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Sample records for germinal center reactions

  1. Regulation of Germinal Center Reactions by B and T Cells

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    Yeonseok Chung

    2013-10-01

    Full Text Available Break of B cell tolerance to self-antigens results in the development of autoantibodies and, thus, leads to autoimmunity. How B cell tolerance is maintained during active germinal center (GC reactions is yet to be fully understood. Recent advances revealed several subsets of T cells and B cells that can positively or negatively regulate GC B cell responses in vivo. IL-21-producing CXCR5+ CD4+ T cells comprise a distinct lineage of helper T cells—termed follicular helper T cells (TFH—that can provide help for the development of GC reactions where somatic hypermutation and affinity maturation take place. Although the function of TFH cells is beneficial in generating high affinity antibodies against infectious agents, aberrant activation of TFH cell or B cell to self-antigens results in autoimmunity. At least three subsets of immune cells have been proposed as regulatory cells that can limit such antibody-mediated autoimmunity, including follicular regulatory T cells (TFR, Qa-1 restricted CD8+ regulatory T cells (CD8+TREG, and regulatory B cells (BREG. In this review, we will discuss our current understanding of GC B cell regulation with specific emphasis on the newly identified immune cell subsets involved in this process.

  2. Aborted germinal center reactions and B cell memory by follicular T cells specific for a B cell receptor V region peptide.

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    Heiser, Ryan A; Snyder, Christopher M; St Clair, James; Wysocki, Lawrence J

    2011-07-01

    A fundamental problem in immunoregulation is how CD4(+) T cells react to immunogenic peptides derived from the V region of the BCR that are created by somatic mechanisms, presented in MHC II, and amplified to abundance by B cell clonal expansion during immunity. BCR neo Ags open a potentially dangerous avenue of T cell help in violation of the principle of linked Ag recognition. To analyze this issue, we developed a murine adoptive transfer model using paired donor B cells and CD4 T cells specific for a BCR-derived peptide. BCR peptide-specific T cells aborted ongoing germinal center reactions and impeded the secondary immune response. Instead, they induced the B cells to differentiate into short-lived extrafollicular plasmablasts that secreted modest quantities of Ig. These results uncover an immunoregulatory process that restricts the memory pathway to B cells that communicate with CD4 T cells via exogenous foreign Ag.

  3. Effect of thumus cell injections on germinal center formation in lymphoid tissues of nude (thymusless) mice

    International Nuclear Information System (INIS)

    Jacobson, E.B.; Caporale, L.H.; Thorbecke, G.J.

    1974-01-01

    Nude mice, partially backcrossed to Balb/c or DBA/2, were injected iv with 5 x 10 7 thymus cells from the respective inbred strain. The response of these mice to immunization with Brucella abortus antigen was studied, with respect to both antibody production and the formation of germinal centers in their lymphoid tissues. The results were compared to those obtained with nude mice to which no thymus cells were given, as well as to Balb/c, DBA/2, or +/question litter mate controls. Nude mice formed less 19S as well as 7S antibody than did litter mate controls and completely lacked germinal centers in lymph nodes and gut-associated lymphoid tissue. Those nude mice which had been injected with thymus cells made a much better secondary response, both for 19S and for 7S antibody, and had active germinal centers in their lymph nodes as early as 3 wk after thymus cell injection. Intestinal lymphoid tissue in nude mice showed only slight reconstitution of germinal center activity several months after thymus cell injection and none at earlier times. Irradiated (3000 R) thymus cells appeared as effective as normal cells in facilitating germinal center appearance and 7S antibody production in the nude mice

  4. Effect of thumus cell injections on germinal center formation in lymphoid tissues of nude (thymusless) mice. [X radiation

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    Jacobson, E.B.; Caporale, L.H.; Thorbecke, G.J.

    1974-09-01

    Nude mice, partially backcrossed to Balb/c or DBA/2, were injected iv with 5 x 10/sup 7/ thymus cells from the respective inbred strain. The response of these mice to immunization with Brucella abortus antigen was studied, with respect to both antibody production and the formation of germinal centers in their lymphoid tissues. The results were compared to those obtained with nude mice to which no thymus cells were given, as well as to Balb/c, DBA/2, or +/question litter mate controls. Nude mice formed less 19S as well as 7S antibody than did litter mate controls and completely lacked germinal centers in lymph nodes and gut-associated lymphoid tissue. Those nude mice which had been injected with thymus cells made a much better secondary response, both for 19S and for 7S antibody, and had active germinal centers in their lymph nodes as early as 3 wk after thymus cell injection. Intestinal lymphoid tissue in nude mice showed only slight reconstitution of germinal center activity several months after thymus cell injection and none at earlier times. Irradiated (3000 R) thymus cells appeared as effective as normal cells in facilitating germinal center appearance and 7S antibody production in the nude mice.

  5. Effectiveness of Germination on Protein Hydrolysis as a Way To Reduce Adverse Reactions to Wheat.

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    Boukid, Fatma; Prandi, Barbara; Buhler, Sofie; Sforza, Stefano

    2017-11-15

    In this work, the aim is to study the effectiveness of germination on wheat protein degradation, with a specific focus on proteins involved in adverse reactions to wheat. The effects of 8 days of germination at 25 °C on the chemical composition and the protein profile were determined. Germination did not have a significant effect on starch, protein, lipid, and ash contents. General protein profile, as indicated by SDS-PAGE analysis, revealed that germination induced a relevant degradation in protein fraction. After in vitro gastrointestinal digestion, gluten peptides involved in celiac disease (CD) were identified and quantified using UPLC/ESI-MS technique. Also, CM3 protein, involved in baker's asthma and intestinal inflammation, was quantified by measuring a marker peptide. Statistical analysis underlined that germination and genotype had significant impact on the amount of both components. Regarding gluten peptides related to CD, germination enabled an average reduction of 47% in peptides eliciting adaptive immune response and 46% in peptides eliciting innate immune response. CM3 protein showed also a high average reduction (56%). Thus, this study suggests that germination might be a good bioalternative to provide a low "impact" raw ingredient for special wheat-based foodstuffs.

  6. Ectopic germinal center and megalin defect in primary Sjogren syndrome with renal Fanconi syndrome.

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    Wang, Jing; Wen, Yubing; Zhou, Mengyu; Shi, Xiaoxiao; Jiang, Lanping; Li, Mingxi; Yu, Yang; Li, Xuemei; Li, Xuewang; Zhang, Wen; Lundquist, Andrew L; Chen, Limeng

    2017-06-02

    This study reports the clinical and pathological features of 12 cases of primary Sjogren syndrome (pSS) with renal involvement presenting with proximal tubular dysfunction in a single center, and investigates the possible correlation of ectopic germinal center formation and megalin/cubilin down-expression. Clinical and pathological records were reviewed. Immunohistochemistry was carried out to detect megalin, cubilin, CD21 and IL-17 expression. Patients presented with different degrees of proximal renal tubule lesion and decreased estimated glomerular filtration rate (eGFR). Renal biopsy revealed tubulointerstitial nephritis, with tubular epithelial cell degeneration, tubular atrophy, interstitial inflammation and focal fibrosis. Immunohistochemistry revealed decreased expression of megalin and cubilin, two important multiligand protein receptors on the brush border of proximal tubular epithelial cells. IL-17 secreted by Th17 subtype effector T cells was diffusely detected in the renal proximal tubule, with a negative correlation of IL-17 and megalin expression. In addition, ectopic germinal centers characterized by CD21 + follicular dendritic cells were present in the renal interstitium. In patients with a decreased eGFR, treatment with 4 weeks of glucocorticoid therapy resulted in an improved eGFR in 75% of patients. We report 12 cases of pSS characterized by Fanconi syndrome. The decreased megalin and cubilin expression may contribute to the proximal tubular reabsorption defect, possibly secondary to Th17 infiltration and formation of ectopic germinal centers.

  7. Cellular interactions in the germinal center: role of adhesion receptors and significance for the pathogenesis of AIDS and malignant lymphoma

    NARCIS (Netherlands)

    Koopman, G.; Pals, S. T.

    1992-01-01

    The germinal center forms a specialized microenvironment that is thought to play a key role in the induction of antibody synthesis, affinity maturation of B cells, isotype switching, and memory B-cell formation. Moreover, the germinal center may also be involved in the maintenance of T-cell memory.

  8. DNA Methylation Dynamics of Germinal Center B Cells Are Mediated by AID

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    Pilar M. Dominguez

    2015-09-01

    Full Text Available Changes in DNA methylation are required for the formation of germinal centers (GCs, but the mechanisms of such changes are poorly understood. Activation-induced cytidine deaminase (AID has been recently implicated in DNA demethylation through its deaminase activity coupled with DNA repair. We investigated the epigenetic function of AID in vivo in germinal center B cells (GCBs isolated from wild-type (WT and AID-deficient (Aicda−/− mice. We determined that the transit of B cells through the GC is associated with marked locus-specific loss of methylation and increased methylation diversity, both of which are lost in Aicda−/− animals. Differentially methylated cytosines (DMCs between GCBs and naive B cells (NBs are enriched in genes that are targeted for somatic hypermutation (SHM by AID, and these genes form networks required for B cell development and proliferation. Finally, we observed significant conservation of AID-dependent epigenetic reprogramming between mouse and human B cells.

  9. Germinal center architecture disturbance during Plasmodium berghei ANKA infection in CBA mice

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    Pelajo-Machado Marcelo

    2007-05-01

    Full Text Available Abstract Background Immune responses to malaria blood stage infection are in general defective, with the need for long-term exposure to the parasite to achieve immunity, and with the development of immunopathology states such as cerebral malaria in many cases. One of the potential reasons for the difficulty in developing protective immunity is the poor development of memory responses. In this paper, the potential association of cellular reactivity in lymphoid organs (spleen, lymph nodes and Peyer's patches with immunity and pathology was evaluated during Plasmodium berghei ANKA infection in CBA mice. Methods CBA mice were infected with 1 × 106 P. berghei ANKA-parasitized erythrocytes and killed on days 3, 6–8 and 10 of infection. The spleen, lymph nodes and Peyer's patches were collected, fixed in Carson's formalin, cut in 5 μm sections, mounted in glass slides, stained with Lennert's Giemsa and haematoxylin-eosin and analysed with bright-field microscopy. Results Early (day 3 strong activation of T cells in secondary lymphoid organs was observed and, on days 6–8 of infection, there was overwhelming activation of B cells, with loss of conventional germinal center architecture, intense centroblast activation, proliferation and apoptosis but little differentiation to centrocytes. In the spleen, the marginal zone disappeared and the limits between the disorganized germinal center and the red pulp were blurred. Intense plasmacytogenesis was observed in the T cell zone. Conclusion The observed alterations, especially the germinal center architecture disturbance (GCAD with poor centrocyte differentiation, suggest that B cell responses during P. berghei ANKA infection in mice are defective, with potential impact on B cell memory responses.

  10. Nuclear Reaction Data Centers

    International Nuclear Information System (INIS)

    McLane, V.; Nordborg, C.; Lemmel, H.D.; Manokhin, V.N.

    1988-01-01

    The cooperating Nuclear Reaction Data Centers are involved in the compilation and exchange of nuclear reaction data for incident neutrons, charged particles and photons. Individual centers may also have services in other areas, e.g., evaluated data, nuclear structure and decay data, reactor physics, nuclear safety; some of this information may also be exchanged between interested centers. 20 refs., 1 tab

  11. Intravascular Large B cell Lymphoma in Taiwan: An Asian Variant of Non-germinal-center Origin

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    Min-Shu Hsieh

    2010-03-01

    Conclusion: Our cases of IVLBCL had a non-germinal center B origin and belonged to the Asian variant of this disease. The liver, spleen, and bone marrow, but rarely the skin or brain, were involved. Thrombocytopenia is a major risk factor for mortality in these cases.

  12. Metabolism and the triggering of germination of Bacillus megaterium

    International Nuclear Information System (INIS)

    Scott, I.R.; Ellar, D.J.

    1978-01-01

    L-[2,3- 3 H]Alanine was used to probe for metabolism of alanine during triggering of germination of spores of Bacillus megaterium KM. No detectable incorporation of label into any compound, including water, was found, indicating that any metabolism involving the alanine germinant must be at a very low rate and also that alanine racemase is absent from spores of this strain. Spores were germinated in 3 H 2 0 to find if any of the many metabolic reactions causing irreversible incorporation of 3 H into reaction products took place during triggering og germination. No incorporation was detected until 2-3 min after addition of germinants. It is therefore concluded that a wide variety of metabolic routes, including glycolysis, the tricarboxylic acid cycle, the pentose phosphate pathway and amino acid metabolism are either not involved in the reactions causing the triggering of germination or operate at an extremely low rate during this process. (author)

  13. Interaction between heavy metals and thiol-linked redox reactions in germination.

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    Smiri, M; Chaoui, A; Ferjani, E E

    2010-09-15

    Thioredoxin (TRX) proteins perform important biological functions in cells by changing the redox state of proteins via dithiol disulfide exchange. Several systems are able to control the activity, stability, and correct folding of enzymes through dithiol/disulfide isomerization reactions including the enzyme protein disulfide-isomerase, the glutathione-dependent glutaredoxin system, and the thioredoxin systems. Plants have devised sophisticated mechanisms to cope with biotic and abiotic stresses imposed by their environment. Among these mechanisms, those collectively referred to as redox reactions induced by endogenous systems. This is of agronomical importance since a better knowledge of the involved mechanisms can offer novel means for crop protection. In the plant life cycle, the seed and seedling stages are key developmental stages conditioning the final yield of crops. Both are very sensitive to heavy metal stress. Plant redox reactions are principally studied on adult plant organs and there is only very scarce informations about the onset of redox regulation at the level of seed germination. In the here presented study, we discussed the importance of redox proteins in plant cell metabolism and defence. Special focus is given to TRX, which are involved in detoxification of ROS and also to their targets.

  14. Synergistic Anti-Tumor Activity of EZH2 Inhibitors and Glucocorticoid Receptor Agonists in Models of Germinal Center Non-Hodgkin Lymphomas.

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    Knutson, Sarah K; Warholic, Natalie M; Johnston, L Danielle; Klaus, Christine R; Wigle, Tim J; Iwanowicz, Dorothy; Littlefield, Bruce A; Porter-Scott, Margaret; Smith, Jesse J; Moyer, Mikel P; Copeland, Robert A; Pollock, Roy M; Kuntz, Kevin W; Raimondi, Alejandra; Keilhack, Heike

    2014-01-01

    Patients with non-Hodgkin lymphoma (NHL) are treated today with a cocktail of drugs referred to as CHOP (Cyclophosphamide, Hydroxyldaunorubicin, Oncovin, and Prednisone). Subsets of patients with NHL of germinal center origin bear oncogenic mutations in the EZH2 histone methyltransferase. Clinical testing of the EZH2 inhibitor EPZ-6438 has recently begun in patients. We report here that combining EPZ-6438 with CHOP in preclinical cell culture and mouse models results in dramatic synergy for cell killing in EZH2 mutant germinal center NHL cells. Surprisingly, we observe that much of this synergy is due to Prednisolone - a glucocorticoid receptor agonist (GRag) component of CHOP. Dramatic synergy was observed when EPZ-6438 is combined with Prednisolone alone, and a similar effect was observed with Dexamethasone, another GRag. Remarkably, the anti-proliferative effect of the EPZ-6438+GRag combination extends beyond EZH2 mutant-bearing cells to more generally impact germinal center NHL. These preclinical data reveal an unanticipated biological intersection between GR-mediated gene regulation and EZH2-mediated chromatin remodeling. The data also suggest the possibility of a significant and practical benefit of combining EZH2 inhibitors and GRag that warrants further investigation in a clinical setting.

  15. Synergistic Anti-Tumor Activity of EZH2 Inhibitors and Glucocorticoid Receptor Agonists in Models of Germinal Center Non-Hodgkin Lymphomas.

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    Sarah K Knutson

    Full Text Available Patients with non-Hodgkin lymphoma (NHL are treated today with a cocktail of drugs referred to as CHOP (Cyclophosphamide, Hydroxyldaunorubicin, Oncovin, and Prednisone. Subsets of patients with NHL of germinal center origin bear oncogenic mutations in the EZH2 histone methyltransferase. Clinical testing of the EZH2 inhibitor EPZ-6438 has recently begun in patients. We report here that combining EPZ-6438 with CHOP in preclinical cell culture and mouse models results in dramatic synergy for cell killing in EZH2 mutant germinal center NHL cells. Surprisingly, we observe that much of this synergy is due to Prednisolone - a glucocorticoid receptor agonist (GRag component of CHOP. Dramatic synergy was observed when EPZ-6438 is combined with Prednisolone alone, and a similar effect was observed with Dexamethasone, another GRag. Remarkably, the anti-proliferative effect of the EPZ-6438+GRag combination extends beyond EZH2 mutant-bearing cells to more generally impact germinal center NHL. These preclinical data reveal an unanticipated biological intersection between GR-mediated gene regulation and EZH2-mediated chromatin remodeling. The data also suggest the possibility of a significant and practical benefit of combining EZH2 inhibitors and GRag that warrants further investigation in a clinical setting.

  16. Prognostic impact of germinal center-associated proteins and chromosomal breakpoints in poor-risk diffuse large B-cell lymphoma

    NARCIS (Netherlands)

    van Imhoff, Gustaaf W.; Boerma, Evert-Jan G.; van der Holt, Bronno; Schuuring, Ed; Verdonck, Leo F.; Kluin-Nelemans, Hanneke C.; Kluin, Philip M.

    2006-01-01

    Purpose Outcome of diffuse large B-cell lymphoma (DLBCL) with a germinal center B-cell (GCB) expression profile is superior to that of non-GCB DLBCL. This conclusion is mainly derived from patients with mixed international prognostic index (IPI) risk profiles treated with CHOP-like therapy

  17. Mathematical Model of Synthesis Catalyst with Local Reaction Centers

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    I. V. Derevich

    2017-01-01

    Full Text Available The article considers a catalyst granule with a porous ceramic passive substrate and point active centers on which an exothermic synthesis reaction occurs. A rate of the chemical reaction depends on the temperature according to the Arrhenius law. Heat is removed from the pellet surface in products of synthesis due to heat transfer. In our work we first proposed a model for calculating the steady-state temperature of a catalyst pellet with local reaction centers. Calculation of active centers temperature is based on the idea of self-consistent field (mean-field theory. At first, it is considered that powers of the reaction heat release at the centers are known. On the basis of the found analytical solution, which describes temperature distribution inside the granule, the average temperature of the reaction centers is calculated, which then is inserted in the formula for heat release. The resulting system of transcendental algebraic equations is transformed into a system of ordinary differential equations of relaxation type and solved numerically to achieve a steady-state value. As a practical application, the article considers a Fischer-Tropsch synthesis catalyst granule with active cobalt metallic micro-particles. Cobalt micro-particles are the centers of the exothermic reaction of hydrocarbons macromolecular synthesis. Synthesis occurs as a result of absorption of the components of the synthesis gas on metallic cobalt. The temperature distribution inside the granule for a single local center and reaction centers located on the same granule diameter is found. It was found that there is a critical temperature of reactor exceeding of which leads to significant local overheating of the centers - thermal explosion. The temperature distribution with the local reaction centers is qualitatively different from the granule temperature, calculated in the homogeneous approximation. It is shown that, in contrast to the homogeneous approximation, the

  18. The three-dimensional structures of bacterial reaction centers.

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    Olson, T L; Williams, J C; Allen, J P

    2014-05-01

    This review presents a broad overview of the research that enabled the structure determination of the bacterial reaction centers from Blastochloris viridis and Rhodobacter sphaeroides, with a focus on the contributions from Duysens, Clayton, and Feher. Early experiments performed in the laboratory of Duysens and others demonstrated the utility of spectroscopic techniques and the presence of photosynthetic complexes in both oxygenic and anoxygenic photosynthesis. The laboratories of Clayton and Feher led efforts to isolate and characterize the bacterial reaction centers. The availability of well-characterized preparations of pure and stable reaction centers allowed the crystallization and subsequent determination of the structures using X-ray diffraction. The three-dimensional structures of reaction centers revealed an overall arrangement of two symmetrical branches of cofactors surrounded by transmembrane helices from the L and M subunits, which also are related by the same twofold symmetry axis. The structure has served as a framework to address several issues concerning bacterial photosynthesis, including the directionality of electron transfer, the properties of the reaction center-cytochrome c 2 complex, and the coupling of proton and electron transfer. Together, these research efforts laid the foundation for ongoing efforts to address an outstanding question in oxygenic photosynthesis, namely the molecular mechanism of water oxidation.

  19. A novel monoclonal antibody, C41, reveals IL-13Ralpha1 expression by murine germinal center B cells and follicular dendritic cells.

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    Poudrier, J; Graber, P; Herren, S; Berney, C; Gretener, D; Kosco-Vilbois, M H; Gauchat, J F

    2000-11-01

    Responsiveness to IL-13 involves at least two chains, IL-4Ralpha and IL-13Ralpha1. Although mouse B cells express IL-4Ralpha, little is known about their expression of IL-13Ralpha chains. To investigate this topic further, we have generated a monoclonal antibody (C41) specific for murine IL-13Ralpha1. Using C41, IL-13Ralpha1 expression was detected on germinal center (GC) B cells by flow cytometry and immunohistochemistry. In addition, IL-13Ralpha1 was observed on follicular dendritic cells, but not interdigitating dendritic cells in the T cell areas. Furthermore, resting B cells also expressed IL-13Ralpha1, and in the presence of IL-13 produced increased amounts of IgM in response to in vitro CD40 stimulation. However, C41 was unable to neutralize this bioactivity. The distribution of IL-13Ralpha1 on murine B cells and during GC reactions suggests a role for IL-13 during B cell differentiation.

  20. Molecular analysis of immunoglobulin variable genes supports a germinal center experienced normal counterpart in primary cutaneous diffuse large B-cell lymphoma, leg-type.

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    Pham-Ledard, Anne; Prochazkova-Carlotti, Martina; Deveza, Mélanie; Laforet, Marie-Pierre; Beylot-Barry, Marie; Vergier, Béatrice; Parrens, Marie; Feuillard, Jean; Merlio, Jean-Philippe; Gachard, Nathalie

    2017-11-01

    Immunophenotype of primary cutaneous diffuse large B-cell lymphoma, leg-type (PCLBCL-LT) suggests a germinal center-experienced B lymphocyte (BCL2+ MUM1+ BCL6+/-). As maturation history of B-cell is "imprinted" during B-cell development on the immunoglobulin gene sequence, we studied the structure and sequence of the variable part of the genes (IGHV, IGLV, IGKV), immunoglobulin surface expression and features of class switching in order to determine the PCLBCL-LT cell of origin. Clonality analysis with BIOMED2 protocol and VH leader primers was done on DNA extracted from frozen skin biopsies on retrospective samples from 14 patients. The clonal DNA IGHV sequence of the tumor was aligned and compared with the closest germline sequence and homology percentage was calculated. Superantigen binding sites were studied. Features of selection pressure were evaluated with the multinomial Lossos model. A functional monoclonal sequence was observed in 14 cases as determined for IGHV (10), IGLV (2) or IGKV (3). IGV mutation rates were high (>5%) in all cases but one (median:15.5%), with superantigen binding sites conservation. Features of selection pressure were identified in 11/12 interpretable cases, more frequently negative (75%) than positive (25%). Intraclonal variation was detected in 3 of 8 tumor specimens with a low rate of mutations. Surface immunoglobulin was an IgM in 12/12 cases. FISH analysis of IGHM locus, deleted during class switching, showed heterozygous IGHM gene deletion in half of cases. The genomic PCR analysis confirmed the deletions within the switch μ region. IGV sequences were highly mutated but functional, with negative features of selection pressure suggesting one or more germinal center passage(s) with somatic hypermutation, but superantigen (SpA) binding sites conservation. Genetic features of class switch were observed, but on the non functional allele and co-existing with primary isotype IgM expression. These data suggest that cell-of origin is

  1. Enriched reaction center preparation from green photosynthetic bacteria. [Chlorobium limicola

    Energy Technology Data Exchange (ETDEWEB)

    Olson, J M; Giddings, Jr, T H; Shaw, E K

    1976-01-01

    Bacteriochlorophyll a reaction-center complex I from Chlorobium limicola f. thiosulfatophilum 6230 (Tassajara) was incubated in 2 M guanidine . HCl and then chromatographed on cross-linked dextran or agarose gel. Two principal components were separated: a larger component with photochemical activity (bacteriochlorophyll a reaction-center complex II) and a smaller component without activity (bacteriochlorophyll a protein). Complex II contains carotenoid, bacteriochlorophyll a, reaction center(s), and cytochromes b and c, but lacks the well characterized bacteriochlorophyll a protein contained in Complex I. Complex II carries out a light-induced reduction of cytochrome b along with an oxidation of cytochrome c.

  2. Barley germination

    DEFF Research Database (Denmark)

    Daneri-Castro, Sergio N.; Svensson, Birte; Roberts, Thomas H.

    2016-01-01

    germination. Lastly, the application of metabolomics to barley grain germination provides essential data on biochemical processes, including insights into the formation of compounds that contribute to malt quality. To maximize the benefits of the 'omics' revolution to the malting industry, there is a need......Germination of barley grain is central to the malting industry and is a valuable model for cereal grain germination. Our current understanding of the complexity of germination at the molecular level is facilitated by access to genomic, transcriptomic, proteomic and metabolomic data. Here we review...... of germination in the context of industrial malting. For transcriptomics, recent advances in sequencing the barley genome allow next-generation sequencing approaches to reveal novel effects of variety and environment on germination. For proteomics, selection of the source tissue(s) and the protein extraction...

  3. RNA-binding protein VICKZ is expressed in a germinal center associated pattern among lymphoma subtypes

    DEFF Research Database (Denmark)

    Natkunam, Y.; Vainer, G.; Zhao, S.C.

    2005-01-01

    and tumorigenesis/metastasis. We generated an antibody that recognizes all three isoforms of VICKZ protein and characterized its expression in normal lymphoid tissue and in lymphoma subtypes. In normal tonsils, VICKZ protein showed a germinal center-specific pattern of expression with staining localized...... to the cytoplasm. Among 868 non-Hodgkin and Hodgkin lymphomas tested by immunohistochemistry on tissue microarrays, staining for VICKZ protein was present in 76% (126/165) of follicular lymphoma, 78% (155/200) of DLBCL, 90% (9/10) of mediastinal large B-cell lymphoma, and 100% (2/2) of Burkitt lymphoma. A subset...... protein in lymphoma subtypes suggests a potential utility for VICKZ in the identification of subgroups of DLBCL associated with different prognoses....

  4. Resident Reactions to Person-Centered Communication by Long-Term Care Staff.

    Science.gov (United States)

    Savundranayagam, Marie Y; Sibalija, Jovana; Scotchmer, Emma

    2016-09-01

    Long-term care staff caregivers who are person centered incorporate the life history, preferences, and feelings of residents with dementia during care interactions. Communication is essential for person-centered care. However, little is known about residents' verbal reactions when staff use person-centered communication. Accordingly, this study investigated the impact of person-centered communication and missed opportunities for such communication by staff on resident reactions. Conversations (N = 46) between staff-resident dyads were audio-recorded during routine care tasks over 12 weeks. Staff utterances were coded for person-centered communication and missed opportunities. Resident utterances were coded for positive reactions, such as cooperation, and negative reactions, such as distress. Linear regression analyses revealed that the more staff used person-centered communication, the more likely that residents reacted positively. Additionally, the more missed opportunities in a conversation, the more likely that the residents reacted negatively. Conversation illustrations elaborate on the quantitative findings and implications for staff training are discussed. © The Author(s) 2016.

  5. Biochemical Changes Associated with Germinating Rice Grains and Germination Improvement

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    Subajiny VELUPPILLAI

    2009-09-01

    Full Text Available To determine biochemical changes during the germination of rice grains (Oryza sativa L. subsp. indica var. Mottaikaruppan and to improve germination rate using gibberellic acid and surfactants [sodium dodecyl sulfate (SDS (1.0 g/L and Triton-X−100 (1.0 mL/L], whole rice grains soaked in distilled water for 12 h at 30°C were germinated in the dark at 30°C for five days. The highest germination rate (77.1% was obtained on the 5th day. An increase in the content of reducing sugars from 7.3 to 58.1 mg/g DM (dry matter was observed from the 1st day of germination. Free amino acids and soluble protein contents increased to 3.69 and 5.29 mg/g DM, respectively on the 5th day of germination. Total protein content decreased from 100.5 to 91.0 g/kg DM during germination. Increases in amylolytic (1.1 to 190.0 U/g DM and proteolytic (0 to 0.12 U/g DM activities were observed during germination. Effects of different concentrations of gibberellic acid on the germination of rice grains were evaluated and 0.1 g/L was found to promote germination. When effects of gibberellic acid (0.1 g/L and surfactants were evaluated individually and together, higher germination rate was observed in the control experiment (grains germinated in distilled water, whereas giberellic acid and surfactants decreased the germination rate. Therefore, the flour obtained from the grains germinated for four days using distilled water to obtain high content of soluble materials and enzyme activities can be used in preparation of bakery items.

  6. Conformational regulation of charge recombination reactions in a photosynthetic bacterial reaction center

    DEFF Research Database (Denmark)

    Katona, Gergely; Snijder, Arjan; Gourdon, Pontus Emanuel

    2005-01-01

    In bright light the photosynthetic reaction center (RC) of Rhodobacter sphaeroides stabilizes the P(+)(870).Q(-)(A) charge-separated state and thereby minimizes the potentially harmful effects of light saturation. Using X-ray diffraction we report a conformational change that occurs within the cy...... the cytoplasmic domain of this RC in response to prolonged illumination with bright light. Our observations suggest a novel structural mechanism for the regulation of electron transfer reactions in photosynthesis....

  7. Photosynthetic antennas and reaction centers: Current understanding and prospects for improvement

    Energy Technology Data Exchange (ETDEWEB)

    Blankenship, R.E. [Arizona State Univ., Tempe, AZ (United States)

    1996-09-01

    A brief introduction to the principles, structures and kinetic processes that take place in natural photosynthetic reaction center complexes is presented. Energy is first collected by an antenna system, and is transferred to a reaction center complex where primary electron transfer takes place. Secondary reactions lead to oxidation of water and reduction of CO{sub 2} in some classes of organisms. Antenna systems are highly regulated to maximize energy collection efficiency while avoiding photodamage. Some areas that are presently not well understood are listed.

  8. Severe Malaria Infections Impair Germinal Center Responses by Inhibiting T Follicular Helper Cell Differentiation

    Directory of Open Access Journals (Sweden)

    Victoria Ryg-Cornejo

    2016-01-01

    Full Text Available Naturally acquired immunity to malaria develops only after years of repeated exposure to Plasmodium parasites. Despite the key role antibodies play in protection, the cellular processes underlying the slow acquisition of immunity remain unknown. Using mouse models, we show that severe malaria infection inhibits the establishment of germinal centers (GCs in the spleen. We demonstrate that infection induces high frequencies of T follicular helper (Tfh cell precursors but results in impaired Tfh cell differentiation. Despite high expression of Bcl-6 and IL-21, precursor Tfh cells induced during infection displayed low levels of PD-1 and CXCR5 and co-expressed Th1-associated molecules such as T-bet and CXCR3. Blockade of the inflammatory cytokines TNF and IFN-γ or T-bet deletion restored Tfh cell differentiation and GC responses to infection. Thus, this study demonstrates that the same pro-inflammatory mediators that drive severe malaria pathology have detrimental effects on the induction of protective B cell responses.

  9. Dynamic changes in Id3 and E-protein activity orchestrate germinal center and plasma cell development

    Science.gov (United States)

    Gloury, Renee; Zotos, Dimitra; Zuidscherwoude, Malou; Masson, Frederick; Liao, Yang; Hasbold, Jhaguaral; Corcoran, Lynn M.; Hodgkin, Phil D.; Belz, Gabrielle T.; Shi, Wei; Nutt, Stephen L.; Tarlinton, David M.

    2016-01-01

    The generation of high-affinity antibodies requires germinal center (GC) development and differentiation of long-lived plasma cells in a multilayered process that is tightly controlled by the activity of multiple transcription factors. Here, we reveal a new layer of complexity by demonstrating that dynamic changes in Id3 and E-protein activity govern both GC and plasma cell differentiation. We show that down-regulation of Id3 in B cells is essential for releasing E2A and E2-2, which in a redundant manner are required for antigen-induced B cell differentiation. We demonstrate that this pathway controls the expression of multiple key factors, including Blimp1, Xbp1, and CXCR4, and is therefore critical for establishing the transcriptional network that controls GC B cell and plasma cell differentiation. PMID:27217539

  10. Quantum measurement corrections to CIDNP in photosynthetic reaction centers

    International Nuclear Information System (INIS)

    Kominis, Iannis K

    2013-01-01

    Chemically induced dynamic nuclear polarization is a signature of spin order appearing in many photosynthetic reaction centers. Such polarization, significantly enhanced above thermal equilibrium, is known to result from the nuclear spin sorting inherent in the radical pair mechanism underlying long-lived charge-separated states in photosynthetic reaction centers. We will show here that the recently understood fundamental quantum dynamics of radical-ion-pair reactions open up a new and completely unexpected pathway toward obtaining chemically induced dynamic nuclear polarization signals. The fundamental decoherence mechanism inherent in the recombination process of radical pairs is shown to produce nuclear spin polarizations of the order of 10 4 times (or more) higher than the thermal equilibrium value at the Earth's magnetic field relevant to natural photosynthesis. This opens up the possibility of a fundamentally new exploration of the biological significance of high nuclear polarizations in photosynthesis. (paper)

  11. Reactions of carbon radicals generated by 1,5-transposition of reactive centers

    Directory of Open Access Journals (Sweden)

    ZIVORAD CEKOVIC

    2005-03-01

    Full Text Available Radical intermediates can undergo specific reactions, such as intramolecular rearrangements, i.e., the transpositions of radical centers, which are not known in classical ionic organic reactions. 1,5-Transposition of a radical center to a non-activated carbon atom are of great synthetic importance. It can be successfully applied for the introduction of different functional groups (oxygen, nitrogen, sulfur, halogens onto a carbon atom remote from the present functional group. In addition to functionalization of a remote non-activated carbon atom, the formation of new C-C bonds on the d-carbon atom have also been achieved. 1,5-Transposition of the radical centers takes place from alkoxyl, aminyl and carbon radicals to a remote carbon atom. Relocation of the radical centers preferentially involves 1,5-transfer of a hydrogen atom, although migrations of some other groups are known. The reactions of the carbon radical generated by 1,5-relocation of the radical center are presented and their synthetic applications are reviewed.

  12. Responses of single germinal-center B cells in T-cell-dependent microculture.

    Science.gov (United States)

    George, A; Cebra, J J

    1991-01-01

    B cells purified from the germinal centers (GCs) of murine Peyer's patches can be stimulated in a clonal microculture containing helper T cells and dendritic cells to divide and secrete immunoglobulin. Intraclonal isotype switching occurs, and a variety of immunoglobulin isotypes, including IgA, is secreted. Memory cells, which generate clones secreting IgA exclusively, are only rarely identified in the GC B-cell subset. Such memory cells can, however, be readily identified among unfractionated Peyer's patch B cells, and in non-GC subsets of B cells. The results suggest that the GC does not contain IgA memory cells that can be restimulated in vitro to secrete only IgA. When division of GC B cells is prevented by irradiation or aphidicholin treatment, a large subset that secretes IgA as the sole immunoglobulin isotype is seen, and the output of presumably single B cells is large enough to be scored by RIA. Both helper T cells and dendritic cells are required for the phenomenon. The data indicate that commitment to IgA secretion occurs in Peyer's patch GCs and suggest that the prolific cell division known to be supported in GCs may forestall terminal differentiation of preplasmablasts to immunoglobulin secretion.

  13. Cell signaling mechanisms and metabolic regulation of germination and dormancy in barley seeds

    Directory of Open Access Journals (Sweden)

    Zhenguo Ma

    2017-12-01

    Full Text Available During germination of barley (Hordeum vulgare L. seeds, important morphological and physiological changes take place, including development of organs and tissues and activation of metabolic pathways. Germination and dormancy of seeds are regulated by abscisic acid, gibberellins, reactive oxygen species (ROS, reactive nitrogen species (RNS and several other factors. Activities of ascorbate–glutathione cycle enzymes, responsible for scavenging ROS, strongly increase. Catalase and superoxide dismutase activities, also scavenging ROS, decrease at the onset of seed germination and then increase. With the increase in aerobic metabolism after radicle protrusion, the activities of the fermentation enzymes lactate and alcohol dehydrogenase decline rapidly. The RNS-scavenging activity of S-nitrosoglutathione reductase decreases in the course of seed germination, in concert with elevation of nitric oxide production and protein nitrosylation. This activity supports the role of RNS in regulating seed germination. Transcription of various genes at different phases of seed germination exhibits phase-specific changes. During imbibition, genes involved in cell wall metabolism are highly expressed; in the middle phase of seed germination before radicle protrusion, genes involved in amino acid synthesis, protein synthesis, and transport and nucleic acid synthesis are upregulated significantly, and after radicle protrusion, genes involved in photosynthetic metabolism are induced. In summary, signal transduction and metabolic regulation of seed germination involve diverse reactions and complex regulation at different levels of metabolic organization. Keywords: Seed germination, Reactive oxygen species, Reactive nitrogen species, Signal transduction, Gene expression

  14. The Effect of Fungicides for Seed Treatment on Germination of Barley

    Directory of Open Access Journals (Sweden)

    Vesna Stevanović

    2009-01-01

    Full Text Available The application of chemicals, such as fungicides for seed treatment, is one of the most reliable and perhaps most efficient measures for integrated preservation of crops, and its practicing has become a legal obligation for all seed producers. This investigation was carried out in the laboratory for seed quality and phytopathology of the Small Grains Research Center in Kragujevac. The objective was to establish the effect of fungicides on germination energy and seed germinability (determined after treatments. Two varieties were tested due to a possibility of specific sensitivities of some varieties, so that the results acquired on one variety would not necessarily be valid for another one. Fungicides based on active ingredients from the triasol chemical group had different effects on the energy of germination of barley seeds. Applying Raxil S040-FS, the average germination of barley seeds was 79.3% for the variety Record, and 91.3% for the Grand variety. The variety Record achieved a lower value than the minimum for barley seed germination (88% stipulated by the Rules on Seed Quality of Agricultural Crops.Regardless of barley type, the product Raxil S040-FS showed a statistically significant effect on the number of atypical seedlings and increase in the number of non-germinated seeds, compared to the control.

  15. The Type 1 Homodimeric Reaction Center in Heliobacterium modesticaldum

    Energy Technology Data Exchange (ETDEWEB)

    Golbeck, John [Pennsylvania State Univ., University Park, PA (United States)

    2018-01-15

    In this funding period, we (i) found that strong illumination of Heliobacterium modesticaldum cells results in saturation of the electron acceptor pool, leading to reduction of the acceptor side and the creation of a back-reacting state that gives rise to delayed fluorescence; (ii) noted that when the FX cluster is reduced in purified reaction centers, no electron transfer occurs beyond A0, even though a quinone is present; (iii) observed by photochemically induced dynamic nuclear polarization (photo-CIDNP) studies of whole cells of Heliobacterium mobilis that primary charge separation is retained even after conversion of the majority of BChl g to Chl aF. ; and (iv) purified a homogeneous preparation of reaction center cores, which led to promising crystallization trials to obtain a three-dimensional structure.

  16. Polyclonal B cell differentiation and loss of gastrointestinal tract germinal centers in the earliest stages of HIV-1 infection.

    Directory of Open Access Journals (Sweden)

    Marc C Levesque

    2009-07-01

    Full Text Available The antibody response to HIV-1 does not appear in the plasma until approximately 2-5 weeks after transmission, and neutralizing antibodies to autologous HIV-1 generally do not become detectable until 12 weeks or more after transmission. Moreover, levels of HIV-1-specific antibodies decline on antiretroviral treatment. The mechanisms of this delay in the appearance of anti-HIV-1 antibodies and of their subsequent rapid decline are not known. While the effect of HIV-1 on depletion of gut CD4(+ T cells in acute HIV-1 infection is well described, we studied blood and tissue B cells soon after infection to determine the effect of early HIV-1 on these cells.In human participants, we analyzed B cells in blood as early as 17 days after HIV-1 infection, and in terminal ileum inductive and effector microenvironments beginning at 47 days after infection. We found that HIV-1 infection rapidly induced polyclonal activation and terminal differentiation of B cells in blood and in gut-associated lymphoid tissue (GALT B cells. The specificities of antibodies produced by GALT memory B cells in acute HIV-1 infection (AHI included not only HIV-1-specific antibodies, but also influenza-specific and autoreactive antibodies, indicating very early onset of HIV-1-induced polyclonal B cell activation. Follicular damage or germinal center loss in terminal ileum Peyer's patches was seen with 88% of follicles exhibiting B or T cell apoptosis and follicular lysis.Early induction of polyclonal B cell differentiation, coupled with follicular damage and germinal center loss soon after HIV-1 infection, may explain both the high rate of decline in HIV-1-induced antibody responses and the delay in plasma antibody responses to HIV-1. Please see later in the article for Editors' Summary.

  17. Mean germination time and germination rate of oat seeds subjected to stationary magnetic field

    International Nuclear Information System (INIS)

    Martinez Ramirez, Elvira; Florez Garcia, Mercedes; Carbonell, Maria Victoria; Amaya Garcia de la Escosura, Jose Manuel

    2007-01-01

    The objective of the present study is to determine and quantify the effect produced by stationary magnetic fields on oat seed germination (Avena sativa, L. var. c obena ) . For this purpose, seeds were exposed to a magnetic field 125 mT of 250 mT during different periods of time: 20 minutes (E1, E5), 1 hour (E2, E6), 24 hours (E3, E7), or in a conic form (E4, E8) during the whole germination process. Germination tests were carried out under laboratory conditions with cylindrical magnets to obtain the magnetic field. For magnetic treatment seed on Petri dishes were placed on magnets during time necessary for each treatment. Seeds without exposition to the magnetic field were used as control group. Parameters used for germination speed analysis were: number of germinated seeds (G), mean germination time (MGT) and necessary time for germination of 1, 10, 25, 50 and 75% of N number of speeds used for each treatment (T1, T10, T25, T50, and T75). These parameters were supplied through the software Seed calculator, as well as the corresponding germination curves. In general, from the results obtained it can be said that the time required to obtain different germination percentages was lower for seeds exposed to the magnetic field (treatments E1 and E8). Reduction in time for E1 treatment stands up with 20 a minutes-exposition-time to 125 mT. MGT obtained for seeds with magnetic treatment E1 was significantly lower (11.48%) than the control group. Parameters T1, T10, T25 were also lower for seeds submitted to treatment, obtaining reductions of 46.62 %, 24.02 % and 13.46 % respectively. Reduction in germination parameters indicates that germination speed is higher. Because parameters T1 and T10 are related to the beginning of germination, this study represents a progress in germination and a reduction in the induction phase in most of the magnetic treatments applied. Previous studies done by authors about the influence of stationary magnetic fields have shown increases in

  18. A Germination Simulation.

    Science.gov (United States)

    Hershey, David R.

    1995-01-01

    Presents an activity that involves using sponge seedlings to demonstrate the germination process without the usual waiting period. Discusses epigeous versus hypogeous germination, and cotyledon number and biodiversity. (JRH)

  19. High-Throughput Scoring of Seed Germination.

    Science.gov (United States)

    Ligterink, Wilco; Hilhorst, Henk W M

    2017-01-01

    High-throughput analysis of seed germination for phenotyping large genetic populations or mutant collections is very labor intensive and would highly benefit from an automated setup. Although very often used, the total germination percentage after a nominated period of time is not very informative as it lacks information about start, rate, and uniformity of germination, which are highly indicative of such traits as dormancy, stress tolerance, and seed longevity. The calculation of cumulative germination curves requires information about germination percentage at various time points. We developed the GERMINATOR package: a simple, highly cost-efficient, and flexible procedure for high-throughput automatic scoring and evaluation of germination that can be implemented without the use of complex robotics. The GERMINATOR package contains three modules: (I) design of experimental setup with various options to replicate and randomize samples; (II) automatic scoring of germination based on the color contrast between the protruding radicle and seed coat on a single image; and (III) curve fitting of cumulative germination data and the extraction, recap, and visualization of the various germination parameters. GERMINATOR is a freely available package that allows the monitoring and analysis of several thousands of germination tests, several times a day by a single person.

  20. 7 CFR 201.63 - Germination.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination. 201.63 Section 201.63 Agriculture... REGULATIONS Tolerances § 201.63 Germination. The following tolerances are applicable to the percentage of germination and also to the sum of the germination plus the hard seed when 400 or more seeds are tested. Mean...

  1. GERMINATOR: a software package for high-throughput scoring and curve fitting of Arabidopsis seed germination.

    Science.gov (United States)

    Joosen, Ronny V L; Kodde, Jan; Willems, Leo A J; Ligterink, Wilco; van der Plas, Linus H W; Hilhorst, Henk W M

    2010-04-01

    Over the past few decades seed physiology research has contributed to many important scientific discoveries and has provided valuable tools for the production of high quality seeds. An important instrument for this type of research is the accurate quantification of germination; however gathering cumulative germination data is a very laborious task that is often prohibitive to the execution of large experiments. In this paper we present the germinator package: a simple, highly cost-efficient and flexible procedure for high-throughput automatic scoring and evaluation of germination that can be implemented without the use of complex robotics. The germinator package contains three modules: (i) design of experimental setup with various options to replicate and randomize samples; (ii) automatic scoring of germination based on the color contrast between the protruding radicle and seed coat on a single image; and (iii) curve fitting of cumulative germination data and the extraction, recap and visualization of the various germination parameters. The curve-fitting module enables analysis of general cumulative germination data and can be used for all plant species. We show that the automatic scoring system works for Arabidopsis thaliana and Brassica spp. seeds, but is likely to be applicable to other species, as well. In this paper we show the accuracy, reproducibility and flexibility of the germinator package. We have successfully applied it to evaluate natural variation for salt tolerance in a large population of recombinant inbred lines and were able to identify several quantitative trait loci for salt tolerance. Germinator is a low-cost package that allows the monitoring of several thousands of germination tests, several times a day by a single person.

  2. Increased expression of TACI on NOD B cells results in germinal centre reaction anomalies, enhanced plasma cell differentiation and immunoglobulin production.

    Science.gov (United States)

    Banday, Viqar S; Thyagarajan, Radha; Sundström, Mia; Lejon, Kristina

    2016-11-01

    B cells have an important pathogenic role in the development of type 1 diabetes in the non-obese diabetic (NOD) mouse. We have previously reported that NOD mice display an increased percentage of TACI high -expressing B cells compared with C57BL/6 mice and this trait is linked to chromosomes 1 and 8. In this paper the genetic association of the transmembrane activator, calcium modulator and cyclophilin ligand interactor (TACI) trait was confirmed using double congenic NOD.B6C1/Idd22 mice. TACI ligation by a proliferation-inducing ligand (APRIL) has been shown to influence plasma cell differentiation, immunoglobulin production and isotype switch. Hence, the functional consequence of the up-regulation of TACI on NOD B cells was analysed both in vitro and in vivo. NOD B cells stimulated with APRIL showed an enhanced plasma cell differentiation and class switch to IgG and IgA compared with B cells from C57BL/6 mice. Moreover, flow cytometry analyses revealed that germinal centre B cells in NOD failed to down-regulate TACI. Availability of the TACI ligand B-cell activating factor (BAFF) has been shown to be a limiting factor in the germinal centre reaction. In line with this, upon immunization with 4-hydroxy-3-nitrophenylacetyl hapten-conjugated hen egg lysozyme, NOD mice produced higher titres of low-affinity antibodies compared with C57BL/6 mice. This observation was supported by the detection of increased levels of BAFF in NOD germinal centres after immunization compared with C57BL/6 by immunofluorescence. Our results support the hypothesis that increased TACI expression on NOD B cells contributes to the pathogenesis of type 1 diabetes in the NOD mouse. © 2016 John Wiley & Sons Ltd.

  3. Seed dormancy and germination.

    Science.gov (United States)

    Penfield, Steven

    2017-09-11

    Reproduction is a critical time in plant life history. Therefore, genes affecting seed dormancy and germination are among those under strongest selection in natural plant populations. Germination terminates seed dispersal and thus influences the location and timing of plant growth. After seed shedding, germination can be prevented by a property known as seed dormancy. In practise, seeds are rarely either dormant or non-dormant, but seeds whose dormancy-inducing pathways are activated to higher levels will germinate in an ever-narrower range of environments. Thus, measurements of dormancy must always be accompanied by analysis of environmental contexts in which phenotypes or behaviours are described. At its simplest, dormancy can be imposed by the formation of a simple physical barrier around the seed through which gas exchange and the passage of water are prevented. Seeds featuring this so-called 'physical dormancy' often require either scarification or passage through an animal gut (replete with its associated digestive enzymes) to disrupt the barrier and permit germination. In other types of seeds with 'morphological dormancy' the embryo remains under-developed at maturity and a dormant phase exists as the embryo continues its growth post-shedding, eventually breaking through the surrounding tissues. By far, the majority of seeds exhibit 'physiological dormancy' - a quiescence program initiated by either the embryo or the surrounding endosperm tissues. Physiological dormancy uses germination-inhibiting hormones to prevent germination in the absence of the specific environmental triggers that promote germination. During and after germination, early seedling growth is supported by catabolism of stored reserves of protein, oil or starch accumulated during seed maturation. These reserves support cell expansion, chloroplast development and root growth until photoauxotrophic growth can be resumed. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

  4. Role of gibberellins and cytokinins in regulation of germination during development and ripening of Triticale caryopses

    Directory of Open Access Journals (Sweden)

    Stanisław Weidner

    2014-01-01

    Full Text Available The germination of caryopses of M-T3 Triticale generation, which were freshly harvested in different growth and developmental phases has been studied. A significant influence of the abscisic acid (ABA accumulation on the increment of number of germinating caryopses has been found. Already in the first phase af the embryogenesis considerable stimulating effects of kinetin and gibberellin-A3 (GA3 on the germination of embryos which were isolated from freshly collected grains have been shown. When both stimulators were used together marked synergetic reaction occurred. It has been also determined that in the initial period of embryogensis premature germination occurs, to a higher extent, under the action of cytokinins than! Whether in the further phases of the caryopse development, when embryo develop mainly through the cell elongation, mostly gibberellins seem to be responsible for the activation of germination processes. The more mature were seeds the quicker germinated whole caryopses and embryos isolated from them at different ripeness, after 3-month storage. The highest stimulation of germination by phytohormones has been found for the most mature caryopses. The action of gibberellic acid has been particulary strong.

  5. cGAS-mediated control of blood-stage malaria promotes Plasmodium-specific germinal center responses.

