The Morphophysiological, Histological, and Biochemical Response of Some Nontarget Organisms to the Stress Induced by the Pesticides in the Environment

Ferns, amphibians, and fish are groups of nontarget organisms affected by many types of pesticides that end up in the environment. This chapter aims to approach the following themes: the influence of different pesticides on the spore germination process and on the differentiation of their gametophyte; aspects regarding the impact of some pesticides on breathing in fish (physiology and histopathology at the branchial level), as well as a series of effects at the hematological and biochemical levels; and changes of some hematological, biochemical, and structural parameters in amphibians. Species that are not directly targeted by the action of the pesticide in the environment, ferns can be used in their gametophyte stage, young or mature sporophyte in different biotests to evaluate the risk associated with these substances. The biochemical, hemathological, and histopathological changes recorded in both fish and amphibians can be considered biomarkers of pesticide pollution

In vitro cytotoxic activity of phytosynthesized silver nanoparticles using Clematis vitalba L. (Ranunculaceae) aqueous decoction

In this study, we report a bottom-up approach for silver nanoparticles (AgNPs) synthesis using aqueous decoction of aerial parts of Clematis vitalba L. The phytosynthesized AgNPs were characterized by X-ray diffraction (XRD), UV-vis spectroscopy, Fourier Transform-Infrared Spectroscopy (FTIR), Scanning Electron Microscopy coupled with Energy Dispersive X-ray Spectroscopy (SEM-EDS) and Bright Field Scanning Transmission Electron Microscopy (BFSTEM). The cytogenotoxicity and phytotoxicity assays of AgNPs were assessed by using Allium test, Evans blue and 2, 3, 5-triphenyl tetrazolium chloride (TTC) staining, root and stem growth potential, and biomass evaluation. The results revealed that AgNPs were in the size range of 1-15 nm and spherical shape. The biosynthesized AgNPs augment the mitodepressive effect, disruption of cellular metabolism, impairment of root and stem growth, and biomass reduction induced by C. vitalba aqueous extracts. These results outline the toxicological profile of the C. vitalba extracts, as well as of the phytogenerated AgNPs and provides scientific perspectives on the use of C. vitalba extracts as reducing and stabilizing agent for the phytosynthesis of metallic nanoparticles

In Vitro Development of Gametophyte and Sporophyte in Several Fern Species

The in vitro differentiation of the gametophyte and sporophyte of Pteridophyta, conducted through the culture, on nutritive media, of the green, incompletely differentiated sporangia and spores, exhibits a variety of peculiarities. Whereas in the case of the spore culture, a single prothallus is usually obtained out of the spore, in the case of the green sporangia (sori) culture, a group (colony) is obtained out of a single explant, a group which is made up of numerous prothalli. The agarized medium ensures a much better physical support for forming larger colonies. The secondary gametophytes can be formed through: the branching out of the prothallic filaments (each ramification representing the intial stage for the development of a new prothallus); the elongation of the cells in the apical area of the gametophyte, (which represent the initial cells of the new prothalli); out of the cells located in the base area of the prothalli, (cells which also function as prothalian initial); out of ramifications of the prothalli. The formation of the sporophyte may be the result of amphimixis, e.g. in Cystopteris fragilis, or of apomixis (apogamy) in Cyrtomium falcatum and Phegopteris connectilis. In the amphimixic species, the embryo is formed after three months from the culture initiation. What is characteristic of the apogamous species is the presence of the tracheides in the gametophyte, and the absence of the root in the first stages of development. The culture of green sporangia on agarized media is recommended, due to the fact that a very large number of gametophytes, and subsequently little plants, are formed.</p

SAXICOLE BRYOPHYTES FROM VÂLSAN KEYS

The paper presents a review of the saxicole species in the Vâlsan Keys and considerations regarding the bryophytic saxicole cenoses from the protected area. To analyze the diversity of the saxicole bryophytes, we considered the number of species, as well as the phytogeografical element, the growth form and the “life strategy” of each species. From the systematic perspective, Vâlsan Keys are featured by a high specific diversity of the saxicole bryophytes

