Search results for " germination"
showing 10 items of 69 documents
Stress integrated tests and cytological analyses reveal Brassica villosa subsp. drepanensis seed quality decrease upon long-term storage
2016
Under stress integrated germination test (SIGT), seeds undergo osmo-saline stresses, which enable to detect differences in vigour of long-term stored seeds with high germination percentage (G%). The quality of Brassica villosa subsp. drepanensis seeds stored in a genebank (at -20°C for 16 years) was compared with seeds at harvest by standard germination tests (GT), SIGT and cytogenetic analysis. No differences were detected in G% and mean germination time under GT. Conversely, SIGT performed with NaCl -0.9MPa osmotic potential did not influence G% at harvest but reduced that of stored seeds, SIGT at -1.4MPa reduced G% of both. Cytogenetic analysis showed reduction of mitotic index, appearan…
Unraveling Salt Tolerance in Halophytes: A Comparative Study on Four Mediterranean Limonium Species with Different Geographic Distribution Patterns
2017
[EN] We have performed an extensive study on the responses to salt stress in four related Limonium halophytes with different geographic distribution patterns, during seed germination and early vegetative growth. The aims of the work were twofold: to establish the basis for the different chorology of these species, and to identify relevant mechanisms of salt tolerance dependent on the control of ion transport and osmolyte accumulation. Seeds were germinated in vitro, in the presence of increasing NaCl concentrations, and subjected to ¿recovery of germination¿ tests; germination percentages and velocity were determined to establish the relative tolerance and competitiveness of the four Limoni…
Control of Erigeron bonariensis with Thymbra capitata, Mentha piperita, Eucalyptus camaldulensis, and Santolina chamaecyparissus Essential Oils
2020
In the search of sustainable and environmentally friendly methods for weed control, there is increasing interest in essential oils (EOs) as an approach to reduce synthetic herbicide use. The phytotoxicity of Thymbra capitata, Mentha piperita, Eucalyptus camaldulensis, and Santolina chamaecyparissus EOs against the noxious weed Erigeron bonariensis were evaluated in pre- and post-emergence assays in greenhouse conditions. The EOs were applied at 2, 4, and 8 µ
Ionizing radiation from Chernobyl affects development of wild carrot plants.
2016
AbstractRadioactivity released from disasters like Chernobyl and Fukushima is a global hazard and a threat to exposed biota. To minimize the deleterious effects of stressors organisms adopt various strategies. Plants, for example, may delay germination or stay dormant during stressful periods. However, an intense stress may halt germination or heavily affect various developmental stages and select for life history changes. Here, we test for the consequence of exposure to ionizing radiation on plant development. We conducted a common garden experiment in an uncontaminated greenhouse using 660 seeds originating from 33 wild carrots (Daucus carota) collected near the Chernobyl nuclear power pl…
Inhibition of Metarhizium anisopliae in the alimentary tract of the eastern subterranean termite Reticulitermes flavipes
2009
Reticulitermes flavipes workers were individually inoculated with 10,000 conidia of the entomopathogenic fungus Metarhizium anisopliae. After being kept in groups of 20 individuals for 1–6 d, histopathological approach showed that most of the inoculated conidia were groomed from the surface of the cuticle by nestmates within 24 h, and that a large number of conidia was subsequently found in different parts of the gut of the groomers. Our observations showed that, among thousands of conidia found in the termite's gut, conidial germination never occurred in all inspected specimens, even when the conidia had the chance to bind to the surface of the cuticular lining of the gut. In addition, whe…
Staying alive on an active volcano: 80 years population dynamics of Cytisus aeolicus (Fabaceae) from Stromboli (Aeolian Islands, Italy)
2020
Abstract Cytisus aeolicus is a narrow endemic species restricted to the Aeolian archipelago (SE Tyrrhenian Sea, Italy) and it is one of the most evolutionarily isolated plants in the Mediterranean flora. Historical and literature data suggest that both metapopulations and isolated individuals of C. aeolicus are gradually shrinking. Field investigations and drone images demonstrate that the C. aeolicus metapopulation from Stromboli experienced a strikingly fast increase during the last decades. As of 2019, more than 7000 ± 3000 mature individuals occur on Stromboli, i.e. 14 to 20 times more than those counted during the last census, 25 years ago. The diachronic analysis of aerial photos conc…
Seed germination under osmotic stress across different wild populations of mountain rye (Secale strictum (C.Presl) C.Presl))
2020
The selection of resilient cultivars could help stem the losses in forage production due to a changing climate. Secale strictum is a wild grass with interesting potential as a forage crop. We studied the germination requirements of six wild S. strictum populations, representative of the whole species distribution range in Italy and occurring under different osmotic conditions (0 MPa, −0.8 MPa, −1.0 MPa, −1.2 MPa, −1.4 MPa and −1.6 MPa). Our aim was to find beneficial seed and germination traits for the possible use of this species as a crop. Different accessions of domesticated Secale cereale and ×Triticosecale were used as comparison. Some populations of S. strictum were drought tolerant a…
Millerandage and flower abscission in ‘Grillo’, ‘Frappato’ and ‘Nero d’Avola’ grapevines: Some probable causes
2018
Some Sicilian cultivars, in particular vintage, showed a high percentage of flower abscissions and shot berries. In this paper, to understand these phenomena, some aspects of the flower morphology of three Sicilian cultivars (two black: ‘Nero d’Avola’ and ‘Frappato’; and one white: ‘Grillo’) was studied. The number of stamens, ovule adherence to the ovary wall and pollen germination were evaluated using standard light microscopy. At harvest, seed number was counted on 30 berries per cultivar. The percentage of six stamens was lowest in ‘Frappato’ and highest in ‘Grillo’. The ovule adherence to the ovary wall was highest in ‘Frappato’ and lowest in ‘Nero d’Avola’. The percentage of pollen ge…
Bacterial rhamnolipids are novel MAMPs conferring resistance to Botrytis cinerea in grapevine
2009
International audience; Rhamnolipids produced by the bacteria Pseudomonas aeruginosa are known as very efficient biosurfactant molecules. They are used for a wide range of industrial applications, especially in food, cosmetics and pharmaceutical formulations as well as in bioremediation of pollutants. In this paper, the role of rhamnolipids as novel molecules triggering defence responses and protection against the fungus Botrytis cinerea in grapevine is presented. The effect of rhamnolipids was assessed in grapevine using cell suspension cultures and vitro-plantlets. Ca2+ influx, mitogen-activated protein kinase activation and reactive oxygen species production form part of early signalling…
Distinct lytic vacuolar compartments are embedded inside the protein storage vacuole of dry and germinating Arabidopsis thaliana seeds.
2011
International audience; Plant cell vacuoles are diverse and dynamic structures. In particular, during seed germination, the protein storage vacuoles are rapidly replaced by a central lytic vacuole enabling rapid elongation of embryo cells. In this study, we investigate the dynamic remodeling of vacuolar compartments during Arabidopsis seed germination using immunocytochemistry with antibodies against tonoplast intrinsic protein (TIP) isoforms as well as proteins involved in nutrient mobilization and vacuolar acidification. Our results confirm the existence of a lytic compartment embedded in the protein storage vacuole of dry seeds, decorated by γ-TIP, the vacuolar proton pumping pyrophospha…