Morphology and genome size of Epipactis helleborine (L.) Crantz (Orchidaceae) growing in anthropogenic and natural habitats

Abstract

BackgroundThe process of apophytism or spreading native species to human-made habitats is one of the main elements in the creation of plant cover in anthropogenic areas. Lately, an increase of anthropogenic localities with valuable flora has been observed. Apophytes are also members of the family Orchidaceae, especially from the genus Epipactis. The aim of the study was to (i) determine and compare the phenotypic variation of E. helleborine (L.) Crantz plants in anthropogenic and natural habitats, (ii) compare the genome size of plants growing in natural and anthropogenic habitats. The results reported in this study may indicate that a habitat influences morphological characteristics of plant species.MethodsField studies were conducted on four native stands and four stands in anthropogenic areas of E. helleborine in Poland in years 2011–2013. Biometrical analyses were performed on shoots and flowers. The flowers were characterised by 25 biometric features and measured using a Nikon SMZ 800 binocular, microscopic Moticam-1SP cameras and the MIPlus07 programme (Conbest Co.). The nuclear DNA content was determined in fresh and young leaves of E. helleborine, collected from four natural and four anthropogenic populations.ResultsWe observed that in anthropogenic populations: (i) shoots were higher than shoots from natural populations, (ii) flowers differed significantly in terms of ten biometric features between habitats, (iii) the genome size of some population differed significantly between plants growing in natural and anthropogenic habitats.DiscussionAccording to some researchers, the presence of phenotypic variability and the occurrence of ecotypes are adaptation strategies of plants to environmental changes. In our opinion, in the case of the studied anthropogenic habitats (roadside) in which the E. helleborine populations grew, we can talk about ecofen due to the often repeated set of characteristic features, i.e., high shoots, long inflorescence and long, broad leaves. We agree, however, that it is difficult to isolate a taxonomic unit for ecofen due to the lack of experimental research.

The Role of Ecological Factors in Distribution and Abundance of Terrestrial Orchids

“…Investigations of morphology and size of the genome of this species in anthropogenic and natural habitats showed that ten biometric features of flowers differed significantly between habitats [190]. These plants were taller in anthropogenic habitats than those from natural populations, and genome size in some populations was significantly different between plants growing in natural and anthropogenic habitats [190]. In addition, it was found that reduced seed weight is characteristic of E. helleborine in anthropogenic habitats, which is in part associated with its inability to adapt to the lower nutrient availability in soils of these habitats [191].…”

“…Several studies provide detailed insights into the performances of orchids growing in anthropogenic vegetation types, including reproductive success, the height of individuals, and inflorescences and pollinator diversity [165,190]. For example, it has been found that Epipactis helleborine in ruderal vegetation in Poland had higher reproductive success than in natural vegetation types, which can be attributed to greater diversity of pollinator species and higher frequency of visits by pollinators, as well as to the larger size of plants growing in such habitats [165].…”

“…For example, it has been found that Epipactis helleborine in ruderal vegetation in Poland had higher reproductive success than in natural vegetation types, which can be attributed to greater diversity of pollinator species and higher frequency of visits by pollinators, as well as to the larger size of plants growing in such habitats [165]. Investigations of morphology and size of the genome of this species in anthropogenic and natural habitats showed that ten biometric features of flowers differed significantly between habitats [190]. These plants were taller in anthropogenic habitats than those from natural populations, and genome size in some populations was significantly different between plants growing in natural and anthropogenic habitats [190].…”

Genome Size Diversity in Rare, Endangered, and Protected Orchids in Poland

“…The species of Apostasioideae subfamily have high genome size variation (16-fold), although have the smallest average genome size comparing with other orchid subfamilies [ 14 ]. The information on genome size of orchids growing wild in Poland are scarce and limited to Epipactis helleborine [ 15 ] and Dactylorhiza species ( D. incarnata var. incarnata , D. incarnata var.…”

The Epipactis helleborine Group (Orchidaceae): An Overview of Recent Taxonomic Changes, with an Updated List of Currently Accepted Taxa

“…[ 31 , 37 , 51 , 52 , 53 , 61 , 62 , 63 ]. It is also increasingly observed in the areas strongly impacted by human activity, such as roadsides, cemeteries, railway embankments, gravel pits, gardens, and urban parks [ 64 , 65 ].…”