RESEARCHES CONCERNING THE IN VITRO DIFFERENTIATION OF THE FERN PHEGOPTERIS CONNECTILIS (MICHX.) WATT

Phegopteris connectilis is an apogamous species, endangered in certain regions. The ex situ conservation, through the in vitro production of the gametophyte, as well as the embryos and the plants, followed by their cryo-stocking, is necessary for ensuring the survival of the endangered species, while at pace with international methodology. The differentiation of the gametophyte is characteristic of the leptosporangiate ferns, passing through the following stages: prothallic filament, prothallic blade, cordate prothallus. The uni- or pluri-serial branchings formed on the gametophytes constitute the initial differentiation stage of a new prothallus. One-cell trichomes are differentiated on the gametophyte, which produce wax, protective against de-hydration. The in vitro culture has evinced the fast life cycle of this species, as the apogamous embryo is formed in the course of only seven weeks after culture inception. The first protophylles are formed out of the apogamous embryo and the initial stem cell is differentiated between the first two. In very few cases, however, it was noticed, at the base of the first leaf, the differentiation of the first root; the latter is formed at a stage when the young sporophyte already has two to three protophylles, as rhizogenesis is favoured by the addition of AIA and Kin in the medium. The plants thus obtained can be utilized for re-establishing the natural populations in the regions where the species is endangered

STRESS RESPONSE TO NICKEL IN ASPLENIUM SCOLOPENDRIUM L. AND DRYOPTERIS FILIX-MAS (L.) SCHOTT.

The aim of this study was to determine the physiological response and the defensive potential in species Asplenium scolopendrium L. and Dryopteris filix-mas (L.) Schott under the action of nickel. The following experimental variants were tested: 0, 250, 500, 1000, 1500 mg Ni kg-1soil. One month, and three months respectively, after the initiation of the experiment, the amount of assimilating pigments was determined. One month after the initiation of the experiment, there were no significant differences between the variants with Ni and the control as far as the content of chlorophyll (a and b) and carotenoids was concerned. The results obtained three months after the inception of the experiment indicate that, at low concentrations, Ni stimulates the synthesis of chlorophyll. In the same period there occurred antioxidant mechanisms: increase in the amount of carotenoids and increased activity of catalase. In the species Dryopteris filix-mas, the variant with 1.000 mg Ni kg-1soil, the amount of chlorophyll was significantly reduced, and the catalase activity was 3 times higher than that obtained in the control group

DIVERSITY OF PTERIDOPHYTES IN THE PROTECTED AREA OF VÂLSAN VALLEY

In the Vâlsan Valley there are two categories of regions that have been declared protected areas: The Natural Reserve Vâlsan Valley, code 2125 and The protected natural area of community interest Vâlsan Valley, code ROSCI0268. The aim of the research was to identify the species of pteridophytes in the protected areas, a necessary step for the conservation of their diversity. Within the area researched 26 species of pteridophytes were determined. Specific diversity across the genera identified ranges from 5 to 1, thus: Equisetum (5), Asplenium (4), Dryopteris (4), Polystichum (3) and Huperzia, Lycopodium, Selaginella, Botrychium, Polypodium, Phegopteris, Athyrium, Cystopteris, Gymnocarpium, Matteuccia with only one species. Concerning the abundance of the species identified, the pteridoflora in the area researched is made up of frequent (73%) and sporadic species (27%), such as Huperzia selago, Lycopodium annotinum, Botrychium multifidum, Asplenium scolopendrium, Matteuccia struthiopteris, Dryopteris expansa, Polystichum braunii

INFLUENCE OF HEAVY METALS ON GAMETOPHYTE DIFFERENTIATION IN TWO DRYOPTERIS SPECIES IN ROMANIA’S FLORA

In this work we aimed to study the influence of Zn, Cu and Pb compounds on spore germination and gametophyte development in the species Dryopteris affinis (Lowe) Fraser-Jenkins and Dryopteris filix-mas (L.) Schott. The following initial variants were prepared: V1Cu 140 mg•L-1 Knop solution, V1Zn 300 mg•L-1 Knop solution, V1Pb 300 mg•L-1 Knop solution. From these variants we considered V2 and V32 as the concentrations, respectively, 5 and 10 times higher than the initial ones. The percentage of spores germinated was noted to decrease with the increase in the metal concentration in the solution so that there are significant differences between the control and metal variants; in some variants there was no germination reported: in V3Pb in both species and in V2Pb in the Dryopteris filix-mas. With regard to the gametophyte differentiation in very few variants, the stage of chordate prothallus was reached (C, V1Pb, V1Zn: in the two species). In V2 and V3, regardless of the species and metal, the spores and filaments turn to necrosis

APPLICATIONS OF PTERIDOPHYTES IN PHYTOREMEDIATION

It is considered that ferns could present new adaptations to the action of stress factors as a result of the wide geographical spread and the diversity of the habitats in which they vegetate, adaptations that could allow them, among other things, hyper-accumulation of metals. This article aims at a brief overview of the results obtained in experimental research aimed at using pteridophytes in phytoremediation