Cistus Creticus Research Articles

Influence of Drying Method on Some Bioactive Compounds and the Composition of Volatile Components in Dried Pink Rock Rose (Cistus creticus L.).

This study investigates the effects of various drying methods applied to leaves of Cistus creticus L. on the contents of polyphenols and the composition of the volatile fraction. The following four drying methods were used: convection drying at a temperature of 40 °C (CD 40 °C), 50 °C (CD 50 °C), and 60 °C (CD 60 °C); vacuum-microwave (VMD 240 W); combined drying, involving convection pre-drying (50 °C) and vacuum-microwave (240 W) finish drying (CPD-VMFD) as well as freeze-drying (FD). Polyphenols in the dried leaves were determined using chromatography-photodiode detector-quadrupole/time of flight-mass spectrometry (UPLC-PDA-Q/TOF-MS). The contents of odoriferous substances in the dry material were determined by means of head space-solid phase microextraction (HS-SPME) with the use of a gas chromatograph (GC). Thirty-seven polyphenol components including 21 flavonols, eight flavan-3-ols, and eight hydrolyzed tannins in dry Pink Rock Rose material were found for the first time. The highest contents of polyphenols, totaling 2.8 g 100 g−1 dry matter (d.m.), were found in the samples subjected to the CPD/VMFD drying method. Pink Rock Rose subjected to this drying method was characterized by large quantities of odoriferous compounds, mainly eugenol, thymol, and carvacrol, which contribute to its antiseptic properties. By using CPD/VMFD methods, it is possible to obtain fine quality dry material from the leaves of C. creticus.

Pollen viability and endophytic yeast species of Cistus creticus and C. monspeliensis

Cistus species are widespread in the Mediterranean basin, especially in places characterized by high temperatures and arid soils. Despite a rich literature concerning the biological and pharmacological properties of Cistus species, to our knowledge, there are only few reports on pollen viability and little is known about microbial endophytes within pollen grains. Pollen viability and germination of Cistus creticus L. and C. monspeliensis L., from two sites of Sicily (Italy) over two years (2016–2017), were determined by 2,3,5 triphenyl-tetrazolium chloride (TTC) staining and an in vitro germination test. Dominant microorganisms, flowing from pollen openings (colpora), were identified by molecular methods. Furthermore, for comparison, in 2017 microbial endophytes of C. eriocephalus Viv. from Serra S. Bruno (Calabria, Italy) were studied. The optimal medium composition for rapid in vitro germination was determined. Pollen viability was in the range of 79.8–90.0% for C. monspeliensis and 86.6–91.6% for C. creticus, while germination was 56.5–62.4% for C. monspeliensis and 50.1–58.8 for C. creticus. Statistical analysis by correlation coefficient showed a significant relationship between viability and germination, whereas significant differences (P < 0.05) were observed between TTC staining and the in vitro germination test. Yeasts were the dominant microorganisms in all pollen samples and dominant species were identified.

Chemical composition, antioxidant, antimicrobial and antifungal activity of Moroccan Cistus Creticus leaves

Abstract The essential oil from the Cistus leaves of Tafraout, Morocco was obtained by hydro-distillation and analyzed using the gas chromatography–mass spectrometry method. The total phenol content, antioxidant and antibacterial properties of crude extract, fractions (flavonoids, tannins, saponins, alkaloids) and essential oil of Cistus Creticus leaves were studied. Total polyphenol, flavonoid, and condensed tannin's contents were determined using Folin-Ciocalteu, aluminum chloride and vanillin colorimetric methods, respectively. The antioxidant activity of essential oil and different extracts from C.leaves was determined by two methods: free radical scavenging method DPPH and the FRAP) The different extracts studied showed an antioxidant activity, with 50% inhibition concentration (IC50) values varied between 0.01 and 2.53 mg/mL for DPPH test and 0.1 to 0.53 mg/mL for FRAP test. The antioxidant capacity was significantly higher for flavonoids and saponins, compared to the other extracts. The crude extract and essential oil were examined for their antimicrobial and antifungal activities.

In vitro antifungal activity of cistus creticus l. against plant pathogenic fungi

In vitro antifungal activity of cistus creticus l. against plant pathogenic fungi

In Vitro Antioxidant, Antithrombotic, Antiatherogenic and Antidiabetic Activities of Urtica dioica, Sideritis euboea and Cistus creticus Water Extracts and Investigation of Pasta Fortification with the Most Bioactive One.

