Erythronium Dens-canis Research Articles

The greater the proportion of Robinia pseudoacacia in a stand the greater its effect on the population characteristics of Erythronium dens-canis

Management of invasive alien plants is an increasing problem throughout the world. In some cases native rare or protected species can appear or even prefer habitats dominated by invasive alien plants, which raises questions about the optimal treatment of such areas. Erythronium dens-canis in Hungary is a protected species which only have several occurrences in the country and a number of these populations situated in Robinia pseudoacacia stands developed after harvesting native forests. In this study a total of five populations of E. dens-canis were surveyed between 2020 and 2022 in southwestern Hungary examining and comparing the ongoing demographic changes under native and Robinia stands by monitoring individual plants. Two populations were situated in forests composed of native tree species, two in Robinia pseudoacacia-dominated stands and one in a Robinia-native tree species mixed stand. We categorized the plants into five age-state categories: dormant, seedling, juvenile, vegetative adult, and reproductive adult. We found some considerable differences (e.g. leaf size, reproduction rate) between the populations situated in native and in Robinia stands, whereas the population in mixed forest showed intermediate character in most examined factors. Based on our results, R. pseudoacacia have a significant effect on the phenology and life history of E. dens-canis, and this effect is greater with higher proportion of R. pseudoacacia in a forest stand where the E. dens-canis occurs.

New floristic data of vascular plants from central Italy

Based on field, herbarium and bibliographic research, we report distributional data for 21 species and subspecies (11 natives included 1 regional alien and 1 cryptogenic, 10 aliens) whose presence has been ascertained for some administrative regions of central Italy. In particular, 10 taxa are new or confirmed to Abruzzo, 7 to Umbria, 2 to Lazio, and 1 to Marche. Some taxa are particularly interesting from a phytogeographical or conservational point of view. Specifically, Astragalus exscapus and Salix pentandra are very rare in Italy. The new findings of Erythronium dens-canis and Thesium alpinum, in Umbria and Lazio respectively, represent the southernmost limits of their Italian distribution.

Intact ribosomal DNA arrays of Potentilla origin detected in Erythronium nucleus suggest recent eudicot-to-monocot horizontal transfer.

During our initial phylogenetic study of the monocot genus Erythronium (Liliaceae), we observed peculiar eudicot-type internal transcribed spacer (ITS) sequences in a dataset derived from genomic DNA of Erythronium dens-canis. This raised the possibility of horizontal transfer of a eudicot alien ribosomal DNA (rDNA) into the Erythronium genome. In this work we aimed to support this hypothesis by carrying out genomic, molecular, and cytogenetic analyses. Genome skimming coupled by PacBio HiFi sequencing of a bacterial artificial chromosome clone derived from flow-sorted nuclei was used to characterise the alien 45S rDNA. Integration of alien rDNA in the recipient genome was further proved by Southern blotting and fluorescence in situ hybridization using specific probes. Alien rDNA, nested among Potentilla species in phylogenetic analysis, likely entered the Erythronium lineage in the common ancestor of E. dens-canis and E. caucasicum. Transferred eudicot-type rDNA preserved its tandemly arrayed feature on a single chromosome and was found to be transcribed in the monocot host, albeit much less efficiently than the native counterpart. This study adds a new example to the rarely documented nuclear-to-nuclear jumps of DNA between eudicots and monocots while holding the scientific community continually in suspense about the mode of DNA transfer.

Effect of structure and dynamics of forests on the occurrence of Erythronium dens-canis

The paper presents the results of a study on the impact of forest stand structure and development in 1998 to 2018 on the occurrence of dog’s tooth violets (Erythronium dens-canis L.) in the Medník National Nature Monument, Czech Republic. The research was carried out in mixed European hornbeam and sessile oak stands, herb-rich European beech stands and the Sázava-river Norway spruce ecotype stands. The site and stand characteristics of the following three forest stand types were compared: 1) oak-hornbeam forests, 2) herb-rich beech forests and 3) secondary spruce forests. The results showed that the ratio of sterile and fertile plants was 2.9 to 1. The occurrence of E. dens-canis was higher in older stands with differentiated structure. On the contrary, stands characterized by a higher number of trees and basal area negatively affected the population size of E. dens‑canis. Significantly, the density of E. dens-canis decreased with increasing stand density index (SDI) and increased with increasing diameter differentiation index in relation to tree neighbours (TM<sub>d</sub>). During the period of 20 years, the E. dens-canis population increased by 40.4% on permanent research plots, while the highest changes were observed on spruce plots (+92.1%) and the lowest increase was in oak-hornbeam forests (+18.0%). The highest numbers of E. dens-canis plants were found in herb-rich beech forests (1 774 plants·ha<sup>–1</sup>), lower numbers occurred in oak-hornbeam forests (784 plants·ha<sup>–1</sup>) and minimal in secondary spruce forests (51 plants·ha<sup>–1</sup>). <br /><br />

