Martin Čertner's research while affiliated with Charles University in Prague and other places

... Nevertheless, since FCM is an indirect method for ploidy estimation, it has to be supported by chromosome counting (see below and reference 21 for example). Advantages of FCM over other methods of ploidy estimation include (i) no need for special preparation of plant material (most tissues of the growing plant can be used), 22 (ii) rapid sample preparation, allowing daily processing of dozens or even hundreds of samples, (iii) an ability to measure DNA content/ploidy in mitotically inactive cells (as compared to chromosome counting, which requires mitotic cells), (iv) nondestructive sampling (a very small sample, about 5-10 mg fresh weight, is sufficient to provide thousands of nuclei for ploidy determination), which enables investigation of rare and endangered species with minimal damage, and allows the same individual to be used for further analyses, (v) the possibility of analysis of bulked samples of pooled individuals at one time, thereby providing large-scale screening, and (vi) very modest operating costs. It must be realized, however, that it is only possible to estimate ploidy levels from FCM measurements within a certain taxonomical rank (mostly within closely related species). ...

... The fact that the gametes are haploid also suggests the presence of molecular mechanisms that enable the isolation of the holoploid genome. This type of endoreplication, which appears to be specific to the Orchidaceae lineage in plants, has been successively termed ''progressively PE Q8 '' (Bory et al., 2008;Trá vní cek et al., 2015;H ribová et al., 2016), strict PE (Brown et al., 2017), and more recently, PE (Chumová et al., 2021;Q9 Trá vní cek et al., 2021). To be in line with the latest works and to harmonize the terminology for this phenomenon, the term PE will be used in this work. ...

... Plant pollen morphology is species specific and can help to analyze honey, pollinator-plant interactions, as well as allergic wind- ). An overview of recent developments of using flow cytometry in pollen analyses is provided by Kron et al., [125]. Automation of pollen analyses has been a research focus since the 1990s [126,127] mainly for its multiple facets in different research areas [128] for example as application in fossil pollen analyses (1. ...

... The study highlighted the importance of combining traditional culture-based analytical methods with fast and high-throughput ones for monitoring the microbiological safety of fruit juice. The comparison (solely on an economic basis) between the classic microbiological technique and flow cytometry for food applications clearly works in favor of the classic technique, but FCM is a tool which extends microbiological analyses capabilities and has a huge number of applications in several fields [65][66][67], and diminishing costs and user-friendly software are increasingly promoting its use. Flow cytometry proved to be capable of providing information on a large number of cells during the different phases of their growth, exceeding the limitation of the traditional culture-based methods, which underestimated bacterial growth. ...

... Firstly, assortative (within-ploidy) mating may occur if the patterns of pollen transfer are non-random due to e.g. spatial clumping of cytotypes (Morgan et al., 2020), flowering-time shifts (Pegoraro et al., 2019) and pollinator preferences (Laport et al., 2021;Roccaforte et al., 2015), or as a result of gametic selection . Different ecological preferences of related diploid and polyploid lineages are not uncommon (e.g. ...

... This DNA-fingerprinting technique has been successfully applied to the study of plant adaptation to metal tolerance in Arabidopsis halleri [93], serpentine adaptation in O. serpyllifolia [33], and genetic structure in rare serpentine endemics of the Balkans [27]. Moreover, it proved its effectiveness also in the detection of recent introgression events in morphologically divergent taxa and in polyploid groups [94][95][96]. ...

... Interestingly, we also found that the Ornstein Uhlenbeck evolutionary model best fitted GC content in our grassland species (Supplementary data Table S1), suggesting that GC content has been under an evolutionary pull towards an optimum value during its evolution. The same evolutionary pattern has been observed in 149 orchid species (Trávníček et al., 2019), which could be the result of physiological and environmental factors (Šmarda et al., 2014) or life-history traits, such as growth form (Trávníček et al., 2019). ...

... formed by genome duplication 83 after hybridization of two different parental genomes more or less divergent) than autopolyploids (i.e. This incongruence between studies has been explained by methodological issues as an inappropriate 93 resolution of environmental variables (Kirchheimer et al., 2016), because niche differentiation might be 94 occurring at a different spatial scale (Čertner, Kúr, Kolář, & Suda, 2019) and/or simply by different 95 evolutionary histories of polyploid cytotype between studied species -an aspect that has been, however, 96 often neglected in purely ecological studies. The presence or absence of niche evolution in polyploids 97 strongly depends on species' history: e.g. ...

... Č ertner et al., 2017;Hanušová et al., 2019;McAllister et al., 2015; reviewed in ...

... Taking into account morphological characters and molecular data, it was proposed to distinguish synuralean algae into a separate class, Synurophyceae [9,10]; however, recent molecular studies of the chrysophytes phylogeny clearly showed their position among Chrysophyceae [1]. The species concept for this group is based on the morphology of siliceous structures (scales and bristles), studied by transmission or scanning electron microscopy (TEM or SEM) [3], and is considered one of the best among the protists and generally confirmed by molecular methods [11,12]. Electron microscopy studies of synuralean algae began in the 1950s [13][14][15][16][17]. Since then, documenting the findings of this group of algae has become mandatory, making this group the model protists for studying biogeographic issues [18][19][20][21]. ...