Leaf and shoot characteristics of the following four European barberry taxa from the Balkan Peninsula and Sicily were investigated in the present study: Berberis croatica, B. vulgaris, B. aetnensis and B. cretica. Analyses were based on 10 populations of B. croatica, five of B. vulgaris and two populations of both B. aetnensis and B. cretica. Populations were randomly selected within the natural distribution area of these species. Eight leaf traits, three shoot traits and the blade length/width ratio were analysed. Multivariate analysis (principal component analysis, canonical discriminant analysis and cluster analysis) distinguished B. cretica and B. aetnensis populations and, to a lesser extent, the populations of B. croatica and B. vulgaris. ANOVA showed that the analysed populations of both B. aetnensis and B. cretica were homogeneous within the species. All populations of both B. croatica and B. vulgaris showed different degrees of intraspecies variability. Lack of complete separation, the observed grouping of populations and high intraspecies variability in B. vulgaris and B. croatica may reflect the fact that the sampled B vulgaris and B.croatica populations were located at environmentally variable sites (unlike B. aetnensis and B. cretica), resulting in high phenotypic plasticity in those populations. Even though the observed patterns of morphological variation support the idea of four barberry taxa on the Balkan Peninsula and in Sicily, because of suspected adaptive phenotypic plasticity of the analysed Berberis taxa, the true taxonomic status of these taxa needs to be additionally confirmed by molecular methods.
This paper presents new records and noteworthy data on the following taxa in SE Europe and adjacent regions: the diatom alga Eunotia boreoalpina; the saprotrophic fungus Clitocybe truncicola; the liverwort Haplomitrium hookeri; the moss Leptodon smithii: the monocots Epipactis purpurata, Stipa tirsa, Typha laxmannii and T. shuttleworthii; and the dicots Krascheninnikovia ceratoides, Polygonum albanicum and Sorbus latifolia.
Of the four species of the genus Satureja (Lamiaceae) that are recognized in Bosnia and Herzegovina, S. subspicata has the the widest distribution. It is taxonomically challenging species of geographically limited distribution and little data on its genetic diversity throughout its range is available. We sampled six geographically distinct populations from Bosnia and Herzegovina and applied nrDNA (ITS1, ITS2), chloroplast markers (matK and trnL) and AFLP to examine genetic diversity of S. subspicata in the center of its distribution range and to explore the possibility of establishing the species DNA barcode. AFLP analysis showed large genetic differentiation among populations as well as moderate correlation between genetic distance among populations and geographic distance among locations. MatK has not proven useful in distinguishing S. subspicata from sympatric species. However, nrDNA sequences provided necessary resolution power, with ITS2 being more informative. Estimates of evolutionary divergence between nrDNA sequences obtained in our research and homologous sequences of sympatric Satureja deposited in the GenBank reveal closer relationship between geographically proximate populations of different species and slight divergence within S. subspicata sequences pool. This outcome highlights the importance of considering overall genetic diversity across the distribution range of a species when assigning DNA barcode.
Abstract Epigenetic variation in natural populations with contrasting habitats might be an important element, in addition to the genetic variation, in plant adaptation to environmental stress. Here, we assessed genetic, epigenetic, and cytogenetic structure of the three Lilium bosniacum populations growing on distinct habitats. One population was growing under habitual ecological conditions for this species and the other two were growing under stress associated with high altitude and serpentine soil. Amplified fragment length polymorphism and methylation-sensitive amplification polymorphism analyses revealed that the three populations did not differentiate genetically, but were clearly separated in three distinct clusters according to DNA methylation profiles. Principal coordinate analysis showed that overall epigenetic variation was closely related to habitat conditions. A new methylation-sensitive amplification polymorphism scoring approach allowed identification of mainly unmethylated (φST = 0.190) and fully CpG methylated (φST = 0.118) subepiloci playing a role in overall population differentiation, in comparison with hemimethylated sites (φST = 0.073). In addition, unusual rDNA repatterning and the presence of B chromosomes bearing 5S rDNA loci were recorded in the population growing on serpentine soil, suggesting dynamic chromosome rearrangements probably linked to global genome demethylation, which might have reactivated some mobile elements. We discuss our results considering our earlier data on morphology and leaf anatomy of several L. bosniacum populations, and suggest a possible role of epigenetics as a key element in population differentiation associated with environmental stress in these particular lily populations.
BACKGROUND AND AIMS Allopolyploidy and intraspecific heteroploid crosses are associated, in certain groups, with changes in the mating system. The genus Sorbus represents an appropriate model to study the relationships between ploidy and reproductive mode variations. Diploid S. aria and tetraploid apomictic S. austriaca were screened for ploidy and mating system variations within pure and sympatric populations in order to gain insights into their putative causalities. METHODS Flow cytometry was used to assess genome size and ploidy level among 380 S. aria s.l. and S. austriaca individuals from Bosnia and Herzegovina, with 303 single-seed flow cytometric seed screenings being performed to identify their mating system. Pollen viability and seed set were also determined. KEY RESULTS Flow cytometry confirmed the presence of di-, tri- and tetraploid cytotype mixtures in mixed-ploidy populations of S. aria and S. austriaca. No ploidy variation was detected in single-species populations. Diploid S. aria mother plants always produced sexually originated seeds, whereas tetraploid S. austriaca as well as triploid S. aria were obligate apomicts. Tetraploid S. aria preserved sexuality in a low portion of plants. A tendency towards a balanced 2m : 1p parental genome contribution to the endosperm was shared by diploids and tetraploids, regardless of their sexual or asexual origin. In contrast, most triploids apparently tolerated endosperm imbalance. CONCLUSIONS Coexistence of apomictic tetraploids and sexual diploids drives the production of novel polyploid cytotypes with predominantly apomictic reproductive modes. The data suggest that processes governing cytotype diversity and mating system variation in Sorbus from Bosnia and Herzegovina are probably parallel to those in other diversity hotspots of this genus. The results represent a solid contribution to knowledge of the reproduction of Sorbus and will inform future investigations of the molecular and genetic mechanisms involved in triggering and regulating cytotype diversity and alteration of reproductive modes.
Sorbus subgenus Soraria encompasses taxa originating from spontaneous hybridization between members of subgenera Aria and Sorbus disjunctly distributed across Europe and Asia. Using molecular data (amplified fragment length polymorphisms, plastid DNA sequences and nuclear microsatellites), flow cytometry (allowing for the determination of ploidy and mode of reproduction) and morphology, we disentangled the relationships among polyploid cytotypes and explored their relationships with their diploid ancestors. Among others, we focused on a large, geographically isolated hybrid population in Bosnia and Herzegovina. Molecular and morphological analyses confirmed the distinct position of this population in relation to its parental (S. aria and S. aucuparia) and other hybridogenous taxa originating independently from the same parents in different parts of Europe. After establishing its genetic and morphological divergence, we describe the isolated Bosnian population as a new tetraploid apomictic species, Sorbus bosniaca, discuss its taxonomic status and propose conservation measures to protect the locus classicus of this new Balkan endemic. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 178, 670–685.
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