Distribution, infection rates and DNA barcoding of Uromyces erythronii (Pucciniaceae), a parasite of Erythronium (Liliaceae) in Europe

This paper presents the European distribution of the understudied, host-specific rust fungus, Uromyces erythronii (Pucciniomycetes, Pucciniales, Pucciniaceae). Distribution data were derived from the survey of herbarium materials of its European host plant, Erythronium dens-canis. We demonstrate the presence of this rust fungus in 14 countries within the distribution area of its host. The temporal trend of emergence of the two rust fungus generations (aecia and telia) is presented. Based on the study of 1700 E. dens-canis individuals, we conclude that the overall infection rate has not changed significantly over the last 200 years. During field surveys, U. erythronii infection was detectable in most of the studied Erythronium populations (88.5%). A high similarity in the nrITS region was detected among samples from Europe (Croatia, Romania) and Asia (Japan).

Patterns of plastid DNA differentiation in Erythronium (Liliaceae) are consistent with allopatric lineage divergence in Europe across longitude and latitude

Little attention has been paid so far to the genetic legacy of the oceanic-continental gradient across Europe. Due to this gradient, steppe regions become more extensive and mesic environments become more scattered towards the East. A well-suited system to study the impact of this gradient on lineage differentiation is the temperate mesophilic plant Erythronium dens-canis (Liliaceae), which is widespread in southern Europe with a distribution gap in the Pannonian Plain. Moreover, the large disjunction between E. dens-canis and its sister species E. caucasicum coincides with the Pontic steppe region. By applying range-wide sampling of E. dens-canis and limited sampling of E. caucasicum, we explored their phylogeography using the plastid regions rpl32-trnL and rps15-ycf1. Three major phylogroups were identified: a Caucasian lineage, a highly structured and narrowly distributed Transylvanian lineage, and a more homogenous and widely distributed ‘non-Transylvanian’ lineage. Apparently, both physiographic (mountain) and climatic (steppe) barriers have caused allopatric differentiation in European Erythronium. The Southern Carpathians constitute a latitudinal barrier and the Pannonian Plain a longitudinal barrier between the Transylvanian and ‘non-Transylvanian’ lineages of E. dens-canis. The eastern Carpathian Basin likely functioned as a combination of cryptic eastern (mesic) and cryptic northern refugia for E. dens-canis during glacial periods. The Eastern Carpathians and particularly the Pontic steppe regions acted as a longitudinal barrier between E. dens-canis and E. caucasicum. Steppe-dominated gaps in the distribution range of Erythronium are mirrored by genetic discontinuities along longitudes; this highlights the important role of the oceanic-continental gradient throughout Europe for lineage differentiation.

Phytosociological description of Quercus petraea forest stands with Chamaecytisus hirsutus and Erica carnea in the Vipavska brda (southwestern Slovenia)

We conducted a phytosociological study of Quercus petraea stands, whose herb layer is dominated by Erica carnea in the flysch hills of Vipavska brda and on the margins of the Vrhe plateau (southwestern Slovenia). We have determined that they are a long-term degradation stage on beech forest sites from the association Seslerio autumnalis-Fagetum. Based on comparisons with similar sessile oak stands from associations Melampyro vulgati-Quercetum petraeae, Seslerio autumnalis-Quercetum petraeae and Erico carneae-Quercetum petraeae, the studied stands are classified into the new association Chamaecytiso hirsuti-Quercetum petraeae. They are best differentiated from the stands of compared communities by the species Erica carnea, Sorbus aria, Lathyrus linifolius, Loranthus europaeus and Erythronium dens-canis. The new association is classified into the alliance Carpinion orientalis and order Quercetalia pubescenti-petraeae.