The present work evaluated the in vitro antioxidant, antithrombotic, antiatherogenic and antidiabetic activities of Urtica dioica, Sideritis euboea and Cistus creticus and investigated pasta fortification with the most bioactive one. The methods employed were total phenolic content (TPC) in mg of gallic acid equivalents per g of dried-herb, 2,2'-azino-bis(3-ethylbenzothiazoline- 6-sulfonic acid) (ABTS) free radical scavenging in mg of dried-herb, cupric reducing antioxidant capacity (CUPRAC) in micromol trolox equivalent per g of dried-herb, platelet aggregation inhibition (PAF-PAI); plasma oxidation inhibition (POxI); and alpha glucosidase inhibition (a-GaseI) all in mg of dried-herb. Pasta fortified with the most bioactive herb was also studied for the above activities. Cistus creticus extract was more bioactive (p < 0.05) compared to Sideritis euboea and Urtica dioica in all but antithrombotic assay, where Sideritis euboea was superior to the others (TPC: 37.9 ± 0.56 versus 9.6 ± 0.83 and 5.4 ± 0.70; SA50-ABTS: 0.040 ± 0.001 versus 0.400 ± 0.010 and 0.520 ± 0.008; ACUPRAC: 860 ± 6.23 versus 170 ± 4.25 and 80 ± 3.63; IA50-PAF: 1.8 ± 0.14 versus 1.2 ± 0.10 and 5.2 ± 0.21; POxI: 0.095 ± 0.016 versus 0.216 ± 0.021 and 0.534 ± 0.029; IA50-aGase: 0.2 ± 0.01 versus 2.1 ± 0.16 and 1.7 ± 0.12). Fortified pasta with cistus creticus extract exhibited significantly higher levels (p < 0.05) in all assays compared to plain pasta (TPC: 0.392 ± 0.064 versus 0.137 ± 0.020; SA50-ABTS: 9.4 ± 0.2 versus 126.9 ± 2.7; ACUPRAC: 5.4 ± 0.5 versus 0.9 ± 0.1; IA50-PAF: 1.87 ± 0.04 versus 2.28 ± 0.06; POxI: 3.21 ± 0.18 versus 12.2 ± 0.73; IA50-aGase: 8.9 ± 1.1 versus 18.2 ± 0.9). The current findings add to the mounting evidence on the potential health benefits to be derived from consuming pasta fortified with herbal extracts and indicate that Cistus creticus could form an ideal raw material towards the production of fortified pasta with increased nutritional value.

Heterologous production of labdane-type diterpenes in the green alga Chlamydomonas reinhardtii

Labdane diterpenes (LDs), and especially sclareol, are important feedstocks for the pharmaceutical and cosmetic industries, and therefore several lines of research have led to their heterologous production in non-photosynthetic microbes and higher plants. The potential of microalgae as bioreactors of natural products has been established for a variety of bioactive metabolites, including terpenes. In this work, a codon optimized sequence encoding a key plant labdane-type diterpene (LD) cyclase, copal-8-ol diphosphate synthase from Cistus creticus (CcCLS), was introduced into the chloroplast genome of Chlamydomonas reinhardtii. Of 49 transplastomic algal lines, 12 produced variable amounts of four LD compounds, namely ent-manoyl oxide, sclareol, labda-13-ene-8α,15-diol and ent-13-epi-manoyl oxide. The total LD concentrations measured in the transplastomic lines reached 1.172 ± 0.05 μg/mg cell DW for the highest overall producer, while the highest yield for sclareol was 0.038 ± 0.001 μg/mg cell DW. Thus, transplastomic expression of a key plant labdane diterpene cyclase in the C. reinhardtii chloroplast genome enabled the production of important plant-specific LD compounds.

