Showing papers in "Acta Botanica Croatica in 2002"

Checklist of phytoplankton in the eastern Adriatic Sea

Abstract: According to recent insights, the phytoplankton of the eastern Adriatic Sea is composed of 888 determined species. The diatoms were composed of 518 species (330 pennates, 176 centric diatoms), dinoflagellates 254, prymnesiophyceae101, chrysophyceae 2, raphidophyceae 1 and euglenophyceae 2 species. The list is accompanied by data on the general distribution of species in the northern, central and southern part of the eastern Adriatic Sea. The sources of data were samples collected in naturally eutrophic areas (bays, highly stratified karstic estuaries), in areas with antropogenic influence (harbours), as well as in the oligotrophic southern Adriatic: The old published data were supplemented with more recent information from the period 1981-2000.

Standardisation of instrumentation in plant DNA image cytometry

Abstract: DNA image cytometry is a relatively new technique for densitometric measurement of nu- clear DNA content, which has only rarely been used in botany and thus no methodological standards exist for this method to be applied to the measurement of plant material. In the present paper we address several problems related to standardisation of DNA image cytometry, such as stability of the measuring system, linearity of optical density measure- ments, correction of uneven illumination of the field of view, and uniformity of integrated optical density measurement over the entire field of view. Furthermore, image processing procedures are described for mitigation of the effects of electronic noise (image averag- ing) and for densitometric calibration of the measuring system. We have developed a macro for plant DNA image cytometry, using a general image analysis software package. The described quality control procedures, adopted from international medical standards for diagnostic DNA image cytometry, were used during software development to test per- formance of our measurement system. Until a specific botanical consensus is reached, we recommend that the quality control standards for instrumentation described in the present paper are considered when DNA image cytometry is used for measurement of plant ge- nome size as well as for any other image analysis-related densitometric measurement based on light microscopy.

Rapid plant regeneration from Gerbera jamesonii Bolus callus cultures

Abstract: A high frequency shoot organogenesis and plant establishment protocol has been developed for Gerbera jamesonii from ex vitro leaf derived callus. The optimal callus was developed on Murashige and Skoog (MS) basal medium supplemented with 0.4 mg L 6-benzylaminopurine (BAP), 4.0 mg L -naphthalene acetic acid (NAA) and 3% (w/v) sucrose. Two callus types differing in their structures and growth rates were observed. A friable and non-chlorophyllous callus with high growth rate appeared at the cut surfaces of the explant, and a compact chlorophyllous callus. The rate of shoot bud regeneration was positively correlated with the concentration of growth regulators in the nutrient media. The explants were highly responsive (83.3%) in a medium containing 2 mg L NAA and 1 mg L BAP after 3 weeks of callus transfer to a medium. Regenerated plantlets were transferred to soil where they grew normally with a survival rate of 95%. This protocol offers rapid build up of selected clones and opens up prospects for using biotechnological approaches for gerbera improvement.

Effect of paclobutrazol and sucrose on in vitro cormel formation in gladiolus

Abstract: Studies with excised shoots of six gladiolus cultivars viz., Bellariana, Blue Moon, Cream White, Friendship, Her Majesty and Top Brass indicated that paclobutrazol enhanced early cormel initiation and development. The interaction between paclobutrazol and sucrose was significant for cormel size. Supplementation of 10 mg L paclobutrazol and 120 g L sucrose to Murashige and Skoog’s medium favored formation of bigger cormels. Among the cultivars response to exogenous sucrose supplementation varied significantly and absence of paclobutrazol produced longer leaves, roots and smaller cormels.

On the ontogeny of stomata and glandular hairs in some Indian mangroves

Abstract: Mature stomata of four mangrove taxa of different families reveal three distinct types of stomatal complex on abaxial surfaces, such as diacytic (in Acanthus ilicifolius), anomocytic (in Aegialitis rotundifolia and Xylocarpus granatum), and paracytic (in Ceriops decandra). In transverse section, there is a beak-like cuticular outgrowth overarching the stomatal pore either at the outer side or at both the outer and inner side of the stomatal pore. The guard-cell mother-cell divides once longitudinally to form two guard cells and the development of subsidiary cells is not at all concerned with the former cell. Ontogenetically it is revealed that the development of a stomatal complex in these investigated taxa is aperiginous (X. granatum) and periginous (A. ilicifolius, A. rotungifolia and C. decandra). Glandular hairs (salt gland) are present only at the adaxial surface of leaves in A. ilicifolius and A. rotundifolia. In A. ilicifolius it is pear-shaped and protrudes from the normal epidermal layer while in A. rotundifolia it is present within a cup-shaped crypt in the epidermal layer. In both the cases, the ontogenic pathway is similar, at least up to the three-celled stage, but at maturity, the morphology is quite different. The salt gland consists of 4–8 radiating terminal cells, two stalk cells and one basal cell.

