Micromorphological features of the leaf epidermis and the inner structure of leaf tissues of eight arborescent taxa of the genus Dracaena were analysed using light and scanning electron microscopy. The plants are xeromorphic or mesomorphic. Their leaves are isobilateral and amphistomatic, and the stomata are anomocytic and tetracytic. The mesophyll in all the species is divided into an outer chlorenchyma and a central region with colourless water-storage cells, chlorophyll cells and vascular bundles. Water-storage cells have wall bands and reticulate thickenings on the walls. The article describes and illustrates several new quantitative and qualitative leaf characters of the dragon tree group. Our findings can be used to identify the dragon tree group leaves, while the shape of epidermal cells and stomata types may be useful in the identification and classification of fragments of fossil leaves. We conclude that D. ombet and D. schizantha are not two distinct species, but should be treated as subspecies of D. ombet.

Pollen grains of 15 species of the genus Sansevieria were examined using light and scanning electron microscopy. The pollen grains were single, but dyads were also found. The basic shape of the pollen grains (with chemical treatment) was subprolate, prolate and prolate-spheroidal and the pollen grains were large (> 50 mm). The pollen grains observed in SEM were prolate-spheroidal, subprolate, prolate and perprolate. The aperture occupied nearly the entire distal hemisphere. The surface of non-apertural areas was microreticulate, psilate-perforate, fossulate and verrucate. The surface of the apertural area was psilate-perforate-verrucate, microreticulate-verrucategemmate and psilate-perforate. The tectum was homogeneous, with perforations. Our results suggest that some species cannot be separated based on pollen grain morphology, but only may be categorized into their groups. The present study investigated pollen grain morphology in eleven species for the first time in terms of pollen micromorphology and provided some important new data.

We compared growth and survival of wild service tree (Sorbus torminalis [L.] Crantz) recruits of different origin (generative: seedlings; vegetative: root suckers) established in a fenced plot at the Forest District of Krzyz (northwestern Poland). Total height, annual growth of the dominant shoot, stem diameter at root collar, number of first-order branches, and mortality were measured every year over the period 2011-2015 (5 years). In 2011, a total of 382 multi-age recruits originated both from seeds (212) and root suckers (170) were recorded. Five-year mortality was higher in the generative progeny (12.3% -only youngest seedlings) as compared with vegetative recruits (2.9%). The growth rate of individuals markedly increased with height as absolute values, but slightly decreased in terms of relative growth. Statistical analysis revealed that the effect of the recruit origin on growth was noticeably weaker than that of age, defined in terms of development (height) classes. The origin of recruits had a major effect on the annual growth of the dominant shoots and a minor (though significant) effect on stem diameter and the number of first-order branches. Overall, the analysis of growth rate showed that generative recruits grow faster than the vegetative ones. Our results highlight the importance of stimulating the generative regeneration and protecting seedlings as a conservation strategy for Sorbus torminalis.

No abstract

Flow cytometry measurement confirmed the genetic stability of Primula veris L. (cowslip) plants obtained during the micropropagation process. The mean 2C DNA content was 0.97 pg/2C and P. veris can be classified in the group of plants of very small genomes. Comparative morphological analysis of cowslip plants regenerated in vitro and derived from seeds was carried out in three subsequent years under common garden conditions, which limited the effects of environmental factors. The origin of specimens significantly influenced most of the morphological traits examined. Plants that originated from seeds were characterized by more intensive development rate and higher total seed production compared to micropropagated plants. Significant differences between the two groups of specimens were observed for the number of flower stalks, flowers, fruits, and seeds per plant. No interseasonal variation within the reproductive traits such as number of seeds per flower stalk and per plant was found for plants derived from in vitro cultures. That allows prediction of seed production from in vitro regenerated plants after their successful acclimatization to field conditions. Importantly, plants derived from in vitro cultures set significantly bigger seeds. Our results are promising for broad uses of the regenerated in vitro cowslip plants in ornamental horticulture and the pharmaceutical industry.