Degassing and Cycling of Mercury at Nisyros Volcano (Greece)

Nisyros Island (Greece) is an active volcano hosting a high-enthalpy geothermal system. During June 2013, an extensive survey on Hg concentrations in different matrices (fumarolic fluids, atmosphere, soils, and plants) was carried out at the Lakki Plain, an intracaldera area affected by widespread soil and fumarolic degassing. Concentrations of gaseous elemental mercury (GEM), together with H2S and CO2, were simultaneously measured in both the fumarolic emissions and the atmosphere around them. At the same time, 130 samples of top soils and 31 samples of plants (Cistus creticus and salvifolius and Erica arborea and manipuliflora) were collected for Hg analysis. Mercury concentrations in fumarolic gases ranged from 10,500 to 46,300 ng/m3, while Hg concentrations in the air ranged from high background values in the Lakki Plain caldera (10-36 ng/m3) up to 7100 ng/m3 in the fumarolic areas. Outside the caldera, the concentrations were relatively low (2-5 ng/m3). The positive correlation with both CO2 and H2S in air highlighted the importance of hydrothermal gases as carrier for GEM. On the other hand, soil Hg concentrations (0.023-13.7 μg/g) showed no significant correlations with CO2 and H2S in the soil gases, whereas it showed a positive correlation with total S content and an inverse one with the soil pH, evidencing the complexity of the processes involving Hg carried by hydrothermal gases while passing through the soil. Total Hg concentrations in plant leaves (0.010-0.112 μg/g) had no direct correlation with soil Hg, with Cistus leaves containing higher values of Hg with respect to Erica. Even though GEM concentrations in the air within the caldera are sometimes orders of magnitude above the global background, they should not be considered dangerous to human health. Values exceeding the WHO guideline value of 1000 ng/m3 are very rare (&lt;0.1%) and only found very close to the main fumarolic vents, where the access to tourists is prohibited.

Labdanum and Labdanes of Cistus creticus and C. ladanifer: Anti-Borrelia activity and its phytochemical profiling✰

BackgroundIntrigued by testimonies of Saxon borreliosis self-help groups concerning considerabl improvements of their symptoms by ingestion of Cistus creticus L. (Cistaceae) leaf preparations, we recently reported on the growth inhibiting activity of extracts with different polarities and its volatile oil against Borrelia burgdorferi sensu stricto (Bbss) in vitro, determined by a bioassay guided procedure. The most active volatile oil (only about 0.10% in leaves) was found to be dominated by labdane-type manoyloxides as well as carvacrol, determined via GC-MS. HypothesisThese terpenes are major active constituents of the old pharmaceutical oleoresin labdanum, which is secreted from the leaf surface of C. creticus and traditionally harvested, e.g., on Crete by brushing the shrubs. MethodsIn order to elucidate the definite anti-Borrelia active principles of C. creticus, preparative scale separation of the diethyl‑ether soluble fraction of Cretan labdanum was achieved by combined silica gel 60-and RP-18 CC and analysed by novel TLC-Extractor/ES-MS as well as by 1d/2d-1H/13C-NMR data. For the antispirochaetal activity tests against Bbss in vitro, all samples were solubilised in water with addition of polysorbate 80, the effect of which on bacterial growth was examined and found to be negligible. ResultsThis led to isolation and identification of the monoterpene carvacrol as well as of the four major manoyloxides manoyloxide (A), 3-acetoxy-manoyloxide (B), 3‑hydroxy-manoyloxide (C), and epi‑manoyloxide (D). Additionally, 2-keto-manoyloxide (E) and sclareol (F) were identified via GC/EI-MS. In subsequent microbiological tests of the isolated compounds, epi‑manoyloxide (D) exhibited by far the strongest individual antispirochaetal effect, equal to the positive control amoxicilline. Furthermore, manoyloxide (A), carvacrol, and the diethyl‑ether soluble fraction of labdanum as a whole contribute to the strong antispirochaetal activity, while the other labdanes were less active. Isolated manoyloxides were further used as external standards for a GC–MS screening of labdanum samples from different origins, revealing exceptionally high contents of all analysed manoyloxides in the samples of Cretan labdanum from C. creticus, while their contents in other commercial available labdanum samples were lower by several orders of magnitude. Especially in Spanish labdanum samples, declared as Cistus ladanifer L., mainly simple alkanes and at most traces of epi‑manoyloxide (D) and of manoyloxide (A) could be detected. ConclusionThe application of C. creticus preparations by Lyme disease self-help groups may be considered as a reasonable therapy approach. For the first time, isolated epi‑manoyloxide and carvacrol could be evaluated as most promising candidates for drug development and labdanum based phytomedicine development, respectively. They should serve as vital active markers for quality assessments of C. creticus preparations.