    Science.gov (United States)

    Hahn, William O; Butler, Noah S; Lindner, Scott E; Akilesh, Holly M; Sather, D Noah; Kappe, Stefan Hi; Hamerman, Jessica A; Gale, Michael; Liles, W Conrad; Pepper, Marion

    2018-01-25

    Sensing of pathogens by host pattern recognition receptors is essential for activating the immune response during infection. We used a nonlethal murine model of malaria (Plasmodium yoelii 17XNL) to assess the contribution of the pattern recognition receptor cyclic GMP-AMP synthase (cGAS) to the development of humoral immunity. Despite previous reports suggesting a critical, intrinsic role for cGAS in early B cell responses, cGAS-deficient (cGAS-/-) mice had no defect in the early expansion or differentiation of Plasmodium-specific B cells. As the infection proceeded, however, cGAS-/- mice exhibited higher parasite burdens and aberrant germinal center and memory B cell formation when compared with littermate controls. Antimalarial drugs were used to further demonstrate that the disrupted humoral response was not B cell intrinsic but instead was a secondary effect of a loss of parasite control. These findings therefore demonstrate that cGAS-mediated innate-sensing contributes to parasite control but is not intrinsically required for the development of humoral immunity. Our findings highlight the need to consider the indirect effects of pathogen burden in investigations examining how the innate immune system affects the adaptive immune response.

  6. Model photo reaction centers via genetic engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zhiyu Wang; DiMagno, T.J.; Popov, M.; Norris, J.R. [Argonne National Lab., IL (United States)]|[Chicago Univ., IL (United States). Dept. of Chemistry; Chikin Chan; Fleming, G. [Chicago Univ., IL (United States). Dept. of Chemistry; Jau Tang; Hanson, D.; Schiffer, M. [Argonne National Lab., IL (United States)

    1992-12-31

    A series of reaction centers of Rhodococcus capsulatus isolated from a set of mutated organisms modified by site-directed mutagenesis at residues M208 and L181 are described. Changes in the amino acid at these sites affect both the energetics of the systems as well as the chemical kinetics for the initial ET event. Two empirical relations among the different mutants for the reduction potential and the ET rate are presented.

  7. Model photo reaction centers via genetic engineering

    Energy Technology Data Exchange (ETDEWEB)

    Zhiyu Wang; DiMagno, T.J.; Popov, M.; Norris, J.R. (Argonne National Lab., IL (United States) Chicago Univ., IL (United States). Dept. of Chemistry); Chikin Chan; Fleming, G. (Chicago Univ., IL (United States). Dept. of Chemistry); Jau Tang; Hanson, D.; Schiffer, M. (Argonne National Lab., IL (United States))

    1992-01-01

    A series of reaction centers of Rhodococcus capsulatus isolated from a set of mutated organisms modified by site-directed mutagenesis at residues M208 and L181 are described. Changes in the amino acid at these sites affect both the energetics of the systems as well as the chemical kinetics for the initial ET event. Two empirical relations among the different mutants for the reduction potential and the ET rate are presented.

  8. Somatic mutation of EZH2 (Y641) in follicular and diffuse large B-cell lymphomas of germinal center origin | Office of Cancer Genomics

    Science.gov (United States)

    Morin et al. describe recurrent somatic mutations in EZH2, a polycomb group oncogene. The mutation, found in the SET domain of this gene encoding a histone methyltransferase, is found only in a subset of lymphoma samples. Specifically, EZH2 mutations are found in about 12% of follicular lymphomas (FL) and almost 23% of diffuse large B-cell lymphomas (DLBCL) of germinal center origin. This paper goes on to demonstrate that altered EZH2 proteins, corresponding to the most frequent mutations found in human lymphomas, have reduced activity using in vitro histone methylation assays.

  9. High Pressure Germination of Bacillus subtilis Spores with Alterations in Levels and Types of Germination Proteins

    Science.gov (United States)

    2014-01-01

    1ITLE AND SUBTITLE 5a CONTRACTNUMBER High pressure germination of Bacillus subtilis spores with W911NF-09-l-0286 alterations in levels and types of...A moderate high pressure (mHP) of 150 megaPascals (MPa) triggers germination of Bacillus subtilis spores via germinant receptors (GRs), while...germination by a very high pressure (vHP) of550 MPa is GR-independent. The mHP and vHP germination of Bacillus subtilis spores with different levels ofGRs

  10. Patients with diffuse large B-cell lymphoma of germinal center origin with BCL2 translocations have poor outcome, irrespective of MYC status: a report from an International DLBCL rituximab-CHOP Consortium Program Study.

    NARCIS (Netherlands)

    Visco, C.; Tzankov, A.; Xu-Monette, Z.Y.; Miranda, R.N.; Tai, Y.C.; Li, Y.; Liu, W.M.; d'Amore, E.S.; Li, Y.O.; Montes-Moreno, S.; Dybkaer, K.; Chiu, A.; Orazi, A.; Zu, Y.; Bhagat, G.; Wang, H.Y.; Dunphy, C.H.; His, E.D.; Zhao, X.F.; Choi, W.W.; Krieken, J.H.J.M. van; Huang, Q.; Ai, W.; O'Neill, S.; Ponzoni, M.; Ferreri, A.J.; Kahl, B.S.; Winter, J.N.; Go, R.S.; Dirnhofer, S.; Piris, M.A.; Moller, M.B.; Wu, L.; Medeiros, L.J.; Young, K.H.

    2013-01-01

    Diffuse large B-cell lymphoma can be classified by gene expression profiling into germinal center and activated B-cell subtypes with different prognoses after rituximab-CHOP. The importance of previously recognized prognostic markers, such as Bcl-2 protein expression and BCL2 gene abnormalities, has

  11. A multi-pathway model for photosynthetic reaction center

    International Nuclear Information System (INIS)

    Qin, M.; Shen, H. Z.; Yi, X. X.

    2016-01-01

    Charge separation occurs in a pair of tightly coupled chlorophylls at the heart of photosynthetic reaction centers of both plants and bacteria. Recently it has been shown that quantum coherence can, in principle, enhance the efficiency of a solar cell, working like a quantum heat engine. Here, we propose a biological quantum heat engine (BQHE) motivated by Photosystem II reaction center (PSII RC) to describe the charge separation. Our model mainly considers two charge-separation pathways which is more than that typically considered in the published literature. We explore how these cross-couplings increase the current and power of the charge separation and discuss the effects of multiple pathways in terms of current and power. The robustness of the BQHE against the charge recombination in natural PSII RC and dephasing induced by environments is also explored, and extension from two pathways to multiple pathways is made. These results suggest that noise-induced quantum coherence helps to suppress the influence of acceptor-to-donor charge recombination, and besides, nature-mimicking architectures with engineered multiple pathways for charge separations might be better for artificial solar energy devices considering the influence of environments.

  12. An influence of abiotic factors on the germinability of Agrostis species and Poa species

    Directory of Open Access Journals (Sweden)

    Pavel Knot

    2006-01-01

    Full Text Available The objective of this contribution is to interpret the impact of some abiotic factors on the germinability. Primarily was observed the stress that they cause on germinability and also on the energy of other perennial grass caryopsis' germinability. Withal there were considered differences in germinability of some perennial grass species, variances of strains and the influence of today`s seeds dressing technologies, which are used to improve the germination. The light factor has the biggest influence of all factors on germination of Agrostis stolonifera (Penn G-2, Providence, Poa supina (Supranova and Poa pratensis (Julius, Julius PreGerm. All these species had germination evidential higher in the light, than in the dark. With species Poa pratensis (Coctail, Coctail Headstart and Poa annua were not observed any essential variations between the dark and the light variants. Only with Poa annua there were reached noticeably lower values with variant in the light, where was used polyethyleneglycol, than in the dark. The analysis of variance demonstrated, that the biggest influence had the factor of stratification together with the light factor with Agrostis capilaris (Bardot and Agrostis stolonifera Providence. With Poa annua there was established the biggest influence of the light factor together with the factor of the used medium. The factor of stratification noticeably affected only the germination of Agrostis capillaris Bardot. The germination of Agrostis stolonifera Providence, Poa pratensis Cocktail, Cocktail Headstart, Julius and Poa annua was not noticeably affected by stratification. The reaction on the factor of stratification was with Agrostis capillaris Bardot in the dark adverse and in the light minimal. Poa pratensis Julius PreGerm germination was negative in the dark as well as in the light. With Poa supina Supranova it was not the most important factor, but still affected the germination significiantly. The nitrogen nutrition, as the

  13. Revealing proteins associated with symbiotic germination of Gastrodia elata by proteomic analysis.

    Science.gov (United States)

    Zeng, Xu; Li, Yuanyuan; Ling, Hong; Chen, Juan; Guo, Shunxing

    2018-03-06

    Gastrodia elata, a mycoheterotrophic orchid, is a well-known medicinal herb. In nature, the seed germination of G. elata requires proper fungal association, because of the absence of endosperm. To germinate successfully, G. elata obtains nutrition from mycorrhizal fungi such as Mycena. However, Mycena is not able to supply nutrition for the further development and enlargement of protocorms into tubers, flowering and fruit setting of G. elata. To date, current genomic studies on this topic are limited. Here we used the proteomic approach to explore changes in G. elata at different stages of symbiotic germination. Using mass spectrometry, 3787 unique proteins were identified, of which 599 were classified as differentially accumulated proteins. Most of these differentially accumulated proteins were putatively involved in energy metabolism, plant defense, molecular signaling, and secondary metabolism. Among them, the defense genes (e.g., pathogenesis-/wound-related proteins, peroxidases, and serine/threonine-protein kinase) were highly expressed in late-stage protocorms, suggesting that fungal colonization triggered the significant defense responses of G. elata. The present study indicated the metabolic change and defensive reaction could disrupt the balance between Mycena and G. elata during mycorrhizal symbiotic germination.

  14. 7 CFR 201.20 - Germination.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination. 201.20 Section 201.20 Agriculture... REGULATIONS Labeling Agricultural Seeds § 201.20 Germination. The label shall show the percentage of germination each kind, or kind and variety, or kind and type, or kind and hybrid of agricultural seed present...

  15. Germinal Center Optimization Applied to Neural Inverse Optimal Control for an All-Terrain Tracked Robot

    Directory of Open Access Journals (Sweden)

    Carlos Villaseñor

    2017-12-01

    Full Text Available Nowadays, there are several meta-heuristics algorithms which offer solutions for multi-variate optimization problems. These algorithms use a population of candidate solutions which explore the search space, where the leadership plays a big role in the exploration-exploitation equilibrium. In this work, we propose to use a Germinal Center Optimization algorithm (GCO which implements temporal leadership through modeling a non-uniform competitive-based distribution for particle selection. GCO is used to find an optimal set of parameters for a neural inverse optimal control applied to all-terrain tracked robot. In the Neural Inverse Optimal Control (NIOC scheme, a neural identifier, based on Recurrent High Orden Neural Network (RHONN trained with an extended kalman filter algorithm, is used to obtain a model of the system, then, a control law is design using such model with the inverse optimal control approach. The RHONN identifier is developed without knowledge of the plant model or its parameters, on the other hand, the inverse optimal control is designed for tracking velocity references. Applicability of the proposed scheme is illustrated using simulations results as well as real-time experimental results with an all-terrain tracked robot.

  16. Portable Diagnostics and Rapid Germination

    Energy Technology Data Exchange (ETDEWEB)

    Dunn, Zachary Spencer [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-12-01

    In the Bioenergy and Defense Department of Sandia National Laboratories, characterization of the BaDx (Bacillus anthracis diagnostic cartridge) was performed and rapid germination chemistry was investigated. BaDx was tested with complex sample matrixes inoculated with Bacillus anthracis, and the trials proved that BaDx will detect Bacillus anthracis in a variety of the medium, such as dirt, serum, blood, milk, and horse fluids. The dimensions of the device were altered to accommodate an E. coli or Listeria lateral flow immunoassay, and using a laser printer, BaDx devices were manufactured to identify E. coli and Listeria. Initial testing with E. coli versions of BaDx indicate that the device will be viable as a portable diagnostic cartridge. The device would be more effective with faster bacteria germination; hence studies were performed the use of rapid germination chemistry. Trials with calcium dipicolinic acid displayed increased cell germination, as shown by control studies using a microplate reader. Upon lyophilization the rapid germination chemistry failed to change growth patterns, indicating that the calcium dipicolinic acid was not solubilized under the conditions tested. Although incompatible with the portable diagnostic device, the experiments proved that the rapid germination chemistry was effective in increasing cell germination.

  17. Salt Stress Represses Soybean Seed Germination by Negatively Regulating GA Biosynthesis While Positively Mediating ABA Biosynthesis.

    Science.gov (United States)

    Shu, Kai; Qi, Ying; Chen, Feng; Meng, Yongjie; Luo, Xiaofeng; Shuai, Haiwei; Zhou, Wenguan; Ding, Jun; Du, Junbo; Liu, Jiang; Yang, Feng; Wang, Qiang; Liu, Weiguo; Yong, Taiwen; Wang, Xiaochun; Feng, Yuqi; Yang, Wenyu

    2017-01-01

    Soybean is an important and staple oilseed crop worldwide. Salinity stress has adverse effects on soybean development periods, especially on seed germination and post-germinative growth. Improving seed germination and emergence will have positive effects under salt stress conditions on agricultural production. Here we report that NaCl delays soybean seed germination by negatively regulating gibberellin (GA) while positively mediating abscisic acid (ABA) biogenesis, which leads to a decrease in the GA/ABA ratio. This study suggests that fluridone (FLUN), an ABA biogenesis inhibitor, might be a potential plant growth regulator that can promote soybean seed germination under saline stress. Different soybean cultivars, which possessed distinct genetic backgrounds, showed a similar repressed phenotype during seed germination under exogenous NaCl application. Biochemical analysis revealed that NaCl treatment led to high MDA (malondialdehyde) level during germination and the post-germinative growth stages. Furthermore, catalase, superoxide dismutase, and peroxidase activities also changed after NaCl treatment. Subsequent quantitative Real-Time Polymerase Chain Reaction analysis showed that the transcription levels of ABA and GA biogenesis and signaling genes were altered after NaCl treatment. In line with this, phytohormone measurement also revealed that NaCl considerably down-regulated active GA 1 , GA 3 , and GA 4 levels, whereas the ABA content was up-regulated; and therefore ratios, such as GA 1 /ABA, GA 3 /ABA, and GA 4 /ABA, are decreased. Consistent with the hormonal quantification, FLUN partially rescued the delayed-germination phenotype caused by NaCl-treatment. Altogether, these results demonstrate that NaCl stress inhibits soybean seed germination by decreasing the GA/ABA ratio, and that FLUN might be a potential plant growth regulator that could promote soybean seed germination under salinity stress.

  18. Salt Stress Represses Soybean Seed Germination by Negatively Regulating GA Biosynthesis While Positively Mediating ABA Biosynthesis

    Directory of Open Access Journals (Sweden)

    Kai Shu

    2017-08-01

    Full Text Available Soybean is an important and staple oilseed crop worldwide. Salinity stress has adverse effects on soybean development periods, especially on seed germination and post-germinative growth. Improving seed germination and emergence will have positive effects under salt stress conditions on agricultural production. Here we report that NaCl delays soybean seed germination by negatively regulating gibberellin (GA while positively mediating abscisic acid (ABA biogenesis, which leads to a decrease in the GA/ABA ratio. This study suggests that fluridone (FLUN, an ABA biogenesis inhibitor, might be a potential plant growth regulator that can promote soybean seed germination under saline stress. Different soybean cultivars, which possessed distinct genetic backgrounds, showed a similar repressed phenotype during seed germination under exogenous NaCl application. Biochemical analysis revealed that NaCl treatment led to high MDA (malondialdehyde level during germination and the post-germinative growth stages. Furthermore, catalase, superoxide dismutase, and peroxidase activities also changed after NaCl treatment. Subsequent quantitative Real-Time Polymerase Chain Reaction analysis showed that the transcription levels of ABA and GA biogenesis and signaling genes were altered after NaCl treatment. In line with this, phytohormone measurement also revealed that NaCl considerably down-regulated active GA1, GA3, and GA4 levels, whereas the ABA content was up-regulated; and therefore ratios, such as GA1/ABA, GA3/ABA, and GA4/ABA, are decreased. Consistent with the hormonal quantification, FLUN partially rescued the delayed-germination phenotype caused by NaCl-treatment. Altogether, these results demonstrate that NaCl stress inhibits soybean seed germination by decreasing the GA/ABA ratio, and that FLUN might be a potential plant growth regulator that could promote soybean seed germination under salinity stress.

  19. Smoke-induced seed germination in California chaparral

    Science.gov (United States)

    Keeley, J.E.; Fotheringham, C.J.

    1998-01-01

    The California chaparral community has a rich flora of species with different mechanisms for cuing germination to postfire conditions. Heat shock triggers germination of certain species but has no stimulatory effect on a great many other postfire species that are chemically stimulated by combustion products. Previous reports have shown that charred wood will induce germination, and here we report that smoke also induces germination in these same species. Smoke is highly effective, often inducing 100% germination in deeply dormant seed populations with 0% control germination. Smoke induces germination both directly and indirectly by aqueous or gaseous transfer from soil to seeds. Neither nitrate nor ammonium ions were effective in stimulating germination of smoke-stimulated species, nor were most of the quantitatively important gases generated by biomass smoke. Nitrogen dioxide, however, was very effective at inducing germination in Caulanthus heterophyllus (Brassicaceae), Emmenanthe penduliflora (Hydrophyllaceae), Phacelia grandiflora (Hydrophyllaceae), and Silene multinervia (Caryophyllaceae). Three species, Dendromecon rigida (Papaveraceae), Dicentra chrysantha, and Trichostema lanatum (Lamiaceae), failed to germinate unless smoke treatment was coupled with prior treatment of 1 yr soil storage. Smoke-stimulated germination was found in 25 chaparral species, representing 11 families, none of which were families known for heat-shock-stimulated germination. Seeds of smoke-stimulated species have many analogous characteristics that separate them from most heat-shock-stimulated seeds, including: (1) outer seed coats that are highly textured, (2) a poorly developed outer cuticle, (3) absence of a dense palisade tissue in the seed coat, and (4) a subdermal membrane that is semipermeable, allowing water passage but blocking entry of large (molecular mass > 500) solutes. Tentative evidence suggests that permeability characteristics of this subdermal layer are altered by

  20. Germination of Afrocarpus usambarensis and Podocarpus ...

    African Journals Online (AJOL)

    ACSS

    farm planting. Seed germination of .... 235. Germination of Afrocarpus usambarensis and Podocarpus milanjianus seeds. Table 2. Mean seed germination of A. usambarensis and P. milanjianus. Species .... National Forestry Authority and District.

  1. Comparative seed germination traits in alpine and subalpine grasslands: higher elevations are associated with warmer germination temperatures.

    Science.gov (United States)

    Fernández-Pascual, E; Jiménez-Alfaro, B; Bueno, Á

    2017-01-01

    Seed germination traits in alpine grasslands are poorly understood, despite the sensitivity of these communities to climate change. We hypothesise that germination traits predict species occurrence along the alpine-subalpine elevation gradient. Phylogenetic comparative analyses were performed using fresh seeds of 22 species from alpine and subalpine grasslands (1600-2400 m) of the Cantabrian Mountains, Spain (43° N, 5° W). Laboratory experiments were conducted to characterise germinability, optimum germination temperature and effect of cold and warm stratification on dormancy breaking. Variability in these traits was reduced by phylogenetic principal component analysis (phyl.PCA). Phylogenetic generalised least squares regression (PGLS) was used to fit a model in which species average elevation was predicted from their position on the PCA axes. Most subalpine species germinated in snow-like conditions, whereas most alpine species needed accumulation of warm temperatures. Phylogenetic signal was low. PCA1 ordered species according to overall germinability, whilst PCA2 ordered them according to preference for warm or cold germination. PCA2 significantly predicted species occurrence in the alpine-subalpine gradient, as higher elevation species tended to have warmer germination preferences. Our results show that germination traits in high-mountain grasslands are closely linked to the alpine-subalpine gradient. Alpine species, especially those from stripped and wind-edge communities, prefer warmer germination niches, suggesting that summer emergence prevents frost damage during seedling establishment. In contrast, alpine snowfield and subalpine grassland plants have cold germination niches, indicating that winter emergence may occur under snow to avoid drought stress. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  2. Temperatures during flower bud development affect pollen germination, self-incompatibility reaction and early fruit development of clementine (Citrus clementina Hort. ex Tan.).

    Science.gov (United States)

    Distefano, G; Gentile, A; Hedhly, A; La Malfa, S

    2018-03-01

    One of the key environmental factors affecting plant reproductive systems is temperature. Characterising such effects is especially relevant for some commercially important genera such as Citrus. In this genus, failure of fertilisation results in parthenocarpic fruit development and seedlessness, which is a much-prized character. Here, we characterise the effects of temperature on flower and ovary development, and on pollen-pistil interactions in 'Comune' clementine (Citrus clementina Hort. ex Tan.). We examine flower bud development, in vitro pollen germination and pollen-pistil interaction at different temperatures (15, 20, 25 or 30 °C). These temperatures span the range from 'cold' to 'hot' weather during the flowering season in many citrus-growing regions. Temperature had a strong effect on flower and ovary development, pollen germination, and pollen tube growth kinetics. In particular, parthenocarpic fruit development (indicated by juice vesicle growth) was initiated early if flowers were exposed to warmer temperatures during anthesis. Exposure to different temperatures during flower bud development also alters expression of the self-incompatibility reaction. This affects the point in the pistil at which pollen tube growth is arrested and confirms the role of sub- and supra-optimal temperatures in determining the numbers of pollen tubes reaching the ovary. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.

  3. Involvement of Polyamine Oxidase-Produced Hydrogen Peroxide during Coleorhiza-Limited Germination of Rice Seeds

    Directory of Open Access Journals (Sweden)

    Bing-Xian Chen

    2016-08-01

    Full Text Available Seed germination is a complicated biological process that requires regulated enzymatic and non-enzymatic reactions. The action of polyamine oxidase (PAO produces hydrogen peroxide (H2O2, which promotes dicot seed germination. However, whether and, if so, how PAOs regulate monocot seed germination via H2O2 production is unclear. Herein, we report that the coleorhiza is the main physical barrier to radicle protrusion during germination of rice seed (a monocot seed and that it does so in a manner similar to that of dicot seed micropylar endosperm. We found that H2O2 specifically and steadily accumulated in the coleorhizae and radicles of germinating rice seeds and was accompanied by increased PAO activity as the germination percentage increased. These physiological indexes were strongly decreased in number by guazatine, a PAO inhibitor. We also identified 11 PAO homologs (OsPAO1–11 in the rice genome, which could be classified into four subfamilies (I, IIa, IIb, and III. The OsPAO genes in subfamilies I, IIa, and IIb (OsPAO1–7 encode PAOs, whereas those in subfamily III (OsPAO8–11 encode histone lysine-specific demethylases. In silico-characterized expression profiles of OsPAO1–7 and those determined by qPCR revealed that OsPAO5 is markedly upregulated in imbibed seeds compared with dry seeds and that its transcript accumulated to a higher level in embryos than in the endosperm. Moreover, its transcriptional abundance increased gradually during seed germination in water and was inhibited by 5 mM guazatine. Taken together, these results suggest that PAO-generated H2O2 is involved in coleorhiza-limited rice seed germination and that OsPAO5 expression accounts for most PAO expression and activity during rice seed germination. These findings should facilitate further study of PAOs and provide valuable information for functional validation of these proteins during seed germination of monocot cereals.

  4. Effect of industrial pollution on seed germination

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, M.Z.; Qadir, S.A.

    1973-01-01

    The germination behavior of seeds in polluted waters and polluted soil extracts was found to be identical, only a few species behaved differently. Prosopis juliflora, Haloxylon recurvum, Acacia senegal showed best germination in the two conditions but Prosopis juliflora was the most resistant to pollution. In Suaeda fruticosa no germination took place in the control treatment whereas highest germination (70%) was seen in treatment with polluted soil extract of EPLA. Blepharis sindica showed a stimulating effect of polluted water on germination, whereas low germination was observed when their seeds were treated with the soil extract of the same site. 40% germination of Suaeda monoica was seen in polluted water of Carbon and Ribbon Mfg. Co., whereas 30% germination was found in a control treatment. Low percentage of germination was found when the seeds of Cassia holosericea were treated with polluted waters of different industries as compared to soil extract treatments of the same industries. Datura alba showed 50, 30 and 10% seed germination in polluted soil extract of Carbon and Ribbon Mfg. Co., in control and in polluted water of Darbar Soap Works, respectively. 5 references, 1 table.

  5. [The research of Valeriana amurensis seed germination characteristics].

    Science.gov (United States)

    Liu, Juan; Yang, Chun-Rong; Jiang, Bo; Fang, Min; Du, Juan

    2011-10-01

    To study the effect of different treatments on the Valeriana amurensis seed germination rate. Used different chemical reagents and seed soakings on the routine germination test and the orthogonal test of the Valeriana amurensis seed, calculated the germination rate under different germination condition. Valeriana amurensis treated with different chemical reagends had different germination rate. The suitable immersion time could enhance Valeriana amurensis seed germination rate. Different treatment time, different disposal temperature, different germination temperature would have an impact on the Valeriana amurensis seed germination rate. In order to raise the Valeriana amurensis seed germination rate, use appropriate treatment on the seed before plant seeds; The seed growing must under suitable time and temperature.

  6. Oxygen requirement of germinating flax seeds

    Science.gov (United States)

    Kuznetsov, Oleg A.; Hasenstein, K. H.

    2003-05-01

    Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax ( Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume = 14 mL) and after 36 h measured the root length. At 90 μl O 2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O 2 we determined the lower limit of reliable germination to be 10 vol. % O 2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination.

  7. Seed germination behavior of swallow wort

    Directory of Open Access Journals (Sweden)

    amir hosein pahlavani

    2009-06-01

    Full Text Available The exotic plant, Swallow- wort, a twining perennial of the Milkweed family, has become increasingly invasive in some place of Iran, especially orchards. Increased knowledge of wort germination biology would facilitate development of an optimum control program. Germination of Swallow wort seeds as affected by environmental factors was studied under controlled-environment growth chamber conditions. The following studies were conducted in plant Pests & Diseases Research Institute during the years 2003-4: 1- Effect of constant temperature on germination that including 10, 15, 18, 20, 25, 30, 35 and 40˚C; 2- Effect of light on constant germination; 3- Effect of temperature fluctuations on seed germination: 15/7, 20/12, 25/17 and 30/22˚C. All experiments were conducted with 8 replications. Swallow wort seeds showed no dormancy when detachment from mother plant. Seed germination was strongly influenced by temperature. Light did not play a crucial role on seed germination of this weed. Therefore Swallow wort seeds were not photoblastic and temperature fluctuations did not increase seed germination of Swallow wort. The above characteristics are very important in making swallowwort an invasive weed. Having precise information of these traits enables us to a better management and control of this troublesome weed.

  8. Factors influencing seed germination in Cerrado grasses

    Directory of Open Access Journals (Sweden)

    Rosana Marta Kolb

    2016-03-01

    Full Text Available Few studies address the ecology of herbs of Cerrado grasslands, which are ecosystems where the long dry season, high temperatures, insolation, fire and invasive grasses greatly influencing germination and the establishment of plants. We assessed germination of 13 species of Poaceae from Cerrado grasslands under nursery conditions or in germination chambers, the latter with i recently collected seeds and seeds after six months storage, ii under constant and alternating temperatures, and iii in the presence and absence of light. Germinability, mean germination time (MGT and required light were quantified to elucidate factors involved in successful germination. Germinability was low for most grasses, probably because of low seed viability. For most species, germinability and MGT were not altered by seed storage. Germination percentages were higher at alternating temperatures and in the presence of light, factors that are more similar to natural environmental situations compared with constant temperature or the absence of light. Our findings indicate that alternating temperatures and light incidence are key factors for germination of species of Poaceae. The maintenance of these environmental factors, which are crucial for the conservation of Cerrado grasslands, depends on appropriate management interventions, such as fire management and the control of biological invasion.

  9. Phytotoxicity of glyphosate in the germination of and its effect on germinated seedlings

    Directory of Open Access Journals (Sweden)

    Subinoy Mondal

    2017-08-01

    Full Text Available The present study evaluated the effects of glyphosate on Pisum sativum germination as well as its effect on the physiology and biochemistry of germinated seedlings. Different physico-chemical biomarkers, viz., chlorophyll, root and shoot length, total protein and soluble sugar, along with sodium and potassium concentration, were investigated in germinated seedlings at different glyphosate concentrations. This study reports the influence of different concentrations of glyphosate on pea seeds and seedlings. Physicochemical biomarkers were significantly changed by glyphosate exposure after 15 days. The germination of seedlings under control conditions (0 mg/L was 100% after 3 days of treatment but at 3 and 4 mg/L glyphosate, germination was reduced to 55 and 40%, respectively. Physiological parameters like root and shoot length decreased monotonically with increasing glyphosate concentration, at 14 days of observation. Average root and shoot length (n=30 in three replicates were reduced to 14.7 and 17.6%, respectively, at 4 mg/L glyphosate. Leaf chlorophyll content also decreased, with a similar trend to root and shoot length, but the protein content initially decreased and then increased with an increase in glyphosate concentration to 3 mg/L. The study suggests that glyphosate reduces the soluble sugar content significantly, by 21.6% (v/v. But internal sodium and potassium tissue concentrations were significantly altered by glyphosate exposure with increasing concentrations of glyphosate. Biochemical and physiological analysis also supports the inhibitory effect of glyphosate on seed germination and biochemical effects on seedlings.

  10. Describing phytotoxic effects on cumulative germination

    OpenAIRE

    Dias, L.S.

    2001-01-01

    Phytotoxic studies strongly depend on evaluation of germination responses, which implies the need for adequate procedures to account for distinct aspects of the germinative process. For this, indices, comparisons among treatments at various times, and model fitting have been proposed. The objective of this work is to compare the three approaches and select the one providing greater insight and precision. Speed of germination, speed of accumulated germination, the coefficient of the rate of ge...

  11. Using In Situ Symbiotic Seed Germination to Restore Over-collected Medicinal Orchids in Southwest China

    Directory of Open Access Journals (Sweden)

    Shi-Cheng Shao

    2017-06-01

    Full Text Available Due to increasing demand for medicinal and horticultural uses, the Orchidaceae is in urgent need of innovative and novel propagation techniques that address both market demand and conservation. Traditionally, restoration techniques have been centered on ex situ asymbiotic or symbiotic seed germination techniques that are not cost-effective, have limited genetic potential and often result in low survival rates in the field. Here, we propose a novel in situ advanced restoration-friendly program for the endangered epiphytic orchid species Dendrobium devonianum, in which a series of in situ symbiotic seed germination trials base on conspecific fungal isolates were conducted at two sites in Yunnan Province, China. We found that percentage germination varied among treatments and locations; control treatments (no inoculum did not germinate at both sites. We found that the optimal treatment, having the highest in situ seed germination rate (0.94-1.44% with no significant variation among sites, supported a warm, moist and fixed site that allowed for light penetration. When accounting for seed density, percentage germination was highest (2.78-2.35% at low densities and did not vary among locations for the treatment that supported optimal conditions. Similarly for the same treatment, seed germination ranged from 0.24 to 5.87% among seasons but also did vary among sites. This study reports on the cultivation and restoration of an endangered epiphytic orchid species by in situ symbiotic seed germination and is likely to have broad application to the horticulture and conservation of the Orchidaceae.

  12. Using In Situ Symbiotic Seed Germination to Restore Over-collected Medicinal Orchids in Southwest China.

    Science.gov (United States)

    Shao, Shi-Cheng; Burgess, Kevin S; Cruse-Sanders, Jennifer M; Liu, Qiang; Fan, Xu-Li; Huang, Hui; Gao, Jiang-Yun

    2017-01-01

    Due to increasing demand for medicinal and horticultural uses, the Orchidaceae is in urgent need of innovative and novel propagation techniques that address both market demand and conservation. Traditionally, restoration techniques have been centered on ex situ asymbiotic or symbiotic seed germination techniques that are not cost-effective, have limited genetic potential and often result in low survival rates in the field. Here, we propose a novel in situ advanced restoration-friendly program for the endangered epiphytic orchid species Dendrobium devonianum , in which a series of in situ symbiotic seed germination trials base on conspecific fungal isolates were conducted at two sites in Yunnan Province, China. We found that percentage germination varied among treatments and locations; control treatments (no inoculum) did not germinate at both sites. We found that the optimal treatment, having the highest in situ seed germination rate (0.94-1.44%) with no significant variation among sites, supported a warm, moist and fixed site that allowed for light penetration. When accounting for seed density, percentage germination was highest (2.78-2.35%) at low densities and did not vary among locations for the treatment that supported optimal conditions. Similarly for the same treatment, seed germination ranged from 0.24 to 5.87% among seasons but also did vary among sites. This study reports on the cultivation and restoration of an endangered epiphytic orchid species by in situ symbiotic seed germination and is likely to have broad application to the horticulture and conservation of the Orchidaceae.

  13. Vasovagal reactions in whole blood donors at 3 REDS-II blood centers in Brazil

    Science.gov (United States)

    Goncalez, T. T.; Sabino, E. C.; Schlumpf, K.S.; Wright, D.J.; Leao, S.; Sampaio, D.; Takecian, P. L.; Carneiro-Proietti, AB; Murphy, E.; Busch, M.; Custer, B.

    2013-01-01

    Background In Brazil little is known about adverse reactions during donation and the donor characteristics that may be associated with such events. Donors are offered snacks and fluids prior to donating and are required to consume a light meal after donation. For these reasons the frequency of reactions may be different than those observed in other countries. Methods A cross-sectional study was conducted of eligible whole blood donors at three large blood centers located in Brazil between July 2007 and December 2009. Vasovagal reactions (VVRs) along with donor demographic and biometric data were collected. Reactions were defined as any presyncopal or syncopal event during the donation process. Multivariable logistic regression was performed to identify predictors of VVRs. Results Of 724,861 donor presentations, 16,129 (2.2%) VVRs were recorded. Rates varied substantially between the three centers: 53, 290 and 381 per 10,000 donations in Recife, São Paulo and Belo Horizonte, respectively. Although the reaction rates varied, the donor characteristics associated with VVRs were similar [younger age (18–29), replacement donors, first time donors, low estimated blood volume (EBV)]. In multivariable analysis controlling for differences between the donor populations in each city younger age, first-time donor status and lower EBV were the factors most associated with reactions. Conclusion Factors associated with VVRs in other locations are also evident in Brazil. The difference in VVR rates between the three centers might be due to different procedures for identifying and reporting the reactions. Potential interventions to reduce the risk of reactions in Brazil should be considered. PMID:22073941

  14. Co-ordination of the nuclear reaction data centers. Report on an IAEA advisory group meeting

    International Nuclear Information System (INIS)

    Schwerer, O.; Lemmel, H.D.

    1996-11-01

    This report summarizes the 1996 co-ordination meeting in Brookhaven, U.S.A., of the national and regional nuclear reaction data center, convened by the IAEA at regular intervals. The main topics are: the international exchange of nuclear reaction data by means of the ''EXFOR'' system, and the further development of this system; the ''CINDA'' system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation and data center services; the exchange and documentation of evaluated data libraries in ''ENDF'' format; the rapid advances of online electronic information technologies, with the goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials. The scope of data covers microscopic cross-sections and related parameters of nuclear reactions induced by neutrons, charged-particles and photons. (author). Refs, figs, tabs

  15. Co-ordination of the nuclear reactions data centers. Report on an IAEA advisory group meeting

    International Nuclear Information System (INIS)

    Pronyaev, V.G.; Schwerer, O.

    1998-07-01

    This report summarizes the 1998 co-ordination meeting at the IAEA Headquarters in Vienna of the regional, national and specialized nuclear reaction data centers, concerned by the IAEA at two-year intervals. The main topics are: the international exchange of nuclear reaction data by means of the ''EXFOR'' system, and the further development of this system; the ''CINDA'' system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation and data center services; the exchange and documentation of evaluated data libraries in ''ENDF'' format; the rapid advances of online electronic information technologies, with goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials. The scope of data covers microscopic cross-sections and related parameters of nuclear reactions induced by neutrons, charged-particles and photons. (author)

  16. Co-ordination of the nuclear reaction data centers. Report on an IAEA advisory group meeting

    Energy Technology Data Exchange (ETDEWEB)

    Schwerer, O; Lemmel, H D [eds.

    1996-11-01

    This report summarizes the 1996 co-ordination meeting in Brookhaven, U.S.A., of the national and regional nuclear reaction data center, convened by the IAEA at regular intervals. The main topics are: the international exchange of nuclear reaction data by means of the ``EXFOR`` system, and the further development of this system; the ``CINDA`` system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation and data center services; the exchange and documentation of evaluated data libraries in ``ENDF`` format; the rapid advances of online electronic information technologies, with the goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials. The scope of data covers microscopic cross-sections and related parameters of nuclear reactions induced by neutrons, charged-particles and photons. (author). Refs, figs, tabs.

  17. The breakdown of vinyl ethers as a two-center synchronous reaction

    Science.gov (United States)

    Pokidova, T. S.; Shestakov, A. F.

    2009-11-01

    The experimental data on the molecular decomposition of vinyl ethers of various structures to alkanes and the corresponding aldehydes or ketones in the gas phase were analyzed using the method of intersecting parabolas. The enthalpies and kinetic parameters of decomposition were calculated for 17 reactions. The breakdown of ethers is a two-center concerted reaction characterized by a very high classical potential barrier to the thermally neutral reaction (180-190 kJ/mol). The kinetic parameters (activation energies and rate constants) of back reactions of the formation of vinyl ethers in the addition of aldehydes or ketones to alkanes were calculated using the method of intersecting parabolas. The factors that influenced the activation energy of the decomposition and formation of ethers were discussed. Quantum-chemical calculations of several vinyl ether decomposition reactions were performed. Ether formation reactions were compared with the formation of unsaturated alcohols as competitive reactions, which can occur in the interaction of carbonyl compounds with alkenes.

  18. Oxygen requirement of germinating flax seeds

    Science.gov (United States)

    Kuznetsov, Oleg A.; Hasenstein, K. H.; Hasentein, K. H. (Principal Investigator)

    2003-01-01

    Plant experiments in earth orbit are typically prepared on the ground and germinated in orbit to study gravity effects on the developing seedlings. Germination requires the breakdown of storage compounds, and this metabolism depends upon respiration, making oxygen one of the limiting factors in seed germination. In microgravity lack of run-off of excess water requires careful testing of water dispensation and oxygen availability. In preparation for a shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware (Magnetic Field Chamber, MFC). We tested between four to 32 seeds per chamber (air volume=14 mL) and after 36 h measured the root length. At 90 microliters O2 per seed (32 seeds/chamber), the germination decreased from 94 to 69%, and the root length was reduced by 20%, compared to 8 seeds per chamber. Based on the percent germination and root length obtained in controlled gas mixtures between 3.6 and 21.6% O2 we determined the lower limit of reliable germination to be 10 vol. % O2 at atmospheric pressure. Although the oxygen available in the MFC's can support the intended number of seeds, the data show that seed storage and microgravity-related limitations may reduce germination. c2003 Published by Elsevier Ltd on behalf of COSPAR.

  19. Germination of Avena fatua under different gaseous environments

    Energy Technology Data Exchange (ETDEWEB)

    Hart, J.W.; Berrie, A.M.M.

    1966-01-01

    The atmosphere in which seeds germinate can profoundly affect the level of germination and dormancy. Seeds were germinated in atmospheres containing various concentrations of carbon dioxide and oxygen. At the same time the effect of light on these systems was examined. The germination of partially dormant populations of wild oat seed is inhibited by white light. This response to light is most apparent when the caryopsis is enclosed in the pales. Investigations into the effect of the ambient atmosphere on germination have indicated that, while oxygen is a necessary factor in the germination of this species, carbon dioxide also has an effect. A lack of carbon dioxide increases the degree of light inhibition of germination; 3% carbon dioxide (by volume) allows germination in light; 20% carbon dioxide inhibits germination in light and darkness at all tested oxygen concentrations.

  20. DOES JASMONIC ACID PREVENT THE GERMINATION

    OpenAIRE

    ÇAVUŞOĞLU, Kürşat

    2009-01-01

    Abstract: Effect of jasmonic acid on seed germination and seedling growth of barley (Hordeum vulgare L. cv. Bülbül 89) was investigated in the present study. Jasmonic acid concentrations less than 1500 µM have not inhibited the seed germination, while 1500 and 2000 µM jasmonic acid levels caused atypical germination. The germination was completely inhibited at 3000 µM level of jasmonic acid. However, the seedling growth clearly slowed down with increasing concentrations of jasmonic acid. Furt...

  1. Co-ordination of the nuclear reactions data centers. Report on an IAEA advisory group meeting

    Energy Technology Data Exchange (ETDEWEB)

    Pronyaev, V G; Schwerer, O [eds.

    1998-07-01

    This report summarizes the 1998 co-ordination meeting at the IAEA Headquarters in Vienna of the regional, national and specialized nuclear reaction data centers, concerned by the IAEA at two-year intervals. The main topics are: the international exchange of nuclear reaction data by means of the ``EXFOR`` system, and the further development of this system; the ``CINDA`` system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation and data center services; the exchange and documentation of evaluated data libraries in ``ENDF`` format; the rapid advances of online electronic information technologies, with goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials. The scope of data covers microscopic cross-sections and related parameters of nuclear reactions induced by neutrons, charged-particles and photons. (author) Refs, figs, tabs

  2. Phytotoxicity of glyphosate in the germination of Pisum sativum and its effect on germinated seedlings

    OpenAIRE

    Mondal, Subinoy; Kumar, Mousumi; Haque, Smaranya; Kundu, Debajyoti

    2017-01-01

    The present study evaluated the effects of glyphosate on Pisum sativum germination as well as its effect on the physiology and biochemistry of germinated seedlings. Different physico-chemical biomarkers, viz., chlorophyll, root and shoot length, total protein and soluble sugar, along with sodium and potassium concentration, were investigated in germinated seedlings at different glyphosate concentrations. This study reports the influence of different concentrations of glyphosate on pea seeds a...

  3. GERMINATION STUDIES ON Tabebuia impetiginosa Mart. SEEDS

    Directory of Open Access Journals (Sweden)

    Edvaldo Aparecido Amaral da Silva

    2004-06-01

    Full Text Available Seed germination and seedling production of native forest tree species are an important step in ex situ conservation programs and in the reforestation with ecological purposes. Therefore, understanding seed germination and its regulation is mandatory for the complete success of the conservation programs and revegetation techniques. Thus, morphological studies, temperature requirements for seed germination and its control by gibberellins (GAs were studied in Tabebuia impetiginosa (“ipê-roxo” seeds. The best temperature for germination under constant light was 30oC. The imbibition of T. impetiginosa seeds followed the common triphasic pattern, with most of the seeds attaining phase II at 24 hours and phase III at 72 hours of imbibition. Visible germination, as radicle elongation, started at 30 hours in water-imbibed seeds and at 24 hours in GA-imbibed seeds. Seeds imbibed in Paclobutrazol, an inhibitor of GA biosynthesis, failed to germinate. However, application of exogenous gibberellins overcame inhibition and allowed germination, suggesting that GAs are regulators of Tabebuia impetiginosa seed germination. The results suggested that germination in Tabebuia impetiginosa seeds is controlled by elongation of the radicle and gibberellins may play an important role in regulating it. The possible role of gibberellins is discussed.

  4. Multiple paths to similar germination behavior in Arabidopsis thaliana.

    Science.gov (United States)

    Burghardt, Liana T; Edwards, Brianne R; Donohue, Kathleen

    2016-02-01

    Germination timing influences plant fitness, and its sensitivity to temperature may cause it to change as climate shifts. These changes are likely to be complex because temperatures that occur during seed maturation and temperatures that occur post-dispersal interact to define germination timing. We used the model organism Arabidopsis thaliana to determine how flowering time (which defines seed-maturation temperature) and post-dispersal temperature influence germination and the expression of genetic variation for germination. Germination responses to temperature (germination envelopes) changed as seeds aged, or after-ripened, and these germination trajectories depended on seed-maturation temperature and genotype. Different combinations of genotype, seed-maturation temperature, and after-ripening produced similar germination envelopes. Likewise, different genotypes and seed-maturation temperatures combined to produce similar germination trajectories. Differences between genotypes were most likely to be observed at high and low germination temperatures. The germination behavior of some genotypes responds weakly to maternal temperature but others are highly plastic. We hypothesize that weak dormancy induction could synchronize germination of seeds dispersed at different times. By contrast, we hypothesize that strongly responsive genotypes may spread offspring germination over several possible germination windows. Considering germination responses to temperature is important for predicting phenology expression and evolution in future climates. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

  5. The BCL6 RD2 Domain Governs Commitment of Activated B Cells to Form Germinal Centers

    Directory of Open Access Journals (Sweden)

    Chuanxin Huang

    2014-09-01

    Full Text Available To understand how the Bcl6 transcriptional repressor functions in the immune system, we disrupted its RD2 repression domain in mice. Bcl6RD2MUT mice exhibit a complete loss of germinal center (GC formation but retain normal extrafollicular responses. Bcl6RD2MUT antigen-engaged B cells migrate to the interfollicular zone and interact with cognate T helper cells. However, these cells fail to complete early GC-commitment differentiation and coalesce as nascent GC aggregates. Bcl6 directly binds and represses trafficking receptors S1pr1 and Gpr183 by recruiting Hdac2 through the RD2 domain. Deregulation of these genes impairs B cell migration and may contribute to GC failure in Bcl6RD2MUT mice. The development of functional GC-TFH cells was partially impaired in Bcl6RD2MUT mice. In contrast to Bcl6−/− mice, Bcl6RD2MUT animals experience no inflammatory disease or macrophage deregulation. These results reveal an essential role for RD2 repression in early GC commitment and striking biochemical specificity in Bcl6 control of humoral and innate immune-cell phenotypes.

  6. Asymbiotic germination in vitro in seeds of four species of Cuban orchids

    Directory of Open Access Journals (Sweden)

    Loexis Rodríguez

    2001-04-01

    Full Text Available About the most of 300 species of Cuban native orchids is have few reference of the micropropagation in the science literature. However, the biotechnical techniques fulfill an important acting in the rescue of threatened species. By that in the laboratory of Vegetable Biotechnology of the Mountain Development Center in Guantanamo, aspects related with the germination were studied in vitro of Campylocentrum micrantrum, Encyclia cochleata, Epidendrum difforme and Oceoclade maculata using the salts of the culture medium Murashige and Skoog (1962 and Knudson (1946, increasing with activate charcoal (0; 1; 2 g.l-1, Agar tachnical No. 3 6 g.l-1 and the adjusted pH at 5.6. The seeds was incubated under conditions of 16 hours light to intensity of 27 uMol.m².s-¹ and 24 ± 1 °C. The reached results showed that the germination of the studied species was obtained under different times and conditions of the medium of cultivation where it stood out for the smallest time used for the germination Encyclia cochleata to the eight weeks in the salts of Murashige and Skoog (1962 and without the addition of activated charcoal, as long as Oceoclade maculata needed 24 weeks to germinate. Key words: antioxidante, biotechnology, flowers, micropropagación, native species

  7. Zinnia Germination and Lunar Soil Amendment

    Science.gov (United States)

    Reese, Laura

    2017-01-01

    Germination testing was performed to determine the best method for germinating zinnias. This method will be used to attempt to germinate the zinnia seeds produced in space. It was found that seed shape may be critically important in determining whether a seed will germinate or not. The ability of compost and worm castings to remediate lunar regolith simulant for plant growth was tested. It was found that neither treatment effectively improves plant growth in lunar regolith simulant. A potential method of improving lunar regolith simulant by mixing it with arcillite was discovered.

  8. Effect of germination on chemical, functional and nutritional characteristics of wheat, brown rice and triticale: a comparative study.

    Science.gov (United States)

    Sibian, Mandeep S; Saxena, Dharmesh C; Riar, Charanjit S

    2017-10-01

    Germination is accompanied by various metabolic reactions in the seed, which lead to alteration of its chemical composition as compared to raw seed. Among the micromolecules, amino acids play an important role in various growth and metabolic activities in seeds. Results indicated that germination altered seeds' chemical composition, which improved/changed the functional properties investigated such as bulk density, foaming capacity, water holding capacity, oil binding capacity and emulsification properties. Essential amino acids were increased during germination, which contributed in enhancing the nutritional quality of protein in seeds. Germination also improved protein-based quality parameters such as essential amino acid index, biological value, protein efficiency ratio and nutritional index in seeds of brown rice, wheat and triticale. Among the grains, the essential amino acid index of brown rice was reported to be highest after germination. Indispensable/essential amino acids such as lysine, methionine, leucine, isoleucine, threonine, phenylalanine and valine showed a significant increase during germination. As a result, amino acid scoring based on the reference pattern of an FAO Expert Consultation Report (2013) for infants and adults was appreciably improved after germination along with an increase in the essential amino acid indices for brown rice (78.78), wheat (76.55) and triticale (73.99). © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  9. Molar extinction coefficients and other properties of an improved reaction center preparation from Rhodopseudomonas viridis

    Energy Technology Data Exchange (ETDEWEB)

    Clayton, R.K.; Clayton, B.J.

    1978-01-01

    Reaction centers have been purified from chromatophores of Rhodopseudomonas viridis by treatment with lauryl dimethyl amine oxide followed by hydroxyapatite chromatography and precipitation with ammonium sulfate. The absorption spectrum at low temperature shows bands at 531 and 543 nm, assigned to two molecules of bacteriopheophytin b. The 600 nm band of bacteriochlorophyll b is resolved at low temperature into components at 601 and 606.5 nm. At room temperature the light-induced difference spectrum shows a negative band centered at 615 nm, where the absorption spectrum shows only a week shoulder adjacent to the 600 nm band. The fluorescence spectrum shows a band at 1000 nm and no fluorescence corresponding to the 830 nm absorption band. Two molecules of cytochrome 558 and three of cytochrome 552 accompany each reaction center. The differential extinction coefficient (reduced minus oxidized) of cytochrome 558 nm was estimated as 20 +- 2 mM/sup -1/.cm/sup -1/ through a coupled reaction with equine cytochrome c. The extinction coefficient of reaction centers at 960 nm was determined to be 123 +- 25 mM/sup -1/.cm/sup -1/ by measuring the light-induced bleaching of P-960 and the coupled oxidation of cytochrome 558. The corresponding extinction coefficient at 830 nm is 300 +- 65 mM/sup -1/.cm/sup -1/. The absorbance ratio ..cap alpha../sub 280nm/..cap alpha../sub 830nm/ in our preparations was 2.1, and there was 190 kg protein per mol of reaction centers. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed three major components of apparent molecular weights 31,000, 37,000, and 41,000.

  10. EFFECTS OF PRE-GERMINATION TREATMENTS AND STORAGE ON GERMINATION OF Astronium fraxinifolium SCHOTT (ANACARDIACEAE DIASPORES

    Directory of Open Access Journals (Sweden)

    Lílian de Lima Braga

    2014-06-01

    Full Text Available http://dx.doi.org/10.5902/1980509814577The goal of this study was to evaluate the germination and the storage capacity of Astronium fraxinifolium diaspores. Six pre-germination treatments were used in the experiment: control treatment (intact diaspores; diaspores immersed in water at room temperature (25º C for 5 min; diaspores immersed in water at 70° C for 5 min; diaspores immersed in water at 100° C for 5 min; diaspores immersed in sodium hypochlorite solution (1:1000 for 2 min; and diaspores mechanically scarified with sandpaper #80. To evaluate storage conditions, we tested two different types of packaging (permeable paper bag and transparent glass jar and two environmental conditions (cold chamber and room conditions, resulting in four treatments. The germination tests were performed for zero (control and 60, 120, 180, 240, 300 and 360 days after storage. The effects of different treatments on germination and storage of diaspores were evaluated by ANOVA, followed by Tukey test. Regarding to pre-germination treatments, high germination rates were observed in the hypochlorite (98.0 ± 4.22%, control (97.0 ± 4.83%, water at room temperature (96.0 ± 6.99% and water at 70º C (83.0 ± 29.08% treatments. Thus, Astronium fraxinifolium diaspores do not present dormancy. During storage, the diaspores remained viable throughout the study period with high germination rates, except for the treatment in paper bags placed in the cold chamber, in which the diaspores lost their viability in the eighth month of storage. Therefore, this is not a recommended storage method for this species.