Pollen grains of 3 species from the genus Chrysodracon and 20 species from the genus Dracaena were examined by light, scanning electron and fluorescence microscopy. The basic shape of the pollen grains is subprolate and prolate, but prolatespheroidal pollen grains may also be found. Pollen of Chrysodracon and Dracaeana is dispersed as monads, rarely as dyads. In terms of size, the pollen grains studied were classified as medium-sized and large. There are two different types of apertures: monosulcate and monoulcerate in Dracaena and monoulcerate in Chrysodracon. The surface of the non-apertural areas is psilate-perforate, irregularly folded, microreticulate and fossulate. Ornamentation of the apertural region is microreticulate, microreticulate-baculate, baculate, psilate-perforate, psilate-perforate-verrucate, granulate and irregularly folded. Irregular perforations are present, and the wall structure is tectate-columellate. Our results suggest that some species of Chrysodracon and Dracaena may be separated based on their pollen grain micromorphology on the distal region.

We know 25-47 species from the genus Malus in Europe, Asia and North America [1,2]. In Poland one species is found in the wild, i.e. Malus sylvestris, and one escaped species is disseminating mainly along transportation routes, i.e. Malus domestica. The latter species in the temperate climate zone, both in the northern and southern hemispheres, is the most commonly cultivated fruit tree. Numerous species, and even more numerous cultivars, are grown for ornamental purposes in parks, in housing district green areas, and in large city green areas. In Poland, these include the following taxa: Malus baccata, M. floribunda, M. pumila, M. ×purpurea, M. ×scheideckeri, and M. sieversii [3].There are no genetic barriers between M. sylvestris and M. domestica [4]. Although literature sources in the description of M. sylvestris state that, at present, it is hardly ever found in the pure form because it frequently crosses with cultivars [1,[5][6][7], a description of the hybrid species is nowhere to be found [8][9][10][11][12][13][14][15][16].The aim of this study was to indicate diagnostic traits for the hybrid between M. sylvestris and M. domestica. In view of the variability in plants caused by environmental factors, additional molecular analyses (PCR RAPD) were conducted verifying the position of the described species in relation to M. sylvestris and M. domestica. This method is used successfully in analyses concerning different aspects of the genus Malus [17][18][19]. Material and methodsIn the course of floristic studies in the Wielkopolska region, four localities of M. domestica × M. sylvestris were found. Traits, on the basis of which the encountered hybrid was identified, included the ratio of the length to the width of sepals within the range of 2-3.5 and sharply pointed sepals, small flowers comparable to M. sylvestris, leaves on long shoots were similar in size and shape to those in M. domestica, while the smallest fruits were largest in M. sylvestris and the largest were smallest in M. domestica.Due to the limited material from M. sylvestris (only one fruit-bearing tree was available) analyses were conducted on one tree from each analyzed taxon ( Fig. 1): M. sylvestris: Ignacewo (N: 52°15'57", E: 19°04'26"), the Chodów commune, Wielkopolska province -an old, no longer used evangelical cemetery. M. ×oxysepala: Ługi (N: 51°58'47", E: 17°11'32"), the Książ Wielkopolski commune, Wielkopolska province -on the roadside next to a forest. M. domestica: Książ Wielkopolski (N: 52°03'28", E: 17°13'50"), the Książ Wielkopolski commune, Wielkopolska province -in an avenue at a road to a no longer used railway station. AbstractA study of the three Malus species (M. domestica, M. sylvestris, and a hybrid species, M. domestica × M. sylvestris, which was named M. ×oxysepala) was carried out based on the morphological and micromorphological features and molecular investigation. Observations performed for 47 quantitative traits showed that this hybrid species exhibits intermediate values between M. domestica and M. sylvestris, or...

Natural interspecific hybridization between Typha latifolia L. and Typha angustifolia L. was analyzed by morpho-anatomical and molecular methods to determine whether the hybrid Typha glauca Godr. is present in Poland and to identify the best diagnostic traits for its identification. Eighty-three samples of the Typha species were collected. Nine random amplified polymorphic DNA (RAPD) primers provided 12 fragments specific for T. angustifolia and eight fragments specific for T. latifolia. DNA of all sampled individuals was analyzed with 20 diagnostic RAPD markers. The morpho-anatomical variability of T. glauca F 1 was found to be quite similar to that observed in parental plants. All of the 41 traits examined in the hybrids overlapped with those observed in the parents, however, the hybrids were visibly closer to T. angustifolia than to T. latifolia. The most discriminate characteristics were the length and pedicel width, as well as the epidermal cell thickness located above vascular bundles in leaf blades. Moreover, preliminary observations of seed sculpture showed that the length of testa cells could also be used to identify T. glauca. Clusters and the hybrid index (for molecular and morphological data) were highly coincident and support the hybridization hypothesis.