The effect of drying methods on the energy consumption, bioactive potential and colour of dried leaves of Pink Rock Rose (Cistus creticus)

This study aimed to investigate the changes in the total polyphenolic content and antioxidant properties after subjecting Pink Rock Rose (Cistus creticus) leaves to three different drying procedures, including convection drying (CD) at 40, 50 and 60 °C; vacuum-microwave drying (VMD) at 240 W microwave power; and combined drying consisting of convective pre-drying at 50 °C followed by vacuum-microwave finish drying at 240 W microwave power (CPD-VMFD). The total polyphenolic content and antioxidant properties (DPPH, ABTS) of leaves subjected to these three drying methods were spectrophotometrically determined. The results show that convection drying at 40 °C and vacuum-microwave drying yielded dried leaves with the highest bioactive potential in terms of the total polyphenol content and antioxidant activity, with the highest and lowest values of final specific energy consumption, respectively. The lowest bioactive potential was found in a product dried at 60 °C, which can be attributed to the possible degradation or changes in polyphenol structures under high temperatures. During the combined treatment (CPD-VMFD), most of the moisture was efficiently removed from the raw material by CPD, whereas the time of drying was significantly reduced by the application of VMFD. Combined drying CPD-VMFD is most suitable for industrial applications as it produces dried leaves with a bioactive potential that is only slightly lower than that achieved with VMD while providing a high-throughput capacity relative to operating costs.

Change in plant species composition on powerline corridor: a case study.

Clear-cutting of powerline corridors (PLCs) adversely affects ecosystem function by fragmenting intact forests and supports biodiversity with the development of a structurally diverse vegetation. The study aimed to determine diversity and composition caused by clear-cutting and monitor change in species composition on the PLC passing through Research Forest of IUC Faculty of Forestry. Species composition was monitored in 10 permanent plots on the clear-cut area (over 3years) paired on the forest edge (over 2years) and forest interior (first year). Diversity, the cover of invasive plants, and life form traits of the sample plots were compared. Change in species composition with time was determined with redundancy analysis (RDA) for repeated measures using CANOCO 5. Open-site conditions caused by clear-cutting promoted the number of hemicryptophyte and therophyte life forms which resulted in a high species richness on the clear-cut area (167 species), followed by forest edge (117 species) and forest interior (60 species). However, species richness which showed a peak in the second year was decreased at the end of 3years. Total cover of invasives was considerably higher on the clear-cut area (23%) compared with the forest (3.78%) and did not make a significant effect on forest interior species in narrow corridors. Clear-cutting combined with slash piling promoted the undesired vertical development of tree sprouts and Robinia pseudoacacia which shortened management rotation in a short period. However, sites dominated by shrubs such as Cistus creticus and Cistus salviifolius suppressed the development and invasion of undesirable trees.

Mediterranean herb extracts inhibit microbial growth of representative oral microorganisms and biofilm formation of Streptococcus mutans

In light of the growing antibiotic resistance, the usage of plant-derived antimicrobial agents could serve as an effective alternative treatment against oral infections. The aim of this study was to investigate the antimicrobial and antibiofilm activity of Mediterranean herb extracts against representative oral microorganisms. The extraction procedures and the analysis of the obtained extracts were performed under established experimental conditions. The minimum inhibitory (MIC) and bactericidal (MBC) concentrations of the methanol extracts of Cistus creticus ssp. creticus, Cistus monspeliensis, Origanum vulgare, Rosmarinus officinalis, Salvia sclarea and Thymus longicaulis against eight typical oral bacteria and the fungus Candida albicans were determined. The antibiofilm activity against Streptococcus mutans was also quantified using the microtiter plate test. Overall, all tested extracts inhibited effectively the screened obligate anaerobic microorganisms and in concentrations ≥0.3 mg ml-1 had moderate to high antibiofilm activity comparable to that of chlorhexidine (CHX) against S. mutans. In particular, R. officinalis (MIC: 0.08–5.00 mg ml-1) and S. sclarea (MIC: 0.08–2.50 mg ml-1) showed the highest antibacterial activity, while Cistus spp., R. officinalis and S. sclarea significantly inhibited S. mutans biofilm formation at 0.60, 1.25 and 2.50 mg ml-1, respectively. Porphyromonas gingivalis and Parvimonas micra were high susceptible to O. vulgare (MIC = 0.30 mg ml-1), whereas T. longicaulis eradicated all oral bacteria (MBC: 0.15–2.50 mg ml-1). Nevertheless, C. albicans showed no sensitivity to the tested extracts. In conclusion, the tested plant extracts could serve as alternative natural antibacterial and antibiofilm components against oral infections.

