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In the present paper we report original thousand-seed weight data for the flora of the Pannonian Basin. Our goal was to demonstrate the usefulness of seed weight databases by analysing seed weight data in relation to social behaviour types and life forms. We specifically asked the following questions: (i) how the seed weights are related to social behaviour type categories; (ii) how the life form of the species influences seed weight differences between respective social behaviour types? Own weight measurements are provided for 1,405 taxa; and for 187 taxa we published seed weight data for the first time: these were mostly endemics, orchids and/or species with Pontic, Caspian or continental distribution. Several taxonomic or functional groups are underrepresented in our database, like aquatic plants, rare arable weeds and sub-Mediterranean species. Problematic taxa, some difficultto-harvest species or species with low seed production and cultivated adventives are also underrepresented. We found that the plant strategies expressed by social behaviour types were significantly different in terms of seed weights. The lowest seed weight scores were found for natural pioneers, whereas the highest ones were found for adventives and introduced cultivated plants. Short-lived herbaceous species had significantly higher seed weight scores than herbaceous perennials. No significant differences were found between specialists and generalists within the stress tolerant group. We found that short-lived graminoids possess heavier seeds than perennial graminoids, perennial and annual forbs. Naturalness scores were negatively correlated with seed weights. Our findings showed that seed collections and databases are not only for storing plant material and seed weight data, but can be effectively used for understanding ecological trends and testing plant trait-based hypotheses. Even the identified gaps underline the necessity of further seed collection and measurements.

Ginkgo biloba, the last extant representative of a lineage of Mesozoic gymnosperms, is one of the few seed plants with an exceptionally long (~300 Myr) evolutionary history free of genome-wide duplications (polyploidy). Despite this genome conservatism, we have recently found a viable spontaneous tetraploid Ginkgo sapling during routine screening of several plants, demonstrating that natural polyploidy is possible in Ginkgo. Here we provide a much wider flow cytometry survey of ploidy in some European Ginkgo collections, and own seedlings (>2200 individuals and ~200 cultivars). We found a surprisingly high level of ploidy variation in modern-day Ginkgo and documented altogether 13 haploid, 3 triploid, and 10 tetraploid Ginkgo plants or cultivars, most of them being morphologically distinct from common diploids. Haploids frequently produced polyploid (dihaploid) buds or branches. Tetraploids showed some genome size variation. The surveyed plants provide a unique resource for future Ginkgo research and breeding, and they might be used to accelerate the modern diversification of this nearly extinct plant lineage.

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The evolution of the karyotype and genome size was examined in species of Crepis sensu lato. The phylogenetic relationships, inferred from the plastid and nrITS DNA sequences, were used as a framework to infer the patterns of karyotype evolution. Five different base chromosome numbers (x = 3, 4, 5, 6, and 11) were observed. A phylogenetic analysis of the evolution of the chromosome numbers allowed the inference of x = 6 as the ancestral state and the descending dysploidy as the major direction of the chromosome base number evolution. The derived base chromosome numbers (x = 5, 4, and 3) were found to have originated independently and recurrently in the different lineages of the genus. A few independent events of increases in karyotype asymmetry were inferred to have accompanied the karyotype evolution in Crepis. The genome sizes of 33 Crepis species differed seven-fold and the ancestral genome size was reconstructed to be 1 C = 3.44 pg. Both decreases and increases in the genome size were inferred to have occurred within and between the lineages. The data suggest that, in addition to dysploidy, the amplification/elimination of various repetitive DNAs was likely involved in the genome and taxa differentiation in the genus.

For understanding local and regional seed dispersal and plant establishment processes and for considering the ecotypes and other forms of specific variability, hard data of locally or regionally measured traits are necessary. We provided newly measured seed weight data of 193 taxa, out of which 24 taxa had not been represented in the SID, LEDA or BiolFlor databases. Our new measurements and formerly published data of locally collected seed weight records together covers over 70% of the Pannonian flora. However, there is still a considerable lack in seed weight data of taxonomically problematic genera, even though they are represented in the Pannonian flora with a relatively high number of species and/ or subspecies (e.g. Sorbus, Rosa, Rubus, Crataegus and Hieracium). Our regional database contains very sporadic data on aquatic plants (including also numerous invasive species reported from Hungary and neighbouring countries) and some rare weeds distributed in the southwestern part of the country. These facts indicate the necessity of further seed collection and measurements.Key words: dry storage, hard trait, herbarium, plant trait, restoration, seed database, seed mass INTRODUCTIONOne of the most easily measurable physical trait of a plant is the weight of its seeds. Seed weight (or referred to also as seed mass) affects the regeneration strategy and the dispersal of plant species both in space (spatial dispersal) and time (development of a seed bank). Seed weight is also strongly related Acta Bot. Hung. 58, 2016 188 TÖRÖK, P., TÓTH, E., TÓTH, K., VALKÓ, O., DEÁK, B., KELBERT, B., BÁLINT, P. et al. to seed predation events (larger seeds are more likely predated), germination processes, seedling establishment and survival (Eriksson 2000). Thus, in the last few decades seed traits (incl. seed weight) became frequently used for explaining crucial dynamical processes in plant communities (Leishman et al. 2001, Moles et al. 2007) and for analysing life trait scenarios (Beaulieu et al. 2007, Moles and Westoby 2003). There is also an increasing trend to collect hard and soft traits into searchable and electronically available databases. This also holds for seed traits, which can be found for the European flora in comprehensive databases, such as BiolFlor (Klotz et al. 2002), BIOPOP (Kleyer 1995), LEDA (Kleyer et al. 2008), TRY (Kattge et al. 2011a, b) the Seed information database SID 7.1 (Kew Botanical Garden, Liu et al. 2008), the Dispersal and diaspore database (Hintze et al. 2013), and the Digital seed atlas of the Netherlands (Cappers et al. 2012). These databases contain data for most of the common European species, especially species with a northwestern or Central European distribution. Species distributed mostly in southern or eastern Europe are generally underrepresented in these databases; thus, providing new, locally collected data on seed weights is a vital task in these regions (see also Csontos et al. 2003, Török et al. 2013. Furthermore, for understanding local and regional seed dispersal and pla...

The fission yeast clade, which has a distinct life history from other yeasts, can provide important clues about evolutionary changes. To reveal these changes the large S. cryophilus supercontigs were assembled into chromosomes using synteny relationships and the conserved pericentromeric, subtelomeric genes. Togetherness of the supercontigs was confirmed by PCR. Investigation of the gene order revealed localisation of the rDNA arrays, more than 300 new conserved orthologues and proved that S. cryophilus supercontigs were mosaics of collinear blocks. PFGE analysis showed that size of the S. cryophilus chromosomes differ from the S. pombe chromosomes. Comparative genomic analyses of the newly assembled chromosomes confirmed that the closest relative of S. cryophilus was S. octosporus not just in sequence similarity but also in a structural way, and revealed that preservation of the conserved regions did not arise from the lower number of chromosomal rearrangements. Translocations were more typical in the closely related species, while the number of inversions increased with the phylogenetic distances. Our data suggested that sites of the chromosomal rearrangements were not random and often associated with repetitive sequences, structural- and nucleotide evolution might correlate. Chromosomal rearrangements of the fission yeasts compared to other lineages were also discussed.