Phytogeographical differentiation in the Dinaric fir-beech forest (Omphalodo-Fagetum s. lat.) of the western part of the Illyrian floral province

Abstract: A phytogeographical assessment of the west-Dinaric fir-beech association Omphalodo-Fagetum s. lat. (Treg. 1957 corr. Puncer 1980) Marin~ek et al. 1993 (=Abieti-Fagetum dinaricum Tregubov 1957 p.p.) in the western part of the Illyrian floral province is provided. The synoptic phytosociological table and the results of hierarchical classification and ordination showed a quite distinct floristic and phytogeographical pattern of differentiation in a northwest-southeast direction. The proportion of Southeast – European-Illyrian (Illyricoid) species decreases towards the northwest while Alpine species decrease in the opposite direction. Stands from the Trnovski gozd plateau form a geographical variant Omphalodo-Fagetum var. geogr. Saxifraga cuneifolia, further divided into two geographical sub-variants, western – subvar. geogr. Anemone trifolia and central-eastern – subvar. geogr. Omphalodes verna. All other stands belong to the geographical variant Omphalodo-Fagetum var. geogr. Calamintha grandiflora, also further divided into two geographical sub-variants, subvar. geogr. Dentaria pentaphyllos and subvar. geogr. Dentaria polyphylla. Although the distribution area of the association is well defined in its northwest part, the question of its south-eastern border is still open. The preliminary results of analyses indicate that the stands southeast of Velebit and Li~ka Plje{ivica should be treated as a different association, distinct from Omphalodo-Fagetum. Further phytosociological and phytogeographical research into the entire Illyrian floral province will therefore be needed to resolve the problem of the southern border of the distribution area of the association Omphalodo-Fagetum and the syntaxonomy of south-eastern Dinaric fir-beech stands.

Effect of a cyanobacterial community on calcium carbonate precipitation in Puente del Inca (Mendoza, Argentina)

Abstract: The involvement of cyanobacteria in the precipitation process forming calcium carbonate was studied in samples collected at a geothermal spring located in an area close to Puente del Inca (Mendoza, Argentina). In the summer season profuse cyanobacterial growth is observed at Puente del Inca in areas exposed to sunlight and over which thermal water flows. Differences in cellular structure allowed the recognition of strains of Oscillatoria, Spirulina, Plectonema, and Nostoc, Oscillatoria and Spirulina being the dominant species. The mass cultivation of Oscillatoria sp. was obtained using a new culture medium (BW3) PI which was formulated according to the chemical composition of the thermal water. On a dry-weight basis the biomass concentration was 0.88 g L–1 at pH 7.5 and 0.44 g L–1 with a free pH evolution after 11 days of incubation. The increase of pH associated with Oscillatoria sp. growth triggered calcium carbonate precipitation at values higher than 8.1. The events observed under laboratory conditions are likely to occur in situ as a consequence of cyanobacterial growth in the saturated thermal water of Puente del Inca.

Comparative morphological, anatomical, ecological and chemical studies on endemic Satureja parnassica subsp. sipylea from Turkey

Abstract: have been investigated. Plant samples were collected from differentregions in Turkey. The morphological features of various organs of the plant such as leafand flower are described in detail. In anatomical studies, transverse sections of the plantstem and leaf have been examined and supported by illustration and photographs. Ecolog-ical studies provide information about the physical and chemical structure of soil types inSpil Mountain and Marmara Island. The chemical composition of the essential oil of ae-rial parts of the plant was examined.

Planktonic Chlorophyceae from the lower Ebro River (Spain)

Abstract: Laboratori d’Enginyeria Maritima, LIM-CIIRC, DEHMA, Universitat Politecnicade Catalunya, Jordi Girona, 1–3, Campus Nord-UPC, Modul D-1, 08034,Barcelona, Spain.On samples obtained in 4 seasonal periods between April 1999 and February 2000 fromthe last 18 km of Ebro River (Spain) some interesting planktonic coccal green algae(Chlorophyceae) were found. This paper offers comments and taxonomical observationson 60 taxa.

Odontito-Ambrosietum Jarolímek et al. 1997 – a ruderal association new to Slovenia

Abstract: Ragweed (Ambrosia artemisiifolia) is a neophytic species of North American origin, which became very common in Slovenia quite some time ago. JOGAN and VRE[ (1998) consider its present occurrence to be steady. Not only is there an increasing number of sites, but we can also see that the species occurs in large stands, where it reaches up to 120 cm in height. Slovakian authors (JAROLIMEK et al. 1997) for the first time classified the stands into a separate association. They consider the phytocoenosis to be relatively rare in Slovakia. This, however, cannot be said of Slovenia, where the stands are very frequent and the plant is still spreading. The ruderal vegetation of both the phytogeographical regions studied (pre-Dinaric and sub-Pannonian) has been studied by many authors (MARKOVI] 1984, 2000; [ILC 2001), but they did not investigate stands dominated by Ambrosia artemisiifolia. Such populations are mentioned in [ILC (2000), who did not, however, present any releve material.

