Search results for "botany"
showing 10 items of 4586 documents
Movement of Metals to New Growing Tissue in the MossHylocomium splendens(Hedw.) BSG
1997
To obtainHylocomium splendens(Hedw.) BSG. that varied in metal (K, Mg, Ca and Zn) content, moss samples were collected from six sites around a zinc contaminated area of Latvia; metal contents were artificially lowered by branch excision. The first fully expanded annual segment (mature segments), together with the unexpanded segment (juvenile segment) were grown in the laboratory with watering from below. The contents of K, Mg, Ca and Zn in new growth were correlated with initial contents in the juvenile+mature segments. However, the concentrations of these metals in the new growth were generally not correlated with those in the pre-experimental segments. The excision of branches from the ma…
The effect of nickel on seed germination and plant sprouting in the case of some Alyssum species
2015
The aim of the researches was to establish the upper limit of nickel concentration in soils that the Alyssum maritimum and Alyssum murale species could tolerate without significantly affecting the germination and the plant sprouting process. The experiment was conducted in 4 variants of 3 repetitions, each repetition including 50 seeds. The watering process of the substrate was performed using distilled water for the control variant (M) and NiSO4 solutions that represented the intervention threshold (V1 – 150 mg/kg) and doses that exceeded the intervention threshold (V2 – 350 mg/kg; V3 – 550 mg/kg and V4 – 750 mg/kg). The Ni influence on seed germination was assessed based on sprouting perc…
Brenneria quercina and Serratia spp. isolated from Spanish oak trees Molecular characterization and development of PCR primers
2008
Brenneria quercina has been reported as one of the causal agents of oak decline in Spain. To investigate the bacterial variability of this pathogen from different Spanish oak forests, a collection of 38 bacterial isolates from seven geographic locations and from different oak species was analysed by sequencing 16S rDNA and rep-PCR fingerprinting. All Spanish isolates of B. quercina were grouped by rep-PCR into a homogenous cluster that differed significantly from B. quercina reference strains from California. 16S rDNA analysis revealed that 34 out of 38 isolates were Brenneria. However, four isolates belonged to the genus Serratia, suggesting that this bacterium could cause cankers in oak t…
Influence of the addition ofHelianthus tuberosusL. fermented with different lactobacilli on acrylamide content in biscuits
2014
Summary The aim of the study was to investigate the effect of the addition of Helianthus tuberosus L. fermented with different lactobacilli (Lactobacillus sakei KTU05-6, Pediococcus acidilactici KTU05-7 and Pediococcus pentosaceus KTU05-9) on acrylamide content in biscuits. Results of study indicated that submerged fermented Helianthus tuberosus L. tubers had the significantly (P ≤ 0.05) lower pH, higher total titratable acidity and from 1.2 to 1.3 times higher protease and from 1.2 to 2.0 higher alpha-amylase activities compared with treated by solid-state fermentation. The acrylamide content in all biscuit samples enriched with submerged fermented Helianthus tuberosus L. was measured lowe…
Effect of CCC and pH on shoot elongation in Sedum rubrotinctum R.T. Clausen
2002
Sedum rubrotinctum plants grown during winter in a glasshouse had decreased leaf density and increased internode length as well as loss of red coloring, leading to diminished ornamental value. Treatment with growth retardant (2-chloroethyl)trimethyl ammonium chloride (CCC) reduced internode length as well as the number of internodes. Concomitant changes of ethylene production and peroxidase activity were found in CCC-treated plants. Substrate pH had a significant effect on the growth of S. rubrotinctum. This leads to the conclusion that increase of shoot growth during winter period could be reversed by means of growth retardant CCC and acidification of substrate.
Composition and allelopathic effect of essential oils of two thistles: Cirsium creticum (Lam.) D.�Urv. ssp. triumfetti (Lacaita) Werner and Carduus n…
2007
Abstract Cirsium and Carduus are two of the main genera of true thistles. Different species in these genera share a quantity of secondary metabolites and have interesting ecological properties. The essential oils of two species, Cirsium creticum and Carduus nutans, were analysed, showing the presence as main compounds of 4-ethyl guaiacol (15%), hexadecanoic acid (10.6%), (E)-β-damascenone (7.8%), dihydroactinidiolide (6.0%) and 4-vinyl guaiacol (4.5%) for C. creticum and hexadecanoic acid (18.6%), hexahydrofarnesylacetone (7.8%), heptacosane (5.9%), 4-vinyl guaiacol (5.8%), pentacosane (3.8%) and eugenol (3.6%) for C. nutans. The oils were evaluated at different doses for their effect on ge…
INFLUENCE OF SEED TREATMENT ON GERMINATION PATTERN OF CHAMAEROPS HUMILIS
2015
Dwarf fan palm (Chamaerops humilis L.) is an important Mediterranean species well known for many uses such as gardening, environmental restoration, and technological uses. Dwarf fan palm is usually propagated from seed, which takes up to 100 days to germinate. The germination pattern of dwarf palm seeds was studied during a 100-days length period in relation to different pre-sowing treatments (hot water, sulphuric acid, or mechanical scarification) in comparison to untreated control. A covariance analysis was performed to test the effect of time within seed-treatment treatment. All germination patterns were significantly fitted by a S-shaped (sigmoidal) distribution function with the genera…
First report of Cucumber mosaic virus infecting Solanum jasminoides in Italy
2008
Solanum jasminoides Paxton (potato vine or jasmine nightshade) is a vegetatively propagated ornamental species within the Solanaceae family. Recently, symptomless plants of this species were reported as natural hosts of the quarantine pest, Potato spindle tuber viroid (PSTVd) in Italy (1). In January 2008, approximately 1,000 potted, 2-year-old plants of S. jasminoides growing in an ornamental nursery in Sicily showed virus-like mosaic and malformation of leaves. Symptoms were observed on approximately 60% of the plants. Leaf tissue, collected from 30 symptomatic and 10 symptomless plants, was analyzed by double-antibody sandwich-ELISA with polyclonal antisera specific to Cucumber mosaic v…
Micropropagation of Lavandula latifolia through nodal bud culture of mature plants
1996
Cultures of Lavandula latifolia Medicus were established from axillary buds of mature field-grown plants. Explants were initially cultured on media with two different macronutrient combinations and benzyladenine or kinetin added either individually or with naphthaleneacetic acid. Subsequently, explants were subcultured in Murashige and Skoog medium supplemented with 20% coconut milk, 0.57 μM indoleacetic acid and 8.88 μM benzyladenine. Shoot proliferation from axillary buds was not affected by seasonal fluctuations in the stock plants but depended on the macronutrient composition and on the type and concentration of cytokinin tested. Best results were obtained in explants initially cultured…
A screening of five Bacillus thuringiensis Vip3A proteins for their activity against lepidopteran pests
2014
Five Bacillus thuringiensis Vip3A proteins (Vip3Aa, Vip3Ab, Vip3Ad, Vip3Ae and Vip3Af) and their corresponding trypsin-activated toxins were tested for their toxicity against eight lepidopteran pests: Agrotis ipsilon, Helicoverpa armigera, Mamestra brassicae, Spodoptera exigua, Spodoptera frugiperda, Spodoptera littoralis, Ostrinia nubilalis and Lobesia botrana. Toxicity was first tested at a high dose at 7 and 10. days. No major differences were found when comparing protoxins vs. trypsin-activated toxins. The proteins that were active against most of the insect species were Vip3Aa, Vip3Ae and Vip3Af, followed by Vip3Ab. Vip3Ad was non-toxic to any of the species tested. Considering the res…