  11. Changes in germination characteristics and seedling growth ...

    African Journals Online (AJOL)

    Changes in germination characteristics and seedling growth between storage ... for up to 1 year and the second group was used for un-stored germination test. ... seed germination performance without loss of longevity of tall fescue species, ...

  12. Rgs13 constrains early B cell responses and limits germinal center sizes.

    Directory of Open Access Journals (Sweden)

    Il-Young Hwang

    Full Text Available Germinal centers (GCs are microanatomic structures that develop in secondary lymphoid organs in response to antigenic stimulation. Within GCs B cells clonally expand and their immunoglobulin genes undergo class switch recombination and somatic hypermutation. Transcriptional profiling has identified a number of genes that are prominently expressed in GC B cells. Among them is Rgs13, which encodes an RGS protein with a dual function. Its canonical function is to accelerate the intrinsic GTPase activity of heterotrimeric G-protein α subunits at the plasma membrane, thereby limiting heterotrimeric G-protein signaling. A unique, non-canonical function of RGS13 occurs following translocation to the nucleus, where it represses CREB transcriptional activity. The functional role of RGS13 in GC B cells is unknown. To create a surrogate marker for Rgs13 expression and a loss of function mutation, we inserted a GFP coding region into the Rgs13 genomic locus. Following immunization GFP expression rapidly increased in activated B cells, persisted in GC B cells, but declined in newly generated memory B and plasma cells. Intravital microscopy of the inguinal lymph node (LN of immunized mice revealed the rapid appearance of GFP(+ cells at LN interfollicular regions and along the T/B cell borders, and eventually within GCs. Analysis of WT, knock-in, and mixed chimeric mice indicated that RGS13 constrains extra-follicular plasma cell generation, GC size, and GC B cell numbers. Analysis of select cell cycle and GC specific genes disclosed an aberrant gene expression profile in the Rgs13 deficient GC B cells. These results indicate that RGS13, likely acting at cell membranes and in nuclei, helps coordinate key decision points during the expansion and differentiation of naive B cells.

  13. Rgs13 constrains early B cell responses and limits germinal center sizes.

    Science.gov (United States)

    Hwang, Il-Young; Hwang, Kyung-Sun; Park, Chung; Harrison, Kathleen A; Kehrl, John H

    2013-01-01

    Germinal centers (GCs) are microanatomic structures that develop in secondary lymphoid organs in response to antigenic stimulation. Within GCs B cells clonally expand and their immunoglobulin genes undergo class switch recombination and somatic hypermutation. Transcriptional profiling has identified a number of genes that are prominently expressed in GC B cells. Among them is Rgs13, which encodes an RGS protein with a dual function. Its canonical function is to accelerate the intrinsic GTPase activity of heterotrimeric G-protein α subunits at the plasma membrane, thereby limiting heterotrimeric G-protein signaling. A unique, non-canonical function of RGS13 occurs following translocation to the nucleus, where it represses CREB transcriptional activity. The functional role of RGS13 in GC B cells is unknown. To create a surrogate marker for Rgs13 expression and a loss of function mutation, we inserted a GFP coding region into the Rgs13 genomic locus. Following immunization GFP expression rapidly increased in activated B cells, persisted in GC B cells, but declined in newly generated memory B and plasma cells. Intravital microscopy of the inguinal lymph node (LN) of immunized mice revealed the rapid appearance of GFP(+) cells at LN interfollicular regions and along the T/B cell borders, and eventually within GCs. Analysis of WT, knock-in, and mixed chimeric mice indicated that RGS13 constrains extra-follicular plasma cell generation, GC size, and GC B cell numbers. Analysis of select cell cycle and GC specific genes disclosed an aberrant gene expression profile in the Rgs13 deficient GC B cells. These results indicate that RGS13, likely acting at cell membranes and in nuclei, helps coordinate key decision points during the expansion and differentiation of naive B cells.

  14. Germination and storage of caranda seeds (Copernicia alba

    Directory of Open Access Journals (Sweden)

    Tathiana Elisa Masetto

    2012-12-01

    Full Text Available Caranda is a Brazilian native palm tree, belonging to Arecaceae family and occurring, predominan,t in the Brazilian Swampland. This work studied the germination and the caranda seeds storage behavior. The germination study was carried out in the temperatures of 25ºC and 30ºC in constant white light and the alternate temperature of 20/30ºC with 10 hours of darkness for the lowest temperature and 14 hours of light for the highest temperature, using paper and paper roll as substratum. At the end of test, the germination percentage, germination speed index, germination medium time and the primary root length were evaluated. After the seeds improvement, it was obtained two sub-samples destined for 30 days storage in two invironments: cold and dry chamber (16ºC/55% UR and freezer (-18ºC. The following tests, water content, germination, germination medium time and primary root length were evaluated. The caranda seeds germination in paper roll and on paper is favored by the temperature of 20/30ºC in paper roll and on paper and paper roll on 30ºC. The freezing and cold camera storage during 30 days are efficient to reduce the germination medium time of caranda seeds and to keep the germination percentage.

  15. [Study on germination characteristics of Disporum cantoniense].

    Science.gov (United States)

    Huang, Nan; Wang, Hua-Lei; Zhao, Zhi; Liu, Hong-Chang; Luo, Chun-Li; Li, Jin-Ling; Luo, Fu-Lai; Huang, Ming-Jin

    2012-11-01

    To study the seed germination characteristic and optimal germination condition of wild Disporum cantoniense. Used wild Disporum cantoniense seed as the test materials, the rate of water absorption of the seed was determined. The germination rates under different conditions, along a temperature gradient (15, 20, 25 and 30 degres C), in light or dark, on top or between wet filter papers, and keeping or removing the seed coat, were determined respectively using petri dish method. At the same time germination trends were observed. The thousand seed weight was 33.24 g, and the seed water-absorbing reached saturation pot after soaking for 30 h. Higher germination rates were respectively recorded at 25 degrees C, between filter papers, and in dark after 24 h soaking in the pretreatment solution. The optimal condition for the germination of the seed of wild Disporum cantoniense is as follow: keeping testa, seed soaking for 24 h in seed germination agent and being incubated between wet filter papers in dark at 25 degrees C.

  16. Oxygen dependency of germinating Brassica seeds

    Science.gov (United States)

    Park, Myoung Ryoul; Hasenstein, Karl H.

    2016-02-01

    Establishing plants in space, Moon or Mars requires adaptation to altered conditions, including reduced pressure and composition of atmospheres. To determine the oxygen requirements for seed germination, we imbibed Brassica rapa seeds under varying oxygen concentrations and profiled the transcription patterns of genes related to early metabolism such as starch degradation, glycolysis, and fermentation. We also analyzed the activity of lactate dehydrogenase (LDH) and alcohol dehydrogenase (ADH), and measured starch degradation. Partial oxygen pressure (pO2) greater than 10% resulted in normal germination (i.e., protrusion of radicle about 18 hours after imbibition) but lower pO2 delayed and reduced germination. Imbibition in an oxygen-free atmosphere for three days resulted in no germination but subsequent transfer to air initiated germination in 75% of the seeds and the root growth rate was transiently greater than in roots germinated under ambient pO2. In hypoxic seeds soluble sugars degraded faster but the content of starch after 24 h was higher than at ambient oxygen. Transcription of genes related to starch degradation, α-amylase (AMY) and Sucrose Synthase (SUS), was higher under ambient O2 than under hypoxia. Glycolysis and fermentation pathway-related genes, glucose phosphate isomerase (GPI), 6-phosphofructokinase (PFK), fructose 1,6-bisphosphate aldolase (ALD), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), pyruvate decarboxylase (PDC), LDH, and ADH, were induced by low pO2. The activity of LDH and ADH was the highest in anoxic seeds. Germination under low O2 conditions initiated ethanolic fermentation. Therefore, sufficient oxygen availability is important for germination before photosynthesis provides necessary oxygen and the determination of an oxygen carrying capacity is important for uniform growth in space conditions.

  17. Nicotinamidase activity is important for germination.

    Science.gov (United States)

    Hunt, Lee; Holdsworth, Michael J; Gray, Julie E

    2007-08-01

    It has been suggested that nicotinamide must be degraded during germination; however, the enzyme responsible and its physiological role have not been previously studied. We have identified an Arabidopsis gene, NIC2, that is expressed at relatively high levels in mature seed, and encodes a nicotinamidase enzyme with homology to yeast and bacterial nicotinamidases. Seed of a knockout mutant, nic2-1, had reduced nicotinamidase activity, retarded germination and impaired germination potential. nic2-1 germination was restored by after-ripening or moist chilling, but remained hypersensitive to application of nicotinamide or ABA. Nicotinamide is a known inhibitor of NAD-degrading poly(ADP-ribose) polymerases (PARP enzymes) that are implicated in DNA repair. We found reduced poly(ADP)ribosylation levels in nic2-1 seed, which were restored by moist chilling. Furthermore, nic2-1 seed had elevated levels of NAD, and germination was hypersensitive to methyl methanesulphonate (MMS), suggesting that PARP activity and DNA repair responses were impaired. We suggest that nicotinamide is normally metabolized by NIC2 during moist chilling or after-ripening, which relieves inhibition of PARP activity and allows DNA repair to occur prior to germination.

  18. Combining Ability for Germination Traits in Jatropha curcas L.

    Directory of Open Access Journals (Sweden)

    A. K. M. Aminul Islam

    2013-01-01

    Full Text Available Six parents of Jatropha curcas were crossed in half diallel fashion, and the F1s were evaluated to determine the combining ability for nine germination parameters. The ratio between general combining ability (GCA and specific combining ability (SCA variances indicated preponderance of additive gene action for all the characters except germination percentage, time of 50% germination, seedling length, and seedling vigor index. The parents P1 and P2 were the best general combiner for most of the characters studied. The cross P1×P5 was the best specific combiner for speed of emergence, germination percentage, germination energy, germination index, and seedling vigor index, the cross P2×P5 for mean germination time, time of 50% germination, and seedling length, and the cross P4×P5 for number of days to first germination. The germination percentage varied from 58.06 to 92.76% among the parents and 53.43 to 98.96% among the hybrids. The highest germination (98.96% was observed in hybrid P2×P4, and none of the hybrids or parents showed 100% germination. The highest germination index (GI and seedling vigor index (SVI were found in hybrid P1×P5 and P2×P5, respectively. The results of this study provide clue for the improvement of Jatropha variety through breeding program.

  19. Synergistic effect of oridonin and a PI3K/mTOR inhibitor on the non-germinal center B cell-like subtype of diffuse large B cell lymphoma

    Directory of Open Access Journals (Sweden)

    Kai Qing

    2016-08-01

    Full Text Available Abstract We demonstrate the synergistic antitumor effect of oridonin and the PI3K/mTOR inhibitor NVP-BEZ235 on the non-germinal center B cell-like subtype of diffuse large B cell lymphoma (non-GCB DLBCL both in vitro and in vivo. The underlying mechanism may be multifunctional, involving apoptosis, AKT/mTOR and NF-kB inactivation, and ROS-mediated DNA damage response. Our findings pave the way for a new potential treatment option for non-GCB DLBCL with the combination of oridonin and NVP-BEZ235.

  20. Practical aspects of temperature intervention in germination and post-germination development of bacterial spores

    International Nuclear Information System (INIS)

    Stastna, J.; Vinter, V.; Babicka, J.

    1974-01-01

    Temperature dependence of germination and post-germination growth was studied in the spores of B a c i l l u s c e r e u s NCIB 8122. It was found that a temperature of 5 0 C slowed down germination, with the cells showing the capacity of synthetizing only a limited amount of proteins. The synthesis of the cellular wall, however, went on for another few hours. Thick-walled, less permeable and less metabolically active cells formed having an altered ultrastructure. A prolonged cultivation at 30 0 C resulted in the reduction of living cells while the low cultivation temperature (5 0 C) was found to have a protective effect. Pre-irradiation with 30g krad of gamma radiation increased the sensitivity of surviving cells to the cultivation conditions. Spores in the post-germination period were found to be much more resistent and alternating use of low and higher temperatures had little effect on growth

  1. Determination of Kinetic and Thermodynamic Parameters that Describe Isothermal Seed Germination: A Student Research Project.

    Science.gov (United States)

    Hageseth, Gaylord T.

    1982-01-01

    Describes a project for students to collect and fit data to a theoretical mathematical model that describes the rate of isothermal seed germination, including activation energy for substrate and produce and the autocatalytic reaction, and changes in enthalpy, entropy, and the Gibb's free energy. (Author/SK)

  2. seed germination and seedlings growth

    African Journals Online (AJOL)

    STORAGESEVER

    2007-12-17

    Dec 17, 2007 ... The role of 20E in plant physiology including seed germination is not studied. ..... GA3, ABA and CKs on lettuce Lactuca sativa seed germination are ..... Practical uses for ecdysteroids in mammals and humans: an update. J.

  3. Etude des potentialites germinatives pour une regeneration ...

    African Journals Online (AJOL)

    ... taux de germination a été obtenu avec des graines de petites tailles à la température ambiante (32°C). Le traitement préalable à l'eau de javel à 8% accroît le taux de germination (40% de réponse). La lumière et l'obscurité n'ont aucun effet sur la germination. Mots clés : Neocarya macrophylla, germination, régénération.

  4. EFFECT OF SOME SEED TREATMENTS ON GERMINATION OF Sideritis perfoliata L.

    Directory of Open Access Journals (Sweden)

    Olcay ARABACI

    2015-08-01

    Full Text Available The genus Sideritis L. belonging to Lamiaceae family is represented with more than 150 species worldwide.. The genus is represented in Turkey by 46 species and 53 taxon within two sections among which 39 are endemic. Endemism rate (79.5% in Turkey is quite high because Turkey is one of the two major gene centers of the genus. Sideritis species are known among people with different local names such as mountain tea, highland tea, sage, sarıkız tea and tail tea. According to some recent researches, extracts obtained from Sideritis species were shown to have antistress, antiulcer, analgesic, antioxidant, antibacterial, anti-inflammatory and insecticidal effects. The interest in and the demand for this plant species has increased particularly due to its antioxidant effect. Seed germination studies of this species have great importance on determination of production strategies of medical and aromatic plants. This study was conducted to determine the effects of some pre-treatments (ethylene, gibberellin, mannitol, seaweed and cold pre-treatment on germination of Sideritis perfoliata L. which is naturally grown in western Anatolia. The study was carried out at 25/15oC day/night temperature conditions. The experiments were performed according to completely randomized design with 3 replications at Adnan Menderes University, Faculty of Agriculture, Field Crops Laboratory. Significant differences were determined between applications with respect to germination rates and germination vigor values.

  5. 7 CFR 201.53 - Source of seeds for germination.

    Science.gov (United States)

    2010-01-01

    ... REGULATIONS Germination Tests in the Administration of the Act § 201.53 Source of seeds for germination. (a) When both purity and germination tests are required, seeds for germination shall be taken from the... to size or appearance. (b) When only a germination test is required and the pure seed is estimated or...

  6. Influence of diesel fuel on seed germination

    International Nuclear Information System (INIS)

    Adam, Gillian; Duncan, Harry

    2002-01-01

    The volatile fraction of diesel fuel played a major role in delaying seed emergence and reducing percentage germination. - The use of plant-based systems to remediate contaminated soils has become an area of intense scientific study in recent years and it is apparent that plants which grow well in contaminated soils need to be identified and screened for use in phytoremediation technologies. This study investigated the effect of diesel fuel on germination of selected plant species. Germination response varied greatly with plant species and was species specific, as members of the same plant family showed differential sensitivity to diesel fuel contamination. Differences were also seen within plant subspecies. At relatively low levels of diesel fuel contamination, delayed seed emergence and reduced percentage germination was observed for the majority of plant species investigated. Results suggest the volatile fraction of diesel fuel played an influential role in delaying seed emergence and reducing percentage germination. In addition, the remaining diesel fuel in the soil added to this inhibitory effect on germination by physically impeding water and oxygen transfer between the seed and the surrounding soil environment, thus hindering the germination response

  7. IAA production during germination of Orobanche spp. seeds.

    Science.gov (United States)

    Slavov, Slavtcho; van Onckelen, Henry; Batchvarova, Rossitza; Atanassov, Atanas; Prinsen, Els

    2004-07-01

    Broomrapes (Orobanche spp.) are parasitic plants, whose growth and development fully depend on the nutritional connection established between the parasite and the roots of the respective host plant. Phytohormones are known to play a role in establishing the specific Orobanche-host plant interaction. The first step in the interaction is seed germination triggered by a germination stimulant secreted by the host-plant roots. We quantified indole-3-acetic acid (IAA) and abscisic acid (ABA) during the seed germination of tobacco broomrape (Orobanche ramosa) and sunflower broomrape (O. cumana). IAA was mainly released from Orobanche seeds in host-parasite interactions as compared to non-host-parasite interactions. Moreover, germinating seeds of O. ramosa released IAA as early as 24 h after the seeds were exposed to the germination stimulant, even before development of the germ tube. ABA levels remained unchanged during the germination of the parasites' seeds. The results presented here show that IAA production is probably part of a mechanism triggering germination upon the induction by the host factor, thus resulting in seed germination.

  8. DELAY OF GERMINATION 1 mediates a conserved coat-dormancy mechanism for the temperature- and gibberellin-dependent control of seed germination

    OpenAIRE

    Graeber, K.; Linkies, A.; Steinbrecher, T.; Tarkowská, D. (Danuše); Turečková, V. (Veronika); Ignatz, M.; Voegele, A.; Urbanová, T. (Terezie); Strnad, M. (Miroslav); Leubner-Metzger, G. (Gerhard)

    2014-01-01

    Seed germination is an important life-cycle transition because it determines subsequent plant survival and reproductive success. To detect optimal spatiotemporal conditions for germination, seeds act as sophisticated environmental sensors integrating information such as ambient temperature. Here we show that the DELAY OF GERMINATION 1 (DOG1) gene, known for providing dormancy adaptation to distinct environments, determines the optimal temperature for seed germination. By reciprocal gene-swapp...

  9. Methods for assessing Phytophthora ramorum chlamydospore germination

    Science.gov (United States)

    Joyce Eberhart; Elilzabeth Stamm; Jennifer Parke

    2013-01-01

    Germination of chlamydospores is difficult to accurately assess when chlamydospores are attached to remnants of supporting hyphae. We developed two approaches for closely observing and rigorously quantifying the frequency of chlamydospore germination in vitro. The plate marking and scanning method was useful for quantifying germination of large...

  10. Early depletion of proliferating B cells of germinal center in rapidly progressive simian immunodeficiency virus infection

    International Nuclear Information System (INIS)

    Zhang Zhiqiang; Casimiro, Danilo R.; Schleif, William A.; Chen, Minchun; Citron, Michael; Davies, Mary-Ellen; Burns, Janine; Liang, Xiaoping; Fu, Tong-Ming; Handt, Larry; Emini, Emilio A.; Shiver, John W.

    2007-01-01

    Lack of virus specific antibody response is commonly observed in both HIV-1-infected humans and SIV-infected monkeys with rapid disease progression. However, the mechanisms underlying this important observation still remain unclear. In a titration study of a SIVmac239 viral stock, three out of six animals with viral inoculation rapidly progressed to AIDS within 5 months. Unexpectedly, there was no obvious depletion of CD4 + T cells in both peripheral and lymph node (LN) compartments in these animals. Instead, progressive depletion of proliferating B cells and disruption of the follicular dendritic cell (FDC) network in germinal centers (GC) was evident in the samples collected at as early as 20 days after viral challenge. This coincided with undetectable, or weak and transient, virus-specific antibody responses over the course of infection. In situ hybridization of SIV RNA in the LN samples revealed a high frequency of SIV productively infected cells and large amounts of accumulated viral RNA in the GCs in these animals. Early severe depletion of GC proliferating B cells and disruption of the FDC network may thus result in an inability to mount a virus-specific antibody response in rapid progressors, which has been shown to contribute to accelerated disease progression of SIV infection

  11. 11. IAEA consultants' meeting of the nuclear reaction data centers. Obninsk, 7-11 October 1991

    International Nuclear Information System (INIS)

    Lemmel, H.D.

    1992-03-01

    This report summarizes the 1991 co-ordination meeting in Obninsk, Russia, of the national and regional nuclear reaction data centers, convened by the IAEA at regular intervals. The main topics are: the international exchange of nuclear reaction data by means of the ''EXFOR'' system, and the further development of this system; the ''CINDA'' system as an international index and bibliography to neutron reaction data; the sharing of the workload for speedy and reliable nuclear data compilation; the exchanged and documentation of evaluated data libraries in ENDF format, with the goal of rendering data center services to data users in IAEA Member States by means of computer retrievals, online services and printed materials

  12. Molecular electronics of a single photosystem I reaction center: Studies with scanning tunneling microscopy and spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, I.; Lee, J.W.; Warmack, R.J.; Allison, D.P.; Greenbaum, E. [Oak Ridge National Lab., TN (United States)

    1995-03-14

    Thylakoids and photosystem I (PSI) reaction centers were imaged by scanning tunneling microscopy. The thylakoids were isolated from spinach chloroplasts, and PSI reaction centers were extracted from thylakoid membranes. Because thylakoids are relatively thick nonconductors, they were sputter-coated with Pd/Au before imaging. PSI photosynthetic centers and chemically platinized PSI were investigated without sputter-coating. They were mounted on flat gold substrates that had been treated with mercaptoacetic acid to help bind the proteins. With tunneling spectroscopy, the PSI centers displayed a semiconductor-like response with a band gap of 1.8 eV. Lightly platinized (platinized for 1 hr) centers displayed diode-like conduction that resulted in dramatic contrast changes between images taken with opposite bias voltages. The electronic properties of this system were stable under long-term storage. 42 refs., 7 figs.

  13. Germination of red alder seed.

    Science.gov (United States)

    M.A. Radwan; D.S. DeBell

    1981-01-01

    Red alder seeds were collected from six locations throughout the natural range of the species. Each seed lot was obtained from a single tree, and the seeds were used to determine germination with and without stratification treatment. Irrespective of treatment, germination varied significantly (P

  14. Germination and elongation of flax in microgravity

    Science.gov (United States)

    Levine, Howard G.; Anderson, Ken; Boody, April; Cox, Dave; Kuznetsov, Oleg A.; Hasenstein, Karl H.

    2003-05-01

    This experiment was conducted as part of a risk mitigation payload aboard the Space Shuttle Atlantis on STS-101. The objectives were to test a newly developed water delivery system, and to determine the optimal combination of water volume and substrate for the imbibition and germination of flax ( Linum usitatissimum) seeds in space. Two different combinations of germination paper were tested for their ability to absorb, distribute, and retain water in microgravity. A single layer of thick germination paper was compared with one layer of thin germination paper under a layer of thick paper. Paper strips were cut to fit snugly into seed cassettes, and seeds were glued to them with the micropyle ends pointing outward. Water was delivered in small increments that traveled through the paper via capillary action. Three water delivery volumes were tested, with the largest (480 μL) outperforming the 400 μL, and 320 μL volumes for percent germination (90.6%) and root growth (mean = 4.1 mm) during the 34-hour spaceflight experiment. The ground control experiment yielded similar results, but with lower rates of germination (84.4%) and shorter root lengths (mean = 2.8 mm). It is not clear if the roots emerged more quickly in microgravity and/or grew faster than the ground controls. The single layer of thick germination paper generally exhibited better overall growth than the two layered option. Significant seed position effects were observed in both the flight and ground control experiments. Overall, the design of the water delivery system, seed cassettes and the germination paper strip concept was validated as an effective method for promoting seed germination and root growth under microgravity conditions.

  15. The oxygen requirement of germinating flax seeds

    Science.gov (United States)

    Kuznetsov, O.; Hasenstein, K.

    Experiments for earth orbit are typically prepared on the ground and often germinated in orbit in order to study gravity effects on developing seedlings. Germination requires the breakdown of storage compounds and respiration. In orbit the formation of a water layer around the seed may further limit oxygen availability. Therefore, the oxygen content of the available gas volume is one of the limiting factors for seed germination. In preparation for an upcoming shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware. We tested per seed chamber (gas volume = 14 mL, O2 = 2.9 mL) between 4 to 32 seeds glued to germination paper by 1% (w/v) gum guar. A lexan cover and a gasket hermetically sealed each of the eight chambers. For imbibition of the seeds a previously optimized amount of distilled water was dispensed through sealed inlets. The seedlings were allowed to grow for either 32 to 48 h on a clinostat or without microgravity simulation. Then their root length was measured. With 32 seeds per chamber, four times the intended number of seeds for the flight, the germination rate decreased from 94 to 69%, and the root length was reduced by 20%. Experiments on the germination and root length in controlled atmospheres (5, 10, 15 and 21% O2 ) suggest that germination and growth for two days requires about 200 :l of O (1 mL air) per seed. Our2 experiments correlate oxygen dependency from seed mass and germination temperature, and analyze accumulation of gaseous metabolites (supported by NASA grant NAG10-0190).

  16. Is seed conditioning essential for Orobanche germination?

    Science.gov (United States)

    Plakhine, Dina; Ziadna, Hammam; Joel, Daniel M

    2009-05-01

    Parasitic Orobanchaceae germinate only after receiving a chemical stimulus from roots of potential host plants. A preparatory phase of several days that follows seed imbibition, termed conditioning, is known to be required; thereafter the seeds can respond to germination stimulants. The aim of this study was to examine whether conditioning is essential for stimulant receptivity. Non-conditioned seeds of both Orobanche cumana Wallr. and O. aegyptiaca Pers. [syn. Phelipanche aegyptiaca (Pers.) Pomel] were able to germinate in response to chemical stimulation by GR24 even without prior conditioning. Stimulated seeds reached maximal germination rates about 2 weeks after the onset of imbibition, no matter whether the seeds had or had not been conditioned before stimulation. Whereas the lag time between stimulation and germination response of non-conditioned seeds was longer than for conditioned seeds, the total time between imbibition and germination was shorter for the non-conditioned seeds. Unlike the above two species, O. crenata Forsk. was found to require conditioning prior to stimulation. Seeds of O. cumana and O. aegyptiaca are already receptive before conditioning. Thus, conditioning is not involved in stimulant receptivity. A hypothesis is put forward, suggesting that conditioning includes (a) a parasite-specific early phase that allows the imbibed seeds to overcome the stress caused by failing to receive an immediate germination stimulus, and (b) a non-specific later phase that is identical to the pregermination phase between seed imbibition and actual germination that is typical for all higher plants.

  17. Germination of beans and snap beans seed

    Directory of Open Access Journals (Sweden)

    Zdravković Milan

    2000-01-01

    Full Text Available The aim of this study was to investigate germination of good bean seed of the variety Galeb and the bad bean seed of the same variety. We were also interested in germination of bean and snap bean seed damaged by grain weevil, and in germination of the seed treated by freezing which was aimed at controlling grain weevil by cold. We also recorded the differences between bean and snap bean seed, which was or was not treated by freezing in laboratory conditions. This investigation was carried out by applying the two factorial block system. The obtained results were evaluated by the variance analysis and x2 test These results suggest that the bean seed of a bad fraction had low levels of germination, but still it was present. Although the seed of good appearance was carefully selected, germination was slightly lower than it should have been. The seed with the large amount of grain weevils performed a high level germination in laboratory conditions. There were no differences in germination between the seed injured by grain weevil either in beans or in snap beans. As for the seed treated or untreated by freezing, there also were no differences between beans and snap beans. .

  18. Germination and storage of pollen

    NARCIS (Netherlands)

    Visser, T.

    1955-01-01

    Germination of pear pollen markedly improved when boric acid was added to the medium. The pollen was more sensitive to boron in water than in 10 % sugar solution. Supplying weak solutions of boron to pear branches before flowering resulted in a good germination of the pollen in sugar solution

  19. Factors Defining Field Germination of Oilseed Radish Seeds

    Directory of Open Access Journals (Sweden)

    N.V. Dorofeev

    2013-08-01

    Full Text Available Influence of temperature, depth of crops and granulometric of soil structure on germination speed, laboratory and field germination of oilseed radish seeds were studied. It was established that the period of seed-germination is defined both by temperature and granulometric structure of soil. The highest field germination was marked on sandy loam at depth of crops' seeds at 3 cm and 20°С.

  20. Germination and elongation of flax in microgravity

    Science.gov (United States)

    Levine, Howard G.; Anderson, Ken; Boody, April; Cox, Dave; Kuznetsov, Oleg A.; Hasenstein, Karl H.

    2003-01-01

    This experiment was conducted as part of a risk mitigation payload aboard the Space Shuttle Atlantis on STS-101. The objectives were to test a newly developed water delivery system, and to determine the optimal combination of water volume and substrate for the imbibition and germination of flax (Linum usitatissimum) seeds in space. Two different combinations of germination paper were tested for their ability to absorb, distribute, and retain water in microgravity. A single layer of thick germination paper was compared with one layer of thin germination paper under a layer of thick paper. Paper strips were cut to fit snugly into seed cassettes, and seeds were glued to them with the micropyle ends pointing outward. Water was delivered in small increments that traveled through the paper via capillary action. Three water delivery volumes were tested, with the largest (480 microliters) outperforming the 400 microliters and 320 microliters volumes for percent germination (90.6%) and root growth (mean=4.1 mm) during the 34-hour spaceflight experiment. The ground control experiment yielded similar results, but with lower rates of germination (84.4%) and shorter root lengths (mean=2.8 mm). It is not clear if the roots emerged more quickly in microgravity and/or grew faster than the ground controls. The single layer of thick germination paper generally exhibited better overall growth than the two layered option. Significant seed position effects were observed in both the flight and ground control experiments. Overall, the design of the water delivery system, seed cassettes and the germination paper strip concept was validated as an effective method for promoting seed germination and root growth under microgravity conditions. c2003 COSPAR. Published by Elsevier Ltd. All rights reserved.

  1. Differential Effects of Carbohydrates on Arabidopsis Pollen Germination.

    Science.gov (United States)

    Hirsche, Jörg; García Fernández, José M; Stabentheiner, Edith; Großkinsky, Dominik K; Roitsch, Thomas

    2017-04-01

    Pollen germination as a crucial process in plant development strongly depends on the accessibility of carbon as energy source. Carbohydrates, however, function not only as a primary energy source, but also as important signaling components. In a comprehensive study, we analyzed various aspects of the impact of 32 different sugars on in vitro germination of Arabidopsis pollen comprising about 150 variations of individual sugars and combinations. Twenty-six structurally different mono-, di- and oligosaccharides, and sugar analogs were initially tested for their ability to support pollen germination. Whereas several di- and oligosaccharides supported pollen germination, hexoses such as glucose, fructose and mannose did not support and even considerably inhibited pollen germination when added to germination-supporting medium. Complementary experiments using glucose analogs with varying functional features, the hexokinase inhibitor mannoheptulose and the glucose-insensitive hexokinase-deficient Arabidopsis mutant gin2-1 suggested that mannose- and glucose-mediated inhibition of sucrose-supported pollen germination depends partially on hexokinase signaling. The results suggest that, in addition to their role as energy source, sugars act as signaling molecules differentially regulating the complex process of pollen germination depending on their structural properties. Thus, a sugar-dependent multilayer regulation of Arabidopsis pollen germination is supported, which makes this approach a valuable experimental system for future studies addressing sugar sensing and signaling. © The Author 2017. Published by Oxford University Press on behalf of Japanese Society of Plant Physiologists. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  2. on seed germination and growth of Garcinia kola

    African Journals Online (AJOL)

    SARAH

    2016-07-31

    Jul 31, 2016 ... Seed germination tests: After 72 h of fermentation in plastic bags, seeds were ... Models (GLM) procedure of the R statistical version 9.1 was used to identify traits .... L-1) had accelerated seed germination. Germination rates.

  3. Model of deep centers formation and reactions in electron irradiated InP

    International Nuclear Information System (INIS)

    Sibille, A.; Suski, J.; Gilleron, M.

    1986-01-01

    We present a model of the production of deep centers and their reactions following electron irradiations in InP. We propose that the dominant hole traps in p-InP and electron traps in p + n InP junctions are complexes between shallow acceptors and a common intrinsic entity, the phosphorus interstitial or vacancy. The reactions observed below and above room temperature are then due to a local mobility of this entity, which can be obtained as well by thermal as by electronic stimulation of the reactions. This model implies the long-range migration (at least down to 16 K) of this entity, and explains the strongly different behavior of n-InP compared to p-InP samples

  4. Freezing tolerance of conifer seeds and germinants.

    Science.gov (United States)

    Hawkins, B J; Guest, H J; Kolotelo, D

    2003-12-01

    Survival after freezing was measured for seeds and germinants of four seedlots each of interior spruce (Picea glauca x engelmannii complex), lodgepole pine (Pinus contorta Dougl. ex Loud.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and western red cedar (Thuja plicata Donn ex D. Donn). Effects of eight seed treatments on post-freezing survival of seeds and germinants were tested: dry, imbibed and stratified seed, and seed placed in a growth chamber for 2, 5, 10, 15, 20 or 30 days in a 16-h photoperiod and a 22/17 degrees C thermoperiod. Survival was related to the water content of seeds and germinants, germination rate and seedlot origin. After freezing for 3 h at -196 degrees C, dry seed of most seedlots of interior spruce, Douglas-fir and western red cedar had 84-96% germination, whereas lodgepole pine seedlots had 53-82% germination. Freezing tolerance declined significantly after imbibition in lodgepole pine, Douglas-fir and interior spruce seed (western red cedar was not tested), and mean LT50 of imbibed seed of these species was -30, -24.5 and -20 degrees C, respectively. Freezing tolerance continued to decline to a minimum LT50 of -4 to -7 degrees C after 10 days in a growth chamber for interior spruce, Douglas-fir and lodgepole pine, or after 15 days for western red cedar. Minimum freezing tolerance was reached at the stage of rapid hypocotyl elongation. In all species, a slight increase in freezing tolerance of germinants was observed once cotyledons emerged from the seed coat. The decrease in freezing tolerance during the transition from dry to germinating seed correlated with increases in seed water content. Changes in freezing tolerance between 10 and 30 days in the growth chamber were not correlated with seedling water content. Within a species, seedlots differed significantly in freezing tolerance after 2 or 5 days in the growth chamber. Because all seedlots of interior spruce and lodgepole pine germinated quickly, there was no correlation

  5. Evolution of 'smoke' induced seed germination in pyroendemic plants

    Science.gov (United States)

    Keeley, J. E.; Pausas, J.G.

    2016-01-01

    Pyroendemics are plants in which seedling germination and successful seedling recruitment are restricted to immediate postfire environments. In many fire-prone ecosystems species cue their germination to immediate postfire conditions. Here we address how species have evolved one very specific mechanism, which is using the signal of combustion products from biomass. This is often termed ‘smoke’ stimulated germination although it was first discovered in studies of charred wood effects on germination of species strictly tied to postfire conditions (pyroendemics). Smoke stimulated germination has been reported from a huge diversity of plant species. The fact that the organic compound karrikin (a product of the degradation of cellulose) is a powerful germination cue in many species has led to the assumption that this compound is the only chemical responsible for smoke-stimulated germination. Here we show that smoke-stimulated germination is a complex trait with different compounds involved. We propose that convergent evolution is a more parsimonious model for smoke stimulated germination, suggesting that this trait evolved multiple times in response to a variety of organic and inorganic chemical triggers in smoke. The convergent model is congruent with the evolution of many other fire-related traits.

  6. 7 CFR 201.6 - Germination.

    Science.gov (United States)

    2010-01-01

    ... REGULATIONS Records for Agricultural and Vegetable Seeds § 201.6 Germination. The complete record shall include the records of all laboratory tests for germination and hard seed for each lot of seed offered for transportation in whole or in part. The record shall show the kind of seed, lot number, date of test, percentage...

  7. Pulse seed germination improves antioxidative activity of phenolic compounds in stripped soybean oil-in-water emulsions.

    Science.gov (United States)

    Xu, Minwei; Jin, Zhao; Peckrul, Allen; Chen, Bingcan

    2018-06-01

    The purpose of this study was to investigate antioxidative activity of phenolic compounds extracted from germinated pulse seed including chickpeas, lentils and yellow peas. Phenolic compounds were extracted at different germination time and total phenolic content was examined by Folin Ciocalteu's reaction. Antioxidative activity of extracts was characterized by in vitro assay including 2, 2-diphenyl-1-picrylhydrazyl radical scavenging capacity (DPPH), oxygen radical absorbance capacity (ORAC), iron-binding assay, and in stripped soybean oil-in-water emulsions. The results suggested that germination time is critical for phenolic compounds production. The form variation of phenolic compounds influenced the antioxidative activity of phenolic compounds both in vitro assay and in emulsion systems. Soluble bound phenolic compounds showed higher antioxidative ability in emulsion system with the order of chickpea > yellow pea > lentil. On the basis of these results, soluble bound phenolic compounds may be considered as a promising natural antioxidant to prevent lipid oxidation in foods. Copyright © 2018 Elsevier Ltd. All rights reserved.

  8. The effects of light-induced reduction of the photosystem II reaction center

    Czech Academy of Sciences Publication Activity Database

    Kutý, Michal

    2009-01-01

    Roč. 8, č. 15 (2009), s. 923-933 ISSN 1610-2940 R&D Projects: GA MŠk(CZ) LC06010 Institutional research plan: CEZ:AV0Z60870520 Keywords : Photosystem II * Reaction center * Pheophytin Subject RIV: CE - Biochemistry Impact factor: 2.336, year: 2009

  9. COMPARATIVE GERMINATION RESPONSES OF COWPEA AND ...

    African Journals Online (AJOL)

    iya beji

    inadequate soil moisture (25%) in both cowpea and maize with greater effect on ... Of all factors controlling productivity, seed germination and vigour are pre- .... depth and date of first irrigation on seed cane germination of two commercial.

  10. Electrostatic dominoes: long distance propagation of mutational effects in photosynthetic reaction centers of Rhodobacter capsulatus.

    Science.gov (United States)

    Sebban, P; Maróti, P; Schiffer, M; Hanson, D K

    1995-07-04

    Two point mutants from the purple bacterium Rhodobacter capsulatus, both modified in the M protein of the photosynthetic reaction center, have been studied by flash-induced absorbance spectroscopy. These strains carry either the M231Arg --> Leu or M43ASN --> Asp mutations, which are located 9 and 15 A, respectively, from the terminal electron acceptor QB. In the wild-type Rb. sphaeroides structure, M231Arg is involved in a conserved salt bridge with H125Glu and H232Glu and M43Asn is located among several polar residues that form or surround the QB binding site. These substitutions were originally uncovered in phenotypic revertants isolated from the photosynthetically incompetent L212Glu-L213Asp --> Ala-Ala site-specific double mutant. As second-site suppressor mutations, they have been shown to restore the proton transfer function that is interrupted in the L212Ala-L213Ala double mutant. The electrostatic effects that are induced in reaction centers by the M231Arg --> Leu and M43Asn --> Asp substitutions are roughly the same in either the double-mutant or wild-type backgrounds. In a reaction center that is otherwise wild type in sequence, they decrease the free energy gap between the QA- and QB- states by 24 +/- 5 and 45 +/- 5 meV, respectively. The pH dependences of K2, the QA-QB QAQB- equilibrium constant, are altered in reaction centers that carry either of these substitutions, revealing differences in the pKas of titratable groups compared to the wild type.(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Germination traits of three weed species in Kosovo

    Directory of Open Access Journals (Sweden)

    A. Mehmeti

    2010-02-01

    Full Text Available Amaranthus retroflexus, Echinochloa crus-galli and Datura stramonium are the most important weed species in Kosovo. They cause severe yield depression, contaminate fodder and negatively affect growth and reproduction of other weed species. To counteract these problems, specific strategies need to be developed. Such strategies should consider information on species germination traits. In this context, our study provides information on temperature requirements for germination. Seeds of A. retroflexus, E. crus-galli and D. stramonium were harvested in two sub-regions of Kosovo (western and eastern parts differing in climate and land use. They were set for germination experiments in growth chambers at temperatures ranging from 3 to 35 °C and under field conditions. In both experiments, the germination rate differed between species and provenances. In the growth chamber experiment, germination of all three species was negligible below 15 °C and reached the highest rates between 24 and 30 °C. Seeds originating from the western part of Kosovo had higher germination rates and required a lower temperature for germination than seeds originating from the eastern part. In the field experiment, the time-dependent germination behaviour of D. stramonium differed between provenances. In general, germination started when soil temperature was above 18 °C and continued as long as the soil was moist. The results are discussed in the context of the need to develop weed management strategies against these weeds in Kosovo.

  12. Germination, seed diameter and pregerminative treatments in species with different purposes of use

    Directory of Open Access Journals (Sweden)

    Ricardo Vinicio Abril-Saltos

    2017-09-01

    Full Text Available The evaluation of vegetal species germination consents to know its characteristics and permits to understand the factors that influence this process. The aim of this research was to know the germination’s characteristics of some species, such as Eugenia stipitata McVaugh, Inga edulis Mart, Inga spectabilis (Vahl Wild, Piptocoma discolor (Kunth Pruski, Stachytarpheta cayennensis (Rich. Vahl, and Verbena officinalis L., and also their reaction to pregerminative treatments depending on the seed’s diameter. This study was carried out in Pastaza, Province of Pastaza, Ecuador, between February and June, 2014. Different diameters of seeds and pregerminative treatments were used in species, which did not present germination percentages higher than 40%. In the first practice I. edulis and I. spectabilis exceeded this value without treatment. Other species had lower values. Seeds were classified considering two diameters and two doses of gibberellin acid, this was applied to, and evaluated in the E. stipitata. In addition, scarification with sulfuric acid was done. After 45 days of its application, 100 ppm of gibberellic acid with larger seed diameter reported higher percentages of germination in S. cayenennsis, and in E. stipitata, which also interacted with the scarification. V. officinalis and P. discolor, did not present any response to the applications made. I. edulis and I. spectabilis presented high germination percentages without pregerminative treatments, E. stipitata and S. cayenennsis showed response to seed diameter and the applied treatments, while P discolor and V. officinalis did not show any response.

  13. The pleiotropic effects of the seed germination inhibitor germostatin.

    Science.gov (United States)

    Ye, Yajin; Zhao, Yang

    2016-01-01

    Seed dormancy and germination are the most important adaptive traits of seed plants, which control the germination in a proper space and time. Internal genetic factors together with environmental cues govern seed dormancy and germination. Abscisic acid (ABA), a key phytohormone induces seed dormancy and inhibits seed germination through its molecular genetic signaling network responding the seed inherent physiological and environmental factors. Recently, auxin has been shown to be another phytohormone that induces seed dormancy. We have recently shown that germonstatin (GS), a small synthetic molecule identified by high through-put chemical genetic screenings, inhibits seed germination through up-regulating auxin signaling and inducing auxin biosynthesis. GERMOSTATIN RESISTANCE LOCUS 1 (GSR1) encodes a plant homeodomain (PHD) finger protein and is responsible for GS seed germination inhibition. Its knockdown mutant gsr1 displays decreased dormancy. In this report, we show that GS is not an ABA analog and provided 2 other GS-resistant mutants related to the chemical's function in seed germination inhibition other than gsr1, suggesting that GS may have pleiotropic effects through targeting different pathway governing seed germination.

  14. Proteins induced by salt stress in tomato germinating seeds

    International Nuclear Information System (INIS)

    Torres-Shumann, S.; Godoy, J.A.; del Pozo, O.; Pintor-Toro, J.A.

    1989-01-01

    Salt effects on protein synthesis in tomato germinating seeds were investigated by two-dimensional polyacrilamide gel electrophoresis of proteins labeled in vivo with ( 35 S)-Methionine. Seeds germinating in NaCl were analyzed at three germination stages (4mm long radicals, 15mm long radicles and expanding cotyledons) and compared to those germinating in water. At the first germination stage several basic proteins of M.W. 13Kd, 16Kd, 17Kd and 18Kd were detected in only salt germinating seeds. Other basic proteins of M.W. 12Kd, 50Kd and 54Kd were salt-induced at the second and third stage of germination. One 14Kd acid protein is observed in every assayed stage and shows several phosphorylated forms. The levels of expression of these proteins are directly correlated to assayed NaCl concentrations. All of these proteins, except 17Kd, are also induced by abscisic acid (ABA) in the same germination stages. A cooperative effect on the synthesis of these proteins is observed when both ABA and NaCl are present

  15. 7 CFR 201.54 - Number of seeds for germination.

    Science.gov (United States)

    2010-01-01

    ... REGULATIONS Germination Tests in the Administration of the Act § 201.54 Number of seeds for germination. At least 400 seeds shall be tested for germination; except that in mixtures, 200 seeds of each of those... 7 Agriculture 3 2010-01-01 2010-01-01 false Number of seeds for germination. 201.54 Section 201.54...

  16. Factors affecting the germination of hybrid rose achenes

    NARCIS (Netherlands)

    Vries, De D.P.; Dubois, L.A.M.

    2015-01-01

    The smooth germination of mature Hybrid rose achenes is hampered by (i) hardseededness (HS), (ii) primary dormancy (PD) and (iii) germination polymorphism (GP). HS is owing to the hard pericarp. PD is, in principle, a natural phenomenon that protects the seeds from precocious germination. For

  17. Ethylene, seed germination, and epinasty.

    Science.gov (United States)

    Stewart, E R; Freebairn, H T

    1969-07-01

    Ethylene activity in lettuce seed (Lactuca satina) germination and tomato (Lycopersicon esculentum) petiole epinasty has been characterized by using heat to inhibit ethylene synthesis. This procedure enabled a separation of the production of ethylene from the effect of ethylene. Ethylene was required in tomato petioles to produce the epinastic response and auxin was found to be active in producing epinasty through a stimulation of ethylene synthesis with the resulting ethylene being responsible for the epinasty. In the same manner, it was shown that gibberellic acid stimulated ethylene synthesis in lettuce seeds. The ethylene produced then in turn stimulated the seeds to germinate. It was hypothesized that ethylene was the intermediate which caused epinasty or seed germination. Auxin and gibberellin primarily induced their response by stimulating ethylene production.

  18. A single residue controls electron transfer gating in photosynthetic reaction centers

    Czech Academy of Sciences Publication Activity Database

    Shlyk, O.; Samish, I.; Matěnová, M.; Dulebo, A.; Poláková, H.; Kaftan, David; Scherz, A.

    2017-01-01

    Roč. 7, MAR 16 (2017), s. 1-13, č. článku 44580. ISSN 2045-2322 R&D Projects: GA ČR GA15-00703S; GA MŠk(CZ) LO1416 Institutional support: RVO:61388971 Keywords : BACTERIAL REACTION CENTERS * INDUCED STRUCTURAL-CHANGES * ATOMIC-FORCE MICROSCOPE Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 4.259, year: 2016

  19. Tumors of germinal cells

    International Nuclear Information System (INIS)

    Plazas, Ricardo; Avila, Andres

    2002-01-01

    The tumors of germinal cells (TGC) are derived neoplasia of the primordial germinal cells that in the life embryonic migrant from the primitive central nervous system until being located in the gonads. Their cause is even unknown and they represent 95% of the testicular tumors. In them, the intention of the treatment is always healing and the diagnostic has improved thanks to the results of the handling multidisciplinary. The paper includes topics like their incidence and prevalence, epidemiology and pathology, clinic and diagnoses among other topics

  20. High-throughput scoring of seed germination

    NARCIS (Netherlands)

    Ligterink, Wilco; Hilhorst, Henk W.M.

    2017-01-01

    High-throughput analysis of seed germination for phenotyping large genetic populations or mutant collections is very labor intensive and would highly benefit from an automated setup. Although very often used, the total germination percentage after a nominated period of time is not very

  1. Protein sequences and redox titrations indicate that the electron acceptors in reaction centers from heliobacteria are similar to Photosystem I

    Science.gov (United States)

    Trost, J. T.; Brune, D. C.; Blankenship, R. E.

    1992-01-01

    Photosynthetic reaction centers isolated from Heliobacillus mobilis exhibit a single major protein on SDS-PAGE of 47 000 Mr. Attempts to sequence the reaction center polypeptide indicated that the N-terminus is blocked. After enzymatic and chemical cleavage, four peptide fragments were sequenced from the Heliobacillus mobilis apoprotein. Only one of these sequences showed significant specific similarity to any of the protein and deduced protein sequences in the GenBank data base. This fragment is identical with 56% of the residues, including both cysteines, found in highly conserved region that is proposed to bind iron-sulfur center Fx in the Photosystem I reaction center peptide that is the psaB gene product. The similarity to the psaA gene product in this region is 48%. Redox titrations of laser-flash-induced photobleaching with millisecond decay kinetics on isolated reaction centers from Heliobacterium gestii indicate a midpoint potential of -414 mV with n = 2 titration behavior. In membranes, the behavior is intermediate between n = 1 and n = 2, and the apparent midpoint potential is -444 mV. This is compared to the behavior in Photosystem I, where the intermediate electron acceptor A1, thought to be a phylloquinone molecule, has been proposed to undergo a double reduction at low redox potentials in the presence of viologen redox mediators. These results strongly suggest that the acceptor side electron transfer system in reaction centers from heliobacteria is indeed analogous to that found in Photosystem I. The sequence similarities indicate that the divergence of the heliobacteria from the Photosystem I line occurred before the gene duplication and subsequent divergence that lead to the heterodimeric protein core of the Photosystem I reaction center.

  2. Pre-treating Seed to Enhance Germination of Desert Shrubs

    Energy Technology Data Exchange (ETDEWEB)

    W. K. Ostler; D. C. Anderson; D. J. Hansen

    2002-06-01

    Creosotebush [Larrea tridentata (D.C.) Cav.] and white bursage [Ambrosia dumosa (A. Gray) W.W. Payne] seeds were subjected to pre-treatments of rinsing and soaking in water and thiourea to enhance germination in laboratory experiments. The effects of darkness, temperature, seed source, and soil moisture were also evaluated in the laboratory. The best pre-treatment from the laboratory experiments, rinsing with water for 36 hours followed by drying, was field-tested at Fort Irwin, California. Two sites and two seeding dates (early March and mid April) were determined for each site. Five mulch treatments (no mulch, straw, gravel, chemical stabilizer, and plastic) were evaluated in combination with the seed pre-treatments. Field emergence was greatly enhanced with the seed pre-treatment for white bursage during the March (18-42% increase in germination) and April seedings (16-23% increase in germination). Creosotebush showed poor germination during March (2-5%) when soil temperatures averaged 15 C, but germination increased during the April trials (6-43%) when soil temperatures averaged 23 C. The seed pre-treatment during the April trials increased germination from 16-23%. The plastic mulch treatment increased germination dramatically during both the March and April trials. The plastic mulch increased soil temperatures (8-10 C)and maintained high humidity during germination. Both the chemical stabilizer and the gravel mulches improved germination over the control while the straw mulch decreased germination. These results suggest that seed pre-treatments combined with irrigation and mulch are effective techniques to establish these two dominant Mojave Desert species from seed.

