Genotypic diversity and clonal structure of Erigeron annuus (Asteraceae) in Lithuania

This study was conducted to assess the clonal structure and genetic diversity of alien herbaceous plant species Erigeron annuus. The global warming and changes in agriculture practice in the past few decades were favourable for the expansion of this species in Lithuania. We used RAPD and ISSR assays to assess genetic variation within and among 29 populations of E. annuus. A total of 278 molecular markers were revealed. Our study detected reduced level of genetic diversity of invasive populations of E. annuus. Significant differences in DNA polymorphism among populations of E. annuus were also found. Some populations of this species are composed of genetically identical plants, while others were polymorphic. Clonal diversity of study populations ranged from 0.083 to 0.4 for both DNA marker systems. The Simpsons diversity index values ranged from 0.0 to 0.636. The average number of genotypes per population established using both assays was about 1.7. Out of 328 E. annuus individuals only 16 showed unique RAPD and 14 unique ISSR banding patterns. The remaining plants were clones of different size. The most common genotype of E. annuus identified in our study was represented by predominate in nine populations.Keywords: Clonal structure, DNA markers, Erigeron annuus, invasive plants, ISSR, RAPDGenetische Vielfalt und Klonstruktur von Erigeron annuus (Asteraceae) in LitauenZusammenfassungDie Untersuchungen verfolgen das Ziel, die genetische Struktur der nicht-einheimischen Pflanzenart Erigeron annuus auszuwerten. Globale Erwärmung sowie Veränderungen in der landwirtschaftlichen Praxis der letzten Jahrzehnte waren bedeutsam für die Verbreitung dieser Art in Litauen. Für die Feststellung der genetischen Verteilungsvielfalt in den 29 E. annuus Populationen haben wir uns der RAPD und ISSR -Methoden bedient. Insgesamt wurden 117 RAPD - und 161 ISSR - Loci festgestellt. Die Untersuchungen haben die verringerte genetische Vielfalt der E. annuus Populationen aufgezeigt. Außerdem wurden bedeutende DNR polymorphe Unterschiede zwischen E. annuus Populationen angetroffen. Einige Populationen dieser Art bestanden aus genetisch identischen Pflanzen, während die anderen polymorphem waren. Die Klonvielfalt der untersuchten Populationen schwankte zwischen 0.083 und 0.4 bei der Verwendung von beiden DNR-Signifikanten. Die durchschnittliche Genotypen Zahl in der Population betrug etwa 1.7 bei der Verwendung von beiden Signifikanten. Nach der Untersuchung der 328 E. annuus Individuen wurden 16 unikale RAPD - und 14 unikale ISSR - Phänotypen festgestellt. Die übriggebliebenen Pflanzen waren Klonen von unterschiedlicher Größe. Der am meisten verbreitete E. annuus Genotyp wurde in neun Populationen ermittelt.Stichwörter: DNS- Marker, Erigeron annuus, ISSR, Klonstruktur, invasive Pflanzen, RAP

Comparison of genetic diversity in two alien plant species

Bunias orientalis and Erigeron annuus are two alien herbal plant species invading native ecosystems in Lithuania. Both species have similar introduction and invasion history but differ in their life history traits and strategies of reproduction. We used random amplified polymorphic DNA (RAPD) data to compare the genetic diversity in invasive populations of these species. 42 RAPD bands were identified in B. orientalis and 70 RAPD bands in E. annuus. All six populations of B. orientalis were polymorphic, while only four of eight study populations of E. annuus were polymorphic. The highest differences between species were established at the level of RAPD phenotypes. 67 RAPD phenotypes were found among 90 plants of B. orientalis but only 10 RAPD phenotypes were identified among 89 plants of E. annuus. This study shows that the level of genetic diversity in populations of different invasive species at the same geographic area may vary considerably. Keywords: Bunias orientalis, Erigeron annuus, genetic diversity, RAPD phenotypeVergleich der genetischen Vielfalt von zwei nicht-einheimischen PflanzenartenBunias orientalis und Erigeron annuus sind zwei nicht-einheimische Pflanzenarten, die in litauische natürliche Ökosysteme eindringen. Eindringungs- und Invasionswege beider Arten sind ähnlich. Unterschiede liegen in den Entwicklungs- und Reproduktionsbesonderheiten. In dieser Arbeit haben wir anhand der Ergebnisse von random amplified polymorphic DNA (RAPD) die genetische Vielfalt von verschiedenen Populationen dieser nicht-einheimischen Arten verglichen. 42 RAPD Banden wurden bei B. orientalis und 70 bei E. annuus festgestellt. Alle sechs B. orientalis-Populationen waren polymorph; bei E. annuus waren es nur vier von acht Populationen. Die größte Differenz zwischen den Arten zeigten die RAPD-Phänotypen. Bei 90 B. orientalis-Pflanzen wurden 67 RAPD-Phänotypen identifiziert aber nur 10 RAPD-Phänotypen bei 89 E. annuus-Pflanzen. Die Ergebnisse zeigen, dass die genetische Vielfalt der nicht-einheimischen Pflanzenarten auf demselben geographischen Territorium wesentliche Unterschiede aufweisen kann. Stichwörter: Bunias orientalis, Erigeron annuus, genetische Vielfalt, RAPD-Phänotype

