Nectar and oleiferous trichomes as floral attractants in Bulbophyllum saltatorium Lindl. (Orchidaceae)

Although many Orchidaceae have deceit flowers that produce no reward, the most common reward, when present, is nectar. Bulbophyllum, however, is unusual in that the labellar secretions of most species investigated to date lack sugars, and, therefore, cannot be considered true nectar. The African species Bulbophyllum saltatorium is an exception in that it produces not only nectar but also possesses specialized, capitate oleiferous trichomes. The nectary of B. saltatorium is borne on the labellum and is represented by a deep, narrow, median longitudinal groove, having a small aperture, and flanked by trichomes. Isodiametric epidermal cells lining this groove secrete nectar which collects both in the groove and on the surface of the labellum. As well as a nectary, the labellum of B. saltatorium also bears three types of unicellular trichomes: the longest trichomes are borne distally and abaxially; the marginal ones form a rim around the entire labellum, and finally, massive, capitate trichomes occur proximally and adaxially. These are oleiferous, containing large quantities of oil which might function as precursors of volatile components of fragrance or provide a food-reward. To the best of our knowledge, this is the first time for such oleiferous trichomes to be described for Bulbophyllum. Therefore, apart from their color and markings, flowers of this species are able to attract pollinators in at least two, possibly three ways: food-reward in the form of nectar; fragrance; and possibly food-rewards in the form of food-hairs

Utricularia bremii (Lentibulariaceae) in Poland

Utricularia bremii Heer ex Kölliker has been found in a former sand quarry in Dąbrowa Górnicza (Silesia-Cracow Upland, S Poland). This subatlantic species is very rarely reported from Western and Southern Europe, and extremely rarely from Central Europe. Some localities were reported from Poland, mainly in the first half of the 20th century, but none of them are considered reliable and the species is not included in the flora of Poland. In the newly discovered locality the species forms a very abundant population in shallow, nutrient-poor ditches and pools. The origin of the population is uncertain, but before sand exploitation started the area was covered by extensive fens

Are there symplastic connections between the endosperm and embryo in some angiosperms? : a lesson from the Crassulaceae family

It is believed that there is symplastic isolation between the embryo (new sporophyte) and the endosperm (maternal-parental origin tissue, which nourishes the embryo) in angiosperms. However, in embryological literature there are rare examples in which plasmodesmata between the embryo suspensor and endosperm cells have been recorded (three species from Fabaceae). This study was undertaken in order to test the hypothesis that plasmodesmata between the embryo suspensor and the endosperm are not so rare but also occur in other angiosperm families; in order to check this, we used the Crassulaceae family because embryogenesis in Crassulaceae has been studied extensively at an ultrastructure level recently and also we tread members of this family as model for suspensor physiology and function studies. These plasmodesmata even occurred between the basal cell of the two-celled proembryo and endosperm cells. The plasmodesmata were simple at this stage of development. During the development of the embryo proper and the suspensor, the structure of plasmodesmata changes. They were branched and connected with electron-dense material. Our results suggest that in Crassulaceae with plasmodesmata between the endosperm and suspensor, symplastic connectivity at this cell–cell boundary is still reduced or blocked at a very early stage of embryo development (before the globular stage). The occurrence of plasmodesmata between the embryo suspensor and endosperm cells suggests possible symplastic transport between these different organs, at least at a very early stage of embryo development. However, whether this transport actually occurs needs to be proven experimentally. A broader analysis of plants from various families would show whether the occurrence of plasmodesmata between the embryo suspensor and the endosperm are typical embryological characteristics and if this is useful in discussions about angiosperm systematic and evolution

The preliminary attempts of in in vitro regeneration from petioles of recalcitrant species of Cephalotus follicularis Labill.