  3. Conserved Transcriptional Regulatory Programs Underlying Rice and Barley Germination

    Science.gov (United States)

    Lin, Li; Tian, Shulan; Kaeppler, Shawn; Liu, Zongrang; An, Yong-Qiang (Charles)

    2014-01-01

    Germination is a biological process important to plant development and agricultural production. Barley and rice diverged 50 million years ago, but share a similar germination process. To gain insight into the conservation of their underlying gene regulatory programs, we compared transcriptomes of barley and rice at start, middle and end points of germination, and revealed that germination regulated barley and rice genes (BRs) diverged significantly in expression patterns and/or protein sequences. However, BRs with higher protein sequence similarity tended to have more conserved expression patterns. We identified and characterized 316 sets of conserved barley and rice genes (cBRs) with high similarity in both protein sequences and expression patterns, and provided a comprehensive depiction of the transcriptional regulatory program conserved in barley and rice germination at gene, pathway and systems levels. The cBRs encoded proteins involved in a variety of biological pathways and had a wide range of expression patterns. The cBRs encoding key regulatory components in signaling pathways often had diverse expression patterns. Early germination up-regulation of cell wall metabolic pathway and peroxidases, and late germination up-regulation of chromatin structure and remodeling pathways were conserved in both barley and rice. Protein sequence and expression pattern of a gene change quickly if it is not subjected to a functional constraint. Preserving germination-regulated expression patterns and protein sequences of those cBRs for 50 million years strongly suggests that the cBRs are functionally significant and equivalent in germination, and contribute to the ancient characteristics of germination preserved in barley and rice. The functional significance and equivalence of the cBR genes predicted here can serve as a foundation to further characterize their biological functions and facilitate bridging rice and barley germination research with greater confidence. PMID

  4. [Study on conditions of seed germination of Cistanche].

    Science.gov (United States)

    Qiao, Xue-Yi; Wang, Hua-Lei; Guo, Yu-Hai

    2007-09-01

    To study the effect of fluridone concentration, stimulating period, temperature and salt on the seed germination of three species of Cistanche. The seeds were cultured in Petri dish, and the germination percentage was counted. The highest germination percentage was observed in Cistanche tubulosa, C. deserticola, C. sala seeds pre-treated by 0.1 mg x L(-1) fluridone for 24-29 h. The optimal temperature for the seeds germination of three species of Cistanche was at 20-30 degrees C, and the seeds did not germinate at sub-or supraoptimal temperatures (5 and 35 degrees C). The salt tolerance of C. sala seeds was strong, and the critical value of NaCl concentration was 0.04 mol x L(-1). By contrast, C. tubulosa and C. deserticola seeds were more sensitive to the salt stress, the critical value of NaCl concentration was 0.02 mol x L(-1). The optimal germination condition and the method of testing germination percentage of three species of Cistanche seeds are as follow: the seeds are pre-treated by 0.1 mg x L(-1) fluridone for 24 h and then cultured at 20-30 degrees C in salt solution which concentration is lower than 0.02 mol x L(-1).

  5. The Germination of Some Species Tropical Legume Seeds

    Directory of Open Access Journals (Sweden)

    Eko Poetri

    2005-09-01

    Full Text Available A study to evaluate the seed germination of Leucaena pallida under climatic and soil conditions in Palu was conducted in village of Taipa, Sub district of North Palu, District of Palu. To compare with other species of legume trees however, this study involved Leucaena leucocephala cv Tarramba, Leucaena leucocephala cv Gumph and Gliricidia maculata. This experiment used completely randomized design with species of tropical tree legumes as treatment.  Each treatment was replicated five times.  Each experimental unit consisted of one tray (size 12.5 x 25 cm and planted by 20 seed.  Each tray was filled with soil while the seeds were planted one cm deep.  All seeds were immersed in warm water (600C for five minutes before planted.  The base of the trays were drilled to create some holes for water to drain out.  The trays were sprayed twice daily (07.00 am and 03.00 pm to keep the soil to be moist using a very smooth sprayer.  The variables recorded included the initiation time of germination, the range time of germination and the percentage of seed germination.  The data obtained were analyses using the Minitab 11. Least significance difference was used to test for possible differences between treatment means. The result revealed that initiation time of germination and the range of germination were not varied (P>0.05 among the seeds tested. The initiation time of germination ranged between 9 to 12 d after sowing.  Gliricidia maculata seed has the shortest period to germinate (12-16 d after sowing, meanwhile Leucaena leucocephala cv. Tarramba appear to be the longest (9-17 d after sowing. The highest seed viability was 60% in Leucaena leucocephala, cv Gump while the lowest was found in Gliricidia maculata (29%. In addition, both Leucaena pallida and Leucaena leucocephala cv Tarramba had medium seed germination (40% and 53% respectively. (Animal Production 7(3: 156-160 (2005Key Words: Seed, Germination, Tropical Leguminous

  6. Investigating small molecules to inhibit germinal center kinase-like kinase (GLK/MAP4K3) upstream of PKCθ phosphorylation: Potential therapy to modulate T cell dependent immunity.

    Science.gov (United States)

    May-Dracka, Tricia L; Arduini, Robert; Bertolotti-Ciarlet, Andrea; Bhisetti, Govinda; Brickelmaier, Margot; Cahir-McFarland, Ellen; Enyedy, Istvan; Fontenot, Jason D; Hesson, Thomas; Little, Kevin; Lyssikatos, Joe; Marcotte, Douglas; McKee, Timothy; Murugan, Paramasivam; Patterson, Thomas; Peng, Hairuo; Rushe, Mia; Silvian, Laura; Spilker, Kerri; Wu, Ping; Xin, Zhili; Burkly, Linda C

    2018-06-01

    Germinal center kinase-like kinase (GLK, also known as MAP4K3) has been hypothesized to have an effect on key cellular activities, including inflammatory responses. GLK is required for activation of protein kinase C-θ (PKCθ) in T cells. Controlling the activity of T helper cell responses could be valuable for the treatment of autoimmune diseases. This approach circumvents previous unsuccessful approaches to target PKCθ directly. The use of structure based drug design, aided by the first crystal structure of GLK, led to the discovery of several inhibitors that demonstrate potent inhibition of GLK biochemically and in relevant cell lines. Copyright © 2018 Elsevier Ltd. All rights reserved.

  7. Comparative analysis of regulatory elements in different germin-like ...

    African Journals Online (AJOL)

    STORAGESEVER

    INTRODUCTION. Germin and germin-like proteins (GLPs) is a member of ..... analysis of germin-like protein gene 2 promoter from Oryza sativa L. ssp. Indica. ... esculenta Crantz) root proteome: Protein identification and differential expression.

  8. Determination of kinetic and thermodynamic parameters that describe isothermal seed germination: A student research project

    Science.gov (United States)

    Hageseth, Gaylord T.

    1982-02-01

    Students under the supervision of a faculty member can collect data and fit the data to the theoretical mathematical model that describes the rate of isothermal seed germination. The best-fit parameters are interpreted as an initial substrate concentration, product concentration, and the autocatalytic reaction rate. The thermodynamic model enables one to calculate the activation energy for the substrate and product, the activation energy for the autocatalytic reaction, and changes in enthalpy, entropy, and the Gibb's free energy. Turnip, lettuce, soybean, and radish seeds have been investigated. All data fit the proposed model.

  9. Asymbiotic germination of immature embryos of a medicinally ...

    African Journals Online (AJOL)

    H.piri

    La germination no simuotica de las semillas de orquideas. Bol. Real. Soc. Esp. Hist. Nat. 21:250-260. Knudson L (1922). Non–symbiotic germination of orchid seeds. Bot. Gaz. 73:1-25. Knudson L (1925). Physiological study of the asymbiotic germination of orchid seeds. Bot. Gaz. 79:345-379. Lawler LJ (1984). Ethnobotany ...

  10. Investigation of coriander germination (Coriandrum sativum L.

    Directory of Open Access Journals (Sweden)

    Aćimović Milica

    2013-01-01

    Full Text Available Coriander seed yield (Coriandrum sativum L. depends of many factors during vegetation period, and also depend of seed quality. Coriander fruit (Coriandri fructus which is used like spice and in medicinal purpose, and also in food and pharmacy, in the same time is and seed material. Because of that, it is very important to take care about its quality. In this paper is analyzed seed material obtained from field experiments village Mošorin, in 2011, and investigated was conducted in harvest year, and one year later. In harvest year, germination energy in average was 38,21%, and total germination 72,75%. After one year, germination energy was statistically significant smaller - 16,50%, as like total germination which was 67,42%.

  11. Germination conditions affect physicochemical properties of germinated brown rice flour.

    Science.gov (United States)

    Charoenthaikij, Phantipha; Jangchud, Kamolwan; Jangchud, Anuvat; Piyachomkwan, Kuakoon; Tungtrakul, Patcharee; Prinyawiwatkul, Witoon

    2009-01-01

    Germinated brown rice has been reported to be nutritious due to increased free gamma-aminobutyric acid (GABA). The physicochemical properties of brown rice (BR) and glutinous brown rice (GNBR) after germination as affected by different steeping times (24, 36, 48, and 72 h depending on the rice variety) and pHs of steeping water (3, 5, 7, and as-is) were determined and compared to those of the nongerminated one (control). As the steeping time increased or pH of steeping water decreased, germinated brown rice flours (GBRF) from both BR and GNBR had greater reducing sugar, free GABA and alpha-amylase activity; while the total starch and viscosity were lower than their respective controls. GBRFs from both BR and GNBR prepared after 24-h steeping time at pH 3 contained a high content of free GABA at 32.70 and 30.69 mg/100 g flour, respectively. The peak viscosity of GBRF obtained from both BR and GNBR (7.42 to 228.22 and 4.42 to 58.67 RVU, respectively) was significantly lower than that of their controls (255.46 and 190.17 RVU, respectively). The principal component analysis indicated that the important variables for discriminating among GBRFs, explained by the first 2 components at 89.82% of total explained variance, were the pasting profiles, alpha-amylase activity, and free GABA.

  12. Cyrtopodium paludicolum germination with two Tulasnella isolates

    Directory of Open Access Journals (Sweden)

    Otieres Cirino de Carvalho

    2017-11-01

    Full Text Available ABSTRACT Symbiosis between orchid seeds and mycorrhizal fungi has been reported to be a determining factor in the success of germination and protocorm development in vitro. The aim of this study was to isolate and identify by molecular analysis the mycorrhizal fungus associated with Cyrtopodium paludicolum, and to evaluate its efficiency in facilitating seed germination and development. Germination experiments were carried out using a fungus isolated from C. paludicolum (CH01 and Epidendrum secundum (M65, which has been successfully used a number of times in symbiotic germination. The experiments were conducted in a completely randomized design with treatments of CH01, M65 as well as under asymbiotic conditions. The mycobiont CH01 was successfully isolated from Cyrtopodium paludicolum and identified as Tulasnella sp. Treatments with both fungi reached a higher germination percentage than under asymbiotic conditions, indicating no specificity in the relationship between Cyrtopodium paludicolum and the fungi. The results presented have the potential to advance research into the propagation and conservation of C. paludicolum, a native of the Cerrado biome.

  13. Biorhythms in conifer seed germination during extended storage

    Science.gov (United States)

    James P. Barnett; N.I. Marnonov

    1989-01-01

    A proportion of sound seeds of conifer species do not germinate during certain periods of the year, even when conditions are favorable. Mamonov et al. (1986) report that the non-germinating seeds have apparently undergone physiological changes that affected germination. This phenomenon may be due to seasonal periodicity, or biorhythms. As early as the mid-1930'...

  14. Detecting free radicals in biochars and determining their ability to inhibit the germination and growth of corn, wheat and rice seedlings.

    Science.gov (United States)

    Liao, Shaohua; Pan, Bo; Li, Hao; Zhang, Di; Xing, Baoshan

    2014-01-01

    Biochar can benefit human society as a carbon-negative material and soil amendment. However, negative biochar impacts on plant germination and growth have been observed, and they have not been fully explained. Therefore, protocols to avoid these risks cannot be proposed. We hypothesized that the free radicals generated during charring may inhibit plant germination and growth. Significant electron paramagnetic resonance (EPR) signals were observed in the biochars derived from several types of common biomass (corn stalk, rice, and wheat straws) and the major biopolymer components of biomass (cellulose and lignin), but not in the original materials, suggesting the ubiquitous presence of free radicals in biochars. EPR signal intensity increased with increasing pyrolysis temperature, and it was dominantly contributed by oxygen centered in the mixture of oxygen- and carbon-centered free radicals as the temperature increased. The free radicals in biochars induced strong ·OH radicals in the aqueous phase. Significant germination inhibition, root and shoot growth retardation and plasma membrane damage were observed for biochars with abundant free radicals. Germination inhibition and plasma membrane damage were not obvious for biochars containing low free radicals, but they were apparent at comparable concentrations of conventional contaminants, such as heavy metals and polyaromatic hydrocarbons. The potential risk and harm of relatively persistent free radicals in biochars must be addressed to apply them safely.

  15. Germination phenology determines the propensity for facilitation and competition.

    Science.gov (United States)

    Leverett, Lindsay D

    2017-09-01

    A single plant can interact both positively and negatively with its neighbors through the processes of facilitation and competition, respectively. Much of the variation in the balance of facilitation and competition that individuals experience can be explained by the degree of physical stress and the sizes or ages of plants during the interaction. Germination phenology partly controls both of these factors, but its role in defining the facilitation-competition balance has not been explicitly considered. I performed an experiment in a population of the winter annual Arabidopsis thaliana (Brassicaceae) to test whether germinating during physically stressful periods leads to facilitation while germinating during periods that promote growth and reproduction leads to competition. I manipulated germination and neighbor presence across two years in order to quantify the effects of the local plant community on survival, fecundity, and total fitness as a function of germination phenology. Neighbors increased survival when germination occurred under conditions that were unsuitable for survival, but they reduced fecundity in germinants that were otherwise the most fecund. Later germination was associated with facilitation in the first year but competition in the second year. These episodes of facilitation and competition opposed each other, leading to no net effect of neighbors when averaged over all cohorts. These results indicate that variation in germination timing can explain some of the variation in the facilitation-competition balance in plant communities. © 2017 by the Ecological Society of America.

  16. Temperature and substrate on Plukenetia volubilis L. seed germination

    Directory of Open Access Journals (Sweden)

    Givanildo Z. da Silva

    Full Text Available ABSTRACT The objective of this work was to evaluate the effect of temperature and substrate on the germination of P. volubilis seeds. Seeds harvested from 25 matrix plants were submitted, in two studies, to conditions of (i sowing in rolled paper towel at the temperatures of 10, 15, 20, 25, 30, 35, 40, and 45 °C, for the evaluation of germination, first count of germination, germination speed index and mean time for germination, and (ii sowing in the substrates paper towel, sand, Bioplant®, Bioplant® and micron, superfine, fine, medium and coarse vermiculite. The same evaluations mentioned in the first study were conducted at the temperature of 30 oC, as well as plant growth. The treatment replicates were distributed in a completely randomized block design and the effects of temperature were compared by polynomial regression analysis. The substrates were compared by the Scott-Knott test at 0.05 probability level. The data show that the ideal range of temperature for the germination of P. volubilis is between 25 and 30 °C. The temperature of 20 °C is the minimum for germination and those above 35 °C are lethal to these seeds. The most favorable substrate for P. volubilis seed germination is micron or fine vermiculite.

  17. Effect of water and saline stress on germination of Atriplex nummularia (Chenopodiaceae)

    International Nuclear Information System (INIS)

    Ruiz, Monica B; Parera, Carlos A

    2013-01-01

    Saline soils, characteristic of arid zones, can affect the germination of the species due to low water potential or ion toxicity. The effect of water and saline stress on germination was evaluated in atriplex nummularia a potential source of forage for arid zones. the seeds were scarified to reduce the inhibitory effect on germination and incubated in at 23 Celsius degrade on germination paper imbibed with solutions of sodium chloride (NaCl) and polyethylene glycol (peg) at three water potentials: -0,5; -1,0 and -1,5 MPA. The percentage germination and germination speed were significantly affected by the concentration of the solution and the solute used. While more negative osmotic potentials, the percentage of germination and germination speed were significantly lower. The seeds germinated in peg solution have higher germination and germination speed than the seeds germinated in NaCl, especially in -1,0 MPA. The data suggest that the seeds of a. nummularia show sensitivity to the presence of Na+ and Cl- ions affecting the germination process.

  18. Effects of graphene on seed germination and seedling growth

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Ming; Gao, Bin, E-mail: bg55@ufl.edu [University of Florida, Department of Agricultural and Biological Engineering (United States); Chen, Jianjun [University of Florida, Department of Environmental Horticulture and Mid-Florida Research & Education Center (United States); Li, Yuncong [University of Florida, Soil and Water Science Department Tropical Research & Education Center (United States)

    2015-02-15

    The environmental impact of graphene has recently attracted great attention. In this work, we show that graphene at a low concentration affected tomato seed germination and seedling growth. Graphene-treated seeds germinated much faster than control seeds. Analytical results indicated that graphene penetrated seed husks. The penetration might break the husks to facilitate water uptake, resulting in faster germination and higher germination rates. At the stage of seedling growth, graphene was also able to penetrate root tip cells. Seedlings germinated from graphene-treated seeds had slightly lower biomass accumulation than the control, but exhibited significantly longer stems and roots than the control, which suggests that graphene, in contrast with other nanoparticles, had different effects on seedling growth. Taken together, our results imply that graphene played complicated roles in affecting the initial stage of seed germination and subsequent seedling growth.

  19. Biological diversity of photosynthetic reaction centers and the solid-state photo-CIDNP effect

    NARCIS (Netherlands)

    Roy, Esha

    2007-01-01

    Photosynthetic reaction centers (RCs) from plants, heliobacteria and green sulphur bacteria has been investigated with photochemically induced dynamic nuclear polarization (photo-CIDNP) MAS NMR. In photosystem (PS) I of spinach, all signals appear negative which is proposed by a predominance of the

  20. Optimization of jenipapo in vitro seed germination process

    Directory of Open Access Journals (Sweden)

    Rafaela Ribeiro de Souza

    Full Text Available ABSTRACT The in vitro seed germination is an effective alternative for quickly obtaining explants with sanitary quality. However, jenipapo seeds present slow and uneven germination. Therefore, internal and external factors to seed which directly interfere in the process, they must be identified, in order to adapt better techniques to obtain seedlings. In this sense, this work aimed to optimize the in vitro germination of Genipa americana L. seeds by evaluating different factors (light quality, GA3 treatment, pre-soaking in distilled water, growing media and stratification in the dark. It was found that the seed germination of G. americana was indifferent to light, however, the best results were obtained under conditions of continuous darkness; There was no effect of the application of exogenous GA3; The pre-soaking in distilled water for 48 h contributes to obtaining better germination rates; And the reduction in MS medium salts, and laminating the pretreatment in the dark maximizes the germination potential of seeds.Therefore, the optimal conditions for in vitro germination of G. americana L. seeds requires pre-soaking in distilled water for 48 hours and inoculation into culture media consisting of 1/2 MS + 15 g L-1 sucrose, with stratification in the dark for 16 days, followed by the transfer to growth chambers with lighting provided by white fluorescent lamps.

  1. Distinct germination response of endangered and common arable weeds to reduced water potential.

    Science.gov (United States)

    Rühl, A T; Eckstein, R L; Otte, A; Donath, T W

    2016-01-01

    Arable weeds are one of the most endangered species groups in Europe. Modern agriculture and intensive land-use management are the main causes of their dramatic decline. However, besides the changes in land use, climate change may further challenge the adaptability of arable weeds. Therefore, we investigated the response pattern of arable weeds to different water potential and temperature regimes during the phase of germination. We expected that endangered arable weeds would be more sensitive to differences in water availability and temperature than common arable weeds. To this end, we set up a climate chamber experiment where we exposed seeds of five familial pairs of common and endangered arable weed species to different temperatures (5/15, 10/20 °C) and water potentials (0.0 to -1.2 MPa). The results revealed a significant relationship between the reaction of arable weed species to water availability and their Red List status. The effects of reduced water availability on total germination, mean germination time and synchrony were significantly stronger in endangered than in common arable weeds. Therefore, global climate change may present a further threat to the survival of endangered arable weed species. © 2015 German Botanical Society and The Royal Botanical Society of the Netherlands.

  2. Proteomic Analysis of Lettuce Seed Germination and Thermoinhibition by Sampling of Individual Seeds at Germination and Removal of Storage Proteins by Polyethylene Glycol Fractionation1

    Science.gov (United States)

    Song, Bin-Yan; Deng, Zhi-Jun; Wang, Yue; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

    2015-01-01

    Germination and thermoinhibition in lettuce (Lactuca sativa ‘Jianyexianfeng No. 1’) seeds were investigated by a proteomic comparison among dry seeds, germinated seeds at 15°C, at 15°C after imbibition at 25°C for 48 h, or at 25°C in KNO3 (all sampled individually at germination), and ungerminated seeds at 25°C, a thermoinhibitory temperature. Before two-dimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two-dimensional gels. A total of 108 protein spots were identified to change more than 2-fold (P lettuce seed germination and thermoinhibition. Accumulation of three proteins and expression of five genes participating in the mevalonate (MVA) pathway of isoprenoid biosynthesis correlated positively with seed germinability. Inhibition of this pathway by lovastatin delayed seed germination and increased the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination and thermoinhibition. PMID:25736209

  3. Monte Carlo simulation of the seed germination process

    International Nuclear Information System (INIS)

    Gladyszewska, B.; Koper, R.

    2000-01-01

    Paper presented a mathematical model of seed germination process based on the Monte Carlo method and theoretical premises resulted from the physiology of seed germination suggesting three consecutive stages: physical, biochemical and physiological. The model was experimentally verified by determination of germination characteristics for seeds of ground tomatoes, Promyk cultivar, within broad range of temperatures (from 15 to 30 deg C)

  4. Factors Affecting the Germination of Akinetes of Nodularia spumigena (Cyanobacteriaceae)

    OpenAIRE

    Huber, Ann L.

    1985-01-01

    Nutritional and physical factors which influence the germination of akinetes of Nodularia spumigena (Cyanobacteriaceae) were examined. Low concentrations of phosphorus (45 μM, inhibited germination. Salinities of >20‰ were inhibitory to germination. Optimum temperatures were 22°C or greater. Germination did not take place in the dark, but only very low light intensities (0.5 microeinstein m−2 s−1) were necessary to initiate germination. Red light (620 to 665 nm) was required. More than 24 h o...

  5. Imbibition and germination in the seeds of Heliotropium supinum L.

    Directory of Open Access Journals (Sweden)

    Ramesh C. Bhatia

    2014-01-01

    Full Text Available Imbibition in the seeds of Heliotropium supinum L. varies under different temperatures. The optimum temperatures for imbibition and germination are also different. For germination 39% imbibition is essential, and this capability is achieved by 12-week-old seeds. With duration of dry storage imbibition increases. The imbibition and germination percentages decline on re-dry storage of seeds after embeding in mud. A soil moisture of 44% is optimal for germination. A correlation exists between imbibition and germination.

  6. A model for quantification of temperature profiles via germination times

    DEFF Research Database (Denmark)

    Pipper, Christian Bressen; Adolf, Verena Isabelle; Jacobsen, Sven-Erik

    2013-01-01

    Current methodology to quantify temperature characteristics in germination of seeds is predominantly based on analysis of the time to reach a given germination fraction, that is, the quantiles in the distribution of the germination time of a seed. In practice interpolation between observed...... time and a specific type of accelerated failure time models is provided. As a consequence the observed number of germinated seeds at given monitoring times may be analysed directly by a grouped time-to-event model from which characteristics of the temperature profile may be identified and estimated...... germination fractions at given monitoring times is used to obtain the time to reach a given germination fraction. As a consequence the obtained value will be highly dependent on the actual monitoring scheme used in the experiment. In this paper a link between currently used quantile models for the germination...

  7. Dormancy and germination in short-lived lepidium perfoliatu l. (brassicaceae) seeds

    International Nuclear Information System (INIS)

    Tang, An-Jun; Tian, M.; Long, Chun-Lin

    2010-01-01

    To understand germination timing in an ecological context, the response to environmental events that effect seed dormancy is central and has to be combined with knowledge of germination responses to different ecological factors. In this study, seed dormancy, germination and seedling survival of annual short-lived clasping pepper weed Lepidium perfoliatum L. (Brassicaceae) were investigated. Three types of pre-treatments viz., various temperature dry storage, light and water stress were tested as possible dormancy and survival-affecting environmental events. Fresh mature seeds were greatly dormant. Warm (30 deg. C) dry storage more facilitated breaking dormancy, they germinated well under apt conditions (e.g. 20 deg. C and 10/20 deg. C plus periodic light, 14 h/d). For those seeds which underwent after-ripening, they could germinate at a range of constant temperatures (4, 10, 15, 20, 25, and 30 deg. C) and one alternating temperature (10/20 deg. C). Under alternating temperature regimes, the final percent germination of L. perfoliatum seeds increased from 37 deg. C to 93% when temperature altered from 4/10 deg. C to 10/20 deg. C in light, then decreased with increasing temperature. The germination pattern under constant temperature conditions was similar to that under alternating temperature and significant differences in final percent germinations and rates of germination were observed among different temperatures. Under different light treatments, final germination of showed significant differences, only with 35% of germination percentage in dark, much lower than those in red and white light (i.e. 93% and 91%, respectively). GA3 could promote the germination of non-dormant seeds in dark. When water potentials were reduced, final percent germination decreased dramatically, and few seeds germinated at -0.98 MPa (generated by PEG-8000). The changes of proline content in resultant seedlings were reverse to that of final percent germination with changing water

  8. Association mapping of soybean seed germination under salt stress.

    Science.gov (United States)

    Kan, Guizhen; Zhang, Wei; Yang, Wenming; Ma, Deyuan; Zhang, Dan; Hao, Derong; Hu, Zhenbin; Yu, Deyue

    2015-12-01

    Soil salinity is a serious threat to agriculture sustainability worldwide. Seed germination is a critical phase that ensures the successful establishment and productivity of soybeans in saline soils. However, little information is available regarding soybean salt tolerance at the germination stage. The objective of this study was to identify the genetic mechanisms of soybean seed germination under salt stress. One natural population consisting of 191 soybean landraces was used in this study. Soybean seeds produced in four environments were used to evaluate the salt tolerance at their germination stage. Using 1142 single-nucleotide polymorphisms (SNPs), the molecular markers associated with salt tolerance were detected by genome-wide association analysis. Eight SNP-trait associations and 13 suggestive SNP-trait associations were identified using a mixed linear model and the TASSEL 4.0 software. Eight SNPs or suggestive SNPs were co-associated with two salt tolerance indices, namely (1) the ratio of the germination index under salt conditions to the germination index under no-salt conditions (ST-GI) and (2) the ratio of the germination rate under salt conditions to the germination rate under no-salt conditions (ST-GR). One SNP (BARC-021347-04042) was significantly associated with these two traits (ST-GI and ST-GR). In addition, nine possible candidate genes were located in or near the genetic region where the above markers were mapped. Of these, five genes, Glyma08g12400.1, Glyma08g09730.1, Glyma18g47140.1, Glyma09g00460.1, and Glyma09g00490.3, were verified in response to salt stress at the germination stage. The SNPs detected could facilitate a better understanding of the genetic basis of soybean salt tolerance at the germination stage, and the marker BARC-021347-04042 could contribute to future breeding for soybean salt tolerance by marker-assisted selection.

  9. Temperature in the seeds germination of pitaya genotypes

    Directory of Open Access Journals (Sweden)

    Alessandro Borini Lone

    2014-09-01

    Full Text Available The optimum temperature for germination of cacti vary with the species. With this work, we aimed to evaluate the seeds germination of pitaya genotypes under different temperatures. The used genotypes were: Hylocereus undatus (PB, H. polyrhizus (PV, Selenicereus megalanthus (PA, H. undatus x H. costaricensis (PH1 and H. costaricensis x H. undatus (PH2. For each genotype we used four replicates of 50 seeds, in a completely randomized design. The sowing was carried out on blotter paper in boxes type Gerbox ®, maintained at temperatures of 15, 20, 25, 30 and 35 oC constant and 15-25, 20-30 and 25-35 oC alternating with photoperiod 12 hours. The test lasted 30 days which were appraised the germination percentage, the germination speed index and the average time of germination. For seeds germination of PB, the result obtained in the temperature of 25 oC didn’t differ of the obtained to 30 and 20-30 oC, however it was superior to the others temperatures. In PV, the result at 25 oC didn’t differ of the obtained to 20 and 30 oC, being superior to the results of the others temperatures. For PA, the best result was obtained to 25 oC. In PH1, the temperatures of 25, 30 and 20-30 oC presented superiors results to the others. For PH2, the result obtained in 15-25oC didn’t differ of the obtained at 25 oC, however it was superior to the others temperatures. The constants temperatures of 25 and 30 °C and alternating 20-30 °C are suitable for germination of H. undatus and for the hybrid H. undatus x H. costaricensis. For H. polyrhizus, constant temperatures of 20, 25 to 30 °C are suitable for seed germination. The constant temperature of 25 °C is the most suitable for the germination of S. megalanthus. For the hybrid H. costaricensis x H. undatus, constant temperature of 25 °C and alternating 15-25°C are suitable for seed germination.

  10. Effect of Estrogen and Progeterone on seed germination

    Directory of Open Access Journals (Sweden)

    Nirmala

    Full Text Available Early pregnancy detection in dairy cattle is an integral part of a successful animal husbandry practice. A simple seed germination technique (Punyakoti test comprises observation of differential seed germination response of wheat seeds to diluted fresh urine samples as reflected by significant inhibition of germination percentage in pregnant cow urine when compared to non pregnant cow urine. Hormone metabolites excreted through urine might affect the seed germination in pregnant cow urine. In the present study an attempt was made to test the effect of hormones (in their natural forms at different concentrations of estrogen (17-ß estradiol and progesterone on wheat and green gram germination. Stock solutions of estrogen and progesterone were prepared in alcohol (1mg/ml and serial dilutions made using distilled water to get the concentrations of T1=10, T2=1, T3=0.1 and T4=0.01 μg/ml respectively in treatment groups. About 15 seeds each of wheat and green gram were taken in sterile Petri dishes into which 15ml of each test preparation was poured. The treatments were compared with distilled water and alcohol controls. The study was conducted for a period of five days during which seed germination was observed after 48 hrs and shoot lengths were also measured by the end of study. The average seed germination and shoot length in treatment groups did not vary significantly (P>0.05 when compared with that of control groups. Thus from the present study, it can be concluded that estrogen and progesterone in their natural form will not affect seed germination and shoot length. [Veterinary World 2008; 1(8.000: 241-242

  11. Germination of Aspergillus niger conidia

    OpenAIRE

    Hayer, Kimran

    2014-01-01

    Aspergillus niger is a black-spored filamentous fungus that forms asexual spores called conidospores (‘conidia’). Germination of conidia, leading to the formation of hyphae, is initiated by conidial swelling and mobilisation of endogenous carbon and energy stores, followed by polarisation and emergence of a hyphal germ tube. These morphological and biochemical changes which define the model of germination have been studied with the aim of understanding how conidia sense and utilise different...

  12. Temperature Effects on Cuscuta campestris Yunk. Seed Germination

    Directory of Open Access Journals (Sweden)

    Marija Sarić-Krsmanović

    2013-01-01

    Full Text Available Studies of biological characteristics of seeds and conditions for their germination havea major importance for planning and executing rational measures of weed control. Theaim of this study was to investigate the effect of different temperatures on germinationof C. campestris seeds. Three treatments (T1- storage at room temperature; T2 – exposureto 4°C for 30 days; T3 – scarification by concentrated sulphuric acid differing in manipulationwith seeds before germination were tested at different temperatures (5°C, 10°C, 15°C,20°C, 25°C, 30°C, 35°C, 40°C, 45°C. Germinated seeds were counted daily for ten days andthe length of seedlings was measured on the last day. The results showed that differencesin germination of C. campestris seeds were very prominent between temperatures, as wellas between treatments T1, T2 and T3. Seeds failed to germinate at 5°C and 45°C in all treatments(T1, T2, T3. Germination ranged from 6.25 at 10°C to 96.88%, the highest percentage,achieved at 30°C.

  13. Mouse model of Epstein-Barr virus LMP1- and LMP2A-driven germinal center B-cell lymphoproliferative disease.

    Science.gov (United States)

    Minamitani, Takeharu; Ma, Yijie; Zhou, Hufeng; Kida, Hiroshi; Tsai, Chao-Yuan; Obana, Masanori; Okuzaki, Daisuke; Fujio, Yasushi; Kumanogoh, Atsushi; Zhao, Bo; Kikutani, Hitoshi; Kieff, Elliott; Gewurz, Benjamin E; Yasui, Teruhito

    2017-05-02

    Epstein-Barr virus (EBV) is a major cause of immunosuppression-related B-cell lymphomas and Hodgkin lymphoma (HL). In these malignancies, EBV latent membrane protein 1 (LMP1) and LMP2A provide infected B cells with surrogate CD40 and B-cell receptor growth and survival signals. To gain insights into their synergistic in vivo roles in germinal center (GC) B cells, from which most EBV-driven lymphomas arise, we generated a mouse model with conditional GC B-cell LMP1 and LMP2A coexpression. LMP1 and LMP2A had limited effects in immunocompetent mice. However, upon T- and NK-cell depletion, LMP1/2A caused massive plasmablast outgrowth, organ damage, and death. RNA-sequencing analyses identified EBV oncoprotein effects on GC B-cell target genes, including up-regulation of multiple proinflammatory chemokines and master regulators of plasma cell differentiation. LMP1/2A coexpression also up-regulated key HL markers, including CD30 and mixed hematopoietic lineage markers. Collectively, our results highlight synergistic EBV membrane oncoprotein effects on GC B cells and provide a model for studies of their roles in immunosuppression-related lymphoproliferative diseases.

  14. Effect of cooking on functional properties of germinated black glutinous rice (KKU-ULR012

    Directory of Open Access Journals (Sweden)

    Thapanan Konwatchara

    2014-06-01

    Full Text Available The aim of this research was to investigate the changes in functional properties of germinated black glutinous rice (KKU-ULR012 after cooking. Black glutinous rice grains were obtained from Faculty of Agriculture, Khon Kaen University, Thailand. The rough grains were soaked for 12 hrs, then germinated for 30 hrs at 35±2°C (95%RH, dried at 45±2°C for 8 hrs, dehusked and cooked either using a microwave oven or a pressure cooker. The cooked grains were dehydrated in two stages, 85±2°C for 1 hr and 45±2°C for 12 hrs until the final moisture content was 10±2%wb. The antioxidant activity, anthocyanins, GABA and -oryzanol contents, and the microstructure of the dehydrated grains were then characterized. Germination process induced a 2.55 fold increase in GABA content compared to non-germinated KKU-ULR012. The germinated KKU-ULR012 gave DPPH value, anthocyanins and -oryzanol contents of 33.74±0.15 mgTrolox/100gdb, 182.89±0.48 mg/100gdb and 37.72±0.16 mg/100gdb, respectively. Anthocyanins in cooked germinated KKU-ULR012 diminished almost 88-89% after cooking. The cooking methods employed strongly influenced the antioxidant activity and anthocyanins content that the pressure cooking tended to prevent loss of anthocyanin content and antioxidant activity. The GABA, -oryzanol and antho-cyanins contents and antioxidant activity of germinated grains cooked in the pressure cooker were higher than the samples cooked in the microwave oven (p<0.05. For pressure cooking, the cooked grains gave DPPH, ABTS, anthocyanins and -oryzanol contents of 9.89±0.35 mgTrolox/100gdb, 1.79±0.04 mgTrolox/100gdb, 21.60±0.14 mg/100gdb and 37.16±0.70 mg/100gdb, respectively. The rice grains cooked by pressure cooking were more moist and sticky than the grains cooked by microwave cooking. The microstructure examined by SEM showed that the center of the dehydrated cooked rice grain was smooth indicating starch gelatinization whereas the surface revealed

  15. Salt tolerance of physalis during germination and seedling growth

    International Nuclear Information System (INIS)

    Yildirim, E.; Karlidag, H.

    2011-01-01

    The study was conducted to evaluate the effect of NaCl salinity on germination and emergence of Physalis ixocarpa and Physalis peruviana. Seeds of P. ixocarpa and P. peruviana were germinated by the use of 0, 30, 60, 90, 120 and 180 mM NaCl solutions in petri dishes. Final germination percentage (FGP) decreased with the increase in NaCl concentration. Both species germinated at the ranges of salinity. P. peruviana gave the greater germination percentages under salt stress than P. ixocarpa. NaCl salinity at different concentrations adversely affected germination rates. For seedling growth, seeds of both species were sown at 10 mm depth in plastic trays filled with peat to determine final emergence percentage (FEP). The trays were irrigated manually to saturation every day with 0, 30, 60, 90, 120, 150 or 180 mM NaCl solutions to maintain the level of salinity. Salinity affected seed emergence and seedlings growth more than seed germination. The study showed that no emergence of Physalis was observed at 90, 120 and 180 mM NaCl salinity. Fresh and dry weights of normal seedlings were also evaluated. Salt stress significantly decreased the plant fresh and dry weight of both species. Based on the results of the experiment, it can be concluded that seedling emergence and growth is more sensitive to salt stress than seed germination in Physalis. (author)

  16. Nuclear dynamics during ascospore germination in Sordaria macrospora.

    Science.gov (United States)

    Teichert, Ines

    2017-01-01

    The ascomycete Sordaria macrospora has a long history as a model organism for studying fungal sexual development. Starting from an ascospore, sexual fruiting bodies (perithecia) develop within seven days and discharge new ascospores. Sexual development has been studied in detail, revealing genes required for perithecium formation and ascospore germination. However, the germination process per se has not yet been examined. Here I analyze nuclear dynamics during ascospore germination using a fluorescently labeled histone. Live-cell imaging revealed that nuclei are transported into germination vesicles that form on one side of the spore. Polar growth is established from these vesicles. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Secondary metabolites profiles and antioxidant activities of germinated brown and red rice

    Science.gov (United States)

    Nurnaistia, Y.; Aisyah, S.; Munawaroh, H. S. H.; Zackiyah

    2018-05-01

    The research aims to investigate the effect of germination on the secondary metabolite profiles and antioxidant activity of brown and red rice. The germination was performed by using a simple laboratory-scale machine that was designed and optimized to provide conditions that support the germination process. The germination was carried out for 2 days in dark conditions at 26°C and 99% humidity. Analysis of the secondary metabolite profile of ungerminated and germinated rice was performed using LC-MS. The antioxidant activities of ungerminated and germinated rice were done by using DPPH method. The results showed that the profiles of secondary metabolites of brown and red rice changed after germination. Some peaks were found to be induced in the germinated rice. However, some peaks were also loss during germination. The antioxidant activity of brown rice was slightly increased due to the germination, from 11.2% to 22.5%. Meanwhile the antioxidant activity of red rice was decreased after germination, from 73.8% to 60.0%.

  18. Bacterial Reaction Centers Purified with Styrene Maleic Acid Copolymer Retain Native Membrane Functional Properties and Display Enhanced Stability**

    Science.gov (United States)

    Swainsbury, David J K; Scheidelaar, Stefan; van Grondelle, Rienk; Killian, J Antoinette; Jones, Michael R

    2014-01-01

    Integral membrane proteins often present daunting challenges for biophysical characterization, a fundamental issue being how to select a surfactant that will optimally preserve the individual structure and functional properties of a given membrane protein. Bacterial reaction centers offer a rare opportunity to compare the properties of an integral membrane protein in different artificial lipid/surfactant environments with those in the native bilayer. Here, we demonstrate that reaction centers purified using a styrene maleic acid copolymer remain associated with a complement of native lipids and do not display the modified functional properties that typically result from detergent solubilization. Direct comparisons show that reaction centers are more stable in this copolymer/lipid environment than in a detergent micelle or even in the native membrane, suggesting a promising new route to exploitation of such photovoltaic integral membrane proteins in device applications. PMID:25212490

  19. Chickpea seeds germination rational parameters optimization

    Science.gov (United States)

    Safonova, Yu A.; Ivliev, M. N.; Lemeshkin, A. V.

    2018-05-01

    The paper presents the influence of chickpea seeds bioactivation parameters on their enzymatic activity experimental results. Optimal bioactivation process modes were obtained by regression-factor analysis: process temperature - 13.6 °C, process duration - 71.5 h. It was found that in the germination process, the proteolytic, amylolytic and lipolytic enzymes activity increased, and the urease enzyme activity is reduced. The dependences of enzyme activity on chickpea seeds germination conditions were obtained by mathematical processing of experimental data. The calculated data are in good agreement with the experimental ones. This confirms the optimization efficiency based on experiments mathematical planning in order to determine the enzymatic activity of chickpea seeds germination optimal parameters of bioactivated seeds.

  20. Geometric phase and quantum interference in photosynthetic reaction center: Regulation of electron transfer

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yuming, E-mail: ymsun@ytu.edu.cn; Su, Yuehua; Dai, Zhenhong; Wang, WeiTian

    2016-10-20

    Photosynthesis is driven by electron transfer in reaction centers in which the functional unit is composed of several simple molecules C{sub 2}-symmetrically arranged into two branches. In view of quantum mechanism, both branches are possible pathways traversed by the transferred electron. Due to different evolution of spin state along two pathways in transmembrane electric potential (TEP), quantum state of the transferred electron at the bridged site acquires a geometric phase difference dependent on TEP, the most efficient electron transport takes place in a specific range of TEP beyond which electron transfer is dramatically suppressed. What’s more, reaction center acts like elaborately designed quantum device preparing polarized spin dependent on TEP for the transferred electron to regulate the reduction potential at bridged site. In brief, electron transfer generates the TEP, reversely, TEP modulates the efficiency of electron transfer. This may be an important approach to maintaining an appreciable pH environment in photosynthesis.

  1. The site effect on germinability of mugwort (Artemisia vulgaris L. achenes

    Directory of Open Access Journals (Sweden)

    Jan Winkler

    2005-01-01

    Full Text Available Mugwort (Artemisia vulgaris L. extremely spreads on uncultivated agricultural land and expands to arable land. Three sites were chosen in the local area of Uherské Hradiště: field (arable land, balk (adjacent to arable land and rubble heap (distant from arable land. At each site, 50 plants were selected from which mature achenes were collected in 2002 and 2003. The achenes germinated in a laboratory at a room temperature and were subjected to various germination conditions. A part of them was exposed to the temperature of – 20 °C in a freezer, the other part was stored at a room temperature. The germination was carried out either on filter paper in Petri dishes or in 30 mm layer of siliceous sand. One part of the achenes germinated in daylight, the other part in Petri dishes in the dark. The achenes cultivated in siliceous sand were covered with a 5 mm layer of the sand. The results were statistically assessed using Unistat software, analysis of variance and methods of least significant differences (LSD. Total average germinability of mugwort achenes was 67,7 %. The differences in germinability of frozen (66,7 % and non-frozen (72,6 % achenes were not statistically significant. Germinability of the achenes that matured in 2003 (69,9 % was highly significantly higher than that of the achenes matured in 2002 (65,4 %. The achenes germinated highly significantly more (77,9 % in daylight as compared with those germinated in the dark (57,4 %. Germinability of the achenes that germinated in siliceous sand was highly significantly higher (70,7 % than of those that germinated in Petri dishes (64,7 %. Germinability of the achenes matured in the field (64,1 % was significantly lower in comparison with the germinability of the achenes from a balk (69,7 % and rubble heap (69,2 %. The results of germinability of the achenes that matured in a rubble heap and balk did not significantly differ.

  2. Utilizing the dynamic stark shift as a probe for dielectric relaxation in photosynthetic reaction centers during charge separation.

    Science.gov (United States)

    Guo, Zhi; Lin, Su; Woodbury, Neal W

    2013-09-26

    In photosynthetic reaction centers, the electric field generated by light-induced charge separation produces electrochromic shifts in the transitions of reaction center pigments. The extent of this Stark shift indirectly reflects the effective field strength at a particular cofactor in the complex. The dynamics of the effective field strength near the two monomeric bacteriochlorophylls (BA and BB) in purple photosynthetic bacterial reaction centers has been explored near physiological temperature by monitoring the time-dependent Stark shift during charge separation (dynamic Stark shift). This dynamic Stark shift was determined through analysis of femtosecond time-resolved absorbance change spectra recorded in wild type reaction centers and in four mutants at position M210. In both wild type and the mutants, the kinetics of the dynamic Stark shift differ from those of electron transfer, though not in the same way. In wild type, the initial electron transfer and the increase in the effective field strength near the active-side monomer bacteriochlorophyll (BA) occur in synchrony, but the two signals diverge on the time scale of electron transfer to the quinone. In contrast, when tyrosine is replaced by aspartic acid at M210, the kinetics of the BA Stark shift and the initial electron transfer differ, but transfer to the quinone coincides with the decay of the Stark shift. This is interpreted in terms of differences in the dynamics of the local dielectric environment between the mutants and the wild type. In wild type, comparison of the Stark shifts associated with BA and BB on the two quasi-symmetric halves of the reaction center structure confirm that the effective dielectric constants near these cofactors are quite different when the reaction center is in the state P(+)QA(-), as previously determined by Steffen et al. at 1.5 K (Steffen, M. A.; et al. Science 1994, 264, 810-816). However, it is not possible to determine from static, low-temperature measurments if the

  3. Proteomic analysis of lettuce seed germination and thermoinhibition by sampling of individual seeds at germination and removal of storage proteins by polyethylene glycol fractionation.

    Science.gov (United States)

    Wang, Wei-Qing; Song, Bin-Yan; Deng, Zhi-Jun; Wang, Yue; Liu, Shu-Jun; Møller, Ian Max; Song, Song-Quan

    2015-04-01

    Germination and thermoinhibition in lettuce (Lactuca sativa 'Jianyexianfeng No. 1') seeds were investigated by a proteomic comparison among dry seeds, germinated seeds at 15°C, at 15°C after imbibition at 25°C for 48 h, or at 25°C in KNO3 (all sampled individually at germination), and ungerminated seeds at 25°C, a thermoinhibitory temperature. Before two-dimensional gel electrophoresis analysis, storage proteins (greater than 50% of total extractable protein) were removed by polyethylene glycol precipitation, which significantly improved the detection of less abundant proteins on two-dimensional gels. A total of 108 protein spots were identified to change more than 2-fold (Pseeds than in ungerminated 25°C seeds. Gene expression of 12 of those proteins correlated well with the protein accumulation. Methionine metabolism, ethylene production, lipid mobilization, cell elongation, and detoxification of aldehydes were revealed to be potentially related to lettuce seed germination and thermoinhibition. Accumulation of three proteins and expression of five genes participating in the mevalonate (MVA) pathway of isoprenoid biosynthesis correlated positively with seed germinability. Inhibition of this pathway by lovastatin delayed seed germination and increased the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination and thermoinhibition. © 2015 American Society of Plant Biologists. All Rights Reserved.

  4. The mechanism underlying fast germination of tomato cultivar LA2711.

    Science.gov (United States)

    Yang, Rongchao; Chu, Zhuannan; Zhang, Haijun; Li, Ying; Wang, Jinfang; Li, Dianbo; Weeda, Sarah; Ren, Shuxin; Ouyang, Bo; Guo, Yang-Dong

    2015-09-01

    Seed germination is important for early plant morphogenesis as well as abiotic stress tolerance, and is mainly controlled by the phytohormones abscisic acid (ABA) and gibberellic acid (GA). Our previous studies identified a salt-tolerant tomato cultivar, LA2711, which is also a fast-germinating genotype, compared to its salt-sensitive counterpart, ZS-5. In an effort to further clarify the mechanism underlying this phenomenon, we compared the dynamic levels of ABA and GA4, the transcript abundance of genes involved in their biosynthesis and catabolism as well as signal transduction between the two cultivars. In addition, we tested seed germination sensitivity to ABA and GAs. Our results revealed that insensitivity of seed germination to exogenous ABA and low ABA content in seeds are the physiological mechanisms conferring faster germination rates of LA2711 seeds. SlCYP707A2, which encodes an ABA catabolic enzyme, may play a decisive role in the fast germination rate of LA2711, as it showed a significantly higher level of expression in LA2711 than ZS-5 at most time points tested during germination. The current results will enable us to gain insight into the mechanism(s) regarding seed germination of tomato and the role of fast germination in stress tolerance. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  5. Effect of fungicides on Wyoming big sagebrush seed germination

    Science.gov (United States)

    Robert D. Cox; Lance H. Kosberg; Nancy L. Shaw; Stuart P. Hardegree

    2011-01-01

    Germination tests of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young [Asteraceae]) seeds often exhibit fungal contamination, but the use of fungicides should be avoided because fungicides may artificially inhibit germination. We tested the effect of seed-applied fungicides on germination of Wyoming big sagebrush at 2 different...

  6. Functional LH1 antenna complexes influence electron transfer in bacterial photosynthetic reaction centers

    NARCIS (Netherlands)

    Visschers, R.W.; Vulto, S.I.E.; Jones, M.R.; van Grondelle, R.; Kraayenhof, R.

    1999-01-01

    The effect of the light harvesting 1 (LH1) antenna complex on the driving force for light-driven electron transfer in the Rhodobacter sphaeroides reaction center has been examined. Equilibrium redox titrations show that the presence of the LH1 antenna complex influences the free energy change for

  7. Functional LH1 antenna complexes influence electron transfer in bacterial photosynthetic reaction centers.

    NARCIS (Netherlands)

    Visschers, R.W.; Vulto, S.I.E.; Jones, M.R.; van Grondelle, R.; Kraayenhof, R.

    1999-01-01

    The effect of the light harvesting 1 (LH1) antenna complex on the driving force for light-driven electron transfer in the Rhodobacter sphaeroides reaction center has been examined. Equilibrium redox titrations show that the presence of the LH1 antenna complex influences the free energy change for

  8. Chemical inhibitors of viviparous germination in the fruit of watermelon.

    Science.gov (United States)

    Kobayashi, Yoshiki; Nabeta, Kensuke; Matsuura, Hideyuki

    2010-09-01

    It is well known that the seeds of watermelon [Citrullus lanatus (Thunb.) Matsum and Nakai] have a high potential to germinate when the fruit has ripened. When removed from the mature fruit, the seeds can germinate under appropriate conditions. However, it is unclear why they cannot germinate in the flesh of the fruit. Here, we show that cis-ABA and its β-D-glucopyranosyl ester (ABA-β-GE) accumulate in the flesh of the fruit at levels high enough to inhibit seed germination. This result indicates the existence of chemical factors that inhibit viviparous seed germination of watermelon.

  9. Germination responses of limonium insigne (coss.) kuntze to salinity and temperature

    International Nuclear Information System (INIS)

    Isabel, C.; Fernandez, D.; Luque, E.G.; Mercado, F.G.

