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

Abstract

Orchidaceae is one of the largest and the most widespread plant families with many species threatened with extinction. However, only about 1.5% of orchids’ genome sizes have been known so far. The aim of this study was to estimate the genome size of 15 species and one infraspecific taxon of endangered and protected orchids growing wild in Poland to assess their variability and develop additional criterion useful in orchid species identification and characterization. Flow cytometric genome size estimation revealed that investigated orchid species possessed intermediate, large, and very large genomes. The smallest 2C DNA content possessed Liparis loeselii (14.15 pg), while the largest Cypripedium calceolus (82.10 pg). It was confirmed that the genome size is characteristic to the subfamily. Additionally, for four species Epipactis albensis, Ophrys insectifera, Orchis mascula, Orchis militaris and one infraspecific taxon, Epipactis purpurata f. chlorophylla the 2C DNA content has been estimated for the first time. Genome size estimation by flow cytometry proved to be a useful auxiliary method for quick orchid species identification and characterization.

Genome Size, Chromosome Number and Morphological Data Reveal Unexpected Infraspecific Variability in Festuca (Poaceae)

“…The use of FCM has uncovered an overlooked heterogeneity of cytotypes at an intraspecific level in many genera of vascular plants [22,[27][28][29]. It has, therefore, been used as an exploratory tool in studies focused on resolving or identifying taxonomically challenging plant groups [30][31][32][33][34][35][36][37][38]. Data on the amounts of nuclear DNA in plants are growing rapidly [39].…”

Cytological Study of Cypripedium japonicum Thunb. (Orchidaceae Juss.): An Endangered Species from Korea

“…No meiotic abnormalities, such as laggards or bridges during cell divisions, were found in any of the analyzed C. japonicum individuals (Figure 2C). The previously reported base chromosome number for Cypripedium was constant (x = 10), with diploids being the most common among the species followed by triploids (Table 2; [29][30][31][32][33]), except for C. macranthos that presents 2n = 22 [11]. The Chinese and Korean populations of C. japonicum clearly showed 2n = 22 (n = 11; Figure 2D-E; [14]), whereas those from the Japanese populations had 2n = 20 (Table 2; [10,12,13]).…”

Investigations on Nuclear DNA Content and DNA Synthesis in Plants and Fungi Using Flow Cytometry and Fluorescence Microscopy

“…However, genome size data are available only for approximately 12,000 plant species (Kew Plant DNA C-values Database (https://cvalues. science.kew.org/, accessed on 12 January 2022), e.g., in the family Orchidaceae, which contains about 30,000 species, genome size is known merely for 1.5% of them [1]. Therefore, there is an urgent need for further measurements.…”

“…Information on genome size (nuclear DNA content) and DNA synthesis has become a required basis for underpinning these advances. However, genome size data are available only for approximately 12,000 plant species (Kew Plant DNA C-values Database ( , accessed on 12 January 2022), e.g., in the family Orchidaceae, which contains about 30,000 species, genome size is known merely for 1.5% of them [ 1 ]. Therefore, there is an urgent need for further measurements.…”

“…Establishing genome size, an important species characteristic, can be helpful in species identification, particularly during early plant development when it is difficult to differentiate between related species based on morphological characteristics. Rewers et al [ 1 ] determined the 2C DNA content of 15 species and one intraspecific taxon of wild orchids growing in Poland. FCM revealed differences in genome size between 12 of the species, which is significant enough to distinguish them.…”