Cephalotus follicularis Labill. is representative of the extraordinary carnivorous group of plants. Carnivorous plants with pitcher traps grow in nutrient poor, sunny and wet habitats, they have adapted themselves to growth in bogs, sandy soils and obtain some nutrients (e.g. nitrogen and phosphate) from insects and other arthropods or protozoa, even from small mammals occasionally (Król et al. 2012). C. follicularis belongs to the monotypic family Cephalotaceae, and it is the endemic plant of south-western Australia. This Australian pitcher plant is heterophyllous with different types of leaves, specialized either for prey capture or photosynthesis. In the spring, non-carnivorous leaves responsible for photosynthesis, while later, in the summer the second type – carnivorous pitcher-shaped leaves occur (Pavlovic 2011). In this paper we present the first observation of tissue culture of C. follicularis for regeneration protocol, taking into account the absence of organic and inorganic nitrogen as well. We kindly achieved the in vitro plants of C. follicularis clones: 00001/01 and 0004/03 from collection of Mr. Kamil Pásek (http://www.bestcarnivorousplants.net/) from Czech Republic. These plants have been maintained on MS (Murashige and Skoog) media, in sterile conditions for several years. Under these conditions the plants are smaller than in the nature, do not develop pitchers properly and do not produce flowers, and intensive multiplication of shoots is observed. Therefore we tried to ensure such conditions, which will enable the proper development of this species in tissue culture. Plants of 00001/01 and 0004/03 clones were transferred to MS solid medium modified by reducing the amount of MS major salts to ½ and ¼ (½ MS and ¼ MS respectively). Plants were placed on these media in two ways: in small groups and individually. These same rules were applied when using subsequent ½ MS based media supplemented with 8,2 μM 2,4-D with 9,3 μM KIN (first fodder) and 4,9 μM IBA with 18,2 μM TDZ (second fodder). In addition, on the same media we put photosynthetic and pitcher leaves separately. All cultures were kept in light conditions. It occurred, that in the long term culture (after 47 days) on the ¼ MS medium the plants growing in small groups, started to develop pitcher and non-carnivorous leaves similar to these in the nature. Plants growing individually on the same medium did not change their appearance. The similar situation was observed for 00001/01 genotype, with one difference, bigger quantity of plants created properly shaped pitcher leaves on ½ MS medium. Decreasing the quantity of MS major salts to ½ gave good results in the case of rooting of plants of the Drosera intermedia Hayne (Kromer et al. 2000) and in Cephalothus regeneration system from root mass (Ko et al. 2010). The first symptoms of morphogenesis were noted on 42 day of culture as the direct organogenesis and somatic embryogenesis. The adventitious shoots and young somatic embryos were observed in 0004/03 on photosynthetic leaves, on the medium supplemented with 2,4‑D and KIN. The pitcher leaves did not induce morphogenesis. Histological analysis confirmed direct morphogenesis. Somatic embryos and adventitious shoots appeared on the petioles without callus formation and originated from epidermal and subepidermal layers of the explants. Taking into account the specific way of nitrogen uptaking by Cephalothus plants, the photosynthetic and pitcher leaves were maintained on the conditions with the lack of organic source of nitrogen and lack of inorganic nitrogen in MS medium. The observations showed that in the absence of inorganic nitrogen in the medium the non-carnivorous leaves become white and slowly degenerate. At the same conditions the pitcher leaves growing in small groups develop well traps, but they are fragile and strong red. In this small group the non-carnivorous leaves are not present. When the medium is free of organic nitrogen the non-carnivorous leaves become white but still alive, while the pitcher leaves are weak and do not develop well shaped traps. Further investigations are necessary for improving the culture protocols for more efficient plant regeneration and improvement of shoots formation, as well as analysis of the nitrogen influence on leaves of this plant

Histological and cytological analysis of microsporogenesis and microgametogenesis of the invasive species Galinsoga quadriradiata Ruiz & Pav. (Asteraceae)

Galinsoga quadriradiataRuiz & Pav. is an annual weedy plant that can be found all over the world. It belongsto the Asteraceae family and is recognised as one of the invasive foreign plants in Poland, which are native toCentral and South America. The aim of this study was to describe the reproductive features of Galinsoga quadri-radiatafocusing on the changes that occur during microsporogenesis and microgametogenesis along with themorphology of its pollen. As it is typical of the eudicot clade of Angiosperms, cytokinesis of G. quadriradiataissimultaneous. The pollen grains are tricolporate with spiny outer walls and the course of the microsporogenet-ic process is fairly typical of the Echinatae group of weed plants. The high viability of the pollen grains, whichmature unequally in the inflorescences, and the proper course of meiosis determine whether a plant has theinvasive character of Galinsoga quadriradiata

Chrysophycean stomatocysts associated with the carnivorous plants (genus Utricularia) from Jeleniak-Mikuliny Nature Reserve

An account is given of chrysophycean stomatocysts and algae occurring together with the carnivorous plants known as bladderworts, Utricularia intermedia, U. minor and U. australis, in the peat bog of Jeleniak-Mikuliny Nature Reserve. Eleven chrysophycean stomatocyst morphotypes were found, all reported for the first time from this nature reserve. Among them, two are new records for Europe (stomatocysts 330 and 208) and another two are new for Poland (stomatocysts 112 and 387). Descriptions are provided together with SEM illustrations. General data about cyanobacteria and eukaryotic algae occurring with these stomatocysts are enumerated

Ovule structure of Scotch thistle Onopordum acanthium L. (Cynareae, Asteraceae)

Studies concerning the ultrastructure of the periendothelial zone integumentary cells of Asteraceae species arescarce. The aim was to check whether and/or what kinds of integument modifications occur in Onopordum acanthium. Ovule structure was investigated using light microscopy, scanning electron microscopy, transmission electron microscopy and histochemistry. For visualization of calcium oxalate crystals, the polarizing microscopy was used. The periendothelial zone of integument in O. acanthium is well developed and composed of mucilage cells near the integumentary tapetum and large, highly vacuolated cells at the chalaza and therefore they differ from other integumentary cells. The cells of this zone lack starch and protein bodies. Periendothelial zone cells do not have calcium oxalate crystals, in contrast to other integument cells. The disintegration of periendothelial zone cells was observed in a mature ovule. The general ovule structure of O. acanthium is similar to other members of the subfamily Carduoideae, although it is different to “Taraxacum”, “Galinsoga” and “Ratibida” ovule types