    2015-01-01

    Limonium insigne (Plumbaginaceae) is a perennial halophyte endemic to the SE of the Iberian Peninsula. Experiments were conducted to determine the effects of different salinities (0, 100, 200 and 400 mM NaCl) on the seed germination of L. insigne under different temperature regimes (20/10, 25/15, 30/20 and 35/25 degree C), both in a 14 h light and 10 h dark photoperiod. Seed germination of L. insigne was affected significantly by salinity levels, temperature and their interaction. Maximum germination was observed in the least saline media (100 mM NaCl) and distilled water (0 mM NaCl) at 20/10 degree C temperature. No seeds germinated at concentrations higher than 200 mM NaCl at the highest temperature (35/25 degree C). The increase in salinity delayed the beginning and ending of germination, reduced final germination percentage and increased mean time to germination. The rate of germination decreased with an increase in salinity and temperature. (author)

  10. Starch bioengineering affects cereal grain germination and seedling establishment

    DEFF Research Database (Denmark)

    Shaik, Shahnoor Sultana; Carciofi, Massimiliano; Martens, Helle Juel

    2014-01-01

    Cereal grain germination is central for plant early development, and efficient germination has a major role in crop propagation and malting. Endosperm starch is the prime energy reserve in germination and seedling establishment. In this study, it was hypothesized that optimized starch granule...... structure, and not only the endosperm starch content per se, is important for germination and seedling establishment. For that purpose, wild-type (WT), and specifically engineered degradable hyperphosphorylated (HP) starch and more resistant amylose-only (AO) starch barley lines were used. The transgenics...... showed no severe phenotypes and the WT and HP lines degraded the starch similarly, having 30% residual starch after 12 d of germination. However, the AO line showed significant resistance to degradation, having 57% residual starch. Interestingly, protein and β-glucan (BG) degradation was stimulated...

  11. Proteomic analysis of lettuce seed germination and thermoinhibition by sampling of individual seeds at germination and removal of storage proteins by polyethylene glycol fractionation

    DEFF Research Database (Denmark)

    Wang, Wei-Qing; Song, Bin-Yan; Deng, Zhi-Jun

    2015-01-01

    the sensitivity of germination to abscisic acid. MVA pathway-derived products, cytokinins, partially reversed the lovastatin inhibition of germination and released seed thermoinhibition at 25°C. We conclude that the MVA pathway for isoprenoid biosynthesis is involved in lettuce seed germination...

  12. Stimulation of lettuce seed germination by ethylene.

    Science.gov (United States)

    Abeles, F B; Lonski, J

    1969-02-01

    Ethylene increased the germination of freshly imbibed lettuce (Lactuca sativa L. var. Grand Rapids) seeds. Seeds receiving either red or far-red light or darkness all showed a positive response to the gas. However, ethylene was apparently without effect on dormant seeds, those which failed to germinate after an initial red or far-red treatment. Carbon dioxide, which often acts as a competitive inhibitor of ethylene, failed to clearly reverse ethylene-enhanced seed germination. While light doubled ethylene production from the lettuce seeds, its effect was not mediated by the phytochrome system since both red and far-red light had a similar effect.

  13. Effects of seed pretreatment and seed source on germination of five ...

    African Journals Online (AJOL)

    The effects of seed pre-sowing treatment and geographic source of seeds on three germination parameters of five Acacia species (GP = germination percent; GMT = germination mean time (days) and GI = germination index) were studied. Pre-sowing treatment included immersion in concentrated sulphuric acid for 5, 10 and ...

  14. Vasovagal reactions in whole blood donors at three REDS-II blood centers in Brazil.

    OpenAIRE

    Gonçalez, TT; Sabino, EC; Schlumpf, KS; Wright, DJ; Leao, S; Sampaio, D; Takecian, PL; Proietti, AB; Murphy, E; Busch, M; Custer, B; NHLBI Retrovirus Epidemiology Donor Study-II REDS-II, International Component,

    2012-01-01

    In Brazil little is known about adverse reactions during donation and the donor characteristics that may be associated with such events. Donors are offered snacks and fluids before donating and are required to consume a light meal after donation. For these reasons the frequency of reactions may be different than those observed in other countries.A cross-sectional study was conducted of eligible whole blood donors at three large blood centers located in Brazil between July 2007 and December 20...

  15. Temperature requirements for seed germination of Pereskia aculeata and Pereskia grandifolia.

    Science.gov (United States)

    Souza, Lucéia F; Gasparetto, Bruno F; Lopes, Rodrigo R; Barros, Ingrid B I

    2016-04-01

    Pereskia aculeata and Pereskia grandifolia have been studied widely due to their high nutritional and therapeutic values. However, little is known about the biological requirements of their seeds for the various germination factors. Thus, this experiment aimed to evaluate the thermal effects on the germination of these species at the temperatures of 24°C, 27°C, 30°C, 33°C and 36°C. After verification of the existence of differences in the performance of germination, a non-linear regression was carried out, relating the germination to temperature and identifying its point of maximum efficiency. We found that the lowest synchronization indexes of germination were observed close to 30°C. The best germination response of the P. aculeata and P. grandifolia was observed at 30°C and 33°C, respectively, with greater germination strength and fewer days to attain 63.21% of germinations. The results obtained from the germination of P. aculeata and P. grandifolia can be described by the Weindull distribution model with three parameters, as proposed by Carneiro and Guedes (1992). Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. Testicular germinal tumors

    International Nuclear Information System (INIS)

    Fresco, R.

    2010-01-01

    This work is about diagnosis, treatment and monitoring of testicular germinal tumors. The presumed diagnosis is based in the anamnesis, clinical examination, testicular ultrasound and tumor markers. The definitive diagnosis is obtained through the inguinal radical orchidectomy

  17. Oral administration of drugs with hypersensitivity potential induces germinal center hyperplasia in secondary lymphoid organ/tissue in Brown Norway rats, and this histological lesion is a promising candidate as a predictive biomarker for drug hypersensitivity occurrence in humans

    International Nuclear Information System (INIS)

    Tamura, Akitoshi; Miyawaki, Izuru; Yamada, Toru; Kimura, Juki; Funabashi, Hitoshi

    2013-01-01

    It is important to evaluate the potential of drug hypersensitivity as well as other adverse effects during the preclinical stage of the drug development process, but validated methods are not available yet. In the present study we examined whether it would be possible to develop a new predictive model of drug hypersensitivity using Brown Norway (BN) rats. As representative drugs with hypersensitivity potential in humans, phenytoin (PHT), carbamazepine (CBZ), amoxicillin (AMX), and sulfamethoxazole (SMX) were orally administered to BN rats for 28 days to investigate their effects on these animals by examinations including observation of clinical signs, hematology, determination of serum IgE levels, histology, and flow cytometric analysis. Skin rashes were not observed in any animals treated with these drugs. Increases in the number of circulating inflammatory cells and serum IgE level did not necessarily occur in the animals treated with these drugs. However, histological examination revealed that germinal center hyperplasia was commonly induced in secondary lymphoid organs/tissues in the animals treated with these drugs. In cytometric analysis, changes in proportions of lymphocyte subsets were noted in the spleen of the animals treated with PHT or CBZ during the early period of administration. The results indicated that the potential of drug hypersensitivity was identified in BN rat by performing histological examination of secondary lymphoid organs/tissues. Data obtained herein suggested that drugs with hypersensitivity potential in humans gained immune reactivity in BN rat, and the germinal center hyperplasia induced by administration of these drugs may serve as a predictive biomarker for drug hypersensitivity occurrence. - Highlights: • We tested Brown Norway rats as a candidate model for predicting drug hypersensitivity. • The allergic drugs did not induce skin rash, whereas D-penicillamine did so in the rats. • Some of allergic drugs increased

  18. Oral administration of drugs with hypersensitivity potential induces germinal center hyperplasia in secondary lymphoid organ/tissue in Brown Norway rats, and this histological lesion is a promising candidate as a predictive biomarker for drug hypersensitivity occurrence in humans

    Energy Technology Data Exchange (ETDEWEB)

    Tamura, Akitoshi, E-mail: akitoshi-tamura@ds-pharma.co.jp; Miyawaki, Izuru; Yamada, Toru; Kimura, Juki; Funabashi, Hitoshi

    2013-08-15

    It is important to evaluate the potential of drug hypersensitivity as well as other adverse effects during the preclinical stage of the drug development process, but validated methods are not available yet. In the present study we examined whether it would be possible to develop a new predictive model of drug hypersensitivity using Brown Norway (BN) rats. As representative drugs with hypersensitivity potential in humans, phenytoin (PHT), carbamazepine (CBZ), amoxicillin (AMX), and sulfamethoxazole (SMX) were orally administered to BN rats for 28 days to investigate their effects on these animals by examinations including observation of clinical signs, hematology, determination of serum IgE levels, histology, and flow cytometric analysis. Skin rashes were not observed in any animals treated with these drugs. Increases in the number of circulating inflammatory cells and serum IgE level did not necessarily occur in the animals treated with these drugs. However, histological examination revealed that germinal center hyperplasia was commonly induced in secondary lymphoid organs/tissues in the animals treated with these drugs. In cytometric analysis, changes in proportions of lymphocyte subsets were noted in the spleen of the animals treated with PHT or CBZ during the early period of administration. The results indicated that the potential of drug hypersensitivity was identified in BN rat by performing histological examination of secondary lymphoid organs/tissues. Data obtained herein suggested that drugs with hypersensitivity potential in humans gained immune reactivity in BN rat, and the germinal center hyperplasia induced by administration of these drugs may serve as a predictive biomarker for drug hypersensitivity occurrence. - Highlights: • We tested Brown Norway rats as a candidate model for predicting drug hypersensitivity. • The allergic drugs did not induce skin rash, whereas D-penicillamine did so in the rats. • Some of allergic drugs increased

  19. Evolution of nutrient ingredients in tartary buckwheat seeds during germination.

    Science.gov (United States)

    Yiming, Zhou; Hong, Wang; Linlin, Cui; Xiaoli, Zhou; Wen, Tang; Xinli, Song

    2015-11-01

    Evolution of nutrient components and the antioxidative activity of seed sprouts of tartary buckwheat (Fagopyrum tataricum L. Gaertn) were investigated in the course of germination. Results showed that the contents of total flavonoids increased with germination time and leveled off after the third germination day with the changing trend of rutin and quercetin opposite to each other. The decrease of total protein and total sugar contents in the germinated seeds was accompanied respectively by an increase of amino acid and reducing sugar contents. The contents of vitamin C (Vc) and B1(V(B1)) exhibited a minimum with no appreciable changes found for vitamin B(2) (V(B2)) and B(6) (V(B6)). The contents of total chlorophyll, chlorophyll A and B all exhibited a maximum on the fifth germination day. The contents of fatty acids had no regular changing trend with germination time. The free radical-scavenging activities of the seeds increased with germination time and were caused by an increase in their antioxidative activity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Seed priming with antioxidants improves sunflower seed germination and seedling growth under unfavorable germination conditions

    OpenAIRE

    DRAGANIC, Ivana; LEKIC, Slavoljub

    2012-01-01

    The results of studying the effects of sunflower seed priming with an aqueous solution of ascorbic acid (A), tocopherol (T), and glutathione (G) performed prior to accelerated ageing and a cold test are presented in this paper. Germination, the percentage of abnormal seedlings, and the lengths of both roots and shoots were monitored. The results showed that the cold test caused a drastic drop in germination, an adverse effect on the shoot length, an increase in the percentage of abnormal seed...

  1. Seed and Germination Characteristics of 20 Amazonian Liana Species

    Directory of Open Access Journals (Sweden)

    Mareike Roeder

    2013-01-01

    Full Text Available Lianas are an important component of tropical forests, and may reach their highest densities in disturbed areas. However, information on seed and germination characteristics is scarce. Twenty Amazon liana species were screened for their germination characteristics, including light dependence, tolerance of desiccation and of alternating temperatures; these characteristics are considered important for the germination success in areas with relatively open canopies. Between 31–1,420 seeds per species were available, as 15 species seeds came from one mother plant. We studied seed biometry and conducted germination trials with fresh seeds (12 h light daily, or dark and desiccated seeds at 25 °C. Germination at alternating temperatures (20/30 °C, 15/35 °C was analyzed for nine species. Of the 20 species, eight species with the largest seeds had desiccation sensitive seeds; this is the first record for species of four genera and one family, where only desiccation tolerant seeds are otherwise recorded. Light-dependent germination was found in three species (0.01–0.015 g and is the first record for two; however, results were based on seeds from one plant per species. Alternating temperatures of 15/35 °C decreased final germination of four out of nine species, and response to 20/30 °C cycles varied compared to constant 25 °C. Seed and germination characteristics of the species ranged from pioneer to climax traits indicating that establishment of lianas from seeds may be confined to species specific niches.

  2. Inhibition of barley grain germination by light

    NARCIS (Netherlands)

    Roth-Bejerano, N.; Meulen, R.M. van der; Wang, M.

    1996-01-01

    Intact grains of barley (Hordeum distichum cv. Triumph) germinated rapidly in the dark or when exposed to brief daily light breaks in the temperature range 15-25°C, although germination proceeded less rapidly at low temperatures. Prolonged illumination (16 h/day) or continuous light inhibited

  3. Seed germination of three species of Fabaceae typical of seasonally dry forest

    Directory of Open Access Journals (Sweden)

    Daniel Meira Arruda

    2015-06-01

    Full Text Available This study evaluates seeds germination of Anadenanthera colubrina, Acacia polyphylla and Bauhinia cheilantha, typical species of deciduous forests. Seeds were submitted to pre-germination treatments and attack of native insects. The seeds of each species were grouped in: seeds scarified with sandpaper; seeds immersed in water heated to 70 °C, seeds with signs of attack by herbivore insects and the control group. The largest proportion of germinated seeds occurred in the first week of incubation and germination peak, ranged from first to third day. All groups of A. polyphylla and B.cheilantha showed high germination rate (> 90%, being reduced only when seeds were attacked by insects (< 25%. Mechanic scarification was efficient in A. polyphylla by enhancing germination to maximum (100% and accelerating germination. A. colubrina showed no difference among groups, and germination rate was lower (< 50%, which was attributed to infestation by fungi, commonly reported in this species and apparently independent of usual hygiene procedures. Finally, except the fungi infestation in A. colubrina, evaluated species were independent of pre-germination treatment to obtain a high rate of germination.

  4. Mathematical model of seed germination process

    International Nuclear Information System (INIS)

    Gładyszewska, B.; Koper, R.; Kornarzyński, K.

    1999-01-01

    An analytical model of seed germination process was described. The model based on proposed working hypothesis leads - by analogy - to a law corresponding with Verhulst-Pearl's law, known from the theory of population kinetics. The model was applied to describe the germination kinetics of tomato seeds, Promyk field cultivar, biostimulated by laser treatment. Close agreement of experimental and model data was obtained [pl

  5. The orphan germinant receptor protein GerXAO (but not GerX3b) is essential for L-alanine induced germination in Clostridium botulinum Group II.

    Science.gov (United States)

    Brunt, Jason; Carter, Andrew T; Pye, Hannah V; Peck, Michael W

    2018-05-04

    Clostridium botulinum is an anaerobic spore forming bacterium that produces the potent botulinum neurotoxin that causes a severe and fatal neuro-paralytic disease of humans and animals (botulism). C. botulinum Group II is a psychrotrophic saccharolytic bacterium that forms spores of moderate heat resistance and is a particular hazard in minimally heated chilled foods. Spore germination is a fundamental process that allows the spore to transition to a vegetative cell and typically involves a germinant receptor (GR) that responds to environmental signals. Analysis of C. botulinum Group II genomes shows they contain a single GR cluster (gerX3b), and an additional single gerA subunit (gerXAO). Spores of C. botulinum Group II strain Eklund 17B germinated in response to the addition of L-alanine, but did not germinate following the addition of exogenous Ca 2+ -DPA. Insertional inactivation experiments in this strain unexpectedly revealed that the orphan GR GerXAO is essential for L-alanine stimulated germination. GerX3bA and GerX3bC affected the germination rate but were unable to induce germination in the absence of GerXAO. No role could be identified for GerX3bB. This is the first study to identify the functional germination receptor of C. botulinum Group II.

  6. Suicidal germination for parasitic weed control.

    Science.gov (United States)

    Zwanenburg, Binne; Mwakaboko, Alinanuswe S; Kannan, Chinnaswamy

    2016-11-01

    Parasitic weeds of the genera Striga and Orobanche spp. cause severe yield losses in agriculture, especially in developing countries and the Mediterranean. Seeds of these weeds germinate by a chemical signal exuded by the roots of host plants. The radicle thus produced attaches to the root of the host plant, which can then supply nutrients to the parasite. There is an urgent need to control these weeds to ensure better agricultural production. The naturally occurring chemical signals are strigolactones (SLs), e.g. strigol and orobanchol. One option to control these weeds involves the use of SLs as suicidal germination agents, where germination takes place in the absence of a host. Owing to the lack of nutrients, the germinated seeds will die. The structure of natural SLs is too complex to allow multigram synthesis. Therefore, SL analogues are developed for this purpose. Examples are GR24 and Nijmegen-1. In this paper, the SL analogues Nijmegen-1 and Nijmegen-1 Me were applied in the field as suicidal germination agents. Both SL analogues were formulated using an appropriate EC-approved emulsifier (polyoxyethylene sorbitol hexaoleate) and applied to tobacco (Nicotiana tabacum L.) fields infested by Orobanche ramosa L. (hemp broomrape), following a strict protocol. Four out of 12 trials showed a reduction in broomrape of ≥95%, two trials were negative, two showed a moderate result, one was unclear and in three cases there was no Orobanche problem in the year of the trials. The trial plots were ca 2000 m 2 ; half of that area was treated with stimulant emulsion, the other half was not treated. The optimal amount of stimulant was 6.25 g ha -1 . A preconditioning prior to the treatment was a prerequisite for a successful trial. In conclusion, the suicidal germination approach to reducing O. ramosa in tobacco fields using formulated SL analogues was successful. Two other options for weed control are discussed: deactivation of stimulants prior to action and

  7. TIME REDUCTION FOR SURINAM GRASS SEED GERMINATION TEST

    Directory of Open Access Journals (Sweden)

    Camila de Aquino Tomaz

    2015-10-01

    Full Text Available ABSTRACTThe period for the germination test of Surinam grass seeds established by the Rules for Seeds Testing is 28 days, considered too lengthy by producers, venders, and seed analysis laboratories. So, the objective of this research was to evaluate the possibility of reducing the time for the germination test of Surinam grass seeds and to establish a method for dormancy breaking and the ideal temperature. Ten seed lots were submitted to the following treatments to overcome seed dormancy: control; substrate moistening with 0.2% KNO3; and scarification with sulfuric acid (98% 36 N for 15 minutes. After the treatments, the lots were submitted to seed water content, germination and tetrazolium tests. During the germination test, conducted with four replicates of 100 seeds per treatment for 28 days, two conditions of alternating temperatures (20-35 °C and 15-35 °C with 8 hours of light were tested. Attempting to determine the test end date, daily counts of the number of normal seedlings were made and for each lot, treatment, and temperature, a growth curve for the evaluation of germination was adjusted. The segmented regression model parameter estimations were calculated for each treatment. The germination test of Braquiaria decumbensseeds may be evaluated in 12 days after sowing using alternating temperatures of 20-35 °C and without any treatment to overcome dormancy.

  8. Ecophysiology of seed germination in Digitaria insularis ((L. Fedde

    Directory of Open Access Journals (Sweden)

    Giovana Soares de Mendonça

    Full Text Available The invasive behaviour of sourgrass (Digitaria insularis in cultivated areas is due to its strategy of aggressive regeneration, which is based on seed germination. Knowledge of the physiological ecology of this species can contribute to the development of management and control strategies. The aim of this research was to understand the effects of provenance, temperature and light on the germination of sourgrass seeds collected in the Brazilian state of São Paulo in the cities of Americana, Botucatu and São José do Rio Preto and in the state of Paraná in the city of São Miguel do Iguaçu. The seeds were left to germinate at temperatures of 15, 25, 35 and 45 °C, both with and without light. The number of normal seedlings was recorded daily from seven to 60 days. After this period, the seeds together with substrate, were transferred to 25 ºC with light, and a daily count was made for all treatments until the end of germination (75 days after sowing. The seeds of D. insularis are positively photoblastic. Seed germination in this species depends on provenance. A temperature of 4 5 °C for germination is lethal to the seeds. The temperature of 35 °C in the presence of light is the most favourable condition for seed germination.

  9. Effects of stress temperatures of germination on polyamine titers of soybean seeds

    Science.gov (United States)

    Pineda-Mejia, Renan

    High and low stress temperatures during seed germination and seedling development limit total germination and the rate of germination and growth. Changes in polyamine (PA) concentrations in seeds of different species have been associated with germination, growth and environmental stresses such as temperature, drought, oxygen, chilling injury and osmotic conditions. Two studies were conducted to determine the effect of stress temperatures during germination and seedling development on polyamine titers in soybean seeds. Three germination temperatures, 25, 30, and 36°C were used in the first study to evaluate their influence on changes in polyamine concentrations in soybean seeds germinated at 76 and 90 hours. The polyamines (PAs), cadaverine (Cad), putrescine (Put), spermidine (Spd), agmatine (Agm), and spermine (Spin) were quantified by HPLC using a cation exchange column and an electrochemical detector. Cad, Put, Agm, and Spd declined as the germination temperatures increased from 25 to 36°C. Conversely, Spin increased considerably with an increase in temperature. Total germination was reduced from 97.2 to 92.5% as germination temperatures increased from 25 to 36°C. Germination time did not affect Cad, Agm and Spm, and total germination, however, the interaction between temperature and germination time for Put and Spd concentrations was significant. In the second study, changes in PA concentrations, seedling growth, germination time (t50), fresh and dry weight, and moisture content were measured in the embryonic axis and cotyledons of soybean seeds germinated at 10 and 25°C through six stages of germination dry seed (DS), testa split (TS), radicle at 10 mm (Ra-10), root hairs visible (RHV), secondary root primordia (SRP), and complete seedling (CS). The concentrations of Cad and Put in the embryonic axis, were significantly higher in seeds germinated under low temperature than in seeds at 25°C (approximately 10 and 3 fold respectively). However, this

  10. Electronically stimulated deep-center reactions in electron-irradiated InP: Comparison between experiment and recombination-enhancement theories

    International Nuclear Information System (INIS)

    Sibille, A.

    1987-01-01

    We present a detailed study of the recombination enhancement of several defect reactions involving the main deep centers in low-temperature electron-irradiated InP. A fairly good agreement is obtained with the Weeks-Tully-Kimerling theory for the activation energies of the enhanced process. On the other hand, a thorough investigation of a thermally and electronically stimulated defect transformation shows evidence that one major approximation (local vibrational equilibrium) fails, and that the recently proposed [H. Sumi, Phys. Rev. B 29, 4616 (1984)] mechanism of coherent recombination on deep centers is responsible for altered reaction rates at high injection levels

  11. DOG1-imposed dormancy mediates germination responses to temperature cues

    NARCIS (Netherlands)

    Murphey, M.; Kovach, K.; Elnacash, T.; He, H.; Bentsink, L.; Donohue, K.

    2015-01-01

    Seed dormancy and environment-dependent germination requirements interact to determine the timing of germination in natural environments. This study tested the contribution of the dormancy gene Delay Of Germination 1 (DOG1) to primary and secondary dormancy induction in response to environmental

  12. The plasma membrane proteome of germinating barley embryos

    DEFF Research Database (Denmark)

    Hynek, Radovan; Svensson, Birte; Jensen, O.N.

    2009-01-01

    Cereal seed germination involves a complex coordination between different seed tissues. Plasma membranes must play crucial roles in coordination and execution of germination; however, very little is known about seed plasma membrane proteomes due to limited tissue amounts combined...... with amphiphilicity and low abundance of membrane proteins. A fraction enriched in plasma membranes was prepared from embryos dissected from 18 h germinated barley seeds using aqueous two-phase partitioning. Reversed-phase chromatography on C-4 resin performed in micro-spin columns with stepwise elution by 2-propanol...... was used to reduce soluble protein contamination and enrich for hydrophobic proteins. Sixty-one proteins in 14 SDS-PAGE bands were identified by LC-MS/MS and database searches. The identifications provide new insight into the plasma membrane functions in seed germination....

  13. Comparative Germination Responses of Cowpea and Maize ...

    African Journals Online (AJOL)

    Germination, emergence and establishment phase are critical to the growth cycle of plant as it determines the density of the stand obtained. However, a number of factors including soil available moisture decrease seed germination and the rate of decline is found to vary with crop species. Pot experiment was therefore ...

  14. Maternal vernalization and vernalization-pathway genes influence progeny seed germination.

    Science.gov (United States)

    Auge, Gabriela A; Blair, Logan K; Neville, Hannah; Donohue, Kathleen

    2017-10-01

    Different life stages frequently respond to the same environmental cue to regulate development so that each life stage is matched to its appropriate season. We investigated how independently each life stage can respond to shared environmental cues, focusing on vernalization, in Arabidopsis thaliana plants. We first tested whether effects of rosette vernalization persisted to influence seed germination. To test whether genes in the vernalization flowering pathway also influence germination, we assessed germination of functional and nonfunctional alleles of these genes and measured their level of expression at different life stages in response to rosette vernalization. Rosette vernalization increased seed germination in diverse ecotypes. Genes in the vernalization flowering pathway also influenced seed germination. In the Columbia accession, functional alleles of most of these genes opposed the germination response observed in the ecotypes. Some genes influenced germination in a manner consistent with their known effects on FLOWERING LOCUS C gene regulation during the transition to flowering. Others did not, suggesting functional divergence across life stages. Despite persistent effects of environmental conditions across life stages, and despite pleiotropy of genes that affect both flowering and germination, the function of these genes can differ across life stages, potentially mitigating pleiotropic constraints and enabling independent environmental regulation of different life stages. © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.

  15. on seed germination and growth of Garcinia kola

    African Journals Online (AJOL)

    SARAH

    2016-07-31

    Jul 31, 2016 ... Parameters related to seed germination and seedlings vigour was evaluated. Results indicated that substrate do not affect seed germination and plant vigour. However ..... Annual plant reviews California, USA, pp. 50-. 6.7.

  16. Germination and growth of Magonia pubescens A. ST.-HIL seedlings

    Directory of Open Access Journals (Sweden)

    Ani Cátia Giotto

    2009-03-01

    Full Text Available This study aimed to analyze the germination, growth and development of Magonia pubescens A. St.-Hil. (tinguí ortimbó, a typical species of the deciduous forest. The germination of seeds of four matrices was evaluated at different treatments: directsowing in greenhouse (50% of shade, direct sowing under full sunlight and moistened paper at laboratory condition and underfluorescent light with photoperiod of 12 hours in ambient temperature. The germinated seeds under laboratory conditions weretransplanted to polyethylene bags with soil under full sunlight and 50% of shade. The variables evaluated were: time of the first andlast germination, germinability; average time and the rates of speed of germination index. In addition there were evaluated the seedlingheight, stem base diameter, number of leaf and leaflets were monitored at 30, 60, 90 and 120 days. The species presented highgerminability at laboratory conditions (G> 90% and under full sunlight (96%>G>56%, however, the germinability in 50% shadepresented inferior result (G0.05. The leaf and leaflets number varied among treatments, with highest average for seedling under full sunlight. Suggesting thatMagonia pubescens A. St.-Hil. is a useful species for rehabilitation of degraded areas.

  17. Nuclear Reaction and Structure Databases of the National Nuclear Data Center

    International Nuclear Information System (INIS)

    Pritychenko, B.; Arcilla, R.; Herman, M. W.; Oblozinsky, P.; Rochman, D.; Sonzogni, A. A.; Tuli, J. K.; Winchell, D. F.

    2006-01-01

    The National Nuclear Data Center (NNDC) collects, evaluates, and disseminates nuclear physics data for basic research and applied nuclear technologies. In 2004, the NNDC migrated all databases into modern relational database software, installed new generation of Linux servers and developed new Java-based Web service. This nuclear database development means much faster, more flexible and more convenient service to all users in the United States. These nuclear reaction and structure database developments as well as related Web services are briefly described

  18. Study of Seed Germination by Soaking Methode of Cacao (Theobroma cacao L.

    Directory of Open Access Journals (Sweden)

    Sulistyani Pancaningtyas

    2014-12-01

    Full Text Available Study of germination methods conduct to get information about seed viability based on germination rate, percentage of germination and vigority. Germination methods was studied to get the efficiency and effectivity of germination, easy to handle, low costs with high vigority. Sand and gunny sack methods  for germination, need extensive place  and 3-4 days germination period after planting. This research will study the alternative of germination method with soaking. This method can be accelerating  germination rate and effectively place usage without decreasing the quality of cacao seedling.The research was done at Kaliwining Experimental Station, Indonesian Coffee and Cocoa Research Institue. This research consist of two experiment was arranged based on factorial completely random design. First experiment will observed to compared germination rate and the second experiment will observed seedling quality between soaking and wet gunny sack germination method.The results showed that length of radicel on soaking method longer than wet gunny sack method. Growth of radicel started from 2 hours after soaking, moreover length of radicel at 4 hours after soaking have significant different value with gunny sack method. On 24 hours after soaking have 3,69 mm and 0,681 mm on wet gunny sack treatment. Except lengt of hipocotyl, there is not different condition between seedling that out came  from soaking and wet gunny sack method. Length of hipocotyl on 36 hours after soaking have 9,15 cm and significant different between wet gunny sack germination method that have 5,40 cm. Keywords : seed germination, soaking method, Theobroma cacao L., cocoa seedlings

  19. Salivary glands act as mucosal inductive sites via the formation of ectopic germinal centers after site-restricted MCMV infection.

    Science.gov (United States)

    Grewal, Jasvir S; Pilgrim, Mark J; Grewal, Suman; Kasman, Laura; Werner, Phillip; Bruorton, Mary E; London, Steven D; London, Lucille

    2011-05-01

    We investigated the hypothesis that salivary gland inoculation stimulates formation of ectopic germinal centers (GCs), transforming the gland into a mucosal inductive site. Intraglandular infection of mice with murine cytomegalovirus (MCMV; control: UV-inactivated MCMV) induces salivary gland ectopic follicles comprising cognate interactions between CD4(+) and B220(+) lymphocytes, IgM(+) and isotype-switched IgG(+) and IgA(+) B cells, antigen presenting cells, and follicular dendritic cells. B cells coexpressed the GC markers GCT (57%) and GL7 (52%), and bound the lectin peanut agglutinin. Lymphoid follicles were characterized by a 2- to 3-fold increase in mRNA for CXCL13 (lymphoid neogenesis), syndecan-1 (plasma cells), Blimp-1 (plasma cell development/differentiation), and a 2- to 6-fold increase for activation-induced cytidine deaminase, PAX5, and the nonexcised rearranged DNA of an IgA class-switch event, supporting somatic hypermutation and class-switch recombination within the salivary follicles. Intraglandular inoculation also provided protection against a systemic MCMV challenge, as evidenced by decreased viral titers (10(5) plaque-forming units to undetectable), and restoration of normal salivary flow rates from a 6-fold decrease. Therefore, these features suggest that the salivary gland participates in oral mucosal immunity via generation of ectopic GCs, which function as ectopic mucosal inductive sites.

  20. Asymbiotic germination in three Chloraea species (Orchidaceae) from Chile

    OpenAIRE

    PEREIRA, GUILLERMO; ALBORNOZ, VERÓNICA; ROMERO, CHRISTIAN; LARA, SEBASTIÁN; SÁNCHEZ-OLATE, MANUEL; RÍOS, DARCY; ATALA, CRISTIAN

    2017-01-01

    ABSTRACT Orchids require symbiotic fungi and/or specific conditions to germinate. Asymbiotic techniques have been shown successful for orchid germination. In Chile, Chloraea include many endemic, and potentially ornamental, terrestrial orchid species. In this study, individuals of Chloraea crispa, C. gavilu and C. virescens were manually autopollinated. The resulting capsules were sterilized and seeds were aseptically obtained. We evaluated asymbiotic germination in: Agar Water (AW), Knudson ...

  1. Effect of Salinity on Germination and Seedling Growth of Four Medicinal Plants

    Directory of Open Access Journals (Sweden)

    A Dadkhah

    2012-07-01

    Full Text Available This experiment was conducted in germinator in order to study the effects of water potential on seed germination, rate of germination and seedlings growth of four medicinal plants (Coriandrum sativum, Plantago psyllium, Discorinia sophia and Portulaca oleracea. Four water potential inclouding distilled water as control (0, -0.37, -0.59 and –0.81 Mpa which made by different salts (NaCl, CaCl2 and NaCl+CaCl2 in 5 to 1 molar ratio. The experiment was carried out based on completly randomized design with six replications. Results showed that the effects of water potential, type of salt on germination percentage, rate of germination, root and shoot length were significant. With decreasing water potential, germination percentage and rate of germination declined but the response of plant were differ. Germination of Portulaca oleracea was not affected by decreasing water potential where as other significantly decreased. The effect of salt composition was significant on rate and percentage germination. The percentage of germination at lower water potential (–0.37 MPa which made by NaCl + CaCl2 significantly was higher than the same water potential made by only NaCl and CaCl2. Although, percentage and rate germination of Portulaca oleracea were not affected by different water potential, seedling growth of Portulaca oleracea significantly decreased.

  2. Effect of germination and thermal treatments on folates in rye.

    Science.gov (United States)

    Kariluoto, Susanna; Liukkonen, Kirsi-Helena; Myllymäki, Olavi; Vahteristo, Liisa; Kaukovirta-Norja, Anu; Piironen, Vieno

    2006-12-13

    Effects of germination conditions and thermal processes on folate contents of rye were investigated. Total folate contents were determined microbiologically with Lactobacillus rhamnosus (ATCC 7469) as the growth indicator organism, and individual folates were determined by high-performance liquid chromatography after affinity chromatographic purification. Germination increased the folate content by 1.7-3.8-fold, depending on germination temperature, with a maximum content of 250 micro g/100 g dry matter. Hypocotylar roots with their notably high folate concentrations (600-1180 micro g/100 g dry matter) contributed 30-50% of the folate contents of germinated grains. Germination altered the proportions of folates, increasing the proportion of 5-methyltetrahydrofolate and decreasing the proportion of formylated folate compounds. Thermal treatments (extrusion, autoclaving and puffing, and IR and toasting) resulted in significant folate losses. However, folate levels in grains that were germinated and then were heat processed were higher than for native (nongerminated) grains. Opportunities to optimize rye processing to enhance folate levels in rye-based foods are discussed.

  3. Behavior of 15N-labelled amino acids in germinated corn

    International Nuclear Information System (INIS)

    Samukawa, Kisaburo; Yamaguchi, Masuro

    1979-01-01

    By investigating the rise and fall of 15 N-labelled amino acids in germinated corns, the behavior of amino radicals in free amino acids, the influence of the hydrolysis products of stored proteins on free amino acids and the change from heterotrophy to autotrophy of seeds were clarified. The amount of amino acid production depending on external nitrogen was very small in the early period of germination. 15 N incorporation into proline was not observed in the early period of germination, which suggested that the proline may be nitrogen-storing source. Most of the amino-state nitrogen of asparagine accumulated at the time of germination was internal nitrogen, and this fact suggested that aspartic acid serve as the acceptor of ammonia produced in the early stage of germination. 15 N content increased significantly on 9 th day after germination, and decreased on 12 th day. These facts prove that there are always active decomposition and production of protein in plant body. (Kobatake, H.)

  4. Hydrogen bonds in the vicinity of the special pair of the bacterial reaction center probed by hydrostatic high-pressure absorption spectroscopy.

    Science.gov (United States)

    Kangur, Liina; Jones, Michael R; Freiberg, Arvi

    2017-12-01

    Using the native bacteriochlorophyll a pigment cofactors as local probes, we investigated the response to external hydrostatic high pressure of reaction center membrane protein complexes from the photosynthetic bacterium Rhodobacter sphaeroides. Wild-type and engineered complexes were used with a varied number (0, 1 or 2) of hydrogen bonds that bind the reaction center primary donor bacteriochlorophyll cofactors to the surrounding protein scaffold. A pressure-induced breakage of hydrogen bonds was established for both detergent-purified and membrane-embedded reaction centers, but at rather different pressures: between 0.2 and 0.3GPa and at about 0.55GPa, respectively. The free energy change associated with the rupture of the single hydrogen bond present in wild-type reaction centers was estimated to be equal to 13-14kJ/mol. In the mutant with two symmetrical hydrogen bonds (FM197H) a single cooperative rupture of the two bonds was observed corresponding to an about twice stronger bond, rather than a sequential rupture of two individual bonds. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Seed Germination and Cuttings Growth of Piper Aduncum

    Science.gov (United States)

    Susanto, D.; Sudrajat; Suwinarti, W.; Amirta, R.

    2018-04-01

    Sirih hutan (Piper aduncum L) is one of group shurbs tropical species, has potential to be developed as raw material of biomass based electricity. The aim of this research was to know seed germination and cuttings growth of P. aduncum plant as the first step in cultivation of this plant. Observation of flowers and fruits were done in secondary forest, while seed germination and growth of shoot cuttings were done in the laboratory. The results showed that P. aduncum seeds can be germinated in a relatively short time of 17 to 25 days with a fairly high germination percentage of 90 ± 8.16% and germination rate of 4.7 ± 0.34%. The growth of seedlings at 2 months old was 4.78 ± 0.42 cm, plant height 3.97 ± 0.27 cm, and relative growth rate 0.33 ± 0.14%. The treatment of synthetic growth regulator had significant effect on shoot growth and root number on the plant stem cuttings. Preparation of seedlings ready to plant in a generative and vegetative for cultivation of these plants in the experimental plot.

  6. Microorganisms control during processing of germinated brown rice

    International Nuclear Information System (INIS)

    Suzuki, K.; Maekawa, T.

    1999-01-01

    In order to limit the growth of microorganisms during processing of germinated brown rice (GBR), three kinds of operations for sanitation control were investigated. For a surface-disinfection treatment of brown rice, soaking in 1% of sodium hypochlorite for 10min. and 0.1% of calcium preparation solutions for 10min. at 30°C, resulted in 2log decrease by aerobic plate count in culture water after 1h of the germination processing. Soaking in 10% of sodium hypochlorite for 10min. and 1% of calcium preparation solutions for 10min at 30°C were found to inhibit germination, respectively. During the germination processing, including aeration stage and non-aeration stage, continuous ultraviolet irradiation on the culture water in the water tank resulted in limited bacterial growth in culture water below 102CFU/ml by aerobic plate count. Moreover, the turbidity of the culture water was improved by filtration of the stored water using activated carbon-hollow fiber filter. The filtration by activated carbon-hollow fiber filter during the germination processing was an effective method to eliminate microorganisms and contamination factor during GBR production. It also improved the efficiency of ultraviolet irradiation effect on the culture water

  7. Germination and seedlings performance of cashew ( Anacardium ...

    African Journals Online (AJOL)

    The effects of nut-sowing orientations on the germination of cashew nuts and the responses of the resultant seedlings to cotyledon removed were studied in the nursery. While cashew nuts sown flat and those with stylar-end up had highest mean germination of 91.67 % and 92.50 % respectively the nuts sown with ...

  8. Reduced seed germination in Arabidopsis over-expressing SWI/SNF2 ATPase genes.

    Science.gov (United States)

    Leeggangers, Hendrika A C F; Folta, Adam; Muras, Aleksandra; Nap, Jan-Peter; Mlynarova, Ludmila

    2015-02-01

    In the life of flowering plants, seed germination is a critical step to ensure survival into the next generation. Generally the seed prior to germination has been in a dormant state with a low rate of metabolism. In the transition from a dormant seed to a germinating seed, various epigenetic mechanisms play a regulatory role. Here, we demonstrate that the over-expression of chromatin remodeling ATPase genes (AtCHR12 or AtCHR23) reduced the frequency of seed germination in Arabidopsis thaliana up to 30% relative to the wild-type seeds. On the other hand, single loss-of-function mutations of the two genes did not affect seed germination. The reduction of germination in over-expressing mutants was more pronounced in stress conditions (salt or high temperature), showing the impact of the environment. Reduced germinations upon over-expression coincided with increased transcript levels of seed maturation genes and with reduced degradation of their mRNAs stored in dry seeds. Our results indicate that repression of AtCHR12/23 gene expression in germinating wild-type Arabidopsis seeds is required for full germination. This establishes a functional link between chromatin modifiers and regulatory networks towards seed maturation and germination. © 2014 Scandinavian Plant Physiology Society.

  9. Elemental variations in the germinating fungus Phytophthora palmivora

    International Nuclear Information System (INIS)

    Mazzolini, A.P.; Sealock, R.M.; Legge, G.J.F.; Grant, B.R.

    1991-01-01

    We have measured the elemental variations between zoospores and germinating cystospores of the fungus Phytophthora palmivora, using a scanning proton microprobe. Averaged over a number of individual cells, our results indicate that the level of Ca is much lower in germinating cystospores than in zoospores. The levels of S, Cl, and Zn also appear to be lower, and the level of K appears to be higher. The spatial distribution of elements within the germinating cystospore is very similar for P, S, Cl, K, Mn, Fe, and Cu, but significantly different for Ca and Zn. (orig.)

  10. Elemental variations in the germinating fungus Phytophthora palmivora

    Science.gov (United States)

    Mazzolini, A. P.; Grant, B. R.; Sealock, R. M.; Legge, G. J. F.

    1991-03-01

    We have measured the elemental variations between zoospores and germinating cystospores of the fungus Phytophthora palmivora, using a scanning proton microprobe. Averaged over a number of individual cells, our results indicate that the level of Ca is much lower in germinating cystospores than in zoospores. The levels of S, Cl, and Zn also appear to be lower, and the level of K appears to be higher. The spatial distribution of elements within the germinating cystospore is very similar for P, S, Cl, K, Mn, Fe, and Cu, but significantly different for Ca and Zn.

  11. Germination Response of Four Alien Congeneric Amaranthus Species to Environmental Factors.

    Science.gov (United States)

    Hao, Jian-Hua; Lv, Shuang-Shuang; Bhattacharya, Saurav; Fu, Jian-Guo

    2017-01-01

    Seed germination is the key step for successful establishment, growth and further expansion of population especially for alien plants with annual life cycle. Traits like better adaptability and germination response were thought to be associated with plant invasion. However, there are not enough empirical studies correlating adaptation to environmental factors with germination response of alien invasive plants. In this study, we conducted congeneric comparisons of germination response to different environmental factors such as light, pH, NaCl, osmotic and soil burials among four alien amaranths that differ in invasiveness and have sympatric distribution in Jiangsu Province, China. The data were used to create three-parameter sigmoid and exponential decay models, which were fitted to cumulative germination and emergence curves. The results showed higher maximum Germination (Gmax), shorter time for 50% germination (G50) and the rapid slope (Grate) for Amaranthus blitum (low-invasive) and A. retroflexus (high-invasive) compare to intermediately invasive A. spinosus and A. viridis in all experimental regimes. It indicated that germination potential does not necessarily constitute a trait that can efficiently distinguish highly invasive and low invasive congeners in four Amaranthus species. However, it was showed that the germination performances of four amaranth species were more or less correlated with their worldwide distribution area. Therefore, the germination performance can be used as a reference indicator, but not an absolute trait for invasiveness. Our results also confirmed that superior germination performance in wide environmental conditions supplementing high seed productivity in highly invasive A. retroflexus might be one of the reasons for its prolific growth and wide distribution. These findings lay the foundation to develop more efficient weed management practice like deep burial of seeds by turning over soil and use of tillage agriculture to control

  12. Strigolactone analogs derived from ketones using a working model for germination stimulants as a blueprint.

    Science.gov (United States)

    Mwakaboko, Alinanuswe S; Zwanenburg, Binne

    2011-04-01

    Strigolactones are important signaling compounds in the plant kingdom. Here we focus on their germination stimulatory effect on seeds of the parasitic weeds Striga and Orobanche spp. and more particularly on the design and synthesis of new active strigolactone analogs derived from simple cyclic ketones. New analogs derived from 1-indanone, 1-tetralone, cyclopentanone, cyclohexanone and a series of substituted cyclohexanones (including carvone and pulegone) are prepared by formylation of the ketones with ethyl formate followed by coupling with a halo butenolide. Both enantiomers of the analog derived from 1-tetralone have been prepared by employing a homochiral synthon for the coupling reaction. For three other strigolactone analogs the antipodes have been obtained by chromatography on a chiral column. All analogs have an appreciable germinating activity towards seeds of Striga hermomonthica and Orobanche crenata and O. cernua. Stereoisomers having the same configuration at the D-ring as in naturally occurring strigol have a higher stimulatory effect than the corresponding antipodes. The analogs obtained from 1-indanone and 1-tetralone have an activity comparable with that of the well known stimulant GR 24. Analogs derived from 2-phenyl-cylohexanone, carvone and pulegone also have a good germinating response. The results show that the working model for designing new bioactive strigolactones is applicable.

  13. BIOSECURITY FOR REDUCING OCHRATOXIN A PRODUCTIVITY AND THEIR IMPACT ON GERMINATION AND ULTRASTRUCTURES OF GERMINATED WHEAT GRAINS

    Directory of Open Access Journals (Sweden)

    M.M.

    2012-08-01

    Full Text Available Ochratoxin A (OTA is a secondary metabolite of some fungi that causes very serious problems for plants, animals and humans. Various microorganisms such as bacteria and microscopic fungi have been tested for their abilities to prevent ochratoxin A contamination or detoxify foods. In this study, Saccharomyces cerevisiae and Lactobacillus bulgaricus reduced OTA production by Aspergillus ochraceus to 40.88 µg/ml ( productivity 60.69% and 13.80 µg/ml (productivity 20.48% respectively compared with the control (67.35 µg/ml (productivity 100%. The results clearly indicated that the seed germinibility in the presence of OTA was decreased with increasing concentration, whereas the germinibility was uncompletely ceased at high concentration (67.35 µg/ml of OTA. The maximum amount of germination was observed in control (without OTA treatment and at low concentration (13.80 µg/ml within 4 days. Antioxidant enzymes catalase and peroxidase decreased in germinated grains treated with OTA. Catalase was 18.12 U/ml in grains treated with low concentration (13.80 µg/ml of OTA while at high concentration (67.35 µg/ml, it was 12.23 U/ml compared with the control (20.33 U/ml. On the other hand, peroxidase decreased only in germinated grains treated with high concentration of OTA. The ultrastructural studies indicate that there were dramatic differences between the cells of root system of wheat seedlings of grains treated and untreated with the OTA. Cell ultrastructures of treated grains with OTA showed that the cytoplasmic membrane collapses away from the cell wall. Plasmodesmata threads were appeared in untreated cells but not formed in treated cells.

  14. Constant and alternating temperature effects on germination and early growth of scorzonera

    OpenAIRE

    Dias, A.S.; Dias, L.S.; Pereira, I.P.

    2013-01-01

    Scorzonera is a threatened species in Portugal. Given the role of temperature in germination and seedling recruitment, the performance of total germination, lag of germination, duration of germination, shape of germination, root and hypocotyl length, and relative root growth of scorzonera was investigated under constant and alternating temperatures between 10 and 25ºC. Because of scorzonera’s rarity and threatened status, seeds of cultivated scorzonera were used, providing the framework for h...

  15. Effects of High Pressure on Bacillus licheniformis Spore Germination and Inactivation.

    Science.gov (United States)

    Borch-Pedersen, Kristina; Mellegård, Hilde; Reineke, Kai; Boysen, Preben; Sevenich, Robert; Lindbäck, Toril; Aspholm, Marina

    2017-07-15

    Bacillus and Clostridium species form spores, which pose a challenge to the food industry due to their ubiquitous nature and extreme resistance. Pressurization at 300 MPa likely triggers germination by opening dipicolinic acid (DPA) channels present in the inner membrane of the spores. In this work, we expose spores of Bacillus licheniformis , a species associated with food spoilage and occasionally with food poisoning, to high pressure (HP) for holding times of up to 2 h. By using mutant spores lacking one or several GRs, we dissect the roles of the GerA, Ynd, and GerK GRs in moderately HP (mHP; 150 MPa)-induced spore germination. We show that Ynd alone is sufficient for efficient mHP-induced spore germination. GerK also triggers germination with mHP, although at a reduced germination rate compared to that of Ynd. GerA stimulates mHP-induced germination but only in the presence of either the intact GerK or Ynd GR. These results suggests that the effectiveness of the individual GRs in mHP-induced germination differs from their effectiveness in nutrient-induced germination, where GerA plays an essential role. In contrast to Bacillus subtilis spores, treatment with very HP (vHP) of 550 MPa at 37°C did not promote effective germination of B. licheniformis spores. However, treatment with vHP in combination with elevated temperatures (60°C) gave a synergistic effect on spore germination and inactivation. Together, these results provide novel insights into how HP affects B. licheniformis spore germination and inactivation and the role of individual GRs in this process. IMPORTANCE Bacterial spores are inherently resistant to food-processing regimes, such as high-temperature short-time pasteurization, and may therefore compromise food durability and safety. The induction of spore germination facilitates subsequent inactivation by gentler processing conditions that maintain the sensory and nutritional qualities of the food. High-pressure (HP) processing is a nonthermal

  16. [Study on influence factors of seed germination and seeding growth of Lonicera macranthoides].

    Science.gov (United States)

    Xu, Jin; Zhang, Ying; Cui, Guang-Lin; She, Yue-Hui; Li, Long-Yun

    2016-01-01

    In order to improve reproductive efficiency and quality standard, the influence factors of seed germination and seeding growth of Lonicera macranthoides werew studied. The fruit and seed morphological characteristics of L. macranthoides were observed, the seed water absorbing capacity was determined, and different wet sand stratification time, temperature and germination bed treatment were set up. The effects of the parameters on seed germination and seedling growth were analysed. There was no obstacles of water absorption on L. macranthoides seed, quantity for 22 h water absorption was close to saturation. In the first 80 d, with the increase of the stratification time, seed initial germination time was shortened, germination rate and germination potential was improved. Stratification for 100 d, germination rate decreased. At 15 ℃, seed germination and seedling growth indicators were the best. The seedling cotyledon width in light was significantly higher than that in dark. Seeds on the top of paper and top of sand germination rate, germination potential, and germination index was significantly higher than that of other germination bed and mildew rate is low. The optimal conditions of seeds germination test was stratified in 4 ℃ wet sand for 80 d, 15 ℃ illuminate culture on the top of paper or top of sand. The first seeding counting time was the 4th day after beginning the test, the final time was the 23th day. The germination potential statistical time was the 13th day after beginning the test. Copyright© by the Chinese Pharmaceutical Association.

  17. Assessment of Seed Germination and Dormancy of Thirty Seeds Lots of

    Directory of Open Access Journals (Sweden)

    H.R Ehyaee

    2012-06-01

    Full Text Available Most seeds of medicinal plants due to ecological adaptation to environmental conditions have several types of dormancy. Hence, it's necessary to recognize ecological factors that affect dormancy and provide optimum conditions for germination in medicinal plant species. Thirty seed lots were used to estimate germination and dormancy of medicinal plants. Treatments were KNO3, (2% and scarification of seeds by sand paper, hypochlorite sodium and removing the seed coat with four replicates of 25 seeds. Maximum and minimum germination observed in H2O for Digitalis purpure 100% and Saponaria officinalis 0%. In KNO3 treatment, Portulaca oleracea had the highest germination of 91% and Hyocyamus niger had no any germinated seeds. In sand paper treatment, the Saponaria officinalis and Datura stramonium had maximum, 33% and minimum 0% germination respectively.