The Butterfly Effect: Mild Soil Pollution with Heavy Metals Elicits Major Biological Consequences in Cobalt-Sensitized Broad Bean Model Plants

Among the heavy metals (HMs), only cobalt induces a polymorphic response in Vicia faba plants, manifesting as chlorophyll morphoses and a ‘break-through’ effect resulting in the elevated accumulation of other HMs, which makes Co-pretreated broad bean plants an attractive model for investigating soil pollution by HMs. In this study, Co-sensitized V. faba plants were used to evaluate the long-term effect of residual industrial pollution by examining biochemical (H2O2, ascorbic acid, malondialdehyde, free proline, flavonoid, polyphenols, chlorophylls, carotenoids, superoxide dismutase) and molecular (conserved DNA-derived polymorphism and transcript-derived polymorphic fragments) markers after long-term exposure. HM-polluted soil induced a significantly higher frequency of chlorophyll morphoses and lower levels of nonenzymatic antioxidants in Co-pretreated V. faba plants. Both molecular markers effectively differentiated plants from polluted and control soils into distinct clusters, showing that HMs in mildly polluted soil are capable of inducing changes in DNA coding regions. These findings illustrate that strong background abiotic stressors (pretreatment with Co) can aid investigations of mild stressors (slight levels of soil pollution) by complementing each other in antioxidant content reduction and induction of DNA changes

Cyto/genotoxicological evaluation of hot spots of soil pollution using Allium bioassays in relation to geochemistry

Soil from industrial and landfill sites affected by anthropogenic activity was screened for implicit negative effects in an Allium test-system in relation to geochemistry. The concentrations of 15 elements were compared to the ecotoxicologically-based soil guideline values. Admitted geoindices were used to classify test-soils according to risk/hazard categories. Test-soils were screened for the possible deleterious effects in common onion (Allium cepa L.) by employing a test battery of cytogenetic bioassays (root growth inhibition, mitotic activity, frequency of chromosome aberrations and micronuclei, and cell death rate) complemented with two assays of molecular DNA markers, random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR). Soil from industrial sites was more severely polluted and more cytotoxic for onions compared to soil from landfill sites. However, the cyto/genotoxic outcome of soil exposure in A. cepa was the same for all test-soils; the detrimental effects were observed in onions treated with every test-soil. Thus, test-soils could not be classified as non- and genotoxic, although certain of them had permissible contamination levels. The chromosome aberration frequency and cell death rates were consistent with the intensity of soil contamination, contrary to the micronuclei rate, which was independent of the soil risk/hazard level. Despite a relationship between risk (RI) and total soil contamination (Z) geoindices, both indices correlated with a different Allium cyto/genotoxicity endpoint, although the Z index was preferred over the RI index as being more informative in correlation analysis. Allium bioassays complemented each other by depicting different aspects of exposure to toxic substances, and determination of cyto/genotoxicity in a battery of different bioassays is important in the risk assessment of ecologically dangerous soils, and an application of a test battery is strongly advised

Soil genotoxicity biomonitoring in recultivated factory area using the cytogenetic and molecular assays in two plant test-systems