Relationships among nutritive value of selected forages, diet composition and milk quality in goats grazing in a Mediterranean woody rangeland

Woody rangelands are important forage resources for grazing goats in the Mediterranean basin. Goats are well adapted in these heterogeneous and complex ecosystems due to their particular anatomic characteristics, metabolic efficiency and browsing ability. However, the mechanism of grazing behavior and forage selection in goats is quite complex and depends on several factors. The present study deals with the seasonal changes of chemical composition in the selected forages and ingested diets as well as their effects on milk yield and composition of goats grazing in a Mediterranean woody rangeland. Hand plucked forage samples similar to those consumed by the goats were collected for chemical analysis. The nutritive value of consumed forages, in combination with the different feeding and grazing system per trial period, influenced milk quality and performance. The replacement of feed supplementation with an increase of the contribution of grazing in the rangeland could maintain the milk yield and quality at the late stage of lactation. In addition, this paper focuses on the influence of the chemical composition of selected forages on the diet selection of goats using a modeling approach. The model showed a high interpretative accuracy and explanatory value (R2 = 0.923) and was able to distinguish the goats' most important criteria for selecting among the forage plant species in relation to several factors. The results indicate that the dietary preferences of goats were influenced, not only by the seasonality of nutritive value and availability of forages in the rangeland, but also by the plant origin of each nutrient source. The selection of Quercus frainetto was highly correlated with its NDF content. Herbaceous species, Cistus creticus and other woody species were mainly selected due to their CP content. The ADL content seemed to have the lowest influence of all nutritive variables on the selection among groups of plant species. The modeling approach, apart from the understanding of grazing behavior of goats, offers additional information that can be useful to the shepherds in order to manage more effectively the feeding and grazing system of their goat's flock.

Analysis and Potential Antimicrobial Activity of Phenolic Compounds in the Extracts of Cistus Creticus Subspecies from Sardinia

Analysis and Potential Antimicrobial Activity of Phenolic Compounds in the Extracts of Cistus Creticus Subspecies from Sardinia

In vitro shoot cultures of pink rock-rose (Cistus ×incanus L.) as a potential source of phenolic compounds

In vitro cultures of &lt;em&gt;Cistus ×incanus&lt;/em&gt; (pink rock-rose) were maintained on two variants of Murashige and Skoog (MS) medium differing in terms of composition of plant growth regulators (PGRs): 6-benzyl­adenine (BA) and 1-naphthaleneacetic acid (NAA) at the following concentrations: 3 mg/L and 0, 3 mg/L and 1 mg/L, respectively, and on a variant without PGRs – a control. Cultures were maintained in a form of agar and agitated shoot cultures. The qualitative and quantitative analyzes of three groups of phenolic compounds (catechins, flavonoids, and free phenolic acids) were performed by using the HPLC-DAD technique in methanolic extracts of in vitro biomasses and of commercial plant raw material. In analyzed extracts from in vitro cultures, the presence of catechin [max. 197.80 mg / 100 g dry weight (DW)], epicatechin gallate (max. 30.74 mg / 100 g DW), gallic acid (max. 83.23 mg / 100 g DW), quercetin (max. 10.15 mg / 100 g DW), and quercitrin (max. 72.89 mg / 100 g DW) was confirmed. The quantities of accumulated compounds varied and depended on the type of in vitro culture and the concentration of PGRs in media. The highest amounts of all estimated compounds were obtained in biomasses from agar cultures cultivated on medium without PGRs in vitro. In extracts obtained from commercial raw material, gallic acid (max. 261.80 mg / 100 g DW) and quercetin (max. 255.96 mg / 100 g DW) were detected as being the dominant compounds.