  18. Esterase activity as a novel parameter of spore germination in Bacillus anthracis

    International Nuclear Information System (INIS)

    Ferencko, Linda; Cote, Mindy A.; Rotman, Boris

    2004-01-01

    Spores of Bacillus anthracis were shown to produce esterase activity about 4 min after exposure to conventional germinants such as combinations of amino acids and purine ribosides. Neither amino acids nor ribosides alone induce germination and esterase activity. Expression of esterase activity was chloramphenicol resistant, and correlated with loss of spore refractivity, a traditional parameter of early germination. Based on these observations, we hypothesized that esterase activity could be used as a novel parameter for quantifying early events during spore germination. To test this hypothesis, we measured expression of esterase activity under a variety of germinating conditions. Using diacetyl fluorescein as fluorogenic substrate of esterases, we demonstrated that esterase activity was invariably induced whenever spores were triggered by known germinants. Moreover, D-alanine, an inhibitor of L-alanine-mediated germination, was found to significantly inhibit expression of esterase activity. In terms of molecular mechanisms, esterase expression could represent activation of proteases at the onset of spore germination

  19. [Study on physiological and germination characteristics of Tulipa edulis seed].

    Science.gov (United States)

    Wu, Zhengjun; Zhu, Zaibiao; Guo, Qiaosheng; Ma, Hongliang; Xu, Hongjian; Miao, Yuanyuan

    2012-03-01

    Current study was conducted to investigate the seed physiological characteristics of Tulipa edulis and improve germination rate. Anatomical characteristics was observed. Seed water absorption curve was tested by soaking method. Dynamic of embryo development and germination rate as well as germination index under different conditions were recorded. And the biological test of cabbage seed was used for detecting the germination inhibitors. The embryo rate of newly matured seeds was about 10%, and there was no obstacle of water absorption on testa of T. edulis. The optimum method for embryo development was exposure to 300 mg x L(-1) gibberellin solution for 24 hours, and stratification at 25 degrees C for 70 days followed by stratification at 5 degrees C for 40 days. The germintion rate and germination index of dormancy-broken seeds under the dark environment at 10 degrees C and 15 degrees C were significantly higher than those under other conditions. Additionally, there were some germination inhibitory substances in dry seeds. The seed of T. edulis can be classified as having complex morphophysiological dormancy, and the morphological embryo dormancy played a leading role. Warm and cold stratification resulted in a fast dormancy breaking effect, and a high germination rate more than 90% could be obtained under the optimum conditions.

  20. RNA synthesis during germination of UV-irradiated Dictyostelium discoideum spores

    International Nuclear Information System (INIS)

    Okaichi, Kumio

    1987-01-01

    UV irradiation to the spores of Dictyostelium discoideum NC4 resulted in a more prolonged delay of amoeba-emergence from swollen spores with increasing UV fluence. During the germination, an inhibition of total RNA synthesis and a shift of stage of maximum RNA synthesis to the later period were observed. The maximum poly(A) + RNA synthetic activity was found on an early stage of amoeba-emergence prior about 1 h to the beginning of rRNA synthesis in unirradiated spore germination; but, in UV-irradiated spore germination, the stage of maximum poly(A) + RNA synthesis shifted to the later stage of germination with increasing UV fluence. A decreased synthesis of poly(A) + RNA and a severe inhibition of rRNA synthesis were observed on UV-irradiated and germinated spores, but no significant inhibition of 4 - 5 S RNA synthesis was detected. Actinomycin D suppressed almost completely the rRNA synthesis of emerged amoebae but the drug apparently did not affect the emergence of amoebae at any stage of germination. It was postulated that the delay of amoeba-emergence in UV-irradiated spore must be mainly due to the shift of the stage of maximum synthesis of poly(A) + RNA to the later stage of germination. (author)

  1. The biological role of exogenic factors in broomrape germination

    International Nuclear Information System (INIS)

    Zhelev, N.

    1987-01-01

    The often observed contradictory effect of the substances stimulating broomrape seed germination were assessed and explained. Low and optimal concentrations of these substances had a stimulating effect, while the high concentrations produced an inhibiting effect. For chemically pure mustard oil, phenylisothiocianate and allylisothiocianate such concentrations are 10 -4 to 10 -3 and more. The effectiveness of substances stimulating germination is conditioned in many cases by their watersoluble or gaseous state. The latter state of the stimulating substances is more natural, more economic and more efficient for the fumigation (in low concentrations) of the soil layer penetrated by the roots where parasitic seeds are present. A considerable number of agricultural crops, releasing by their roots essential oils containing glucosides, the hydrolysis of which results in elimination of volatile products of mustard oil type, represent natural stimulators for the germination of broomrape seeds. The effect of gamma-ray irradiation of parasitic seeds depends on their state. Dry seeds endure 80-120 krad, while moist ones - only 40-80 krad. Broomrape (O. ramosa and O. mutella) seeds begin their germination at 10 grad C. The optimal temperature for germination is 18-30 grad C, while 35-40 grad C irreversively discontinues the germination

  2. The role of hull in germination and salinity tolerance in some ...

    African Journals Online (AJOL)

    hulled and dehulled) of sunflower seeds of Opal, Shelly (Confectionary) and Pactol (Oily) were tested to determine the effects of the hull on salinity tolerance during germination. Germination percentage (%), mean germination time (day), root and ...

  3. Substrates for the tree of seed germination of carmar (Carthamus tinctorius L.

    Directory of Open Access Journals (Sweden)

    R. B. Freitas

    2018-06-01

    Full Text Available The objective of this work was to evaluate the different substrates in the germination potential of safflower seeds. A completely randomized design was used, with five substrates: paper roll, between paper, on paper; Between sand and sand. Seeds of two safflower cultivars were used, with four replicates of 50 seeds each. It was evaluated: percentage of germination (GER; First germination count (GPC; Germination speed index (IVG; Mean germination time (TMG; Percentage of dead seeds (SM; Length of seedling (CP; Root length (CR and shoot length (CPA. The data were submitted to analysis of variance and the means were compared by the Tukey test, at 5% probability, using the statistical program SISVAR 5.1. It was observed that: the germination (G of the safflower seeds did not differ between any of the substrates, varying between 77.5% and 85.25%; For the first germination count (PCG, mean germination time (TMG, germination velocity index (IVG and root length (CR, the best substrates were between paper, paper and sand; And the substrates between paper and sand obtained better results for seedling length and shoot length.

  4. Variation of germination of eggplant (Solanum melongena L.) seed during storage life

    OpenAIRE

    Ristić, Nevena; Todorović, Vesna; Adžić, Slađan; Zdravković, Jasmina

    2013-01-01

    Eggplant (Solanum melongena L.) seed is dormant, which means that the maximum germination is achieved after some time. The research was performed on one genotype (Domaci srednje dugi - DSD). The seed, studied for germination rate, originates from year 2007 and the germination variation was studied for period 2007 - 2011. Eggplant seed was dormant after yield in 2007, but the germination increased over the years. The trial was conducted at the standard germination test method, defined in the R...

  5. Germination rate is the significant characteristic determining coconut palm diversity.

    Science.gov (United States)

    Harries, Hugh C

    2012-01-01

    This review comes at a time when in vitro embryo culture techniques are being adopted for the safe exchange and cryo-conservation of coconut germplasm. In due course, laboratory procedures may replace the options that exist among standard commercial nursery germination techniques. These, in their turn, have supplanted traditional methods that are now forgotten or misunderstood. Knowledge of all germination options should help to ensure the safe regeneration of conserved material. This review outlines the many options for commercial propagation, recognizes the full significance of one particular traditional method and suggests that the diversity of modern cultivated coconut varieties has arisen because natural selection and domestic selection were associated with different rates of germination and other morphologically recognizable phenotypic characteristics. The review takes into account both the recalcitrant and the viviparous nature of the coconut. The ripe fruits that fall but do not germinate immediately and lose viability if dried for storage are contrasted with the bunches of fruit retained in the crown of the palm that may, in certain circumstances, germinate to produce seedlings high above ground level. Slow-germinating and quick-germinating coconuts have different patterns of distribution. The former predominate on tropical islands and coastlines that could be reached by floating when natural dispersal originally spread coconuts widely-but only where tides and currents were favourable-and then only to sea-level locations. Human settlers disseminated the domestic types even more widely-to otherwise inaccessible coastal sites not reached by floating-and particularly to inland and upland locations on large islands and continental land masses. This review suggests four regions where diversity has been determined by germination rates. Although recent DNA studies support these distinctions, further analyses of genetic markers related to fruit abscission and

  6. Germination rate is the significant characteristic determining coconut palm diversity

    Science.gov (United States)

    Harries, Hugh C.

    2012-01-01

    Rationale This review comes at a time when in vitro embryo culture techniques are being adopted for the safe exchange and cryo-conservation of coconut germplasm. In due course, laboratory procedures may replace the options that exist among standard commercial nursery germination techniques. These, in their turn, have supplanted traditional methods that are now forgotten or misunderstood. Knowledge of all germination options should help to ensure the safe regeneration of conserved material. Scope This review outlines the many options for commercial propagation, recognizes the full significance of one particular traditional method and suggests that the diversity of modern cultivated coconut varieties has arisen because natural selection and domestic selection were associated with different rates of germination and other morphologically recognizable phenotypic characteristics. The review takes into account both the recalcitrant and the viviparous nature of the coconut. The ripe fruits that fall but do not germinate immediately and lose viability if dried for storage are contrasted with the bunches of fruit retained in the crown of the palm that may, in certain circumstances, germinate to produce seedlings high above ground level. Significance Slow-germinating and quick-germinating coconuts have different patterns of distribution. The former predominate on tropical islands and coastlines that could be reached by floating when natural dispersal originally spread coconuts widely—but only where tides and currents were favourable—and then only to sea-level locations. Human settlers disseminated the domestic types even more widely—to otherwise inaccessible coastal sites not reached by floating—and particularly to inland and upland locations on large islands and continental land masses. This review suggests four regions where diversity has been determined by germination rates. Although recent DNA studies support these distinctions, further analyses of genetic markers

  7. Seed germination of Phillyrea angustifolia L., a species of difficult propagation

    Energy Technology Data Exchange (ETDEWEB)

    Mira, Sara; Arnal, Alberto; Pérez-García, Félix

    2017-11-01

    Aim of study: The purpose was to determine the type of dormancy and the optimal germination conditions of Phillyrea angustifolia (Oleaceae) seeds. Area of study: Germination requirements of P. angustifolia seeds collected from wild plants growing in the province of Ávila (Central Spain) were studied. Materials and methods: Seed water uptake was measured. Seeds with and without an endocarp were germinated at different temperatures, and several treatments were tested. Main results: The lignified endocarp interferes mechanically with the emergence of the radicle, and the treatments that achieved the highest germination percentages were the total removal of the endocarp with pliers (84%) or the immersion in liquid nitrogen for 1 min (97%). Scarification with concentrated sulphuric acid did not significantly increase germination compared to the control seeds, and treatments with dry heat or wet heat were detrimental to seed germination. The optimum temperature for germination was 15 ºC. A pre-sowing treatment of soaking in distilled water for 24 h slightly increased germination speed. Neither cold stratification at 5 ºC nor soaking in a gibberellic acid solution improved seed germination. Research highlights: Phillyrea angustifolia seeds have physiological dormancy – that is, the embryo does not have enough growth potential to overcome the mechanical restriction of the lignified endocarp. The seeds do not exhibit physical dormancy, given their water-permeable lignified endocarp. Our results suggest that the optimum germination protocol for P. angustifolia would be the total removal of the endocarp or immersion in liquid nitrogen for 1 min, followed by immersion in distilled water for 24 h and then seed incubation at 15 ºC in light or darkness.

  8. Omethoate treatment mitigates high salt stress inhibited maize seed germination.

    Science.gov (United States)

    Yang, Kejun; Zhang, Yifei; Zhu, Lianhua; Li, Zuotong; Deng, Benliang

    2018-01-01

    Omethoate (OM) is a highly toxic organophophate insecticide, which is resistant to biodegradation in the environment and is widely used for pest control in agriculture. The effect of OM on maize seed germination was evaluated under salt stress. Salt (800mM) greatly reduced germination of maize seed and this could be reversed by OM. Additionally, H 2 O 2 treatment further improved the effect of OM on seed germination. Higher H 2 O 2 content was measured in OM treated seed compared to those with salt stress alone. Dimethylthiourea (DTMU), a specific scavenger of reactive oxygen species (ROS), inhibited the effect of OM on seed germination, as did IMZ (imidazole), an inhibitor of NADPH oxidase. Abscisic acid (ABA) inhibited the effect of OM on seed germination, whereas fluridone, a specific inhibitor of ABA biosynthesis, enhanced the effect of OM. Taken together, these findings suggest a role of ROS and ABA in the promotion of maize seed germination by OM under salt stress. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Effect of mutagens on seed germination in chilli (Capsicum annuum L.)

    International Nuclear Information System (INIS)

    Dhamayanthi, K.P.M.; Reddy, V.R.K.

    2002-01-01

    Seeds of chilli variety CO-2 (Coimbatore-2) were irradiated with gamma rays ranging from 10 kR to 35 kR at an interval of 5 kR and the effect on seed germination, seedling survival, percent lethality and seedling injury were studied. Lower doses were stimulative, while higher doses had inhibitory effect on seed germination and seedling survival. The highest percentage of seed germination (37.5) and seedling survival (31.3) was recorded at 10 kR as compared to 28 percent of germination and 3.3 percent seedling survival in control. Percent lethality (9.6%) and seedling injury (6.5%) were comparatively low than the lethality percentage and seedling injury of the higher dose treatments. In chemical mutagen treatments, the maximum seed germination (54.5%) and seedling survival (51.2%), seedling lethality (0.97%) and seedling injury (1.37%) were obtained in the treated seeds of EMS at 0.5% concentration followed by 39.5% seed germination and 30.0% seedling survival, seedling lethality (3.8%) and seedling injury (3.06%) of MMS. The stimulative effect of seed germination is more in chemical mutagens than the physical mutagen. There was a proportionate decrease in germination percentage and seedling survival with an increase in dose/concentration of both the chemicals. (author)

  10. PP4 is essential for germinal center formation and class switch recombination in mice.

    Directory of Open Access Journals (Sweden)

    Ming-Yu Chen

    Full Text Available PP4 is a serine/threonine phosphatase required for immunoglobulin (Ig VDJ recombination and pro-B/pre-B cell development in mice. To elucidate the role of PP4 in mature B cells, we ablated the catalytic subunit of murine PP4 in vivo utilizing the CD23 promoter and cre-loxP recombination and generated CD23(crePP4(F/F mice. The development of follicular and marginal zone B cells was unaffected in these mutants, but the proliferation of mature PP4-deficient B cells stimulated by in vitro treatment with either anti-IgM antibody (Ab or LPS was partially impaired. Interestingly, the induction of CD80 and CD86 expression on these stimulated B cells was normal. Basal levels of serum Igs of all isotypes were strongly reduced in CD23(crePP4(F/F mice, and their B cells showed a reduced efficiency of class switch recombination (CSR in vitro upon stimulation by LPS or LPS plus IL-4. When CD23(crePP4(F/F mice were challenged with either the T cell-dependent antigen TNP-KLH or the T cell-independent antigen TNP-Ficoll, or by H1N1 virus infection, the mutant animals failed to form germinal centers (GCs in the spleen and the draining mediastinal lymph nodes, and did not efficiently mount antigen-specific humoral responses. In the resting state, PP4-deficient B cells exhibited pre-existing DNA fragmentation. Upon stimulation by DNA-damaging drug etoposide in vitro, mutant B cells showed increased cleavage of caspase 3. In addition, the mutant B cells displayed impaired CD40-mediated MAPK activation, abnormal IgM-mediated NF-κB activation, and reduced S phase entry upon IgM/CD40-stimulation. Taken together, our results establish a novel role for PP4 in CSR, and reveal crucial functions for PP4 in the maintenance of genomic stability, GC formation, and B cell-mediated immune responses.

  11. [Effects of illumination and seed-soaking reagent on seed germination of Solanum nigrum].

    Science.gov (United States)

    Yang, Chuan-Jie; Wei, Shu-He; Zhou, Qi-Xing; Hu, Ya-Hu; Niu, Rong-Cheng

    2009-05-01

    To explore a rapid seed germination method for hyperaccumulator Solanum nigrum, a germination experiment with different illumination and seed-soaking treatments was conducted in constant temperature box and greenhouse, with filter as burgeon base. Under illumination, the germination rate was about 5 times high of that without illumination (P seed germination of S. nigrum. All test seed-soaking reagents could significantly improve the germination rate of S. nigrum (P seeds treated with H2O2 had the shortest germination time. The germination rate of seeds soaked but without cleaning was 2-3 times as high as that of seeds soaked and cleaned with water.

  12. A Clostridium difficile-Specific, Gel-Forming Protein Required for Optimal Spore Germination

    Directory of Open Access Journals (Sweden)

    M. Lauren Donnelly

    2017-01-01

    Full Text Available Clostridium difficile is a Gram-positive spore-forming obligate anaerobe that is a leading cause of antibiotic-associated diarrhea worldwide. In order for C. difficile to initiate infection, its aerotolerant spore form must germinate in the gut of mammalian hosts. While almost all spore-forming organisms use transmembrane germinant receptors to trigger germination, C. difficile uses the pseudoprotease CspC to sense bile salt germinants. CspC activates the related subtilisin-like protease CspB, which then proteolytically activates the cortex hydrolase SleC. Activated SleC degrades the protective spore cortex layer, a step that is essential for germination to proceed. Since CspC incorporation into spores also depends on CspA, a related pseudoprotease domain, Csp family proteins play a critical role in germination. However, how Csps are incorporated into spores remains unknown. In this study, we demonstrate that incorporation of the CspC, CspB, and CspA germination regulators into spores depends on CD0311 (renamed GerG, a previously uncharacterized hypothetical protein. The reduced levels of Csps in gerG spores correlate with reduced responsiveness to bile salt germinants and increased germination heterogeneity in single-spore germination assays. Interestingly, asparagine-rich repeat sequences in GerG’s central region facilitate spontaneous gel formation in vitro even though they are dispensable for GerG-mediated control of germination. Since GerG is found exclusively in C. difficile, our results suggest that exploiting GerG function could represent a promising avenue for developing C. difficile-specific anti-infective therapies.

  13. Comparison of Germination and Viability Tests for Southern Hardwood Seed

    Science.gov (United States)

    F. T. Bonner; J. L. Gammage

    1967-01-01

    This paper summarizes a 3-year evaluation of 10 methods for testing germinability and viability of the seed of six species of southern hardwood. In five of the methods, the seeds were germinated. In the others, visual, biochemical, or physical properties were the criteria. Cutting tests were best for sweetgum and Nuttall oak seed, while cutting or water germination...

  14. Seed after-ripening and dormancy determine adult life history independently of germination timing.

    Science.gov (United States)

    de Casas, Rafael Rubio; Kovach, Katherine; Dittmar, Emily; Barua, Deepak; Barco, Brenden; Donohue, Kathleen

    2012-05-01

    • Seed dormancy can affect life history through its effects on germination time. Here, we investigate its influence on life history beyond the timing of germination. • We used the response of Arabidopsis thaliana to chilling at the germination and flowering stages to test the following: how seed dormancy affects germination responses to the environment; whether variation in dormancy affects adult phenology independently of germination time; and whether environmental cues experienced by dormant seeds have an effect on adult life history. • Dormancy conditioned the germination response to low temperatures, such that prolonged periods of chilling induced dormancy in nondormant seeds, but stimulated germination in dormant seeds. The alleviation of dormancy through after-ripening was associated with earlier flowering, independent of germination date. Experimental dormancy manipulations showed that prolonged chilling at the seed stage always induced earlier flowering, regardless of seed dormancy. Surprisingly, this effect of seed chilling on flowering time was observed even when low temperatures did not induce germination. • In summary, seed dormancy influences flowering time and hence life history independent of its effects on germination timing. We conclude that the seed stage has a pronounced effect on life history, the influence of which goes well beyond the timing of germination. © 2012 The Authors. New Phytologist © 2012 New Phytologist Trust.

  15. Seedling survival of Handroanthus impetiginosus (Mart ex DC Mattos in a semi-arid environment through modified germination speed and post-germination desiccation tolerance

    Directory of Open Access Journals (Sweden)

    J. R. Martins

    Full Text Available Abstract Uniform rapid seed germination generally forms a great risk for the plant population if subsequent intermittent precipitation causes desiccation and seedling death. Handroanthus impetiginosus can be found commonly in a wide range of biomes within Brazil including those that are semi-arid. Germination and early growth was studied to understand how germinated seeds survive under these stringent conditions. Accessions were sampled from four seasonally dry biomes in Brazil. Precipitation at the start of the rainy season in the Caatinga, a semi-arid biome, is less predictable and the number of successive dry days per dry interval in the first four months of the rainy season was higher than in the other studied biomes. Plants from the Caatinga produced thicker seeds and this trait concurred with slow germination and stronger osmotic inhibition of germination across the accessions, forming a stress avoidance mechanism in the Caatinga. Post-germination desiccation tolerance was high in the Caatinga accession, could be re-induced in accessions from biomes with more regular precipitation (Cerrado and transition zone, but remained poor in the Cerradão accession; thus forming a stress tolerance mechanism. Production of adventitious roots ascertained survival of all tested individuals from all four locations, even if protruded radicles did not survive desiccation, forming an additional stress tolerance mechanism. A sequence of stress avoidance and stress tolerance mechanisms in seeds and germinated seeds was associated with precipitation patterns in different biomes. These mechanisms purportedly allow rapid seedling establishment when conditions are suitable and enable survival of the young seedling when conditions are adverse.

  16. Pre-germination treatments on palm tree seeds

    Directory of Open Access Journals (Sweden)

    Maitê dos Santos Ribeiro

    2015-12-01

    Full Text Available Palm tree seeds present slow and uneven germination. Therefore, the objective of this research was to evaluate the efficiency of pre-germination treatments in promoting germination and early seedling growth of palm tree (Euterpe edulis Martius. Treatments were: control, immersion in GA3 solution, exposure to ethylene, water immersion, H2SO4 immersion, mechanical scarification, stratification for 30 days at 10 °C, and scarification followed by stratification. Soaking seeds in gibberellic acid (GA3; 2000 µL L-1 for 24 h or their exposure to ethylene (1000 µL L-1 for 24 h are effective for promoting emergence, which started 30 days after seed treatment, and for early seedling growth of palm tree.

  17. Nitric oxide participates in cold-inhibited Camellia sinensis pollen germination and tube growth partly via cGMP in vitro.

    Directory of Open Access Journals (Sweden)

    Yu-Hua Wang

    Full Text Available Nitric oxide (NO plays essential roles in many biotic and abiotic stresses in plant development procedures, including pollen tube growth. Here, effects of NO on cold stress inhibited pollen germination and tube growth in Camellia sinensis were investigated in vitro. The NO production, NO synthase (NOS-like activity, cGMP content and proline (Pro accumulation upon treatment with NO scavenger cPTIO, NOS inhibitor L-NNA, NO donor DEA NONOate, guanylate cyclase (GC inhibitor ODQ or phosphodiesterase (PDE inhibitor Viagra at 25°C (control or 4°C were analyzed. Exposure to 4°C for 2 h reduced pollen germination and tube growth along with increase of NOS-like activity, NO production and cGMP content in pollen tubes. DEA NONOate treatment inhibited pollen germination and tube growth in a dose-dependent manner under control and reinforced the inhibition under cold stress, during which NO production and cGMP content promoted in pollen tubes. L-NNA and cPTIO markedly reduced the generation of NO induced by cold or NO donor along with partly reverse of cold- or NO donor-inhibited pollen germination and tube growth. Furthermore, ODQ reduced the cGMP content under cold stress and NO donor treatment in pollen tubes. Meanwhile, ODQ disrupted the reinforcement of NO donor on the inhibition of pollen germination and tube growth under cold condition. Additionally, Pro accumulation of pollen tubes was reduced by ODQ compared with that receiving NO donor under cold or control condition. Effects of cPTIO and L-NNA in improving cold-treated pollen germination and pollen tube growth could be lowered by Viagra. Moreover, the inhibitory effects of cPTIO and L-NNA on Pro accumulation were partly reversed by Viagra. These data suggest that NO production from NOS-like enzyme reaction decreased the cold-responsive pollen germination, inhibited tube growth and reduced Pro accumulation, partly via cGMP signaling pathway in C. sinensis.

  18. Approaches to the indirect evaluation of germination and vigour

    Directory of Open Access Journals (Sweden)

    Matthews S.

    1998-01-01

    Full Text Available In comparisons of six seed lots of different F1 hybrid cultivars of cauliflower with similarly high laboratory germinations (above 90% separation in germination was achieved after controlled deterioration (C.D. at 24% moisture content (m.c. and 45 0C for 24 hours. This measure of vigour was related to the position of the lots on the seed survival curve and was highly predictive of the longevity of the lots when stored at 15% m.c. and 20 0C for 12 and 16 weeks. When each seed lot was deteriorated at 24% m.c. for increasing times (from 0 to 36 hours a reduction in the subsequent percentage germination was seen, which, using probit transformed percentages, was significantly and linearly related to the leakage of electrolytes into seed soak water over 24 hours. The case is made for an approach to the indirect evaluation of germination and vigour using C.D. followed by measurements of leakage that could be more discerning and rapid than the present laboratory germination test.

  19. Secondary Metabolites Produced during the Germination of Streptomyces coelicolor

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    Matouš Čihák

    2017-12-01

    Full Text Available Spore awakening is a series of actions that starts with purely physical processes and continues via the launching of gene expression and metabolic activities, eventually achieving a vegetative phase of growth. In spore-forming microorganisms, the germination process is controlled by intra- and inter-species communication. However, in the Streptomyces clade, which is capable of developing a plethora of valuable compounds, the chemical signals produced during germination have not been systematically studied before. Our previously published data revealed that several secondary metabolite biosynthetic genes are expressed during germination. Therefore, we focus here on the secondary metabolite production during this developmental stage. Using high-performance liquid chromatography-mass spectrometry, we found that the sesquiterpenoid antibiotic albaflavenone, the polyketide germicidin A, and chalcone are produced during germination of the model streptomycete, S. coelicolor. Interestingly, the last two compounds revealed an inhibitory effect on the germination process. The secondary metabolites originating from the early stage of microbial growth may coordinate the development of the producer (quorum sensing and/or play a role in competitive microflora repression (quorum quenching in their nature environments.

  20. Isolated photosystem I reaction centers on a functionalized gated high electron mobility transistor.

    Science.gov (United States)

    Eliza, Sazia A; Lee, Ida; Tulip, Fahmida S; Mostafa, Salwa; Greenbaum, Elias; Ericson, M Nance; Islam, Syed K

    2011-09-01

    In oxygenic plants, photons are captured with high quantum efficiency by two specialized reaction centers (RC) called Photosystem I (PS I) and Photosystem II (PS II). The captured photon triggers rapid charge separation and the photon energy is converted into an electrostatic potential across the nanometer-scale (~6 nm) reaction centers. The exogenous photovoltages from a single PS I RC have been previously measured using the technique of Kelvin force probe microscopy (KFM). However, biomolecular photovoltaic applications require two-terminal devices. This paper presents for the first time, a micro-device for detection and characterization of isolated PS I RCs. The device is based on an AlGaN/GaN high electron mobility transistor (HEMT) structure. AlGaN/GaN HEMTs show high current throughputs and greater sensitivity to surface charges compared to other field-effect devices. PS I complexes immobilized on the floating gate of AlGaN/GaN HEMTs resulted in significant changes in the device characteristics under illumination. An analytical model has been developed to estimate the RCs of a major orientation on the functionalized gate surface of the HEMTs. © 2011 IEEE

  1. Isolated Photosystem I Reaction Centers on a Functionalized Gated High Electron Mobility Transistor

    Energy Technology Data Exchange (ETDEWEB)

    Eliza, Sazia A. [University of Tennessee, Knoxville (UTK); Lee, Ida [ORNL; Tulip, Fahmida S [ORNL; Islam, Syed K [University of Tennessee, Knoxville (UTK); Mostafa, Salwa [University of Tennessee, Knoxville (UTK); Greenbaum, Elias [ORNL; Ericson, Milton Nance [ORNL

    2011-01-01

    In oxygenic plants, photons are captured with high quantum efficiency by two specialized reaction centers (RC) called Photosystem I (PS I) and Photosystem II (PS II). The captured photon triggers rapid charge separation and the photon energy is converted into an electrostatic potential across the nanometer-scale nm reaction centers. The exogenous photovoltages from a single PS I RC have been previously measured using the technique of Kelvin force probe microscopy (KFM). However, biomolecular photovoltaic applications require two-terminal devices. This paper presents for the first time, a micro-device for detection and characterization of isolated PS I RCs. The device is based on an AlGaN/GaN high electron mobility transistor (HEMT) structure. AlGaN/GaN HEMTs show high current throughputs and greater sensitivity to surface charges compared to other field-effect devices. PS I complexes immobilized on the floating gate of AlGaN/GaN HEMTs resulted in significant changes in the device characteristics under illumination. An analytical model has been developed to estimate the RCs of a major orientation on the functionalized gate surface of the HEMTs.

  2. In vitro pollen germination of five citrus species

    International Nuclear Information System (INIS)

    Khan, S.A.; Perveen, A.

    2014-01-01

    The aim of present study is In vitro germination of the pollen grains of five Citrus species belonging to the family Rutaceae viz., Citrus aurantium L. var., aurantium Hook.f., C. limon (L.) Brum. f., C. paradisii Macfad, C. reticulata Blanco and C. sinensis (L.) Osbeck. using hanging drop technique. The germination was checked up to 48 weeks, for the pollen stored at different temperatures like 4 degree C, -20 degree C, -30 degree C and -60 degree C. The study indicates that low temperature and low relative humidity is better than high temperature and humidity with respect to pollen germination capacity and viability. Freeze dryer (-60 degree C) seems to be the best method to maintain pollen viability of stored pollen grains for a long period of time. Among five species Citrus aurantium, C. limon and C. sinensis showed high percentage of germination as compared to C. reticulata and C. paradisii. (author)

  3. An efficient synthesis of α-amino-δ-valerolactones by the ugi five-center three-component reaction

    International Nuclear Information System (INIS)

    Kim, Young Bae; Lee, Duck Hyung; Park, Soo Jung; Keum, Gyo Chang; Jang, Min Seok; Kang, Soon Bang; Kim, You Seung

    2002-01-01

    A novel approach to α-amino-δ-valerolactones derivatives 8 by the intramolecular Ugi five-center three-component reaction (U-5C-3CR) using the multifunctional starting material, L-pentahomoserine 5 is described

  4. Proteomic analysis of Magnolia sieboldii K. Koch seed germination.

    Science.gov (United States)

    Lu, Xiu-Jun; Zhang, Xiao-Lin; Mei, Mei; Liu, Guang-Lin; Ma, Bei-Bei

    2016-02-05

    Magnolia sieboldii is a deciduous tree native to China. This species has a deep dormancy characteristic. To better understand seed germination, we used protein analysis of changes in seed protein at 0, 65, 110 and 150 d of stratification. Comparative 2DE analysis of M. sieboldii seed protein profiles at 0, 65, 110 and 150 d of stratification revealed 80 differentially abundance protein species. Comparative analysis showed that ADP-glucose pyrophosphorylase small subunit was degraded during germination. In particular, it was degraded almost completely at 110 d of germination. Starch granules in the microstructure decreased after 65 d of stratification. Starch granules provided a sufficient amount of substrates and ATPs for subsequent germination. Four storage protein species were identified, of which all were down accumulated. Spots 44 and 46 had different MW and pI values, spots 36 and 46 had nearly the same MW with pI shift in the 2-DE gels, suggesting that they might be present as different isoforms of the same protein family and the post translational modification. Our results suggested that degradation of starch granules and storage protein species prepared the seed embryo for growth, as well as regulated seed germination. The present proteomics analysis provides novel insights into the mobilisation of nutrient reserves during the germination of M. sieboldii seeds. To better understand seed germination, a complex developmental process, we developed a proteome analysis of M. sieboldii seed. We performed the first comprehensive proteomic and microstructure analysis during different seed stratification stages of M. sieboldii. Among the 80 protein species, 26 were identified, 7 and 14 protein species were up or down accumulated significantly. Many of the identified key proteins were involved in embryo development, starch biosynthesis and energy metabolism, Microstructure of stratification seed analysis revealed degradation of starch was used for preparing the seed

  5. Seed germination and sowing options [Chapter 8

    Science.gov (United States)

    Tara Luna; Kim Wilkinson; R. Kasten Dumroese

    2009-01-01

    Seeds of many native species are challenging to germinate. One important thing a grower can do is learn as much as possible about the life history, ecology, and habitat of the species they wish to grow.What processes do seeds of this species go through in nature? Any observations will be valuable when trying to germinate and grow species that have little or no...

  6. Investigating the Influence of Karrikins on Seed Germination

    Science.gov (United States)

    de Beer, Josef

    2012-01-01

    Recent research has identified a karrikin (a butenolide derative) known as 3-methyl-2H-furo[2,3-c]pyran-2-one, formed from burning cellulose, that stimulates seed germination. Here, I present ideas on how to investigate the influence of karrikins on seed germination in the laboratory.

  7. Asymbiotic germination of immature embryos of a medicinally ...

    African Journals Online (AJOL)

    The immature embryos (28 weeks after pollination) were inoculated on M (Mitra et al., 1976), and PDA (Potato Dextrose Agar) media, with and without different growth additives. The seeds showed positive germination response in both the nutrient media but the frequency and onset of germination response and associated ...

  8. Contrasting germination responses to vegetative canopies experienced in pre- vs. post-dispersal environments

    Science.gov (United States)

    Leverett, Lindsay D.; Auge, Gabriela A.; Bali, Aman; Donohue, Kathleen

    2016-01-01

    Background Seeds adjust their germination based on conditions experienced before and after dispersal. Post-dispersal cues are expected to be more accurate predictors of offspring environments, and thus offspring success, than pre-dispersal cues. Therefore, germination responses to conditions experienced during seed maturation may be expected to be superseded by responses to conditions experienced during seed imbibition. In taxa of disturbed habitats, neighbours frequently reduce the performance of germinants. This leads to the hypotheses that a vegetative canopy will reduce germination in such taxa, and that a vegetative canopy experienced during seed imbibition will over-ride germination responses to a canopy experienced during seed maturation, since it is a more proximal cue of immediate competition. These hypotheses were tested here in Arabidopsis thaliana. Methods Seeds were matured under a simulated canopy (green filter) or white light. Fresh (dormant) seeds were imbibed in the dark, white light or canopy at two temperatures (10 or 22 °C), and germination proportions were recorded. Germination was also recorded in after-ripened (less dormant) seeds that were induced into secondary dormancy and imbibed in the dark at each temperature, either with or without brief exposure to red and far-red light. Key Results Unexpectedly, a maturation canopy expanded the conditions that elicited germination, even as seeds lost and regained dormancy. In contrast, an imbibition canopy impeded or had no effect on germination. Maturation under a canopy did not modify germination responses to red and far-red light. Seed maturation under a canopy masked genetic variation in germination. Conclusions The results challenge the hypothesis that offspring will respond more strongly to their own environment than to that of their parents. The observed relaxation of germination requirements caused by a maturation canopy could be maladaptive for offspring by disrupting germination responses

  9. In vitro germination of desert rose varieties(

    Directory of Open Access Journals (Sweden)

    Tatiane Lemos Varella

    2015-08-01

    Full Text Available The drought stress resistance is a characteristic of the desert rose and its estimable beauty flowers, which gave it great relevance in the ornamental market. However, the desert rose production and germination is hampered by possible sterility of their male and female flowers and frequent problems in pollination, so the tissue culture is a promising alternative to the propagation of these plants. This study aimed to evaluate the effect of gibberellic acid on four commercial varieties of desert rose (Adenium obesum cultivated in vitro. The seeds of the varieties ‘Orange Pallet’, ‘Carnation violet’, ‘Diamond ring’ and ‘Vermiliont’ were sterilized and inoculated on Water + Agar (T0, medium MS (T1, ½ MS (T2, MS + 0.25 mg L-1 GA3 (T3, MS + 0.5 mg L-1 GA3 (T4, ½ MS + 0.25 mg L-1 GA3 (T5, ½ MS 0.5 mg L-1 GA3 (T6. The seeds germination of A. obesum was initiated on the fourth day of cultivation and on the tenth day was possible to observe the expansion of the cotyledons and leaf expansion with subsequent development of early secondary root. The ‘Orange pallet’ variety germinated 100% of seeds on water + agar and MS ½ + 0.5 mg L-1 of GA3. For ‘Diamond Ring’ and ‘Carnation violet’ the highest rate of germination occurred in treatments MS ½; 0.25 mg L-1 GA3; MS + 0.5 mg L-1 GA3 MS ½ + 0.5 mg L-1 GA3 averaging 80% and 70%, respectively. For ‘Vermiliont’ the best response was in MS and MS ½ + 0.5 mg L-1 GA3 ranging between 70-90% germinated embryos. It was registered different malformations in all treatments like absence of roots and apexes during seedling development. The concentrations of GA3 did not affect significantly the seed germination.

  10. pre-germination treatments in castor seeds, cultivar IAC 226

    International Nuclear Information System (INIS)

    Costa Nobre, Danubia Aparecida; Gomes Damascena, Joyce; Marcia, Andreia; Santos de Souza, David; Pereira dos Santos, Marlucia; Rodrigues Pereira, Adriana; Goncalves Pereira, Cassio

    2013-01-01

    The present study aimed to evaluate the efficiency of different pre-germination treatments in castor beans, IAC 226. The experimental design was completely randomized in a factorial 4 x 4 (four temperatures and four immersion times), with four replications. Pre-germination treatments were: immersion in water at room temperature (25 Celsius degrade) and immersion in hot water at temperatures of 60, 70 and 80 Celsius degrade for 2, 4, 6 and 8 minutes. Water content of the seeds was determined before treatments. Before and after each treatment, seeds were subjected to germination test; 20-30 Celsius degrade alternating temperature, determining the percentages of normal and abnormal seedlings, dormant and dead seeds. Independent of time, immersion in 70 Celsius degrade, water was the most efficient treatment for accelerating germination of castor bean cultivar IAC 226.

  11. Germination, carbohydrate composition and vigor of cryopreserved Caesalpinia echinata seeds

    Directory of Open Access Journals (Sweden)

    Rafael Fonsêca Zanotti

    2012-10-01

    Full Text Available The present study investigated the germination and vigor of Caesalpinia echinata (Brazilwood seeds stored at negative temperatures. Recently harvested seeds were cryopreserved at -18º or -196ºC and periodically evaluated for germination, seed vigor and carbohydrate composition. The temperatures did not influence the germination percentages or vigor. The germination percentage decreased from 88% in recently harvested seeds to 60% after 730 days of storage. The different temperature and storage times tested did not affect the vigor seed germination as indicated by the measures of plant growth and survival. The different temperatures used did not cause changes in the carbohydrate composition. The tegument cell walls were rich in lignin, arabinose and xylose. The cytoplasm of the cotyledons and embryos had high levels of glucose, fructose, and sucrose. The cryopreservation technique here presented was effective in the conservation of Brazilwood seeds for the medium term.

  12. LKB1 inhibition of NF-κB in B cells prevents T follicular helper cell differentiation and germinal center formation.

    Science.gov (United States)

    Walsh, Nicole C; Waters, Lynnea R; Fowler, Jessica A; Lin, Mark; Cunningham, Cameron R; Brooks, David G; Rehg, Jerold E; Morse, Herbert C; Teitell, Michael A

    2015-06-01

    T-cell-dependent antigenic stimulation drives the differentiation of B cells into antibody-secreting plasma cells and memory B cells, but how B cells regulate this process is unclear. We show that LKB1 expression in B cells maintains B-cell quiescence and prevents the premature formation of germinal centers (GCs). Lkb1-deficient B cells (BKO) undergo spontaneous B-cell activation and secretion of multiple inflammatory cytokines, which leads to splenomegaly caused by an unexpected expansion of T cells. Within this cytokine response, increased IL-6 production results from heightened activation of NF-κB, which is suppressed by active LKB1. Secreted IL-6 drives T-cell activation and IL-21 production, promoting T follicular helper (TFH ) cell differentiation and expansion to support a ~100-fold increase in steady-state GC B cells. Blockade of IL-6 secretion by BKO B cells inhibits IL-21 expression, a known inducer of TFH -cell differentiation and expansion. Together, these data reveal cell intrinsic and surprising cell extrinsic roles for LKB1 in B cells that control TFH -cell differentiation and GC formation, and place LKB1 as a central regulator of T-cell-dependent humoral immunity. © 2015 The Authors.

  13. Endophytic bacterial effects on seed germination and mobilization of reserves in ammodendron biofolium

    International Nuclear Information System (INIS)

    Zhu, Y.; She, X.P.

    2017-01-01

    The main aim of this study was to analyze the mobilization of storage reserves during seed germination of Ammodendron bifolium by host plant-endophytic bacteria interaction and to determine the contribution of endophytic bacteria in plant establishment. The seeds were inoculated with three different endophytic bacteria from A. bifolium, Staphylococcus sp. AY3, Kocuria sp. AY9 and Bacillus sp. AG18, and they were germinated in the dark. Fresh weight changes and early seedling growth were assessed, and the content of storage compounds was quantified using biochemical assays in all germinated and non-germinated seeds. To understand the mechanism promoting seed germination, the activities of extracellular enzymes of bacterial isolates were also analyzed by the plate assay method. The results showed that treatment with endophytic bacteria accelerated seed germination; promoted further water absorption and radicle growth; and also promoted degradation of sucrose, protein and lipids during the germination process. At the same time, our results also showed that strain AG18 was able to produce protease and amylase, strain AY9 had only amylase activity, and strain AY3 had no extracellular enzyme activity. In summary, our current study showed that (i) endophytic bacteria improved seed germination and post-germination seedling growth of A. bifolium; (ii) inoculation with endophytic bacteria could promote storage reserve mobilization during or following germination; (iii) the degradation of protein, lipids and sucrose could provide essential energy for post-germination growth; and (iv) three bacterial isolates might have different action mechanisms on seed germination. (author)

  14. Behavior of /sup 15/N-labelled amino acids in germinated corn

    Energy Technology Data Exchange (ETDEWEB)

    Samukawa, K; Yamaguchi, M [Osaka Prefectural Univ., Sakai (Japan). Coll. of Agriculture

    1979-06-01

    By investigating the rise and fall of /sup 15/N-labelled amino acids in germinated corns, the behavior of amino radicals in free amino acids, the influence of the hydrolysis products of stored proteins on free amino acids and the change from heterotrophy to autotrophy of seeds were clarified. The amount of amino acid production depending on external nitrogen was very small in the early period of germination. /sup 15/N incorporation into proline was not observed in the early period of germination, which suggested that the proline may be nitrogen-storing source. Most of the amino-state nitrogen of asparagine accumulated at the time of germination was internal nitrogen, and this fact suggested that aspartic acid serve as the acceptor of ammonia produced in the early stage of germination. /sup 15/N content increased significantly on 9 th day after germination, and decreased on 12 th day. These facts prove that there are always active decomposition and production of protein in plant body.

  15. Effect of Different Germination Conditions on Antioxidative Properties and Bioactive Compounds of Germinated Brown Rice

    Directory of Open Access Journals (Sweden)

    You-Tung Lin

    2015-01-01

    Full Text Available This study investigates antioxidative activity and bioactive compounds of ungerminated brown rice (UBR and germinated brown rice (GBR. We used two rice cultivars (Oryza sativa L., Taiwan Japonica 9 (TJ-9 and Taichung Indica 10 (TCI-10, as the materials in our experiments. The conditions for inducing germination are soaking time in water 24, 48, or 72 h; temperature 26 or 36°C; incubation in light or darkness; and open or closed vessels, in which the antioxidative activities and bioactive compounds of GBR were determined. We found that, in order to maximize antioxidative activity and bioactive compounds, germination should be under higher temperature (36°C, long soaking time (72 h, darkness, and closed vessel. GBR contains much higher levels of antioxidative activity and bioactive compounds than ungerminated brown rice (UBR. We found a strong correlation between antioxidative activities (DPPH radical scavenging ability, reducing power, and Trolox equivalent antioxidant capacity and bioactive compounds (γ-oryzanols, tocopherol, and tocotrienol. Higher temperature (36°C is also conducive to the production of GABA in GBR. These results are considered very useful research references for the development of future functional foods and additives.

  16. Production and germination of Tussilago farfara (L. diaspores

    Directory of Open Access Journals (Sweden)

    Anna Namur-Ochocka

    2014-01-01

    Full Text Available In the paper the production of generative diaspores in Tussilago farfara (L. was assessed in four different ecological systems. Also their morphological characteristics, as well as their germinability under natural and laboratory conditions were analysed, depending upon the age, density and size of diaspores, as well as sowing depth, substrate type and light conditions. The studies showed that diaspores: 1 were highly germinable under laboratory conditions; 2 did not germinate effectively under natural conditions; 31 were short-lived; 4 were tolerant to unfavourable habitat agents. Tussilago farfara was determined to exhibit high diaspore production only under conditions of suppresed interspecific competition.

  17. [Characteristics of Cannabis sativa L.: seed morphology, germination and growth characteristics, and distinction from Hibiscus cannabinus L].

    Science.gov (United States)

    Yoshimatsu, Kayo; Kitazawa, Takashi; Kawano, Noriaki; Iida, Osamu; Kawahara, Nobuo

    2010-02-01

    Illegal cannabis (Cannabis sativa L.) cultivation is still a social problem worldwide. Fifty inquiries on cannabis that Research Center for Medicinal Plant Resources (Tsukuba Division) received between January 1, 2000 and March 31, 2009 were itemized in to 8 categories; 1: seed identification, 2: plant identification, 3: indoor cultivation, 4: outdoor cultivation, 5: germination and growth characteristics, 6: expected amount of cannabis products derived from illegal cannabis plant, 7: non-narcotic cannabis and 8: usage of medicinal cannabis. Top three inquiries were 1: seed identification (16 cases), 3: indoor cultivation (10 cases) and 4: outdoor cultivation (6 cases). Characteristics of cannabis, namely seed morphology, germination and growth characteristics, and distinction from kenaf (Hibiscus cannabinus L.) that is frequently misjudged as cannabis, were studied to contribute for prevention of illegal cannabis cultivation.

  18. Germination and Inactivation of Alicyclobacillus acidoterrestris Spores Induced by Moderate Hydrostatic Pressure.

    Science.gov (United States)

    Sokołowska, Barbara; Skapska, Sylwia; Fonberg-Broczek, Monika; Niezgoda, Jolanta; Porebska, Izabela; Dekowska, Agnieszka; Rzoska, Sylwester J

    2015-01-01

    Given the importance of spoilage caused by Alicyclobacillus acidoterrestris for the fruit juice industry, the objective of this work was to study the germination and inactivation of A. acidoterrestris spores induced by moderate hydrostatic pressure. Hydrostatic pressure treatment can induce the germination and inactivation of A. acidoterrestris spores. At low pH, spore germination of up to 3.59-3.75 log and inactivation of 1.85-2.04 log was observed in a low pressure window (200-300 MPa) applied at 50 degrees C for 20 min. Neutral pH suppressed inactivation, the number of spores inactivated at pH 7.0 was only 0.24-1.06 log. The pressurization temperature significantly affected spore germination and inactivation. The degree of germination in apple juice after pressurization for 30 min with 200 MPa at 20 degrees C was 2.04 log, with only 0.61 log of spores being inactivated, while at 70 degrees C spore germination was 5.94 log and inactivation 4.72 log. This temperature strongly stimulated germination and inactivation under higher (500 MPa) than lower (200 MPa) pressure. When the oscillatory mode was used, the degree of germination and inactivation was slightly higher than at continuous mode. The degree of germination and inactivation was inversely proportional to the soluble solids content and was lowest in concentrated apple juice.

  19. Germination and seedling establishment in orchids: a complex of requirements.

    Science.gov (United States)

    Rasmussen, Hanne N; Dixon, Kingsley W; Jersáková, Jana; Těšitelová, Tamara

    2015-09-01

    Seedling recruitment is essential to the sustainability of any plant population. Due to the minute nature of seeds and early-stage seedlings, orchid germination in situ was for a long time practically impossible to observe, creating an obstacle towards understanding seedling site requirements and fluctuations in orchid populations. The introduction of seed packet techniques for sowing and retrieval in natural sites has brought with it important insights, but many aspects of orchid seed and germination biology remain largely unexplored. The germination niche for orchids is extremely complex, because it is defined by requirements not only for seed lodging and germination, but also for presence of a fungal host and its substrate. A mycobiont that the seedling can parasitize is considered an essential element, and a great diversity of Basidiomycota and Ascomycota have now been identified for their role in orchid seed germination, with fungi identifiable as imperfect Rhizoctonia species predominating. Specificity patterns vary from orchid species employing a single fungal lineage to species associating individually with a limited selection of distantly related fungi. A suitable organic carbon source for the mycobiont constitutes another key requirement. Orchid germination also relies on factors that generally influence the success of plant seeds, both abiotic, such as light/shade, moisture, substrate chemistry and texture, and biotic, such as competitors and antagonists. Complexity is furthermore increased when these factors influence seeds/seedling, fungi and fungal substrate differentially. A better understanding of germination and seedling establishment is needed for conservation of orchid populations. Due to the obligate association with a mycobiont, the germination niches in orchid species are extremely complex and varied. Microsites suitable for germination can be small and transient, and direct observation is difficult. An experimental approach using several

  20. Autotoxicity of chard and its allelopathic potentiality on germination ...

    African Journals Online (AJOL)

    SERVER

    2008-04-03

    Apr 3, 2008 ... Abbreviation: (W+C), Wheat germinated with chard; (C+W), chard germinated with ..... hull extracts which have inhibitory effect on the growth of barnyardgrass seedlings. .... John Wiley and Sons,. New York, pp. 171-188.

  1. Potential germination and initial growth of Sclerocarya birrea (A ...

    African Journals Online (AJOL)

    SARAH

    2014-04-30

    Apr 30, 2014 ... Methodology: The parameters studied for the germination test were: latency duration, germination capacity .... for family consumption or in the cosmetic industry. (Murray ... the crowns of trees and in the stall of the animals.

  2. Evaluation and Selection for Drought Tolerance in Iranian Fenugreek (Trigonella foenum-graecum Landraces at Germination and Seedling Growth Stages

    Directory of Open Access Journals (Sweden)

    D. Sadeghzadeh Ahari

    2016-07-01

    reactions to drought stress. Materials and Methods: In order to evaluate the Iranian fenugreek landraces reactions to drought stress induced by Poly Ethylene Glycol 6000, twenty fenugreek landraces originated from different parts of Iran were used in this study. The experiment was conducted at Maragheh experimental station of the Dry land Agricultural Research Institute (DARI under laboratory condition, with a factorial experiment based on randomized complete blocks design and three replications. The stress levels were zero (di-ionized water,-2, -4,-6 and -8 bar. Fifteen normal and health seeds from each landraces were cultivated in petridishes and stayed under fixed temperature (25±1 degree of centigrade, 12 hour day/night for fourteen days. Seedling characteristics (seed germination percentage, root and stem lengths, ratio of stem length to root length, root and stem fresh weights, ratio of stem fresh weight to root fresh weight, root and stem dry weights were noted. Data were analyzed by MSTAT-C software and comparisons of noted traits means done by Duncan’s Multiple Range Test at 5% probability level. In order to distinguish tolerant and susceptible genotypes, landraces ranked by using of Sarmadnia et al.,(1988 and Kafi et al.(2005 methods, and with using of the main traits such as seed germination percentage, root and stem lengths, root and stem fresh weights, root and stem dry weights. Results and Discussion: Results showed that, drought stress levels had significantly affected on all study traits (seed germination percentage, root and stem lengths, ratio of stem length to root length, root and stem fresh weights, ratio of stem fresh weight to root fresh weight, root and stem dry weights. The differences among landraces were highly significant in all traits except in primary root dry weight. The most visible differences among the genotypes in germination percentage monitored at less than -4 bars. Based on ranking of genotypes with seven main studied traits (seed

  3. Effects of salt stress on germination of some maize (Zea mays L ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-10-05

    Oct 5, 2009 ... Key words: Maize, NaCl, germination percentage, stress tolerance ındex, germination ındex. .... interactions between salt treatments and cultivars. This ..... Hormones and Abiotic Stresses on Germination, Growth and Phos-.