Soil pollution with industrial leftovers is of real danger to living organisms since harmful effects can arise after exposure to the contaminants in the soil. In our study, we applied a plant bioassay battery to monitor soil genotoxicity after short-term exposure to the soil. The soil was collected in 3 rounds: at the central part of the brownfield before (S-I) and after (S-III) topsoil removal, and at the brownfield periphery (S-II). The permissible value of the total contamination index is <16 and the corresponding values were 780 in S-I, 69 in S-II and 133 in S-III soil showing that whole brownfield territory is extremely polluted with heavy metals. Cytogenetic markers were recorded in Allium and Tradescantia test-systems and two types of molecular markers, RAPD and ISSR, were analysed in Allium. Our results revealed that the most polluted soil sample has induced an alarming increase of apoptotic cells in onion roots. Chromosome aberration and micronuclei frequency in Allium decreased inconsistently along with the pollution reduction in the soil. Increased frequencies of all cytogenetic markers were revealed in Tradescantia cuttings after exposure to the S-I soil extracts. Cluster analysis of Allium RAPD and ISSR markers showed that the most polluted soil samples induced genetic changes in onions different from those induced by the least polluted soil. Both plant test-systems in this study confirm that soil from the brownfield is harmful to plants and is potentially hazardous to humans

Different Habitats Show Similar Genetic Structure of <i>Bunias orientalis</i> L. (Brassicaceae)in Lithuania

We studied genetic diversity within and among populations of warty cabbage (Bunias orientalis L.), which is an alien species in Lithuania and other Baltic countries. In Lithuania, this weed colonises two main types of habitats: railway/roadsides and meadows on riversides. The aim of this study was to assess the genetic structure of invasive populations of B. orientalis in Lithuania and consider the impact of diverse habitats on the partitioning of genetic diversity using inter-simple sequence repeat (ISSR) markers. An analysis of molecular variance (AMOVA) carried out on the basis of ISSR showed that there is high genetic differentiation (46%) among populations of B. orientalis, which is probably caused by the founder effect and limited gene flow. However, we observed no impact of habitat on the genetic difference among populations. Similar levels of ISSR polymorphic loci were observed in riverside (P = 31.67%) and railway/roadsides (P = 30.51%) populations. UPGMA cluster analysis and principal coordinate analysis (PCoA) also did not show grouping of studied populations according to habitat type. High genetic differentiation among populations, as indicated by ISSR markers, confirm multiple independent introductions of this species in Lithuania

Evaluation and comparison of the genetic structure of Bunias orientalis populations in their native range and two non-native ranges

We studied the invasive warty cabbage Bunias orientalis (Brassicaceae) in three geographically distinct areas. Using inter-simple sequence repeat fingerprinting, we analyzed warty cabbages, including non-native populations, from the eastern Baltic and western Siberian regions and native populations from southwestern Russia. The eastern Baltic region and western Siberia represent the two opposite directions of B. orientalis spread in climatically different zones. The genetic structures of the native and non-native B. orientalis populations were assessed through analysis of molecular variance (AMOVA) and the Bayesian clustering method and by determining the main measures of genetic diversity. AMOVA revealed considerable population differentiation in both the native and invasive ranges. Our results did not indicate a decrease in genetic diversity in the non-native populations of B. orientalis. Similar measures of genetic diversity and genetic structure were determined in the invasive populations in two geographically and ecologically distinct, non-native regions located in Europe and Asia. In both of these regions, higher genetic diversity was detected in the non-native populations than in the native region populations, which may be due to multiple introductions. However, Bayesian clustering analysis revealed slightly different sources of invasive populations in the two non-native regions. Genetic diversity patterns revealed the lack of isolation by distance between populations and confirmed the influence of anthropogenic factors on the spread of B. orientalis. The significance of native populations as germplasm resources for breeding is discussed

Genetic variability of bunias orientalis within its native and introduced ranges

Warty cabbage (Bunias orientalis) (Brassicaceae) is widely spread across Europe (except the southern part), western Asia, Siberia, Russian Far East, and North America. In some parts of central and northern Europe, this species is considered an invasive species where it penetrates in seminatural ecosystem