AUTHOR=Wróblewska Ada , Ostrowiecka Beata , Brzosko Emilia , Jermakowicz Edyta , Tałałaj Izabela , Mirski Paweł 

TITLE=The patterns of inbreeding depression in food-deceptive Dactylorhiza orchids

JOURNAL=Frontiers in Plant Science

VOLUME=15

YEAR=2024

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2024.1244393

DOI=10.3389/fpls.2024.1244393

ISSN=1664-462X

ABSTRACT=<sec><title>Introduction</title><p>Inbreeding depression (ID) in food-deceptive plants have been reported previously, however, it has not been often proven that selfed seeds germinate better than outbred ones or that selfing affects ID. To resolved these issues, food-deceptive related <italic>Dactylorhiza majalis</italic>, <italic>D. incarnata</italic> var. <italic>incarnata</italic> and <italic>D. fuchsii</italic> orchids were investigated.</p></sec><sec><title>Methods</title><p>Hand pollination treatments and control pollination were conducted. Fruit set, number of seeds per fruit, seed length, number of well-developed seeds per fruit, and proportion of <italic>in vitro</italic> asymbiotic germination seeds, were analyzed in relation to inflorescence levels and used as fitness indicators for these orchids. The ID and pollen limitation were measured.</p></sec><sec><title>Results</title><p>The lowest ID (<italic>δ</italic> = −1.000) was in <italic>D. majalis</italic>, and present in combination with a high pollen limitation in its populations. <italic>D. fuchsii</italic> showed higher ID (<italic>δ</italic> = 0.366), and <italic>D. incarnata</italic> var. <italic>incarnata</italic> weak ID (<italic>δ</italic> = 0.065), although ID varied between its fitness components. The seed number per fruit differed significantly between the treatments and the inflorescence levels in treatments.</p></sec><sec><title>Discussion</title><p>This study emphasizes that the breeding system rather than the flower position on the inflorescence shaped the quality and quantity of reproductive output. The ID and its effect on germination of food-deceptive orchid seeds undoubtedly played an important role.</p></sec>