  4. Observations on the germination of three species of Citharexylum Jacq. used for ecological restoration

    International Nuclear Information System (INIS)

    Perez Suarez, Bibiana

    2011-01-01

    High-quality plant material is needed to allow the development of large-scale projects in ecological restoration. For this reason, three native species from the Andean forest were prioritized to study their germination: Citharexylum montanum, Citharexylum sulcatum and Citharexylum subflavescens. Pyrenes of these species were subjected to different pre-germination methods such as: scarification and hydration, hydration for 96 hours and hydration for 72 hours respectively for each species mentioned.The total percentage of germination, day of initiation of germination and mean germination time (MGT) were assessed for each species. As a result, total germination percentage was low for all species; C. subflavescens was the species that presented the highest value (41.3%). Only the treatment of scarification and hydration applied to C. montanum favored the germination percentage. The fastest time for germination initiation was 20 days for the species C. subflavescens and C. montanum. Due to the fact that the three species showed heterogeneous germination, the mean germination time (MGT) was high for all species. The observations suggest that physical scarification prior to hydration promotes both the percentage and the day of initiation of germination in Citharexylum.

  5. IMPORTANCE OF STORAGE CONDITIONS AND SEED TREATMENT FOR SUNFLOWER HYBRIDS SEEDS GERMINATION

    Directory of Open Access Journals (Sweden)

    Goran Krizmanić

    2014-12-01

    Full Text Available In this research we have determined germination energy and germination of seeds of sunflower hybrids ‘Luka’ and ‘Apolon’, at the beginning of storage and 6, 12 and 18 months after of storage period (2011-2012 in the floor concrete storage at two different air temperatures and humidity (S-1: air temperature 15-18°C and relative air humidity 65-70% as well as in climate chamber (S-2: air temperature 10-12°C and relative air humidity 60-65%, stored in four treatments (Control: processed-untreated seed; T-1: treated with A.I. metalaxyl-M; T-2: treated with A.I. metalaxyl-M + A.I. imidacloprid and T-3: treated with A.I. metalaxyl-M + A.I. clothianidin. Based on the obtained results we have determined that sunflower hybrid ‘Luka’, compared to hybrid ‘Apolon’, in the given storage conditions and with the same seed treatment has 5-8% higher germination energy and seed germination and that in climate chamber both hybrids have 5-7% higher germination energy. Seed treatment of both sunflower hybrids with A.I. imidacloprid maximally reduced initial germination energy and seed germination in all tested periods and conditions of storage. On the average, natural seed, after 18 months of storage did not have better seed quality compared to seed treated with A.I. metalaxyl-M while other treatments had more significant influence on reduction of germination energy and seed germination, 6-15%. On the average, compared to other variants, seeds treated with A.I. metalaxyl-M after 18 months of storage in both storage conditions had higher germination energy by 4-15%, and seed germination by 2-12%.

  6. Salinity Effects on Germination Properties ofPurslane (Portulaca oleracea L.

    Directory of Open Access Journals (Sweden)

    m Kafi

    2011-02-01

    Full Text Available Abstract In order to study seed germination and seedling growth responses of purslane to different levels of salinity, an experiment was conducted in a completely randomized desgin with six levels of salinity (0, 7, 14, 21, 28 and 35 dS/m using NaCl and five replications. Persentage and rate of germination, length and dry weight of radicle and plumule were measured, and ratio radicle to plumule length, mean germination time and seedling vigor index were calculated. The results showed that up to 28 dS/m salinity did not impose any significant different in germination percentage compared with control, but in 35 dS/m salinity it decreased to 19%. germination rate did not show any significant different up to 14 dS/m in comparison with control but beyond this level it significantly decreased with increasing salt stress. Mean germination time up to 21 dS/m did not have significant different in comparison with control, but increased with increasing salinity significantly. Length, fresh and dry weight of radicle and plumule, and seedling vigor index significantly decreased by increasing salinity. Ratio of radicle to plumule length decreased with increasing salt concentration, but there were not significant different among salt levels. According to the results, the germination stage of purslane is remarkably resistant to elevated levels of salinity and it seems that by exerting proper management in farms, it could be established in saline environments. Keywords: Plumule, Radicle, Seedlings of purslane

  7. Spore Heat Activation Requirements and Germination Responses Correlate with Sequences of Germinant Receptors and with the Presence of a Specific spoVA2mob Operon in Foodborne Strains of Bacillus subtilis.

    Science.gov (United States)

    Krawczyk, Antonina O; de Jong, Anne; Omony, Jimmy; Holsappel, Siger; Wells-Bennik, Marjon H J; Kuipers, Oscar P; Eijlander, Robyn T

    2017-04-01

    Spore heat resistance, germination, and outgrowth are problematic bacterial properties compromising food safety and quality. Large interstrain variation in these properties makes prediction and control of spore behavior challenging. High-level heat resistance and slow germination of spores of some natural Bacillus subtilis isolates, encountered in foods, have been attributed to the occurrence of the spoVA 2mob operon carried on the Tn 1546 transposon. In this study, we further investigate the correlation between the presence of this operon in high-level-heat-resistant spores and their germination efficiencies before and after exposure to various sublethal heat treatments (heat activation, or HA), which are known to significantly improve spore responses to nutrient germinants. We show that high-level-heat-resistant spores harboring spoVA 2mob required higher HA temperatures for efficient germination than spores lacking spoVA 2mob The optimal spore HA requirements additionally depended on the nutrients used to trigger germination, l-alanine (l-Ala), or a mixture of l-asparagine, d-glucose, d-fructose, and K + (AGFK). The distinct HA requirements of these two spore germination pathways are likely related to differences in properties of specific germinant receptors. Moreover, spores that germinated inefficiently in AGFK contained specific changes in sequences of the GerB and GerK germinant receptors, which are involved in this germination response. In contrast, no relation was found between transcription levels of main germination genes and spore germination phenotypes. The findings presented in this study have great implications for practices in the food industry, where heat treatments are commonly used to inactivate pathogenic and spoilage microbes, including bacterial spore formers. IMPORTANCE This study describes a strong variation in spore germination capacities and requirements for a heat activation treatment, i.e., an exposure to sublethal heat that increases

  8. Germination Ecology of Johnsongrass Seeds (Sorghum halepense (L. PERS.

    Directory of Open Access Journals (Sweden)

    Mehdi Mojab

    2018-01-01

    Full Text Available Introduction Johnsongrass (Sorghum halepense (L. PERS is one of the most controversial and problematic weed. It is damaging at more than 30 different crops in 53 different countries. S. halepense (L. is a perennial weed reproducing by seed and rhizome. Since it produces many seeds and rhizomes, it is difficult to control it. A weed germination plays an important role in attaining a prosper establishment in a typical agri-ecosystem; and this trend is adjusted with some environmental factors such as light, temperature, salinity, pH and soil moisture. If you consider the pattern of germination and emergence of weed species, you will able to provide comprehensive information to develop weed management strategies in the future. Thus, the purpose of current research has been to evaluate the breaking methods of the seed dormancy, effect of constant and alternative temperature, light, salinity and drought stress and burial depth on germination and seedling emergence of Johnsongrass. Materials and Methods Seeds of Johnsongrass (S. halepense L. were collected in June 2013 from plants located at the research farmlands of the Agriculture research centre of Fars province in Zarghan town, Iran. Experimental treatments of Breaking Dormancy consist of six level of scarification with 95-98% acid sulfuric (4, 8, 15, 30, 45 and 60 minutes, in the other one, there were the soaked seeds in the water for 24, 48, 72 and 96 hours, and in the next group the seeds were heated in a 95- 98 boiling water for two and five minutes, and again in the next group, for 15, 30, 45 and 60 days, the seeds were chilled in 3 C, and in the last group, the seeds stored in 3 and 12 months after harvest comparing to control treatment. A number of 25 seeds were transferred to incubators to identify a suitable temperature and light regime for subsequent experiments of germination and determine under alternative day/night temperatures (15/5, 20/10, 30/15 and 35/20 C and constant temperature

  9. [Effects of fluridone, gibberellin acid and germination temperature on dormancy-breaking for Epimedium wushanense].

    Science.gov (United States)

    Su, He; Wang, Yue; Yang, Yang; Dong, Xue-Hui

    2016-07-01

    We introduced Epimedium wushanense seed which has been stratified for 90 days at 10/20 ℃ as experimental materials, with which we studied the effects of fluridone, gibberellin acid and temperature on E. wushanense germination. The results were suggested as shown below. ①Temperature, fluridone and gibberellin acid can both solely or jointly affect germination energy, germination rate significantly. Among those factors, fluridone affect germination rate and germination energy the most, followed by gibberellin acid and temperature. The highest germination rate under 4 ℃ and 10/20 ℃ stratification are 79.3%, 72.0% respectively, which resulted from treatment of F10GA300 and F20GA200 respectively. The highest germination energy under 4 ℃ and 10/20 ℃ stratification are 52.7%, 52.0%, respectively, which both resulted from F20GA200. ②Compared with 4 ℃ germination, seed could not germinate at 10/20 ℃ germination. Nontheless, application of fluridone can lead E. wushanense seeds to germinating.③The effects of gibberellin acid and interaction between gibberellin acid and fluridone significantly affect seed rotten rate during germination. In addition, soaking is another remarkable factor which increased seed rotten rate. As a result, it is feasible to promote E. wushanense dormancy releasing with gibberellin acid and fluridone associating with a proper germination temperature. Further, it is necessary taking actions to avoid seed rotten rate for saving E. wushanense nurseries'cost. Copyright© by the Chinese Pharmaceutical Association.

  10. Impact of crop residues on seed germination of native desert plants ...

    African Journals Online (AJOL)

    Crop residues produce allelochemicals that may inhibit seed germination of many weeds. In this study, I assessed the effect of aqueous extracts of three crop residues (radish, rocket and rhodes) on final germination percentage and germination rate of four desert plants recorded as weeds in the United Arab Emirates farms ...

  11. Mechanism of fluridone-induced seed germination of cistanche tubulosa

    International Nuclear Information System (INIS)

    Chen, Q.L.; Tu, P.

    2016-01-01

    Our previous study disclosed that fluridone, a synthesis inhibitor of abscisic acid (ABA), could stimulate seed germination in the holoparasitic plant Cistanche tubulosa . Nonetheless, the underlying mechanisms have not been thoroughly elucidated. In the present study, an attempt was made to reveal the mechanism of fluridone breaking seed dormancy in C. tubulosa and to determine the contribution of hormones in this process. The ABA level in seeds initially decreased following fluridone treatment and was subsequently maintained at a concentration of 31 ng g/sup -1/ DW (dry weight) three days later. The contents of gibberellins (GAs) initially in creased and subsequently were maintained at a level of 40 ng g-1 DW after ten days. However, the increment of seed germination induced by fluridone was inhibited after the introduction of exogenous ABA or paclobutrazol (a synthesis inhibitor of GAs). Furthermore, inhibition from paclobutrazol was reversed by an additional treatment with exogenous GA3. When the ratio of endogenous GAs to ABA reached 4:3, C. tubulosa seeds initiated germination. By contrast, although the ratio of endogenous GAs to ABA content reached 2:1 by cold stratification, C. tubulosa seeds could not germinate unless exogenous GA3 was added. In summary, our current study revealed that (i) GAs and ABA play key roles for the seed germination of C. tubulosa , (ii) fluridone inhibited ABA biosynthesis but increased the concentration of GAs in seeds, and (iii) fluridone might initiate other processes associated with germination. (author)

  12. Substrates and temperatures in the germination of Eriotheca gracilipes seeds

    Directory of Open Access Journals (Sweden)

    Paulo Alexandre Fernandes Rodrigues de Melo

    Full Text Available ABSTRACT The Eriotheca gracilipes (K. Schum. A. Robyns is a forest specie that belongs to the Bombacaceae family and is considered an endemic specie from the Brazilian savanna. The aim of this study was to evaluate the best substrate and temperature for the vigor and germination test of E. gracilipes seeds. The experiment was carried out in a randomized design with a 4 x 7 factorial, with 28 treatments with the combination of four temperatures (20; 25; 30 and 20-30 ºC and seven substrates (coarse vermiculite, medium vermiculite, sand, Basaplant®, paper towel, on and between filter papers, with 4 repetitions of 25 seeds each. It was assessed germination, first count of germination, and germination speed index. In conclusion, for germination and vigor tests of Eriotheca gracilipes seeds it is recommended the paper roll as substrate at temperatures of 20-30, 25 or 30 ºC, and the Basaplant® and paper roll at the temperature of 30 ºC, respectively.

  13. Performance of seeds Crambe exposed to pre-germination treatments

    International Nuclear Information System (INIS)

    Rocha Cardoso, Rebeca; Costa Nobre, Danubia Aparecida; Santos de Souza David, Andreia Marcia; Ribeiro Amaro, Hugo Tiago; Borghetti, Renato Antonio; Costa, Marcia Regina

    2014-01-01

    Encouraging the production and use of biodiesel, seeds of crambe today constitute one of the best options for the supply of raw material, is also an excellent alternative for autumn-winter crop rotation order. The aim of this study was to evaluate the efficiency of combined pre-germination treatments on the seed behavior of Crambe. From a seed sample of FMS Brilhante cultivar, an experimental design completely randomized with a 2 x 5 factorial arrangement was performed. it was formed from combination of two structural conditions, seeds with or without pericarp, and treatments with or without giberelic acid, being: control (no treatment); seeds pre-soaked in distilled water for 24 hours as control; and seeds pre-soaked in gibberellic acid at 4 % at different concentrations (400, 500 and 600 mg.L"-1). Water content, first count germination, germination, seedling emergence and emergence rate index were determined. From these results it is concluded that removal of the pericarp in seed of Crambe, cultivar FMS brilhante, accelerated the germination rate, however, decreased your final percentage. The pre-soaking in gibberellic acid (400, 500 and 600 mg L"-1) for 24 hours, increased the germination and seed vigor crambe with pericarp.

  14. Seed germination of Stenocereus thurberi (Cactaceae) under different solar irradiation levels

    International Nuclear Information System (INIS)

    Nolasco, H.; Vega-Villasante, F.; Diaz-Rondero, A.

    1997-01-01

    Germination of Stenocereus thurberi seeds was evaluated under different conditions of solar irradiation and humidity. Seed germination increased under higher humidity and low solar irradiation which provided cooler temperatures and higher water availability. Seedlings were also greener and more turgid under these conditions. Increased solar irradiation reduced seed germination and decreased seedling size and water content. The results of this study support the importance of natural shelter systems in the arid zones in providing better conditions for S. thurberi seeds germination and seedling establishment, particularly in the desert of Baja California. (author)

  15. Functional type 2 photosynthetic reaction centers found in the rare bacterial phylum Gemmatimonadetes

    OpenAIRE

    Zeng, Yonghui; Feng, Fuying; Medová, Hana; Dean, Jason; Koblížek, Michal

    2014-01-01

    Photosynthesis is one of the most fundamental biological processes on Earth. To date, species capable of performing (bacterio)chlorophyll-based phototrophy have been reported in six bacterial phyla. Here we report a phototrophic bacterium belonging to the rare and understudied phylum Gemmatimonadetes. This strain, isolated from a freshwater lake in the Gobi Desert, contains fully functional photosynthetic reaction centers. Its photosynthesis genes appear to originate from an ancient horizonta...

  16. Proteomic dissection of seed germination and seedling establishment in Brassica napus

    Directory of Open Access Journals (Sweden)

    Jianwei Gu

    2016-10-01

    Full Text Available The success of seed germination and the establishment of a normal seedling are key determinants of plant species propagation. At present, only few studies have focused on the genetic control of the seed germination by proteomic approach in Brassica napus. In the present study, the protein expression pattern of seed germination was investigated using differential fluorescence two-dimensional gel electrophoresis (2-D DIGE in B. napus. One hundred thirteen differentially expressed proteins (DEPs, which were mainly involved in storage proteins (23.4%, energy metabolism (18.9%, protein metabolism (16.2%, defense/disease (12.6%, seed maturation (11.7%, carbohydrate metabolism (4.5%, lipid metabolism (4.5%, amino acids metabolism (3.6%, cell growth/division (3.6%, and some unclear proteins (2.7% were observed by proteomic analysis. Seventeen genes corresponding to 11 DEPs were identified within or near the associated linkage disequilibrium regions related to seed germination and vigor quantitative traits reported in B. napus in previous studies. The expression pattern of proteins showed the heterotrophic metabolism could be activated in the process of seed germination and the onset of defense system might start during seed germination. These findings will help us more in-depth understanding of the mobilization of seed storage reserves and regulation mechanisms of germination process in B. napus.

  17. Effects of drought and salt stress on seed germination of three ...

    African Journals Online (AJOL)

    use

    2011-12-07

    Dec 7, 2011 ... At sowing, inadequate soil moisture results in irregular seed germination and unsynchronised seedling ... Soil salinity affects germination by either an osmotic stress or ion toxic effect (Bewley and Black, ..... Zhu et al., 2006) as an inert osmoticum in germination tests (Dodd and Donovan, 1999) and is a non- ...

  18. Germination of Chenopodium Album in Response to Microwave Plasma Treatment

    International Nuclear Information System (INIS)

    Sera, Bozena; Stranak, Vitezslav; Sery, Michal; Spatenka, Petr; Tichy, Milan

    2008-01-01

    The seeds of Lamb's Quarters (Chenopodium album agg.) were stimulated by low-pressure discharge. The tested seeds were exposed to plasma discharge for different time durations (from 6 minutes to 48 minutes). Germination tests were performed under specified laboratory conditions during seven days in five identical and completely independent experiments. Significant differences between the control and plasma-treated seeds were observed. The treated seeds showed structural changes on the surface of the seat coat. They germinated faster and their sprout accretion on the first day of seed germination was longer. Germination rate for the untreated seeds was 15% while it increased approximately three times (max 55%) for seeds treated by plasma from 12 minutes to 48 minutes.

  19. Japan Nuclear Reaction Data Center (JCPRG), Faculty of Science, Hokkaido University, Steering Committee progress report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-11-15

    The Japan Nuclear Reaction Data Center (JCPRG) was approved as an organisation of Faculty of Science, Hokkaido University and established on April 1, 2007. In addition to nuclear data activities carried out by JCPRG (Japan-Charged Particle Nuclear Reaction Data Group), the centre is concerned with the evaluation of nuclear reaction data in nucleosynthesis in the universe. In order efficiently to compile reaction data obtained by using radioactive ion beam, the centre signed a research contract with RIKEN Nishina Center. We are scanning 16 journals for Japanese charged-particle and photo-nuclear nuclear reaction data compilation. From April 2006 to March 2007, CPND and PhND in 45 references (453 records, 1.83 MB) have been newly compiled for NRDF. Usually new data are released at the JCPRG web site several months prior to EXFOR. Since the 2006 NRDC meeting, we have made 104 new entries and have revised or deleted 142 old entries. Intensive numerical data compilations have been done. These data were shown in tabular form in dissertations which are (partially) published in Journals. About 30 new entries were compiled from these data. We have prepared CINDA batches for CPND published in Japan every half year. Each batch covers 6 issues of each of 4 Japanese journals JPJ, PTP, NST and JNRS. Bibliographies for neutron induced reaction data have been compiled by JAEA Nuclear Data Center as before. A new web-based NRDF search and plot system on MySQL was released in July, 2007. New compilation, which has been finalized for NRDF, but not for EXFOR, can be obtained from this site. DARPE (another NRDF search and plot system written in Perl) is also available at http://www.jcprg.org/darpe/. EXFOR/ENDF (http://www.jcprg.org/exfor/) search and plot system is available. We have also developed following utilities: PENDL (http://www.jcprg.org/endf/) and RENORM (http://www.jcprg.org/renorm). We are developing a new search system of CINDA. This is an extension of EXFOR/ENDF search

  20. Phenolic Profiles and Antioxidant Activity of Germinated Legumes

    Directory of Open Access Journals (Sweden)

    Do Tan Khang

    2016-04-01

    Full Text Available Bioactive compounds, which are naturally produced in plants, have been concerned with the food and pharmaceutical industries because of the pharmacological effects on humans. In this study, the individual phenolics of six legumes during germination and antioxidant capacity from sprout extracts were determined. It was found that the phenolic content significantly increased during germination in all legumes. Peanuts showed the strongest antioxidant capacity in both the DPPH• (1,1-diphenyl-2-picrylhydrazyl method and the reducing power assay (32.51% and 84.48%, respectively. A total of 13 phenolic acids were detected and quantified. There were 11 phenolic constituents identified in adzuki beans; 10 in soybeans; 9 in black beans, mung beans, and white cowpeas; and 7 compounds in peanuts. Sinapic acid and cinnamic acid were detected in all six legume sprouts, and their quantities in germinated peanuts were the highest (247.9 µg·g−1 and 62.9 µg·g−1, respectively. The study reveals that, among the investigated legumes, germinated peanuts and soybeans obtained maximum phenolics and antioxidant capacity.

  1. Germination in vitro embryo of Walnut (Juglans boliviana

    Directory of Open Access Journals (Sweden)

    Pérez-Guzmán Jheanete

    2015-05-01

    Full Text Available Bolivian Juglans is an important forest species found in the rain forests of Bolivia. The seed of this species is recalcitrant with hardened cover, which hinders germination and propagation of the species. The aim of this study was to determine the culture medium for in vitro germination of mature embryos of Bolivian Juglans. Technique initially scarification and disinfection process was determined. Subsequently in vitro culture was performed using the culture medium Woody Plant Medium (WPM with the addition of plant growth regulators (indole butyric acid and 6-benzyl aminopurine in different concentrations. As control WPM, culture medium was used 100%. Response variables evaluated were percentage of contamination and germination; vitroplant length, number of leaves, number of shoots, number of roots per vitroplant, root length and percentage of survival. The plantlets in vitro germination in treatments and the control in the middle l culture WPM supplemented with 0.15 mg / l of IBA and 1.5 mg / l BAP was 90%; other treatments inhibit the growth of the stem and roots of plantlets.

  2. Kinetics of the inhibition of cotton seeds germination by lucerne saponins

    International Nuclear Information System (INIS)

    Marchaim, U.; Birk, Y.; Dovrat, A.; Berman, T.

    1975-01-01

    The extent of inhibition of cotton-seed germination by lucerne saponins depends upon the period of pre-immersion in the saponin solution prior to germination. After 5 hr of pre-immersion in a 0.5% lucerne saponin solution, a 40% drop in germination was noted. The respiration rate decreased after 3hr of pre-immersion. The diffusion of oxygen through the membranes of seeds pre-immersed in saponins also decreased with an increasing pre-immersion time. Inhibition of germination was irreversible after pre-immersion in saponins for 6 hr or more. The effect of saponins does not appear to be biochemically specific because the germination and respiration rates of the cotton seeds which were immersed in aqueous solutions of anionic, nonionic or cationic commercial surfactants were similarly inhibited. (auth.)

  3. Changes of the phenolic compounds and antioxidant activities in germinated adlay seeds.

    Science.gov (United States)

    Xu, Lei; Wang, Pei; Ali, Barkat; Yang, Na; Chen, Yisheng; Wu, Fengfeng; Xu, Xueming

    2017-09-01

    Over the years, germinated adlay products have been used as both food source and folk medicine. This study investigated the changes of total phenolic content (TPC), total flavonoid content (TFC), antioxidant activities, and phenolic acid profiles of adlay seed during germination. Results revealed that phenolic compounds and antioxidant activities varied with the germination stages. Germination significantly increased the free form phenolic and flavonoid contents by 112.5% and 168.3%, respectively. However, both of the bound form phenolic and flavonoid contents significantly decreased after germination. Phenolic acid compositions were quantified via HPLC analysis, and the levels of vanillic, p-coumaric, caffeic, hydroxybenzoic and protocatechuic acids in the free phenolic extracts were found to be significantly increased. The improvement of the free and total phenolic and flavonoid contents by the germination process led to a significant enhancement of the antioxidant activities (evaluated by the ABTS, FRAP and ORAC assays). The TPC showed the highest correlation with ORAC values (r = 0.9979). Germinated adlay had higher free and total phenolic and flavonoid contents, and antioxidant activities than ungerminated adlay. This study indicates that germinated adlay could be a promising functional food, more suitable for human consumption. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  4. Germination conditions affect selected quality of composite wheat-germinated brown rice flour and bread formulations.

    Science.gov (United States)

    Charoenthaikij, Phantipha; Jangchud, Kamolwan; Jangchud, Anuvat; Prinyawiwatkul, Witoon; Tungtrakul, Patcharee

    2010-08-01

    Brown rice has been reported to be more nutritious after germination. Germinated brown rice flours (GBRFs) from different steeping conditions (in distilled water [DI, pH 6.8] or in a buffer solution [pH 3] for either 24 or 48 h at 35 degrees C) were evaluated in this study. GBRF obtained from brown rice steeped at pH 3 for 48 h contained the highest amount of free gamma aminobutyric acid (GABA; 67 mg/100 g flour). The composite flour (wheat-GBRF) at a ratio of 70 : 30 exhibited significantly lower peak viscosity (PV) (56.99 - 132.45 RVU) with higher alpha-amylase activity (SN = 696 - 1826) compared with those of wheat flour (control) (PV = 136.46 RVU and SN = 1976). Bread formulations, containing 30% GBRF, had lower loaf volume and greater hardness (P rice flour (BRF). Acceptability scores for aroma, taste, and flavor of breads prepared with or without GBRFs (30% substitution) were not significantly different, with the mean score ranging from 6.1 (like slightly) to 7 (like moderately). Among the bread formulations containing GBRF, the one with GBRF prepared after 24 h steeping at pH 3 had a slightly higher (though not significant) overall liking score (6.8). This study demonstrated that it is feasible to substitute wheat flour with up to 30% GBRF in bread formulation without negatively affecting sensory acceptance. Practical Application: Our previous study revealed that flours from germinated brown rice have better nutritional properties, particularly gamma-aminobutyric acid (GABA), than the nongerminated one. This study demonstrated feasibility of incorporating up to 30% germinated brown rice flour in a wheat bread formulation without negatively affecting sensory acceptance. In the current United States market, this type of bread may be sold as frozen bread which would have a longer shelf life. Further study is thus needed.

  5. [A comparative study on seed germination of 15 grass species in Keeqin Sandyland].

    Science.gov (United States)

    Liu, Zhimin; Li, Xuehua; Li, Rongping; Jiang, Deming; Cao, Chengyou

    2003-09-01

    A laboratory study was made on the germination characteristics of freshly-collected seeds of grass species at the Wulanaodu area of Keeqin Sandyland in Eastern Inner-Mongolia. Of the 15 species examined, 8 species including Clinelymus dahuricus, Cleistogenes squarrosa, Pappophorum boreale, Spodiopogon sibiricus, Phragmites communis, Chloris virgata, Arundinella hirta, Pennisetum alopecuroides had a germination rate of over 80%, but 4 species including Echinochloa hispidula, Hemarthria compressa, Tragus berteronianus and Setaria viridis had a value of less than 10%. Spodiopogon sibiricus, Eragrostis pilosa, Phragmites communis, Chloris virgata, Clinelymus dahuricus, Pappophorum boreale, Digitaria cilliaris and Cleistogenes squrrosa began to germinate within 1-3 days after the test began, while Setaria viridis, Tragus berteronianus and Hemarthria compressa failed to germinate in a period of more than 10 days. For the species such as Digitaria cilliaris, Echinochloa hispidula, Phragmites communis, Eragrostis pilosa and Spodiopogon sibiricus, their germination period was less than 10 days, while Clinelymus dahuricus and Pappophorum boreale had a germination period of more than 20 days. The days required for half the final germination rate to be reached were: 2 days for Chloris virgata, 3 days for Phragmites communis, 4 days for Spodiopogon sibiricus, 5 days for Clinelymus dahuricus and Cleistogenes squarrosa, 7 days for Arundinella hirta and Pappophorum boreale, and 10 days for Pennisetum alopecuriodes. Compared with the Sheffield region in Britain, the Wulanaodu area of Kerqin Sandyland had a higher proportion of annul grasses with a low germination rate and a longer germination period, and the perennial grasses at the Wulanaodu area had an approximately same germination rate, but a longer germination period. During germination, ruderals showed the potential for risk-sharring, and thus, they had a relatively higher disturbance-resistance capacity.

  6. Transcriptional regulatory programs underlying barley germination and regulatory functions of Gibberellin and abscisic acid

    Science.gov (United States)

    2011-01-01

    Background Seed germination is a complex multi-stage developmental process, and mainly accomplished through concerted activities of many gene products and biological pathways that are often subjected to strict developmental regulation. Gibberellins (GA) and abscisic acid (ABA) are two key phytohormones regulating seed germination and seedling growth. However, transcriptional regulatory networks underlying seed germination and its associated biological pathways are largely unknown. Results The studies examined transcriptomes of barley representing six distinct and well characterized germination stages and revealed that the transcriptional regulatory program underlying barley germination was composed of early, late, and post-germination phases. Each phase was accompanied with transcriptional up-regulation of distinct biological pathways. Cell wall synthesis and regulatory components including transcription factors, signaling and post-translational modification components were specifically and transiently up-regulated in early germination phase while histone families and many metabolic pathways were up-regulated in late germination phase. Photosynthesis and seed reserve mobilization pathways were up-regulated in post-germination phase. However, stress related pathways and seed storage proteins were suppressed through the entire course of germination. A set of genes were transiently up-regulated within three hours of imbibition, and might play roles in initiating biological pathways involved in seed germination. However, highly abundant transcripts in dry barley and Arabidopsis seeds were significantly conserved. Comparison with transcriptomes of barley aleurone in response to GA and ABA identified three sets of germination responsive genes that were regulated coordinately by GA, antagonistically by ABA, and coordinately by GA but antagonistically by ABA. Major CHO metabolism, cell wall degradation and protein degradation pathways were up-regulated by both GA and seed

  7. Transcriptional regulatory programs underlying barley germination and regulatory functions of Gibberellin and abscisic acid

    Directory of Open Access Journals (Sweden)

    Lin Li

    2011-06-01

    Full Text Available Abstract Background Seed germination is a complex multi-stage developmental process, and mainly accomplished through concerted activities of many gene products and biological pathways that are often subjected to strict developmental regulation. Gibberellins (GA and abscisic acid (ABA are two key phytohormones regulating seed germination and seedling growth. However, transcriptional regulatory networks underlying seed germination and its associated biological pathways are largely unknown. Results The studies examined transcriptomes of barley representing six distinct and well characterized germination stages and revealed that the transcriptional regulatory program underlying barley germination was composed of early, late, and post-germination phases. Each phase was accompanied with transcriptional up-regulation of distinct biological pathways. Cell wall synthesis and regulatory components including transcription factors, signaling and post-translational modification components were specifically and transiently up-regulated in early germination phase while histone families and many metabolic pathways were up-regulated in late germination phase. Photosynthesis and seed reserve mobilization pathways were up-regulated in post-germination phase. However, stress related pathways and seed storage proteins were suppressed through the entire course of germination. A set of genes were transiently up-regulated within three hours of imbibition, and might play roles in initiating biological pathways involved in seed germination. However, highly abundant transcripts in dry barley and Arabidopsis seeds were significantly conserved. Comparison with transcriptomes of barley aleurone in response to GA and ABA identified three sets of germination responsive genes that were regulated coordinately by GA, antagonistically by ABA, and coordinately by GA but antagonistically by ABA. Major CHO metabolism, cell wall degradation and protein degradation pathways were up

  8. The impact of germination on the characteristics of brown rice flour and starch.

    Science.gov (United States)

    Xu, Jie; Zhang, Hui; Guo, Xiaona; Qian, Haifeng

    2012-01-30

    In recent years, germinated brown rice as a functional food has received great attention with its improved sensory and nutritional properties. Particularly of interest are the high levels of γ-amino butyric acid (GABA) which can be obtained during germination. However, more studies are needed to fully understand the effect of germination on the physicochemical properties of brown rice. Germination altered the chemical composition of brown rice, resulting in an increase in reducing sugar and ash content, and a reduction in amylose. Solubility, paste viscosity, transition temperatures (T(o) , T(p) and T(c) ) and percentage of retrogradation (%Retrogradation) were decreased, while swelling power and turbidity were significantly increased. Scanning electron micrographs indicated that starch granules from germinated brown rice became smaller and less homogeneous. Moreover, germination shortened the chain length of amylopectin and amylose molecules. This investigation provides information on changes in the characteristics of rice flour and rice starch during germination, leading to a better understanding on the chemistry of brown rice germination. Copyright © 2011 Society of Chemical Industry.

  9. Germination of Themeda triandra (Kangaroo grass) as affected by ...

    African Journals Online (AJOL)

    Low rainfall in range areas restricts germination, growth and development of majority of range grasses. However, germination and establishment potential of forage grasses vary and depends on environmental conditions. Themeda triandra is an excellent known grass to grow under different environmental conditions.

  10. Improving the seed germination of little bluestem with selection

    Science.gov (United States)

    Rapid seed germination is an important characteristic when it comes to plant stand establishment under variable environmental conditions. This research was designed to improve the seed germination of six experimental Syn-0 lines of little bluestem [Schizachyrium scoparium (Michx.) Nash]. Two cycle...

  11. Effects of UV-B radiation on the isoflavone accumulation and physiological-biochemical changes of soybean during germination: Physiological-biochemical change of germinated soybean induced by UV-B.

    Science.gov (United States)

    Ma, Meng; Wang, Pei; Yang, Runqiang; Gu, Zhenxin

    2018-06-01

    In this study, the effects of UV-B radiation on the isoflavones accumulation, physiological and nutritional quality, water status, and characteristics of proteins in germinated soybeans were investigated. The results showed that isoflavones content in soybeans increased with appropriate intensity and time of UV-B radiation and decreased with excessive treatment. Fresh weight, length, free amino acids, reducing sugar contents and bulk water (T 23 ) in germinated soybeans decreased with increasing radiation time, indicating that UV-B inhibited the growth and nutrients metabolism of soybean during germination. Cell damage was detected in germinated soybeans with excessive UV-B radiation, as shown by the black spots in cotyledons and the increased intercellular water determined by LF-NMR. Germination resulted in an increase in random coil structures, while UV-B radiation induced no obvious changes in FT-IR spectrum and protein conformation of soybeans. Both UV-B radiation and germination caused the increase in soluble proteins, especially in 1.0-75.0 kDa fraction. Copyright © 2018 Elsevier Ltd. All rights reserved.

  12. GERMINATION OF GRASSES DUE TO INOCULATION DIAZOTROPHIC BACTERIA

    Directory of Open Access Journals (Sweden)

    C. D. A. Moreira

    2014-07-01

    Full Text Available The germination of forage grasses suffers from numbness and a natural tendency to low quality. The use of microorganisms inoculated in seeds with the purpose of increasing and meet the demand of some nutrient has been shown to be efficient, but the role of the microorganism in germination and rate of force is still unknown. Therefore the goal as study was to evaluate the germination rate of seeds of three cultivars of Brachiaria brizantha CV. Marandu, b., b. brizantha CV. Xaraés and b. humidícola cv Tupi and a cultivar of millet, P. hybrid cv Massai depending on the bacterium Azospirillum brasilense diazotrofic inoculation (nitrogen-fixing. Germination test was used in seed dispersal to assess the effect of first count (VPC in the treatments with and without inoculation. It was done also conducted further tests of electrical conductivity, weight of thousand seeds and water content. The delineation used was randomized entirely (DIC and the statistical analysis carried out through the analysis of variance and comparison of means using the Tukey test, the 5% probability. Massai grass seeds have the highest rate of force of first count in both treatments. Inoculation of bacterium Azospirillum brasilense did not affect the values of force of first count on seeds of the cultivars Marandu, Xaraés, Tupi and Massai. The seeds of the massai have higher germination speed relative the other cultivars evaluated when inoculated.

  13. EFFECTS OF LIGHT WAVELENGTHS AND COHERENCE ON BASIDIOSPORES GERMINATION

    Directory of Open Access Journals (Sweden)

    Natalia Poyedinok

    2015-02-01

    Full Text Available The effects of light wavelengths and coherence on basidiospore germination of Agaricus bisporus, Flammulina velutipes, Ganoderma applanatum, Ganoderma lucidum, Hericium erinaceus, Lentinus edodes and Pleurotus ostreatus have been studied. Short-term low-intensity irradiation by coherent (laser light wavelength 488.0 nm and 632.8 nm at doses 45 and 230 mJ/cm2 has significantly increased the number of germinated basidiospores. It has established that there are differences in the photosensitivity not only between species but also between strains. Spores irradiation by 514.5 nm light has been either neutral or inhibitory. A comparative analysis of basidiospores sensitivity to laser and LED light has also been conducted. To stimulate germination of basidiospores and growth of monokaryons the most suitable solution was to use red coherent and incoherent light of 632.8 nm and 660,0 nm for A. bisporus, G. applanatum and P. ostreatus, red and blue coherent light of 632.8 nm and 488,0 nm for F. velutipes, and both red and blue laser and LED light G. lucidum and H. erinaceus and for L. edodes. No essential difference of a continuous wave mode and intermittent mode light effect at the same doses and wavelength on spore germination were revealed. Light influence has reduced germination time and formation of aerial mycelium on agar medium as compared to the original value and increased the growth rate of monosporous isolates. Characterization of basidiospores photosensitivity and development of environmentally friendly stimulating methods of their germination is important for creating highly effective technologies of mushrooms selection and cultivation.

  14. Salinity induced metabolic changes in rice (oryza sativa l.) seeds during germination

    International Nuclear Information System (INIS)

    Shereen, A.; Ansari, R.; Raza, A.; Mumtaz, S.; Khan, M.A.; Khan, M.A.

    2011-01-01

    Six inbred lines of rice exhibiting differential tolerance to salinity were exposed to 0, 50, 75, 100 and 200 mM NaCl for 24, 48, 72 and 96 h. The salinity induced metabolic changes (solute leakage, K efflux and a-amylase activity) were studied during germination. Germination of rice seeds was not affected by NaCl concentration less than 100 mM. At higher salinity levels (100 and 200 mM NaCl), a delay of 3-6 days in germination was observed. In the present study, comparatively higher values of solute leakage were observed in those lines in which germination was comparatively affected more adversely (sensitive). Sodium chloride reduced alpha-amylase activity in germinating rice seeds to varying degree even at low NaCl concentrations (50 and 75 mM), where germination was not affected greatly. The tolerant lines exhibited higher enzymatic activity than the sensitive ones. (author)

  15. Sweet passion fruit (Passiflora alata Curtis germination: Phases and effect of plant growth regulator

    Directory of Open Access Journals (Sweden)

    Sheila Zambello de Pinho

    2008-09-01

    Full Text Available This work aimed to characterize Passiflora alata germination phases and evaluate the effects of GA3 and GA4+7, associated with phenylmethylaminepurine, on P. alata seed germination. Two experiments were conducted. In the first, two treatments were carried out: seeds submerged in distilled water in a Becker and seeds conditioned in containers on filter paper soaked in distilled water; five replications of 25 seeds were used. The moisture level and the percentage of germination (%G were evaluated. In the second, six treatments and five replications of 25 seeds for each regulator were used. The seeds were imbibed in 0, 50, 100, 150, 200 and 250mg.L-1 of GA3 and GA4+7, associated with to phenylmethylaminepurine, for 11 hours. The seeds were sown in black containers and deposited in to the germination chamber. The numbers of germinated and dormant seeds were evaluated daily. The percentage of germination, the percentage of dormant seeds, and the mean germination time (TMG were estimated. Significant differences in the germination phases between the methods were verified. The germination was affected by the regulators with an increase in the percentage of germination and a reduction in the mean germination time. The highest values were observed with 250mg.L-1 of GA4+7 plus phenylmethylaminepurine.

  16. Strategy for selection of soybean genotypes tolerant to drought during germination.

    Science.gov (United States)

    Dantas, S A G; Silva, F C S; Silva, L J; Silva, F L

    2017-05-10

    Water deficit is the main reason for instability in the context of soybean culture. The development of strategies for the selection of more tolerant genotypes is necessary. These strategies include the use of polyethylene glycol 6000 solutions (PEG-6000) for conducting the germination test under conditions of water restriction. Thus, the objective of this study was to determine the osmotic potential and the main characteristics that promote the discrimination of soybean genotypes with regard to water stress tolerance during germination and the vigor test. Thirteen soybean cultivars were used. The seeds were allowed to germinate on sheets of germitest paper moistened in solution with PEG-6000, simulating different levels of water availability, which is expressed as osmotic potential (0.0, -0.2, -0.4, and -0.6 MPa). We assessed germination, length, and dry mass for seedlings and seeds, as well as reserve dynamics. Germination and variables related to the dynamics of reservation have great influence on the expression of variability in environments under stress. Among the different osmotic potentials, the -0.2 MPa was the most efficient for the expression of genetic variability among the cultivars. Conducting the germination test with PEG-6000 solution to -0.2 MPa was efficient for selecting soybean cultivars tolerant to water stress. This was accomplished by evaluating the percentage of germination, along with variables related to the dynamics of reservation.

  17. Interplay between excitation kinetics and reaction-center dynamics in purple bacteria

    International Nuclear Information System (INIS)

    Caycedo-Soler, Felipe; RodrIguez, Ferney J; Quiroga, Luis; Johnson, Neil F

    2010-01-01

    Photosynthesis is arguably the fundamental process of life, since it enables energy from the Sun to enter the food chain on the Earth. It is a remarkable non-equilibrium process in which photons are converted to many-body excitations, which traverse a complex biomolecular membrane, where they are captured and fuel chemical reactions within a reaction center (RC) in order to produce nutrients. The precise nature of these dynamical processes-which lie at the interface between quantum and classical behavior and involve both noise and coordination-is still being explored. Here, we focus on a striking recent empirical finding concerning an illumination-driven transition in the biomolecular membrane architecture of the purple bacteria Rsp. photometricum. Using stochastic realizations to describe a hopping rate model for excitation transfer, we show numerically and analytically that this surprising shift in preferred architectures can be traced to the interplay between the excitation kinetics and the RC dynamics. The net effect is that the bacteria profit from efficient metabolism at low illumination intensities while using dissipation to avoid an oversupply of energy at high illumination intensities.

  18. Energetic change of the primary quinone in photosynthetic reaction center. Mutation, delayed fluorescence and model calculations (Theses of the Ph.D. dissertation)

    International Nuclear Information System (INIS)

    Rinyu, L.

    2007-01-01

    Complete text of publication follows. Photosynthesis is one of the basic metabolic processes of living organisms. Photosynthesizing species (bacteria, algae and higher class plants) convert the energy of light into other forms of free energy (redox potential, electro- chemical potential of ions and protons and phosphate-potential) which are directly suit- able either to cover the energy need of the vital processes of the cell or to storage. In reaction center (RC) protein of photo- synthetic bacteria, electron transfer is initiated upon light excitation from the excited bacteriochlorophyll dimer (P) to the secondary quinone (Q B ) via bacteriopheophytine (Bph) and the primary quinone (Q A ). In Rhodobacter sphaeroides purple bacteria, both quinones are ubiquinone-10, but due to the different protein environment, their electrochemical properties is highly different. Whereas Q A makes one-electron chemistry, Q B can be doubly reduced to form hydroquinone, Q B H 2 by uptake of two protons. Q B H 2 subsequently leaves the RC and is replaced by an oxidized quinone from to membrane pool. The semiquinones are important intermediates in the quinone reduction cycle of the RC. The redox midpoint potentials of the Q/Q - redox pairs (E m ) are also different: the Q A /Q A - has 60 mV more negative potential than the Q B /Q B - couple (pH 8) to make the (interquinone) electron transfer favorable. For fine tuning of the midpoint redox potentials of the quinones, the protein assures appropriate steric and electrostatic environment. The most important aim of this study was the design and production of reaction center mutants in the binding pocket of the primary quinone to investigate the effect of the amino acids of the protein and lipids of the membrane on the thermodynamics of the primary quinone. The first priority was the determination of the absolute free energy gap between the P* and the P + Q A - states in wild type and mutant reaction centers by comparison of the

  19. Disentangling the role of heat and smoke as germination cues in Mediterranean Basin flora.

    Science.gov (United States)

    Moreira, B; Tormo, J; Estrelles, E; Pausas, J G

    2010-04-01

    The role of fire as a germination cue for Mediterranean Basin (MB) plants is still unclear. The current idea is that heat stimulates germination mainly in Cistaceae and Fabaceae and that smoke has a limited role as a post-fire germination cue, in comparison with other Mediterranean-type ecosystems (MTEs), suggesting that fire-stimulated germination is less relevant in the MB than in other MTEs. However, recent studies showed that the assembly of Mediterranean plant communities is strongly driven by post-fire germination, suggesting an important role for fire as a germination cue. We hypothesize that both heat and smoke have important effects on the different post-fire recruitment processes of MB species (e.g. level and rate of germination and initial seedling growth). To ascertain the role of heat and smoke in the post-fire germination response of MB woody plants, a germination experiment was performed with seven heat and two smoke treatments on 30 MB woody species from seven different families, including species with water-permeable seeds and species with water-impermeable seeds. Heat stimulated the germination (probability and rate) of 21 species and smoke in eight species, out of the 30 species studied. In addition, six species showed enhanced initial seedling growth after the smoke treatments. The results suggest that both heat and smoke are important germination cues in a wide range of MB woody species and that fire-cued germination in woody plants of the MB may be as important as in other MTEs.

  20. Influence de différents traitements de prégermination des graines de Vigna unguiculata (L. Walp. sur les performances germinatives et la tolérance au stress hydrique

    Directory of Open Access Journals (Sweden)

    Boucelha, L.

    2015-01-01

    Full Text Available Influence of different pre-germination treatments of Vigna unguiculata (L. Walp. seeds on germination performance and water stress tolerance. Description of the subject. Priming or hardening is a pregermination treatment. This treatment consists of incorporating an osmotic seed treatment (osmopriming or a hormonal (hormopriming and/or a redehydration (hydropriming treatment. The approach allows the elimination of dormancy, homogenization (synchronization of germination, better growth, earlier flowering and a tolerance to abiotic stresses such as drought and salinity. In this kind of treatment, the seed is soaked and then dehydrated before radicle breakthrough, i.e. during the reversible phase of germination. Thus, the seed can return to its initial stage without any damage. Objectives. In this paper, we aimed to study the consequences of hydropriming and osmopriming (by PEG6000 at 10 and 30% on cowpea seeds (Vigna unguiculata, on germination performance and on the water stress tolerance of plants from these seeds. Method. Vigna unguiculata seeds were hydroprimed, hydroprimed twice or osmoprimed (with PEG6000 10 and 30%. For each treatment, germination performance (germination capacity, speed and the water stress tolerance of the plants were studied. Results. Results showed that increased hardness of the seed allowed a faster, more uniform germination and better growth of both the radicle and aerial parts. We also demonstrated that a double redehydration was more effective in improving these parameters. Conclusions. Application of these pretreatments, adapted according to the plant species, will has the capacity to improve seed germination and crop yield, as well as tolerance to water deficit.

  1. Germination of native understorey species for revegetation of New South Wales coal mines

    Energy Technology Data Exchange (ETDEWEB)

    Gillespie, M.J.; Bellairs, S.M.; Mulligan, D.R. [University of Queensland, St. Lucia, Qld. (Australia). Dept. of Agriculture and Centre for Mined Land Rehabilitation

    1997-06-01

    This project investigates the suitability of a range of native understorey species for rehabilitation at several coal mines in New South Wales. The germination of seeds from 69 species representing 12 families was tested under controlled laboratory conditions. Germination occurred in all but two of the species tested and 50% germination was exceeded by 29 species. Species of the Mimosaceae, Fabaceae and Proteaceae tended to have above average germination; however species representing other families had variable germination results. A pre-germination heat treatment applied to all of the Acacia species increased germination in some but not all species. Seeds of these understorey species which were used in this trial, are native to the New South Wales coal fields and available commercially or are relatively easy to collect. Glasshouse and field trials are now being undertaken to assess establishment and growth on mine soil, spoil and coal reject materials. 9 refs., 5 figs.

  2. The effect of different treatments on improving seed germination ...

    African Journals Online (AJOL)

    Creating optimal conditions for germination of medicinal plants seed is essential for their cultivation. Therefore, to evaluate the effect of different treatments on seed germination of two medicinal species, Descurainia sophia and Plantago ovata collected in 2009 from Tehran Province, an experiment with a factorial ...

  3. Germination potential index of Sindh rice cultivars on biochemical ...

    African Journals Online (AJOL)

    use

    2011-12-14

    Dec 14, 2011 ... Alpha amylase activities were found to be directly correlated with germination percentage. Gradual increase in reducing sugars along with α-amylase activity was observed, while total ... seed vigor and alpha amylase activity along with germination period. .... strates for energy generation for fast and uniform.

  4. Mapping QTLs for submergence tolerance during germination in rice

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-04

    Aug 4, 2008 ... Key words: Oryza sativa L, anaerobic germination, QTL analysis. INTRODUCTION. Two main ... The study was conducted at NG-01 greenhouse, Genome and. Mapping (GML), the .... ABC transporter family protein ..... differences of germination habits in rice seeds with special reference to plant breeding (in ...

  5. Pollen characteristics and in vitro pollen germination of Cedrus ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-11-02

    Nov 2, 2009 ... This study aims to determine the germination characteristics, pollen tube developments, effects of germination media and temperature and incubation durations of the pollens obtained from the four clones (11342, 11344, 11345 and 11351) of Cedrus libani A. Rich. (Lebanon Cedrus) obtained from clonal.

  6. A Clostridium difficile alanine racemase affects spore germination and accommodates serine as a substrate.

    Science.gov (United States)

    Shrestha, Ritu; Lockless, Steve W; Sorg, Joseph A

    2017-06-23

    Clostridium difficile has become one of the most common bacterial pathogens in hospital-acquired infections in the United States. Although C. difficile is strictly anaerobic, it survives in aerobic environments and transmits between hosts via spores. C. difficile spore germination is triggered in response to certain bile acids and glycine. Although glycine is the most effective co-germinant, other amino acids can substitute with varying efficiencies. Of these, l-alanine is an effective co-germinant and is also a germinant for most bacterial spores. Many endospore-forming bacteria embed alanine racemases into their spore coats, and these enzymes are thought to convert the l-alanine germinant into d-alanine, a spore germination inhibitor. Although the C. difficile Alr2 racemase is the sixth most highly expressed gene during C. difficile spore formation, a previous study reported that Alr2 has little to no role in germination of C. difficile spores in rich medium. Here, we hypothesized that Alr2 could affect C. difficile l-alanine-induced spore germination in a defined medium. We found that alr2 mutant spores more readily germinate in response to l-alanine as a co-germinant. Surprisingly, d-alanine also functioned as a co-germinant. Moreover, we found that Alr2 could interconvert l- and d-serine and that Alr2 bound to l- and d-serine with ∼2-fold weaker affinity to that of l- and d-alanine. Finally, we demonstrate that l- and d-serine are also co-germinants for C. difficile spores. These results suggest that C. difficile spores can respond to a diverse set of amino acid co-germinants and reveal that Alr2 can accommodate serine as a substrate. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  7. Seed reserve utilization and hydrolytic enzyme activities in germinating seeds of sweet corn

    International Nuclear Information System (INIS)

    Cheng, X.; Xiong, F.; Wang, C.; He, S.; Zhou, Y.