Evaluation of Phenolic Compounds in Cistus creticus Bee Pollen from Greece. Antioxidant and Antimicrobial Properties

This study was carried out to evaluate the antioxidant properties of Greek endemic Cistus creticus L. (rock rose) bee pollen and define its phenolic compounds. In the framework of our scientific studies on Greek bee keeping products, we report herein our research on three Greek bee pollen samples from Cistus. Their pollinic spectra were obtained by Louveaux's quantitative microscopical analysis and it showed that one of them had Cistus sp. (Cistaceae) as abundant pollen (together with low percentage of Brassica sp. (Cruciferae). Throughout the chemical analysis of the extracts, several secondary metabolites of flavonoid structure have been identified as major components. Specifically, quercetin-7-rhamnoside (1), quercetin-3-neohesperidoside (2), kaempferol-3-neohesperidoside (3), myricetin-3-neohesperidoside (4), kaempferol-3-glucoside (5) and quercetin-3-glucoside (6) have been isolated and their structures were elucidated on the basis of spectral evidence. Moreover, the total phenolic and flavonoid content was estimated and the free radical scavenging activity was determined by DPPH and ABTS assays. The antimicrobial activity of the extracts was tested against six Gram-positive and -negative bacteria and three pathogenic fungi, and the butanol extract showed a very interesting broad antimicrobial profile (MIC 1.98•10−3 - 2.98•10−3 mg/ml) against all the assayed microorganisms.

Ethnobotanical Survey of Medicinal Plants Used for the Treatment of Diabetes in the Tizi n’ Test Region (Taroudant Province, Morocco)

In Morocco, diabetes mellitus is a major public health problem with over than 1.5 million cases in 2014. Medicinal plants are widely used by the Moroccan population to treat the illness. This study was carried out to identify the medicinal plants traditionally used in human therapy to treat diabetes in the Tizi n’Test region, and contribute to safeguarding knowledge and local expertise in traditional herbal medicine. A total of 280 interviews were conducted with traditional health practitioners and knowledgeable villagers. Data were collected by semi-structured and structured questionnaires. Indices on Fidelity Level (FL), Use Value (UV) and Relative Frequency of Citation (RFC) were calculated. The ethnobotanical survey has identified 39 species representing 24 families. The most encountered medicinal plant families were Asteraceae and Lamiaceae. The following plant species were showed the high significant FL, UV and RFC: Artemisia herba-alba, Cistus creticus, Lavandula maroccana, Salvia lavandulifolia and Olea europaea. Plant leaves were the most commonly used plant part, and decoction was the most common method of traditional drug preparation. Our study showed that medicinal plants continue to play an important role in the primary healthcare system for the local population of the Tizi n’Test region and represents a useful documentation, which can contribute to preserving knowledge on the use of medicinal plants for diabetes treatment and to explore the phytochemical and pharmacological potential of medicinal plant.

Trichome patterning control involves TTG1 interaction with SPL transcription factors.

Epidermal cell differentiation is a paramount and conserved process among plants. In Arabidopsis, a ternary complex formed by MYB, bHLH transcription factors and TTG1 modulates unicellular trichome morphogenesis. The formation of multicellular glandular trichomes of the xerophytic shrub Cistus creticus that accumulate labdane-type diterpenes, has attained much attention renowned for its medicinal properties. Here, we show that C. creticus TTG1 (CcTTG1) interacts with the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE (SPLA/B) proteins, putative homologs of AtSPL4/5 that in turn interact with AtTTG1. These interactions occur between proteins from evolutionarily distant species supporting the conserved function of TTG1-SPL complex. Overexpression of AtSPL4 and AtSPL5 decreased the expression of GLABRA2 (AtGL2), the major regulator of trichome morphogenesis, resulting in trichome reduction on the adaxial surface of cauline leaves, thereby illuminating the significance of TTG1-SPLs interactions in trichome formation control. AtGL2 and AtSPL4 have opposite expression patterns during early stages of leaf development. We postulate an antagonistic effect between SPLs and the heterogeneous MYB-bHLH factors binding to TTG1. Hence, the SPLs potentially rearrange the complex, attenuating its transcriptional activity to control trichome distribution.