A study on Reseda lutea L. distributed naturally in West Anatolia in Turkey

Abstract: Morphology and seed germination of Reseda lutea L. (Resedaceae), which is distributed naturally in Turkey, were investigated. Germination trial was observed at 10, 15, 20, 25, 30, 35 and 40 °C. In laboratory conditions at 25 °C, 87% of the seeds of R. lutea germinated, while in soil conditions, the best germination rate was only 23%, achieved with seeds sowed at 10 mm depth. The results of germination under different light conditions showed that the germination rate at 25 °C in continuous darkness was 87%, 76% with 6 hours of light, 67% with 12 hours of light, 52% with 18 hours of light and 42% with continuous light. Measurements of samples collected from different localities showed that the length of the plant is inversely proportional to the altitude.

Taxonomic and chorologic revision of the Polypodium vulgare complex in Herbarium Croaticum and the Ivo and Marija Horvat Herbarium

Abstract: The occurrences of Polypodium interjectum and P. x mantoniae in Croatia has been already listed by HR[AK (2000). These taxa had been already recorded in neighbouring Slovenia (MAYER and HORVATI] 1967, MLAKAR 1987). The herbarium specimens in the Herbarium Croaticum (ZA) and the Ivo and Marija Horvat Herbarium (ZAHO) in the Department of Botany in Zagreb are old and determined by different methodologies. The distribution area of these species in Croatia was not known previously. This was the reason for the revision of herbarium specimens in the two largest public herbaria in Croatia. The importance of these data is even greater if we take into consideration the circumstance that detailed floristic mapping has never been carried out in Croatia. It was for this reason that the publication of distribution data based on a revision of herbarium specimens was announced in HR[AK (2000).

The taxonomy, chorology and ecology of Stachys menthifolia Vis. (Lamiaceae) in the north-west part of its distribution area

Abstract: The taxonomy, chorology and ecology of Stachys menthifolia Visiani were studied in its north-west distribution area. Two new localities of the same species were discovered in the eastern part of the Biokovo Massif, showing that the species is spreading in a north-west direction. As these localities present the only sure and verified finding places in Croatia, and as they form the north-west border of its distribution area, the autors suggest including this species as a rare subendemic in the next edition of the »Red book«, the vascular flora of Croatia.

The communicability of the journal Acta Botanica Croatica over the 1991–2000 period

Abstract: The papers published in the journal Acta botanica croatica are analyzed from a scientometric point of view. The purpose of this article is to determine the communicability of this journal through parameters such as the extent to which institutions and countries are represented in the authors of the papers, the number of citations per years, the distribution of and list of journals that cite Acta botanica croatica, and the geographical origin of the journals that cite it. Acta botanica croatica is read and available in 24 countries, it has been cited by 101 journals covered by ISI ; since 1998 original scientific papers have been written in English, and the potential accessibility of the journals has been increased. In 2000 the percentage of foreign authors publishing in the journal rose to 57%.

Biological and taxonomical investigations of some oak species

Abstract: Hermaphroditic flowers blooming unseasonably on an oak tree (»the green oak«) of uncertain hybrid origin prompted a detailed investigation into the biology of the flowering, and the morphology of various traits of the tree, which is growing in an urban area near Zadar, northern Dalmatia, Croatia. Hermaphroditic flowers were also detected on one holm oak tree from Weihenstephan, Germany. Since the first oak tree was described as a hybrid between Q. cerris f. austriaca Q. ilex, scanning electron microscope investigations of pollen and hairs on the leaves of three species were made, on: Q. ilex L., Q. cerris L. and the »green oak«. Oak pollen is of elliptical shape and tricolpate. The ornamentation of the pollen grains of Q. cerris and the »green oak« were similar concerning the ornamentation of the exine – warty and rough and with small rounded protrusions – as well as the size of the pollen grain. Q. ilex pollen was much smaller and the surface lacked the small irregularly shaped protrusions typical of the other oaks. Within samples of holm oak pollen, significant difference in the surface structures was observed. Concerning the different types and number of hairs on the leaf surfaces, Q. ilex revealed a much greater number of stellate hairs on the upper leaf side as compared to Q. cerris and the »green oak«. Simple uniseriate hairs and simple unicellular hairs were missing on the leaves of Q. ilex, but were present on both the other oaks. To sum up the results, the »green oak« and Q. cerris reveal some similarities whereas Q. ilex does not.