Romanian Journal of Biology - Plant Biology
2004-2005, VOLUMES 49-50 (2007)
IRINA HOLOBIUC, ANCA PĂUNESCU, RODICA BLÎNDU
The diminishing of the genetic resources of the plants strongly imposed the development of new conservation techniques. In vitro techniques allow the increase of the propagation rate and the obtaining of a healthy material. In the case of the endangered plant species with a reduced number of individuals, seed sterility and low intrapopulational variability, the in vitro techniques represent the only viable conservation method.
The aim of our study is to elaborate micropropagation and conservation protocols for a medium-term period in some Caryophyllaceae endemic species.
The species taken in study are: Dianthus callizonus Schott et Kotschy, Dianthus tenuifolius Schur, Cerastium transsilvanicum Schur, Dianthus spiculifolius Schur. and Dianthus superbus L. ssp. alpestris Kablik ex Èelak.
2. Dynamics of alkaloid biosynthesis in case of intraspecific somatic hybridization in some Claviceps purpurea strains
ȘTEFANIA SURDU, ELENA TRUȚĂ, ZENOVIA OLTEANU. MARIA-MAGDALENA ZAMFIRACHE
In this paper, the dynamics of T:S:P ratio and of total alkaloid content was registered, for Claviceps purpurea sclerotia of ergotamine (T), ergocristine (S) and ergocryptine (P) type and their descendance, both for parental strains and hybridization products (also for those of backcrosses), and their descendance, in successive generations. The results differed depending on origin-sclerotia alkaloid type, hybrid or non-hybrid nature of ascendants, number of analysed generations. Thus, in ergotamine strain hybridizations, possibly a manifestation of so-called “variability of generation average”, for the case of multiple selection generations was observed. Also, a hybrid vigour effect was noted for F1 hybrid descendances, as a result of heterokaryosis degree and gene heterozygosity increase after somatic hybridization, phenomenon not evidenced in F1 ergocristine hybridizations. In ergocryptine strain hybridizations, frequently a turning from ergocryptine to the ergocristine or ergotamine type takes place. The nuclear reassortment and the new rates between genetically different nucleuses determined the significant modification of the alkaloid spectrum.
3. Microbiological study of a Bacillus megaterium strain with soil phosphorus solubilization potential
SIMONA DUNCA, MARIUS ȘTEFAN, ERICA NIMITAN, OCTĂVIȚA AILIESEI
The isolation of bacterial strains exhibiting high ability to solubilize soil phosphorus is a matter of great interest with practical applicability. This paper focused on the isolation, selection, characterization and identification of Bacillus megaterium strains from different natural environments to the purpose of solubilizing the phosphorus from the soil. The research investigations conducted resulted in the isolation of 15 bacterial strains as pure cultures from 5 samples of cultivated soil; upon the examination of the micromorphological characteristics, the strains were assigned to the Bacillus (13 strains) and Staphylococcus (2 strains) genera. The researches on their morphological, growth-related characters and the physiological and biochemical properties allowed the taxonomic classification of the R4-UAIC strain into the Bacillus genus, megaterium species, in which the capacity to solubilize soil phosphorus was observed.
4. Histo-anatomical investigations on some Cuscuta species
C. TOMA, ASPAZIA ANDRONACHE, IRINA TOMA
The authors investigated the stem and haustoria structure in three Cuscuta species parasite on different dicotyledonous species. In all 3 species, the stems have not tector hairs; the vascular bundles are not typical, being collaterally closed, the mechanical tissues are weakly developed or absent. The haustoria penetrate the host plant, especially in the phloem, sometimes arising in the pith. The haustoria xylem contacts the host plant xylem. Rarely, (C. epithymum) the haustoria penetrate wholly the thickness of the leaves (of Inula salicina).
5. Morphological data concerning the influence of atmosphere pollutants on some species of cultivated and spontaneous ligneous plants
LĂCRĂMIOARA IVĂNESCU, CONSTANTIN TOMA
In this paper we have studied 19 species of ligneous plants – gymnosperms and angiosperms, spontaneous and cultivated ones – in areas adjacent to industrial platforms: Borzești (Bacău county), Bicaz and Tașca (Neamț county). Our investigations have focused (during the period 1996–2005) on observations concerning species of ligneous plants in various phenophases and the state of the leaf surfaces under the influence of the atmosphere pollutants.
6. Cyto-histological data concerning the influence of atmosphere pollutants on five species of gymnosperms
LĂCRĂMIOARA IVĂNESCU, CONSTANTIN TOMA
In this paper we have studied five species of gymnosperms, spontaneous and cultivated ones – in areas adjacent to industrial platforms: Borzești (Bacău county), Bicaz and Tașca (Neamț county). Our investigations (have focused during the period 1996–2005) concerning the histo-anatomical changes induced by the (gaseous and solid) atmosphere pollutants on the lamina; the changes have been observed in protecting tissues, assimilatory tissues (the palisade layer and the lacunose tissue), vascular and mechanical tissues. Some leaves have presented disorders in all the component tissues, while in others, the structure changes have only appeared in part of the lamina.
7. Research regarding the biology of some species of the Pelargonium genus cultivated in green houses of the Botanical Gardens in lași
MARIA MAGDALENA ZAMFIRACHE, BURZO IOAN, MIHĂESCU DAN, IRINA TOMA, ZENOVIA OL TEANU, ROXANA IULIANA APETREI, ȘTEFANIA SURDU
We took into consideration aspects regarding the biology of the two species belonging to Pelarginium genus: P. zonale (L.) L’ Herit. and P. odoratissimum (L.) L’ Herit. ex Ait., during their ontogenetic cycle in conditions of protected cultivation (greenhouse of temperate type). We also talked about aspects related to the morphology of secretory formations of volatile oils and about some special biochemical and physiological parameters. The researches of vegetal morphology and physiology have used classical methods of investigation and the volatile oil was extracted by steam distillation using a modified Clevenger apparatus, whereas the chemical composition was analyzed by GC – MS. The secretory formations of the volatile oils are characteristic for each taxon. The biochemical and physiological parameters investigated vary depending on the studied taxon and the ontogenetic moment. The efficiency of extraction of volatile oils has different values depending on the species and the ontogenetic stage of producing plant; the composition of the volatile oils differs in quantity and quality, giving specific aromatic characteristics to the analyzed samples.
8. Spruce forests from the Ceahlău Mountain
OANA ZAMFIRESCU, TOADER CHIFU, CIPRIAN MÂNZU
The aim of our research is to describe the characteristics of the spruce forests from the Ceahlău Mountain. The research area was the central part of the northern Oriental Carpathians, where the spruce forests form a continuous belt between the altitudes of 1010 m and 1820 m, the upper limit being just below the sub-alpine plateau. Based on a significant number of relevés, the spruce communities were classified in three associations belonging to the class Vaccinio-Piceetea, order Picetalia excelsae, alliance Piceion excelsae, which are Soldanello montanae-Piceetum, Hieracio transsilvanio-Piceetum, Leucanthemo waldsteinii-Piceetum. For each association we present the location, the phytosociological and ecological characterisation and the phytosociological table of relevés.
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