Conopsea, and Platanthera Bifolia

Abstract

The breeding system in Orchidaceae generates many questions about the selfing potential of its representatives. We investigated the ability of spontaneous autogamy of four orchid species: Cephalanthera rubra and Neottia ovata of the Neottieae tribe and Gymnadenia conopsea and Platanthera bifolia of the Orchideae tribe. These species represent diverse specializations of the gynostemium architecture. The self-compatibility and properties of autogamous seeds were determined in a bagging experiment and seed development analysis. After induced autogamy, a high level of fruiting (80-100%) was noted in all of the four study species. C. rubra, N. ovata, and G. conopsea are completely self-compatible, and P. bifolia is suggested to be partially self-compatible. If autogamy occurred, inbreeding depression and resource limitation on seed development appeared only in the two Orchideae species. Independent of flower specialization, both Neottieae species and P. bifolia were completely allogamous, whereas G. conopsea could be facultatively autogamous.

A global systematic review on orchid data in Protected Areas

“…Raventós et al, 2015;Khapugin et al, 2016Khapugin et al, , 2017aBr-zosko et al, 2017;Puchnina, 2017;Kirillova & Kirillov, 2020). However, there are a few studies (Pierce et al, 2006;Stefaniak et al, 2013;Talalaj et al, 2017) concerning a higher number of orchid species which are more valuable for further comparison. Finally, the lowest number of studies on orchids in PAs was devoted to economic importance and use of orchids.…”

How Are the Flower Structure and Nectar Composition of the Generalistic Orchid Neottia ovata Adapted to a Wide Range of Pollinators?

“…Each flower possesses two pollinia attached to each other, being removed as a pair. N. ovata is self-compatible but has a mechanism (well-developed rostellum) to prevent self-fertilization [ 76 , 78 ]. Flowers emit a distinct and somewhat sweet scent and secrete nectar on the labellum [ 107 ].…”

“…Therefore, it seems interesting to choose the generalist orchid N. ovata as a model species to test in which way flower traits are adapted to pollination by a wide range of pollinators. N. ovata was the object of studies on pollination mechanism [ 76 , 77 , 78 ], demographic processes [ 79 , 80 , 81 ], genetic variation [ 82 , 83 ], and flower anatomy [ 84 ]. So far, there are no published data on nectar composition and floral structure in this orchid and their role in the effectiveness of reproduction.…”

Initial stages of Gymnadenia conopsea (Orchidaceae) morphogenesis in in vitro culture

“…The low germination of G. conopsea seeds (17.28%) (Fig. 2) under the experiment conditions may be the result of species inbreeding due to low number of the flowering plants in the local CP, because spontaneous autogamy in G. conopsea was found to be accidental [13]. But if it occurs, significant inbreeding depression manifesting in selfed seeds was revealed, e.g.…”