Tuber borchii Vitt. mycorrhiza protects Cistus creticus L. from heavy metal toxicity

Heavy metals (HMs), such as copper, zinc, lead, mercury and cadmium, are the most abundant and dangerous inorganic environmental pollutants. Growing pieces of evidence suggest that mycorrhizal fungi can alleviate metal toxicity in plants. In this study, we focused attention on the ectomycorrhizal (ECM) fungus Tuber borchii Vitt., which is widespread in Italy and is of great ecological interest because of the mutualistic associations and the advantages it provides to host plants. Seedlings of the Mediterranean shrub Cistus creticus L., mycorrhized and non mycorrhized with the ECM fungus T. borchii, were treated with HMs (zinc, lead and chromium). HMs induced leaves’ chlorosis in non mycorrhized seedlings; while no significant difference was observed in pigmentation of mycorrhized seedlings’ leaves. This observation was confirmed by Euclidean Distance of color measurements in L*a*b* units from RGB digital images of leaves. The decrease in leaves pigmentation observed in HM treated non mycorrhized seedlings strongly correlated with a reduced expression of key genes associated with chlorophyll biosynthesis; instead, no significant variation of gene expression was detected in mycorrhized seedlings treated with HMs.Finally, a comet test on nuclei isolated from leaves of mycorrhized and non mycorrhized C. creticus seedlings, treated or not with HMs, confirmed that the DNA damage induced by HMs stress was lower in mycorrhized than in non mycorrhized seedlings. Taken together, the data suggest the involvement of the mycorrhizal fungus T. borchii in the improvement of HM stress tolerance in C. creticus host.

Impact of honeybee (Apis mellifera L.) density on wild bee foraging behaviour

Abstract Honey bees are globally regarded as important crop pollinators and are also valued for their honey production. They have been introduced on an almost worldwide scale. During recent years, however, several studies argue their possible competition with unmanaged pollinators. Here we examine the possible effects of honey bees on the foraging behaviour of wild bees on Cistus creticus flowers in Northern Greece. We gradually introduced one, five, and eight honey-bee hives per site, each containing ca. 20,000 workers. The visitation frequency and visit duration of wild bees before and after the beehive introductions were measured by flower observation. While the visitation frequencies of wild bees were unaffected, the average time wild bees spent on C. creticus increased with the introduction of the honey-bee hives. Although competition between honey bees and wild bees is often expected, we did not find any clear evidence for significant effects even in honey-bee densities much higher than the European-wide average of 3.1 colonies/km2.

English

Listing and describing plant diversity in terms of the status of flowering vascular plants in Al-Balqa Governorate (North West Amman/Jordan) has been evaluated. Collections of plant specimens have been made during the field trips that have been conducted, in order to study and evaluate the composition and the diversity of the flowering wild plants in Al-Balqa Governorate. A total number of 527 species belonging to 296 genera and 61 families have been recorded. A number of 91 medicinal plants are recorded; some examples are known as medicinal plants like: Arum palaestinum, Achillea santolina, Carduus australis, and others. Poisonous plants such as Retama raetam, Solanum luteum, Ferula communis etc. were also recorded. A number of 30 recorded species are considered as endemic such as Daucus carota and Apium nodiflorum, and some others are known as edible plant species like: Salvia hierosolymitana, Gundelia tournefortii, Eruca sativa etc. a number of 25&nbsp;&nbsp; species are endangered such as:&nbsp; Gundelia tournefortii, Sinapis alba, Sternbergia clusiana and Cistus creticus. Some reported species are rare like: Lactuca serriola, Varthemia iphionoides, Echium judaeum, Lupinus varius, Iris atrophosca and others. Deciduous Oak (Quercus ithaburensis) forest is occurring in the study area mixed with remnants of wild olive (Olea europaea), and with shrubs such as Crataegus azarolus, and a wild almond tree&nbsp; (Amygdalus communis), also with herbaceous bushes such as Dactylis glomeratus, Urginea maritima, Colchicum hierosolymitanum, Sarcopoterium spinosum, Euphorbia hierosolymitana, Salvia indica, Alcea setosa, and Tulipa stylosa. However the study area is considered as one of the richest geographical area in Jordan in terms of its plant diversity, but unfortunately the area is negatively affected by different factors that are contributing in the habitat loss and degradation. &nbsp; Key words: Plant diversity, Flora, Al-Balqa, Jordan.