Erythronium dens-canis L. (Liliaceae): An unusual case of change of leaf mottling

Erythronium dens-canis is an early-flowering understory lily of southern Europe with two leaves and a single flower, although a number of plants have only one leaf and do not flower. The leaves are mottled with silvery flecks and brown patches, that gradually vanish turning to a lively green color. The nature and function of this striking variegation pattern were investigated in differently colored leaf parts following the springtime color change. Tissue organization was examined by light and electron microscopy; photosynthetic pigments were analyzed by spectrophotometry and HPLC; chlorophyll fluorescence parameters were evaluated by MINI-PAM. The results showed that brown patches originated in vacuolar anthocyanins in the subepidermal cell layer while air spaces between the upper epidermis and underlying chlorenchyma resulted in silvery flecks. The two leaf areas did not differ in photosynthetic pigments, chloroplast organization and photosynthetic parameters (Fv/Fm, NPQ, rETR). Greening of brown patches due to anthocyanin resorption was faster in non-flowering plants than in flowering ones, occurring only when young fruits were developing. Anthocyanin disappearance did not change the structural-functional features of photosynthetic tissues. As a whole the results suggest that the anthocyanin pigmentation of E. dens-canis leaves does not affect the photosynthetic light use and has no photoprotective function. It is proposed that the complex leaf color pattern may act as a camouflage to escape herbivores, while the reflective silvery spots may have a role in attracting pollinators of this early-flowering species.

Belső-Somogy homoki gyertyános-tölgyesei, (Fraxino pannonicae-Carpinetum Soó et Borhidi in Soó 1962)

I present the results of a phytosociological analy-sis of 50 samples of oak-hornbeam forests on sand (Fraxino pannonicae-Carpinetum), which grow in the southwestern part of Hungary in Inner Somogy. The habitat of these forests is un-der slight influence of groundwater, which manifests itself in the species composition of these forests. The forests differ sharply from the oak-hornbeam forests (Helleboro dumetorum-Carpin-etum) growing on loess in the neighbouring Zselic. The species composition somewhat resembles that of hardwood gallery for-ests on sand (Knautio drymeiae-Ulmetum), beech woods on sand (Leucojo verno-Fagetum), and oak-hornbeam forests along the Dráva River (Veronico montanae-Carpinetum). The Fagetalia elements in its understorey (Actaea spicata, Astran-tia major, Dentaria enneaphyllos, Oxalis acetosella, etc.) are probably relics of the Beech I. phase (2500 and 800 B.C.) of the Holocene, when the climate was more humid and less ex-treme. It also hosts species typical of the Aremonio-Fagion alli-ance (pl. Carex strigosa, Cyclamen purpurascens, Doronicum orientale, Erythronium dens-canis, Knautia drymeia, Polysti-chum setiferum, Primula vulgaris, Ruscus aculeatus, Tamus communis, Tilia tomentosa), whereby it exhibits a moderate sub-Mediterranean character.

Recurrent Outbreaks of Myelodysplasia in Newborn Calves

The present study records recurrent outbreaks of myelodysplasia of unknown origin occurring in a specific geographical location in the north of Spain, and involving up to 30% of the calves born in affected herds. The affected calves were of different breeds and displayed non-progressive signs of spinal cord dysfunction. The disease has occurred annually in February-March over a period of at least 15 years. Only calves born to cattle grazed on mountainside pastures and under high grazing pressure were affected. Seven calves were subjected to necropsy examination. Myelodysplasia was not associated with vertebral defects or arthrogryposis and involved the entire length of the spinal cord. Microscopically, there was abnormal distribution of the grey matter, aberrations of the central canal and failure of formation of the ventral median fissure. Infectious, nutritional and physical disorders were ruled out as possible aetiologies. A critical period of embryonic susceptibility to the causal agent was identified. This was during the time of secondary neurulation when cows in the early stages of gestation were grazed on mountainside pastures. Consequently, the presence of neuroteratogenic plants in these pastures is proposed as a likely cause. Two plants, Carex brevicollis and Erythronium dens-canis, which contain alkaloids, were identified on the mountainsides where affected cattle were grazed and not in other pastures, and are proposed as the possible aetiology of the disease.

