Agnieszka Sutkowska

Multiple cryptic refugia of forest grass Bromus benekenii in Europe as revealed by ISSR fingerprinting and species distribution modelling

Despite not having been fully recognized, the cryptic northern refugia of temperate forest vegetation in Central and Western Europe are one of the most important in the Holocene history of the vegetation on the subcontinent. We have studied a forest grass Bromus benekenii in 39 populations in Central, Western and Southern Europe with the use of PCR-ISSR fingerprinting. The indices of genetic population diversity, multivariate, and Bayesian analyses, supplemented with species distribution modelling have enabled at least three putative cryptic northern refugial areas to be recognized: in Western Europe—the Central and Rhenish Massifs, in Central Europe—the Bohemia–Moravia region and in the Eastern/Western Carpathians. Central Poland is the regional genetic melting-pot where several migratory routes might have met. Southern Poland had a different postglacial history and was under the influence of an Eastern/Western Carpathian cryptic refugium. More forest species should be checked in a west–east gradient in Europe to corroborate the hypothesis on the Western European glacial refugia.

Complex characterization of oat (Avena sativa L.) lines obtained by wide crossing with maize (Zea mays L.)

Background The oat × maize addition (OMA) lines are used for mapping of the maize genome, the studies of centromere-specific histone (CENH3), gene expression, meiotic chromosome behavior and also for introducing maize C4 photosynthetic system to oat. The aim of our study was the identification and molecular-cytogenetic characterization of oat × maize hybrids. Methods Oat DH lines and oat × maize hybrids were obtained using the wide crossing of Avena sativa L. with Zea mays L. The plants identified as having a Grande-1 retrotransposon fragment, which produced seeds, were used for genomic in situ hybridization (GISH). Results A total of 138 oat lines obtained by crossing of 2,314 oat plants from 80 genotypes with maize cv. Waza were tested for the presence of maize chromosomes. The presence of maize chromatin was indicated in 66 lines by amplification of the PCR product (500 bp) generated using primers specific for the maize retrotransposon Grande-1. Genomic in situ hybridization (GISH) detected whole maize chromosomes in eight lines (40%). All of the analyzed plants possessed full complement of oat chromosomes. The number of maize chromosomes differed between the OMA lines. Four OMA lines possessed two maize chromosomes similar in size, three OMA—one maize chromosome, and one OMA—four maize chromosomes. In most of the lines, the detected chromosomes were labeled uniformly. The presence of six 45S rDNA loci was detected in oat chromosomes, but none of the added maize chromosomes in any of the lines carried 45S rDNA locus. Twenty of the analyzed lines did not possess whole maize chromosomes, but the introgression of maize chromatin in the oat chromosomes. Five of 66 hybrids were shorter in height, grassy type without panicles. Twenty-seven OMA lines were fertile and produced seeds ranging in number from 1–102 (in total 613). Sixty-three fertile DH lines, out of 72 which did not have an addition of maize chromosomes or chromatin, produced seeds in the range of 1–343 (in total 3,758). Obtained DH and OMA lines were fertile and produced seeds. Discussion In wide hybridization of oat with maize, the complete or incomplete chromosomes elimination of maize occur. Hybrids of oat and maize had a complete set of oat chromosomes without maize chromosomes, and a complete set of oat chromosomes with one to four retained maize chromosomes.

Genetic Variation of Aconitum sect. Aconitum (Ranunculaceae) at a Macrogeographical Scale in the Carpathians

ABSTRACT The tetraploid (2n = 32) Aconitum sect. Aconitum in the Eastern Carpathians, Southern Carpathians and Apušeni Mts. is represented by high-mountain A. bucovinese, A. firmum subsp. fissurae and their putative taxonomic hybrid A. ×nanum. The aim of the paper was to reveal which delimiting system: taxonomic vs. geographic-population better explains genetic variability (ISSR — Inter Simple Sequence Repeats) of the Aconitum individuals in the Eastern/Southern Carpathians. Twenty nine plants sampled in five populations within entire range of taxa distribution were assigned to genetic groups according to a Bayesian STRUCTURE analysis, neighbour-net classification (NN), and nonmetric multidimensional scaling ordination (NMDS). Three taxa were distributed in four (NN, NMDS) or two (STRUCTURE) genetic groups, and the partitioning of genetic variation with analysis of molecular variance (AMOVA) revealed the highest percentage of variation attributed to the four ISSR genetic groups (22.6%), then to the two STRUCTURE groups (18.9%) and three taxa (15.6%, all P < 0.001), and finally to the three geographic regions (6.5%, P = 0.013). Genetic groups harbored specimens from distant regions: A. f. subsp. fissurae had similar genetic profiles in the Southern Carpathians and Apušeni Mts. (100% support), and some specimens of A. bucovinense had genetic links with A. f. subsp. fissurae. The hybrid species A. ×nanum was genetically specific. We concluded that (i) genetic links between nowadays distantly located populations could have originated in the effect of ancient contacts and hybridization, (ii) probably in the Carpathians two ancient genetic centers of the A. sect. Aconitum existed and (iii) high genetic specificity of the hybrid species A. ×nanum deserves further studies.