Temperature controls seed germination and dormancy in the European woodland herbaceous perennial Erythronium dens‐canis (Liliaceae)

We examined the germination ecology and the temperature requirements for germination of Erythronium dens-canis, under both outdoor and laboratory conditions. E. dens-canis is a spring flowering woodland geophyte widely distributed across Europe. Germination phenology, including embryo development and radicle and cotyledon emergence, were investigated in a natural population growing in Northern Italy. Immediately after harvest, seeds of E. dens-canis were either sown on agar in the laboratory under simulated seasonal temperatures or placed in nylon mesh sachets and buried in the wild. Embryos, undifferentiated at the time of seed dispersal, grew during summer and autumn conditions in the laboratory and in the wild, culminating in radicle emergence in winter when temperatures fell to ≈ 5 °C. Emergence of cotyledons did not occur immediately after radicle emergence, but was delayed until the end of winter. Laboratory experiments showed that temperature is the main factor controlling dormancy and germination, with seeds becoming non-dormant only when given warmth, followed by cold stratification. Unlike seeds of E. dens-canis that germinate in winter, in other Erythronium species radicle emergence occurs in autumn, while in some it is delayed until seeds are transferred from winter to spring conditions. Our results suggest that there is genetic and environmental control of the expression of seed dormancy amongst Erythronium species, which is related to local climate.

Flora and vegetation in the catchment area of the stream “La Bolza” in the Merse valley (Siena, southern Tuscany)

Summary This study illustrates the results of a floristic and phytosociological study conducted in a small portion (375 ha) of the Merse valley. Following a brief description of the geomorphologic and climatic aspects, the bryological and vascular flora is presented, obtained through floristic field studies and bibliographic data. The bryological flora includes 25 moss species including Sphagnum subnitens and S. capillifolium, which are of interest from a conservationist viewpoint, and 5 liverworts; the vascular flora comprises 252 species (belonging to 68 families and 186 genera); there are only three endemic entities but many species considered as rare or of interest, including Anagallis minima, Blechnum spicant, Carex viridula, Dryopteris dilatata, Erythronium dens-canis, Juncus bulbosus, Osmunda regalis and Radiola linoides, thus highlighting the phytogeographical relevance of this biotope. Chorological analysis highlighted the dominance of eurosiberian and boreal elements. The principal vegetation types sampled can be ascribed to the following alliances: Cicendio filiformis-Solenopsion laurentiae (Isoetetalia, Isoeto-Nanojuncetea), Osmundo-Alnion and Alnion incanae (Populetalia albae, Querco-Fagetea), Erythronio dens-canis-Quercion petraeae and Teucrio siculi-Quercion cerridis (Quercetalia-pubescen- ti-petraeae, Querco-Fagetea), Sarothamnion scoparii (Cytisetalia scopario-striati, Cytisetea scopario-striati). There are three habitats of Community interest: alluvial forests with Alnus glutinosa (code 91EO), woods of Castanea sativa (code 9260) and rare short-lived small coenoses of Isoeto-Nanojuncetea (code 3130).

Seed dispersal in Erythronium dens-canis L. (Liliaceae): variation among habitats in a myrmecochorous plant

Erythronium dens-canis is a geophyte which produces a single flower each season. The fruits produce small seeds with relatively large elaiosomes. We performed experiments to investigate primary and secondary seed dispersal mechanisms of this species in different habitats in the western part of the Cantabrian Range in northwest Spain. Sticky traps were used to measure primary dispersal of seeds up to 0.5 m from mother plants. Seed cafeteria experiments were performed in different habitats to examine the role of ants and rodents in secondary seed transport and seed predation. Our results indicate that: (a) primary seed dispersal is positively skewed (99% of seeds fall within 20 cm of the mother plant) and seed dispersal distances vary significantly among plants; (b) secondary dispersal is exclusively by myrmecochory, although the proportion of seeds removed by ants differs significantly among habitats; (c) ant species composition and abundances vary among habitats; and (d) freshly dropped seeds are more likely to be removed than seeds that have begun to dry out. We conclude that secondary dispersal of seeds is greatly influenced by habitat but not by small-scale microhabitat.

Quarantine pests intercepted in consignments of ornamental plants imported into Poland in 1993/19981

During inspections of consignments of ornamental plants (cuttings, bulbs, rhizomes, pot plants, cut flowers) imported into Poland in 1993/1998, the following quarantine pests were intercepted most frequently: Frankliniella occidentalis (32 consignments), Aphelenchoides fragariae (17), Steneotarsonemus laticeps (12) and Bemisia tabaci (11). These pests were found in plants for planting, pot plants and cut flowers imported mainly from The Netherlands. Thrips palmi (EPPO A1 list) was intercepted on orchid cut flowers from Thailand (2) and Cacoecimorpha pronubana on pot plants of Thuja occidentalis from The Netherlands. Ditylenchus destructor was intercepted on bulbs of Erythronium denscanis (not previously described as a host). The methods of inspection and identification of particular intercepted pests are presented.