    2018-01-01

    In this study, two sh2 sweet corn cultivars (i.e., the initial seed dry weight for FT018 and TB010 was 0.16+-0.02 g/grain and 0.09+-0.01 g/grain, respectively) were used to determine the physiological characteristics of seed reserve utilization in germination. The data implied that the weight of mobilized seed reserve (WMSR) and seed reserve utilization efficiency (SRUE) increased with seed germination. FT018 exhibited higher SRUE than TB010 due to its sufficient energy production for growth. Sugar (sucrose and fructose) contents were at different levels in the germinating seed of sh2 sweet corn. The protein content and number of protein species were highest in the early stage of germination. Enzyme activity in the germinating seed indicated that enzymes for starch and sugar hydrolysis were important and that enzyme activities significantly differed at each germination stage and between the cultivars under dark conditions. Succinate dehydrogenase, sucrose synthase, and glucose-6-phosphate dehydrogenase accumulated in the late germination stage. Thus, appropriate efforts should be focused on improving the seed reserve utilization in sweet corn by identifying the physiological mechanism of germinating seed. (author)

  8. Effect of surfactants and temperature on germination and vegetative growth of Beauveria bassiana

    Directory of Open Access Journals (Sweden)

    Lizzy A. Mwamburi

    2015-03-01

    Full Text Available Three non-ionic surfactants: Tween20, Tween80 and Breakthru® were screened for their effects on spore germination and mycelial growth rates and for their influence on three isolates of Beauveria bassianaspore germination at various temperatures. Tween20 and Tween80 were compatible with all the B. bassiana isolates in the germination studies, but inhibited germination at higher surfactant concentrations, irrespective of the conidial concentrations. Breakthru® had an inhibitory effect on germination even at the lowest concentration of 0.1% on all the B. bassiana isolates. The effects of the surfactants on spore germination did not correspond with their effects on colony growth. Conidial viability within the same formulation declined significantly with increases in temperature, irrespective of the surfactant. The optimal temperature for conidial germination of B. bassiana isolates was approximately 25 °C with an upper limit at 30 °C. Isolate 7320 was identified as the least affected by the different surfactants. This isolate was able to germinate rapidly in a broad temperature range of 25–30 °C after 24 h, this characteristic being an essential factor in controlling house fly populations in poultry houses.

  9. Effect of surfactants and temperature on germination and vegetative growth of Beauveria bassiana.

    Science.gov (United States)

    Mwamburi, Lizzy A; Laing, Mark D; Miller, Ray M

    2015-03-01

    Three non-ionic surfactants: Tween20, Tween80 and Breakthru (®) were screened for their effects on spore germination and mycelial growth rates and for their influence on three isolates of Beauveria bassiana spore germination at various temperatures. Tween20 and Tween80 were compatible with all the B. bassiana isolates in the germination studies, but inhibited germination at higher surfactant concentrations, irrespective of the conidial concentrations . Breakthru (®) had an inhibitory effect on germination even at the lowest concentration of 0.1% on all the B. bassiana isolates. The effects of the surfactants on spore germination did not correspond with their effects on colony growth. Conidial viability within the same formulation declined significantly with increases in temperature, irrespective of the surfactant. The optimal temperature for conidial germination of B. bassiana isolates was approximately 25 °C with an upper limit at 30 °C. Isolate 7320 was identified as the least affected by the different surfactants. This isolate was able to germinate rapidly in a broad temperature range of 25-30 °C after 24 h, this characteristic being an essential factor in controlling house fly populations in poultry houses.

  10. The effects of Fusarium oxysporum on broomrape (Orobanche egyptiaca) seed germination.

    Science.gov (United States)

    Hasannejad, S; Zad, S Javad; Alizade, H Mohamad; Rahymian, H

    2006-01-01

    Broomrape (Orobanche aegyptiaca L.), one of the most important parasitic weeds in Iran, is a root parasitic plant that can attack several crops such as tobacco, sunflower, tomato and etc. Several methods were used for Orobanche control, however these methods are inefficient and very costly. Biological control is an additional recent tool for the control of parasitic weeds. In order to study of the fungus Fusarium oxysporum (biocontrol agent) effects on broomrape seed germination, two laboratory studies were conducted in Tehran University. In the first experiment, different concentration of GR60 (0, 1, 2 and 5 ppm) as stimulation factor for Orobanche seeds germination were experimented. Results showed that concentrations of GR60 had a significant effect on seed germination. The highest seed germination percent was obtained in 1 ppm. In the second experiment, the effect of Fusarium oxysporum was tested on O. aegyptiaca seeds germination. The fungus Fusarium oxysporum were isolated from infested and juvenile O. aegyptiaca ower stalks in tomato field in karaj. Fungus spores suspension in different concentrations (0 (Control), 10(5) (T1), 10(6) (T2), 10(7) (T3) and 3 x 10(7) (T4)) from potato dextrose agar (PDA) prepared and together with 1ppm of GR60 concentration were tested on O. aegyptiaca seeds. Results show that the highest inhibition of seed germination obtained in 10(5) spores/ml. With increasing of suspension concentrations, inhibition percent was reduced and mortality of seeds germ tube was increased. In this investigation, Fusarium oxysporum can be used to inhibit seed germination, stimulate the "suicidal germination" of seeds and reduce the Orobanche seed bank.

  11. Phytotoxic effects of argan shell biochar on salad and barley germination

    Directory of Open Access Journals (Sweden)

    Laila Bouqbis

    2017-08-01

    Full Text Available Biochar produced from argan shells can be contaminated by toxic substances accumulated during the pyrolysis process. To determine the potential impact of toxic substances and salt stress, this study focused on the effect argan shell biochar had on the germination of salad (0%, 0.5%, 1%, 2%, 4% or 8% biochar dry weight in a sand-biochar mixture and barley seeds (0%, 1%, 2.5%, 5% or 10% biochar dry weight in a peat-biochar mixture. No negative salt stress effect of argan biochar on the germination of salad was observed nor on the germination rate and fresh weight of seedlings. Additionally, biochar application increased the germination rate and the fresh biomass weight in all of the treatments. No significant difference was observed from the control with the barley germination rate, fresh and dry weights of barley seedlings, water content and water use efficiency of different mixtures (peat-biochar. Thus, for both the salad and barley germination tests, no negative effects of biochar produced from argan shells were identified, providing a preliminary indication that it could be safely used for agriculture.

  12. Different modes of hydrogen peroxide action during seed germination

    Directory of Open Access Journals (Sweden)

    Łukasz eWojtyla

    2016-02-01

    Full Text Available Hydrogen peroxide was initially recognized as a toxic molecule that causes damage at different levels of cell organization and thus losses in cell viability. From the 1990s, the role of hydrogen peroxide as a signaling molecule in plants has also been discussed. The beneficial role of H2O2 as a central hub integrating signaling network in response to biotic and abiotic stress and during developmental processes is now well established. Seed germination is the most pivotal phase of the plant life cycle, affecting plant growth and productivity. The function of hydrogen peroxide in seed germination and seed aging has been illustrated in numerous studies; however, the exact role of this molecule remains unknown. This review evaluates evidence that shows that H2O2 functions as a signaling molecule in seed physiology in accordance with the known biology and biochemistry of H2O2. The importance of crosstalk between hydrogen peroxide and a number of signaling molecules, including plant phytohormones such as abscisic acid, gibberellins and ethylene and reactive molecules such as nitric oxide and hydrogen sulfide acting on cell communication and signaling during seed germination, is highlighted. The current study also focuses on the detrimental effects of H2O2 on seed biology, i.e., seed aging that leads to a loss of germination efficiency. The dual nature of hydrogen peroxide as a toxic molecule on one hand and as a signal molecule on the other is made possible through the precise spatial and temporal control of its production and degradation. Levels of hydrogen peroxide in germinating seeds and young seedlings can be modulated via pre-sowing seed priming/conditioning. This rather simple method is shown to be a valuable tool for improving seed quality and for enhancing seed stress tolerance during post-priming germination. In this review, we outline how seed priming/conditioning affects the integrative role of hydrogen peroxide in seed germination and

  13. Mutagenic effects of gamma rays on soybean (Glycine max L.) germination and seedlings

    Science.gov (United States)

    Kusmiyati, F.; Sutarno; Sas, M. G. A.; Herwibawa, B.

    2018-01-01

    Narrow genetic diversity is a main problem restricting the progress of soybean breeding. One way to improve genetic diversity of plant is through mutation. The purpose of this study was to investigate effect of different dose of gamma rays as induced mutagen on physiological, morphological, and anatomical markers during seed germination and seedling growth of soybean. Seeds of soybean cultivars Dering-1 were irradiated with 11 doses of gamma rays (0, 5, 10, 20, 40, 80, 160, 320, 640, 1280, and 2560 Gy [Gray]. The research design was arranged in a completely randomized block design in three replicates. Results showed that soybean seed exposed at high doses (640, 1280, and 2560 Gy) did not survive more than 20 days, the doses were then removed from anatomical evaluation. Higher doses of gamma rays siginificantly reduced germination percentage at the first count and final count, coefficient of germination velocity, germination rate index, germination index, seedling height and seedling root length, and significantly increased mean germination time, first day of germination, last day of germination, and time spread of germination. However, the effects of gamma rays were varies for density, width, and length of stomata. The LD50 obtained based on survival percentage was 314.78 Gy. It can be concluded that very low and low doses of gamma rays (5-320 Gy) might be used to study the improvement of soybean diversity.

  14. Effects of water stress on germination of Pinus nigra Arnold. seeds

    International Nuclear Information System (INIS)

    Topacoglu, O.; Sevik, H.; Akkuzu, E.

    2016-01-01

    Climate change, global warming and the deterioration of related environmental conditions cause an important problem for forest tree species. For this reason, it is necessary to determine the response of trees to these conditions. The Objective of this study was to investigate the effects of water stress on seed germination of fifteen Pinus nigra Arnold. provenances in Turkey. For this purpose, the water stresses between 0 and -8.0 bars were obtained using polyethylene glycol-6000 (PEG) solutions. Seeds were kept for 35 days at 20 ± 0.5 degree C. In this study, significant variations between the provenances were found. Ankara Uluhan ( percent 95, 08) and Isparta Tota ( percent 85, 41) provenances at -8.0 bars having the highest cumulative germination percentages were the most resistant provenances against the water stress. This study has shown that the water stress reduced the germination speed, germination percentage and germination value. (author)

  15. DNA damage checkpoint kinase ATM regulates germination and maintains genome stability in seeds.

    Science.gov (United States)

    Waterworth, Wanda M; Footitt, Steven; Bray, Clifford M; Finch-Savage, William E; West, Christopher E

    2016-08-23

    Genome integrity is crucial for cellular survival and the faithful transmission of genetic information. The eukaryotic cellular response to DNA damage is orchestrated by the DNA damage checkpoint kinases ATAXIA TELANGIECTASIA MUTATED (ATM) and ATM AND RAD3-RELATED (ATR). Here we identify important physiological roles for these sensor kinases in control of seed germination. We demonstrate that double-strand breaks (DSBs) are rate-limiting for germination. We identify that desiccation tolerant seeds exhibit a striking transcriptional DSB damage response during germination, indicative of high levels of genotoxic stress, which is induced following maturation drying and quiescence. Mutant atr and atm seeds are highly resistant to aging, establishing ATM and ATR as determinants of seed viability. In response to aging, ATM delays germination, whereas atm mutant seeds germinate with extensive chromosomal abnormalities. This identifies ATM as a major factor that controls germination in aged seeds, integrating progression through germination with surveillance of genome integrity. Mechanistically, ATM functions through control of DNA replication in imbibing seeds. ATM signaling is mediated by transcriptional control of the cell cycle inhibitor SIAMESE-RELATED 5, an essential factor required for the aging-induced delay to germination. In the soil seed bank, seeds exhibit increased transcript levels of ATM and ATR, with changes in dormancy and germination potential modulated by environmental signals, including temperature and soil moisture. Collectively, our findings reveal physiological functions for these sensor kinases in linking genome integrity to germination, thereby influencing seed quality, crucial for plant survival in the natural environment and sustainable crop production.

  16. Germination sensitivity to water stress in four shrubby species across the Mediterranean Basin.

    Science.gov (United States)

    Chamorro, D; Luna, B; Ourcival, J-M; Kavgacı, A; Sirca, C; Mouillot, F; Arianoutsou, M; Moreno, J M

    2017-01-01

    Mediterranean shrublands are generally water-limited and fire-driven ecosystems. Seed-based post-fire regeneration may be affected by varying rainfall patterns, depending on species sensitivity to germinate under water stress. In our study, we considered the germination response to water stress in four species from several sites across the Mediterranean Basin. Seeds of species with a hard coat (Cistus monspeliensis, C. salviifolius, Cistaceae, Calicotome villosa, Fabaceae) or soft coat (Erica arborea, Ericaceae), which were exposed or not to a heat shock and smoke (fire cues), were made to germinate under water stress. Final germination percentage, germination speed and viability of seeds were recorded. Germination was modelled using hydrotime analysis and correlated to the water balance characteristics of seed provenance. Water stress was found to decrease final germination in the three hard-seeded species, as well as reduce germination speed. Moreover, an interaction between fire cues and water stress was found, whereby fire cues increased sensitivity to water stress. Seed viability after germination under water stress also declined in two hard-seeded species. Conversely, E. arborea showed little sensitivity to water stress, independent of fire cues. Germination responses varied among populations of all species, and hydrotime parameters were not correlated to site water balance, except in E. arborea when not exposed to fire cues. In conclusion, the species studied differed in germination sensitivity to water stress; furthermore, fire cues increased this sensitivity in the three hard-seeded species, but not in E. arborea. Moreover, populations within species consistently differed among themselves, but these differences could only be related to the provenance locality in E. arborea in seeds not exposed to fire cues. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  17. Desiccation effects on germination and vigor of King palm seeds

    Directory of Open Access Journals (Sweden)

    Martins Cibele C.

    2003-01-01

    Full Text Available The desiccation tolerance of Archontophoenix alexandrae (Wendl. & Drude seeds was determined and the most sensitive vigor test for assessing seed deterioration of this species was identified. Mature fruits were harvested in the palm collection of the Instituto Agronomico in Campinas, Brazil. Depulped fruits were transported in impermeable packages to the Faculdade de Agronomia in Botucatu, where the seeds were dried. As the seed moisture decreased, germination, seedling length, electrical conductivity and moisture were measured. The seeds of A. alexandrae are recalcitrant, with high germination percentage (over 67% when undried (47% seed moisture. Lowering seed moisture below 31.5% reduced the germination rate significantly (<52.5%. Total germination failure was observed when seed moisture reached 15.1%. The electrical conductivity was the most sensitive vigor test to identify seed deterioration.

  18. Elucidating hormonal/ROS networks during seed germination: insights and perspectives

    DEFF Research Database (Denmark)

    Diaz-Vivancos, Pedro; Barba Espin, Gregorio; Hernández, José Antonio

    2013-01-01

    ” technologies together with physiological and biochemical approaches have revealed that seed germination is a very complex process that depends on multiple biochemical and molecular variables. The pivotal role of phytohormones in promoting germination now appears to be interdependent with ROS metabolism......While authors have traditionally emphasized the deleterious effects of reactive oxygen species (ROS) on seed biology, their role as signaling molecules during seed dormancy alleviation and germination is now the focus of many studies around the world. Over the last few years, studies using “-omics......, involving mitogen-activated protein kinase cascade activation, gene expression and post-translational protein modifications. This review is, thus, an attempt to summarize the new discoveries involving ROS and seed germination. The study of these interactions may supply markers of seed quality that might...

  19. Comparative Study of Pre-Germination Treatments and their Effects ...

    African Journals Online (AJOL)

    FIRST LADY

    of leaves (10.05) respectively. Pre-germination treatments of seeds soaked in running water (SRW) for 24 hours were found to be more effective in seedlings growth and biomass production. Keywords: Tectona grandis, pre-germination treatment, seed dormancy, seedling growth. Introduction. Tectona grandis is one of the ...

  20. Abscisic acid regulates seed germination of Vellozia species in response to temperature.

    Science.gov (United States)

    Vieira, B C; Bicalho, E M; Munné-Bosch, S; Garcia, Q S

    2017-03-01

    The relationship between the phytohormones, gibberellin (GA) and abscisic acid (ABA) and light and temperature on seed germination is still not well understood. We aimed to investigate the role of the ABA and GA on seed germination of Vellozia caruncularis, V. intermedia and V. alutacea in response to light/dark conditions on different temperature. Seeds were incubated in GA (GA 3 or GA 4 ) or ABA and their respective biosynthesis inhibitors (paclobutrazol - PAC, and fluridone - FLU) solutions at two contrasting temperatures (25 and 40 °C). Furthermore, endogenous concentrations of active GAs and those of ABA were measured in seeds of V. intermedia and V. alutacea during imbibition/germination. Exogenous ABA inhibited the germination of Vellozia species under all conditions tested. GA, FLU and FLU + GA 3 stimulated germination in the dark at 25 °C (GA 4 being more effective than GA 3 ). PAC reduced seed germination in V. caruncularis and V. alutacea, but did not affect germination of V. intermedia at 40 °C either under light or dark conditions. During imbibition in the dark, levels of active GAs decreased in the seeds of V. intermedia, but were not altered in those of V. alutacea. Incubation at 40 °C decreased ABA levels during imbibition in both V. caruncularis and V. alutacea. We conclude that the seeds of Vellozia species studied here require light or high temperature to germinate and ABA has a major role in the regulation of Vellozia seed germination in response to light and temperature. © 2016 German Botanical Society and The Royal Botanical Society of the Netherlands.

  1. The effects of temperature and salinity on Acacia harpophylla (brigalow) (Mimosaceae) germination

    Energy Technology Data Exchange (ETDEWEB)

    Reichman, S.M.; Bellairs, S.M.; Mulligan, D.R. [Lincoln University, Lincoln (New Zealand). Division of Agriculture & Life Science

    2006-07-01

    Some coal mining companies in central Queensland have become interested in providing habitat for the endangered bridle nail-tailed wallaby that lives in brigalow vegetation. However, there is little known about establishment techniques for brigalow on mine sites and other disturbed ground; an understanding of brigalow biology and ecology is required to assist in the conservation of this threatened vegetation community and for re-creation of bridled nail-tail wallaby habitat in the post mining landscape. Brigalow is an unusual species of Acacia because it is not hard-seeded and germinates readily without the need to break seed-coat imposed dormancy. Germination trials were undertaken to test the ability of brigalow seed to germinate with a range of temperatures and salinity levels similar to those experienced in coal mine spoil. Optimum germination was found to occur at temperatures from 15 to 38{sup o}C and no germination was recorded at 45{sup o}C. Brigalow was very tolerant of high salt levels and germinated at percentages greater than 50% up to the highest salinity tested, 30 dS/m. Germination of greater than 90% occurred up to an electrical conductivity of 20 dS/m. The results indicate brigalow seed can be sown in summer when rains are most likely to occur; however, shading of the seed with extra soil or mulch may ensure the ground surface does not become too hot for germination. Because of its ability to germinate at high salinity levels, brigalow may be suitable for use in saline mine wastes which are common on sites to be rehabilitated after mining.

  2. Studies on seed germination and in vitro shoot multiplication of ...

    African Journals Online (AJOL)

    Yomi

    2011-12-21

    Dec 21, 2011 ... vitro seed germination and plantlet regeneration of this plant. ... Key words: Germination, gibberellic acid, growth regulators, node explants, Satureja ..... Abscisic Acid: A. Seed Maturation and Antistress Signal, 3rd ed. Sinauer ...

  3. Physical characterization of Rhipsalis (Cactaceae fruits and seeds germination in different temperatures and light regimes

    Directory of Open Access Journals (Sweden)

    A. B. Lone

    Full Text Available Abstract The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.

  4. Physical characterization of Rhipsalis (Cactaceae) fruits and seeds germination in different temperatures and light regimes.

    Science.gov (United States)

    Lone, A B; Colombo, R C; Andrade, B L G; Takahashi, L S A; Faria, R T

    2016-06-01

    The germination characteristics of the native cactus species are poorly known, being the temperature and the light the factors that the most interferes in that process. Thus, the objective of the present work was to characterize the fruits and evaluate the influence of the temperature and the light in the seed germination of Rhipsalis floccosa, Rhipsalis pilocarpa and Rhipsalis teres. The tested constant temperatures were 15, 20, 25, 30 and 35 °C and the alternate of 20-30 °C and 25-35 °C in a photoperiod of 10 hours, and with determination of the most appropriate temperature, the germination was tested in light absence. The germination percentage, the index of germination speed and medium time of germination were evaluated. For R. floccosa, the highest germination percentage was at 20 °C. For R. pilocarpa and R. teres, the highest germination percentages occurred in 15 °C and 20 °C. There was correlation to germination percentage between the three species, indicating that they had similar germination behavior. Total absence of germination was verified for the three species in condition of light absence. In conclusion, the temperature of 20 °C is the most suitable for the seed germination of R. floccosa. For the species R. pilocarpa and R. teres, the temperatures of 15 and 20 °C are the most suitable.

  5. Salinity on the germination of seed and index of germination speed of three ornamental species

    Directory of Open Access Journals (Sweden)

    Marcos Vieira Ferraz

    2016-09-01

    Full Text Available Salinity is a factor that interferes on seed germination in most species. The objective of this work was to study the effects of different concentrations of NaCl on the emergence and vigor of Petunia x hybrida hort. Vilm E. ex., Torenia fournieri Lind and Tagetes patula L. seedlings. The experimental design was entirely randomized with five treatments (five concentrations of NaCl: zero, 25, 50, 75 and 100 mM and four replications of 50 seeds, for each species. The seeds were germinated in germitest paper at the alternating temperature of 20-30°C. Emergence (% and Emergence Rate (ER were performed daily until 14 days. Salt stress caused negative effects on the emergence and vigor on seedlings of these three ornamentals species.

  6. A gene encoding an abscisic acid biosynthetic enzyme (LsNCED4) collocates with the high temperature germination locus Htg6.1 in lettuce (Lactuca sp.).

    Science.gov (United States)

    Argyris, Jason; Truco, María José; Ochoa, Oswaldo; McHale, Leah; Dahal, Peetambar; Van Deynze, Allen; Michelmore, Richard W; Bradford, Kent J

    2011-01-01

    Thermoinhibition, or failure of seeds to germinate when imbibed at warm temperatures, can be a significant problem in lettuce (Lactuca sativa L.) production. The reliability of stand establishment would be improved by increasing the ability of lettuce seeds to germinate at high temperatures. Genes encoding germination- or dormancy-related proteins were mapped in a recombinant inbred line population derived from a cross between L. sativa cv. Salinas and L. serriola accession UC96US23. This revealed several candidate genes that are located in the genomic regions containing quantitative trait loci (QTLs) associated with temperature and light requirements for germination. In particular, LsNCED4, a temperature-regulated gene in the biosynthetic pathway for abscisic acid (ABA), a germination inhibitor, mapped to the center of a previously detected QTL for high temperature germination (Htg6.1) from UC96US23. Three sets of sister BC(3)S(2) near-isogenic lines (NILs) that were homozygous for the UC96US23 allele of LsNCED4 at Htg6.1 were developed by backcrossing to cv. Salinas and marker-assisted selection followed by selfing. The maximum temperature for germination of NIL seed lots with the UC96US23 allele at LsNCED4 was increased by 2-3°C when compared with sister NIL seed lots lacking the introgression. In addition, the expression of LsNCED4 was two- to threefold lower in the former NIL lines as compared to expression in the latter. Together, these data strongly implicate LsNCED4 as the candidate gene responsible for the Htg6.1 phenotype and indicate that decreased ABA biosynthesis at high imbibition temperatures is a major factor responsible for the increased germination thermotolerance of UC96US23 seeds.

  7. GABA content and Antioxidant activity of Thai waxy corn seeds germinated by hypoxia method

    Directory of Open Access Journals (Sweden)

    Pisamai Polthum

    2014-06-01

    Full Text Available Germinated seeds have a greater amount of the naturally-occurring -aminobutyric acid (GABA which has many health benefits. Further, colored seeds have higher antioxidant activity. Thai waxy corn is widely consumed after cooking, due to its palatable glutinous texture. However, it is not commonly germinated before use. In this study, two varieties of Thai waxy corn, KKU-KND (purple seed and KKU-SLE (white seed, were germinated and converted to corn flour with the aim of investigating the effect of germination on GABA content and antioxidant activity. Further, the microstructure of starch granules was also examined. KKU-KND and KKU-SLE were grown and harvested in 2012. The seeds were soaked in distilled water for 6 hrs to attain a moisture content of 31-32%wb and then germinated by employing two methods, i in an open plastic box, and ii in a closed plastic box with a headspace of 3 cm for devoid oxygen (hypoxia method; the germination period varied between 12-48 hrs at 35±2°C in both cases. The germinated samples were then dried at 50°C to a moisture content of 10±2%wb. The results showed that non-germinated KKU-KND and KKU-SLE contained 2.68±0.77 and 1.58±0.05 mgGABA/ 100gdb, respectively, whereas the samples germinated by the hypoxia method contained significantly higher GABA which increased with germination time (p<0.05. The highest GABA contents found in KKU-KND and KKU-SLE were 37.20±3.27 and 54.47±2.08 mg/100gdb, respectively after 48 hrs of germination under the hypoxia method. In addition, the germinated KKU-KND gave ABTS and DPPH values of 388.32±0.53 and 140.29±0.57 mgTrolox/100gdb, whereas the germinated KKU-SLE gave ABTS and DPPH values of 183.69±1.75 and 38.43±1.64 mgTrolox/100gdb, respectively. The pictures of starch granules obtained by means of SEM displayed differences in the shape and size of the non-germinated and germinated granules in both verities. In conclusion, the hypoxia method is able to induce higher GABA

  8. Effect of chromium toxicity on germination and early seedling growth ...

    African Journals Online (AJOL)

    USER

    2010-07-19

    Jul 19, 2010 ... germination and early seedling growth of melon (Cucumis melo L.). Chromium ... chromium on seed germination and seedling growth- biomass in early ..... such critical regulatory mechanisms are likely to operate in seeds at ...

  9. The Effects of water and salt stresses on germination in two bread ...

    African Journals Online (AJOL)

    Results showed those germination rate was delayed by both solutions in both varieties, with differences between genotypes among growth stages, given that Saisonez genotype showed a higher germination rate than Cascogne genotype in NaCl. NaCl had a lesser effect on genotypes in terms of germination rate and the ...

  10. Reduced seed germination in Arabidopsis over-expressing SWI/SNF2 ATPase genes

    NARCIS (Netherlands)

    Leeggangers, H.A.C.F.; Folta, A.; Muras, A.; Nap, J.P.H.; Mlynarova, L.

    2015-01-01

    In the life of flowering plants, seed germination is a critical step to ensure survival into the next generation. Generally the seed prior to germination has been in a dormant state with a low rate of metabolism. In the transition from a dormant seed to a germinating seed, various epigenetic

  11. WATER AND SODIUM CHLORIDE EFFECTS ON Mimosa Tenuiflora (WILLD. POIRET SEED GERMINATION

    Directory of Open Access Journals (Sweden)

    Ivonete Alves Bakke

    2006-01-01

    Full Text Available Water shortage and saline soils of the Brazilian semi-arid northeastern region are limiting factors to the development of many plants. Jurema preta (Mimosa tenuiflora (Willd. Poiret is a small, multiple use tree that abundantly colonizes unfavorable sites, including environments with severe water stress. This work had the objective of investigating the tolerance of jurema preta seeds to water and salt stresses during germination. Seeds germination in polyethylene glycol (PEG-6000 and sodium chloride (NaCl solutions was analyzed under five different osmotic potentials (0.0; -0.3, -0.6, -0.9 and -1.2MPa, in order to simulate water and salt stress, respectively, in four 100-seed replications for each treatment. Seeds were placed into 10cmx10cmx4cm boxes, and germination accomplished in BOD germinator adjusted to 30oC. The number of germinated seeds was monitored every 24 hours, and percentage and speed of seed germination were generated from these data. Mean percentage germination in the control treatment was ~95%, reducing to 63-53% at -0.9 to -1.2-MPa PEG solutions, and to 27- 9.5% at NaCl solutions at equivalent osmotic potentials. Velocity of germination index was more affected, and decreased up to 1/8 of the control, at -0.6 MPa. Jurema preta seeds showed lower tolerance to NaCl than to water stress, and this species can be classified as a glycophyte.

  12. A Gompertz regression model for fern spores germination

    Directory of Open Access Journals (Sweden)

    Gabriel y Galán, Jose María

    2015-06-01

    Full Text Available Germination is one of the most important biological processes for both seed and spore plants, also for fungi. At present, mathematical models of germination have been developed in fungi, bryophytes and several plant species. However, ferns are the only group whose germination has never been modelled. In this work we develop a regression model of the germination of fern spores. We have found that for Blechnum serrulatum, Blechnum yungense, Cheilanthes pilosa, Niphidium macbridei and Polypodium feuillei species the Gompertz growth model describe satisfactorily cumulative germination. An important result is that regression parameters are independent of fern species and the model is not affected by intraspecific variation. Our results show that the Gompertz curve represents a general germination model for all the non-green spore leptosporangiate ferns, including in the paper a discussion about the physiological and ecological meaning of the model.La germinación es uno de los procesos biológicos más relevantes tanto para las plantas con esporas, como para las plantas con semillas y los hongos. Hasta el momento, se han desarrollado modelos de germinación para hongos, briofitos y diversas especies de espermatófitos. Los helechos son el único grupo de plantas cuya germinación nunca ha sido modelizada. En este trabajo se desarrolla un modelo de regresión para explicar la germinación de las esporas de helechos. Observamos que para las especies Blechnum serrulatum, Blechnum yungense, Cheilanthes pilosa, Niphidium macbridei y Polypodium feuillei el modelo de crecimiento de Gompertz describe satisfactoriamente la germinación acumulativa. Un importante resultado es que los parámetros de la regresión son independientes de la especie y que el modelo no está afectado por variación intraespecífica. Por lo tanto, los resultados del trabajo muestran que la curva de Gompertz puede representar un modelo general para todos los helechos leptosporangiados

  13. Seed germination of peanuts irradiated with cobalt (60CO)

    International Nuclear Information System (INIS)

    Alves, Niedja Marrize C.; Almeida, Francisco de Assis C.; Gomes, Josivanda P.; Pessoa, Elvira B.; Leal, Artur S. Cavalcanti

    2010-01-01

    This work was realized to evaluate the effect of gamma irradiation ( 60 Co) at doses 0, 0.50, 1.00, 1.50, 2.00, 2.50, 3.00 and 4.00 kGy, on germination of seeds of peanut, cultivar BR1. Irradiation Department of Nuclear, UFPE, where he received after the irradiation, they were stored in packing of PET and polyethylene braided with a time of 90 days. Through the results, obtained monthly, concluded that the dose of 0.5 kGy was effective in the germination of seeds of peanut, not affecting its power of germination and overcoming the witness within 30 to 60 days. (author)

  14. Can heavy metal pollution defend seed germination against heat stress? Effect of heavy metals (Cu(2+), Cd(2+) and Hg(2+)) on maize seed germination under high temperature.

    Science.gov (United States)

    Deng, Benliang; Yang, Kejun; Zhang, Yifei; Li, Zuotong

    2016-09-01

    Heavy metal pollution, as well as greenhouse effect, has become a serious threat today. Both heavy metal and heat stresses can arrest seed germination. What response can be expected for seed germination under both stress conditions? Here, the effects of heavy metals (Cu(2+), Cd(2+) and Hg(2+)) on maize seed germination were investigated at 20 °C and 40 °C. Compared with 20 °C, heat stress induced thermodormancy. However, this thermodormancy could be significantly alleviated by the addition of a low concentration of heavy metals. Heavy metals, as well as heat stress induced H2O2 accumulation in germinating seeds. Interestingly, this low concentration of heavy metal that promoted seed germination could be partly blocked by DMTU (a specific ROS scavenger), irrespective of temperature. Accordingly, H2O2 addition reinforced this promoting effect on seed germination, which was induced by a low concentration of heavy metal. Furthermore, we found that the NADPH oxidase derived ROS was required for seed germination promoted by the heavy metals. Subsequently, treatment of seeds with fluridone (a specific inhibitor of ABA) or ABA significantly alleviated or aggravated thermodormancy, respectively. However, this alleviation or aggravation could be partly attenuated by a low concentration of heavy metals. In addition, germination that was inhibited by high concentrations of heavy metals was also partly reversed by fluridone. The obtained results support the idea that heavy metal-mediated ROS and hormone interaction can finally affect the thermodormancy release or not. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Maternal habitat affects germination requirements of Anabasis setifera, a succulent shrub of the Arabian deserts

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    Ali El-Keblawy

    2016-03-01

    Full Text Available The effects of maternal habitat on light and temperature requirements during germination were assessed for the succulent desert shrub Anabasis setifera. Seeds were collected from the Mediterranean habitats of Egypt and the hyper-arid subtropical habitats of the United Arab Emirates (UAE. Seeds from the two populations were germinated in three temperature treatments in both a light/dark regime and continuous darkness. Seeds from the Egyptian population germinated significantly greater and faster than those of UAE. Seeds stored for four months at room temperatures have little dormancy and germinate at wide range of temperatures and light conditions, but seeds stored four months in the natural habitat lost their ability to germinate and rotted 10 days after incubation. The germination response to temperature depended on the habitat type. Seeds of the Egyptian population attained a significantly greater germination at lower temperatures, compared with seeds from the UAE population, but there was no difference in germination between the two populations at higher temperatures. Germination of A. setifera was very fast; most seeds germinated within four days. These results reflect the adaptive strategy of germination in both populations, and may help explain the wide distribution of this species in different climatic regions.

  16. Seed Hydropriming and Smoke Water Significantly Improve Low-Temperature Germination of Lupinus angustifolius L.

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    Agnieszka Płażek

    2018-03-01

    Full Text Available Seed imbibition under cold temperature is dangerous when dry seeds have relatively low water content. The aim of this study was to investigate germination of 20 lines/cultivars of narrow-leaf lupine at 7 °C (cold and 13 °C (control under the influence of smoke water and following seed hydropriming for 3 h at 20 °C. The efficacy of individual treatments was examined with regard to seed protection during low-temperature germination. Based on seed germination, vigour at cold was evaluated four days after sowing by means of hypocotyl length, the studied lines/cultivars were divided into three groups with low, high and very high germination rates. Germination vigour correlated with cell membrane permeability, dehydrogenase activity and abscisic acid (ABA content and was analysed in the seeds one day after sowing. Gibberellin content did not correlate with germination vigour. The seeds of weakly germinating lines/cultivars had the highest cell permeability and ABA content as well as the lowest amylolytic activity at both studied temperatures. Additionally, the vigour of weakly germinating seeds at 7 °C correlated with dehydrogenase activity. Three-hour hydropriming was the most effective for seed germination under cold due to reduced cell membrane permeability and ABA level. Stimulating effects of smoke water on germination under cold could be explained by enhanced dehydrogenase activity.

  17. Effect of exogenous gibberellic acid on germination, seedling growth ...

    African Journals Online (AJOL)

    The effect of gibberellic acid on germination and seedling growth of lettuce variety, Vista, under salinity conditions was studied. A reduction in germination percentage, roots and shoots length and fresh weight were observed under salt stress. At the same time, acid phosphatase and phytase activities in roots were reduced ...

  18. Seed germination in Miconia theaezans (Bonpl. Cogniaux (Melastomataceae

    Directory of Open Access Journals (Sweden)

    Simone Godoi

    2007-07-01

    Full Text Available The effects of light and temperature were studied on the seeds of Miconia theazeans by isothermic and alternating temperature incubations. The optimum temperature for seed germination was determined by final percentage and germination rates as located in the range of 27.5 to 30 °C and by germination kinetics at the range of 19.5 to 30 °C. The germination was dependent on diffusion processes. The minimum and maximum temperatures were 12.5-15°C and 32.5-35°C, respectively. The seeds showed strong light dependence for germination with the necessity of daily 4-6 h white light irradiation for the maximum induction of germination. However, under 30-20 °C alternating temperatures, daily 2 hours white light was enough to induce germination and attained maximum under 4 h photoperiod. The results indicated that M. theazeans presented characteristics of early successional species.O efeito da luz e da temperatura na germinação de sementes de Miconia theazeans foi analisado através de incubações isotérmicas e de alternâncias de temperaturas. Através das porcentagens finais e velocidade de germinação concluímos que a temperatura ótima de germinação localizaram-se entre 27,5 e 30 °C e pela cinética de germinação verificamos que entre 19,5 e 30 °C a germinação é dependente de processos de difusão. As temperaturas mínima e máxima foram de 12,5-15 °C e 32,5-35 °C, respectivamente. As sementes apresentaram forte dependência da presença de luz branca para a indução da germinação com a necessidade de 4-6 horas de luz diária para a máxima indução do processo. Entretanto, com a alternância de temperaturas de 30 e 20 °C, fotoperíodo de 2 horas foi suficiente para a indução da germinação sendo o máximo de indução obtida a partir de 4 horas diárias. Estes resultados indicam que Miconia theazeans é uma espécie importante que coloniza clareiras e áreas perturbadas em uma floresta natural.

  19. Responses of quinoa (Chenopodium quinoa Willd. seeds stored under different germination temperatures

    Directory of Open Access Journals (Sweden)

    Andressa Strenske

    2017-01-01

    Full Text Available In this experiment, we assessed the germination and vigor of quinoa seeds packed in paper bags and stored at room temperature for 36, 85, 119, 146, 177 and 270 days. The seeds were harvested under experimental conditions in Marechal Candido Rondon, Paraná, during the 2012/13 growing seasons. Four replicates of 100 seeds each were established for each storage time, and the seeds were evaluated, on paper, based on the BOD under the following experimental temperature conditions: alternating temperatures of 20 and 30°C and a constant temperature of 25°C. The seeds from both treatments were subject to seven-hour photoperiods and 25°C under continuous darkness. The germinated seeds were counted daily for eight days after sowing, and we evaluated the percentages of normal and abnormal seedlings and the germination index. The experimental design was completely randomized using a split-plot design. Increasing the storage time decreased the percentage of germinated seeds and seed vigor due to the increased number of abnormal seedlings. Over the 430-day study period, quinoa seed germination completely declined under the experimental conditions. The final number of germinating seeds should be evaluated 7 days after the beginning of the germination test.

  20. Response of vegetable seed germination to solar radiation penetrating through soil

    International Nuclear Information System (INIS)

    Hamamoto, H.

    1999-01-01

    Response of vegetable seeds to irradiation and emergence of plants seeded at various depths were investigated to clarify the effects of solar radiation through soil on vegetable seed germination. Seeds of eight vegetable species were germinated in Petri dishes under 11-h irradiation per day. Seed germination was delayed in tomato (Licopersicon esculentum Mill.) but accelerated in perilla (Perilla ocymoides L.) and Japanese hornwort (Cryptotaenia japonica Hassk.) with increase in irradiation at the intensities higher than 0.4W m -2 . Seeds of Japanese radish (Raphanus sativus L.), watermelon (Citrullus lanatus Matsum.), and Chinese cabbage (Brassica campestris L.) showed delayed germination at more than 4-6W m -2 . No effect of irradiation on lettuce (Lactuca sativa L.) and carrot (Daucus carota L.) seed germination was seen. For tomato, Japanese radish and Japanese hornwort, the effects of irradiation time on germination were also investigated. Tomato seed germination was delayed and Japanese hornwort seed germination was accelerated with increase in irradiation time beyond 2h per day. The emergence of tomato and Japanese hornwort covered with Shimokuriyagawa loam soil (Kuriyagawa soil) and vermiculite at depths of less than 5mm, 5-10mm and 10-15mm was observed. Plants emerged more rapidly from 5-10mm depths than from less than 5mm depth in tomato. The plants seeded at 10-15mm depths emerged as rapidly as those at 5-10mm depths using vermiculite but later than those at other depths using Kuriyagawa soil, probably due to high bulk density. The early emergence of Japanese hornwort was fastest from less than 5mm depth. The plants seeded at 5-10mm depths did not emerge much slower than those at less than 5mm depth. A seeding depth of 5-10mm was suitable for the rapid emergence of those vegetables covered with both the soil and vermiculite. (author)

  1. Phylogeny and source climate impact seed dormancy and germination of restoration-relevant forb species.

    Science.gov (United States)

    Seglias, Alexandra E; Williams, Evelyn; Bilge, Arman; Kramer, Andrea T

    2018-01-01

    For many species and seed sources used in restoration activities, specific seed germination requirements are often unknown. Because seed dormancy and germination traits can be constrained by phylogenetic history, related species are often assumed to have similar traits. However, significant variation in these traits is also present within species as a result of adaptation to local climatic conditions. A growing number of studies have attempted to disentangle how phylogeny and climate influence seed dormancy and germination traits, but they have focused primarily on species-level effects, ignoring potential population-level variation. We examined the relationships between phylogeny, climate, and seed dormancy and germination traits for 24 populations of eight native, restoration-relevant forb species found in a wide range of climatic conditions in the Southwest United States. The seeds were exposed to eight temperature and stratification length regimes designed to mimic regional climatic conditions. Phylogenetic relatedness, overall climatic conditions, and temperature conditions at the site were all significantly correlated with final germination response, with significant among-population variation in germination response across incubation treatments for seven of our eight study species. Notably, germination during stratification was significantly predicted by precipitation seasonality and differed significantly among populations for seven species. While previous studies have not examined germination during stratification as a potential trait influencing overall germination response, our results suggest that this trait should be included in germination studies as well as seed sourcing decisions. Results of this study deepen our understanding of the relationships between source climate, species identity, and germination, leading to improved seed sourcing decisions for restorations.

  2. Influence of hydrogel on germination of lettuce and onion seed at different moisture levels

    Directory of Open Access Journals (Sweden)

    Kateřina Pazderů

    2013-01-01

    Full Text Available The influence of Agrisorb (water solution 1, 3, 5 g/l on lettuce and onion seed germination was tested in different moisture conditions (30 ml and 15 ml of water in germination box. Variants with reduced water level germinated much more slowly (MGT parameter than standard variants, though differences in total germination at the end of the test were insignificant. Treated variants of lettuce seeds showed a statistically significant increase in germination energy (GE on the first day (GE1, both water levels, but a significant decrease on the second day (columns GE2, 15 ml. Higher doses of Agrisorb slowed lettuce seed germination (GE2, 30 ml, dose 5 g significantly, similarly see GE2 (15 ml, doses 1, 3, 5 g. This slowdown was apparent for GE3 (both water amount as well. A similar but insignificant effect was evident for onions. There was an influence of cultivar and seed vigour on sensitivity to water stress. The hydrogel application influenced germination of lettuce and onion seeds. Treated lettuce seeds germinated faster than non-treated control in the beginning of germination process. This effect was not recorded in case of slowly germinated onion seed lots. Although influence of Agrisorb was positive in the beginning, higher doses of hydrogel reduced germination energy of treated seed lots (for example GE2, GE4 of both crops in comparison with non-treated control. Higher doses of hydrogel caused longer MGT of lettuce and onion as well.

  3. Small heat shock proteins can release light dependence of tobacco seed during germination.

    Science.gov (United States)

    Koo, Hyun Jo; Park, Soo Min; Kim, Keun Pill; Suh, Mi Chung; Lee, Mi Ok; Lee, Seong-Kon; Xinli, Xia; Hong, Choo Bong

    2015-03-01

    Small heat shock proteins (sHSPs) function as ATP-independent molecular chaperones, and although the production and function of sHSPs have often been described under heat stress, the expression and function of sHSPs in fundamental developmental processes, such as pollen and seed development, have also been confirmed. Seed germination involves the breaking of dormancy and the resumption of embryo growth that accompany global changes in transcription, translation, and metabolism. In many plants, germination is triggered simply by imbibition of water; however, different seeds require different conditions in addition to water. For small-seeded plants, like Arabidopsis (Arabidopsis thaliana), lettuce (Lactuca sativa), tomato (Solanum lycopersicum), and tobacco (Nicotiana tabacum), light is an important regulator of seed germination. The facts that sHSPs accumulate during seed development, sHSPs interact with various client proteins, and seed germination accompanies synthesis and/or activation of diverse proteins led us to investigate the role of sHSPs in seed germination, especially in the context of light dependence. In this study, we have built transgenic tobacco plants that ectopically express sHSP, and the effect was germination of the seeds in the dark. Administering heat shock to the seeds also resulted in the alleviation of light dependence during seed germination. Subcellular localization of ectopically expressed sHSP was mainly observed in the cytoplasm, whereas heat shock-induced sHSPs were transported to the nucleus. We hypothesize that ectopically expressed sHSPs in the cytoplasm led the status of cytoplasmic proteins involved in seed germination to function during germination without additional stimulus and that heat shock can be another signal that induces seed germination. © 2015 American Society of Plant Biologists. All Rights Reserved.

  4. Seed germination bioassay using maize seeds for phytoxicity evaluation of different composted materials

    International Nuclear Information System (INIS)

    Haq, T.; Begum, R.; Ali, T.A.

    2014-01-01

    In this paper we evaluated the phytotoxicity of different composts obtained by two different composting methods using seed germination bioassay. Seeds of Zea mays were sown in 1:5 extract of composts and these were compared with the control (100% distilled water) for each type of material. Composting of herbal pharmaceutical solid waste (HPSW) was carried out using both conventional bin and pit method. HPSW was mixed separately with poultry manure, cow-manure and goat manure in three different ratios. Uncomposted and composted HPSW were tested to study the Phytotoxicity on Zea mays seed germination, after composting increase in percent germination as well as germination index (GI) values were observed in all combinations regardless, composted by pit or bin method. The results clearly showed that composting reduced Phytotoxicity. The results showed that use of completely composted organic waste reduces the phytotoxicity and is better than the use of uncomposted waste. It was found that pit method was more suitable than bin method. Herbal waste with goat manure in 1:1 ratio was found to be the most effective combination as compared to other combinations here. Germination was 100% and the germination index was 1.4 whereas uncomposted HPSW showed the lowest percent germination i.e., 77% and germination index 52.31 respectively. (author)

  5. The Responses of Mulch Closure on the Germination of Mindi (Melia azedarach Linn.

    Directory of Open Access Journals (Sweden)

    Nurmawati Siregar

    2017-08-01

    Full Text Available One of the factors that determine the successful of the development of mindi is the availability of seedling. The seedlings can be propagated generatively by using seeds, however there is a problem related to the hardness of the testa that make it difficult to germinate, so it needs environment condition treatments to get optimal germination, one of this is mulching. The use mulch possibly get the improvement of temperature, humidity, infiltration and evapotranspiration. The study is aimed to determine the effect of mulch and to find out the best mulch type on the germination of mindi (Melia azedarach Linn. seed. Randomized completely design was employed that arranged factorially, consisted of (A mulch types factor and mulch thicknesses factor (B. There were 5 (five types of mulch treatment i.e rice straws, transparent plastics, dark plastics, zeolite and without mulch. The thicknesses of mulch consisted of one layer and two layers of mulch. Germination capacity, germination speed and growth simultaneously were observed. The results showed, mulching effect on germination mindi the best type of mulch is black or transparent plastic mulch while the thickness of the mulch does not affect the germination. Mindi seed capable of germination in the dark and light conditions on the conditions of temperature and humidity high temperatures.

  6. In Vitro Pollen Viability and Pollen Germination in Cherry Laurel (Prunus laurocerasus L.

    Directory of Open Access Journals (Sweden)

    Melekber Sulusoglu

    2014-01-01

    Full Text Available Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.. Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride and IKI (iodine potassium iodide, were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r2 = 0.0614 and r2 = 0.0015, resp.. Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media.

  7. In vitro pollen viability and pollen germination in cherry laurel (Prunus laurocerasus L.).

    Science.gov (United States)

    Sulusoglu, Melekber; Cavusoglu, Aysun

    2014-01-01

    Pollen quality is important for growers and breeders. This study was carried out to determine in vitro pollen viability and pollen germination in seven genotypes of cherry laurel (Prunus laurocerasus L.). Two pollen viability tests, TTC (2,3,5-triphenyl tetrazolium chloride) and IKI (iodine potassium iodide), were used. Pollen traits of genotypes were studied using an in vitro medium containing 0%, 5%, 10%, 15%, and 20% sucrose to determine the best sucrose concentrations for germination. In the second step, the germinated pollen was counted 1, 4, 6, 10, 12, 24, and 48 hours later until there was no further germination. The viability rates were different according to genotypes and tests used. The IKI and TTC staining tests and pollen germination had low correlation (r(2) = 0.0614 and r(2) = 0.0015, resp.). Painted pollen rate was higher and pollen was well-stained with IKI test and pollen viability estimated with TTC staining test was better than that estimated with the IKI staining test. 15% sucrose gave the best germination rates in most of the genotypes. Pollen germination rates were recorded periodically from one hour to 48 hours in 15% sucrose and the results showed that pollen germination rates increased after 6 hours of being placed in culture media.

  8. Optimal treatment increased the seed germination of Salvia verticillata L.

    Directory of Open Access Journals (Sweden)

    ALALEH KHAKPOOR

    2015-12-01

    Full Text Available Most seeds of the medicinal species are variable regarding their ecological compatibility with environmental conditions. Therefore, identifying the ecophysiological factors that affect dormancy and create optimal conditions for seed germination of medicinal plants is necessary for their culture and production. To evaluate the effect of different treatments on seed germination of medicinal species of Salvia verticillata, collected in the summer of 2010 in Eastern Azarbaijan, we have performed completely randomized experimental tests with 4 replications. The experimental design of treatment prior to growth included: scrape the skin with sandpaper, treatment with 500 ppm gibberellic acid for 24 and 48 h, treatment with citric acid for 10, 20 and 30 minutes, chilling for 2 and 4 weeks, treatment with warm water at 70°C and control treatment. Results showed that the effect of different treatments was significant on seed germination percent of the medicinal plant Salvia verticillata. Scrape the skin with sandpaper, citric acid treatment for 10, 20 and 30 minutes, and gibberellic acid treatment for 24 hours, increased the germination percentage compared to the control treatment. The most positive impact was observed on the dormancy breaking and germination of medicinal species Salvia verticillata.

  9. Evaluation of Oxygen Deficit Stress on Germination Indicators and Seedling

    Directory of Open Access Journals (Sweden)

    F Hoseini

    2012-06-01

    Full Text Available To investigate the relationship oxygen deficit stress on germination indicators and seedling growth of five wheat cultivars in laboratory condition, an experiment with Randomized Complete Block design in factorial arrangement with three replications was conducted in 2008. The treatments consisted of five wheat cultivars (Chamran, Flat, Roshan, Stare and Shole as A factor, and two oxygen level (normal seed and seed under oxygen deficit stress conditions as B factor in each of these figures was done. Results showed that oxygen deficit stress caused to decrease for various cultivars germination percentage, germination rate, allometric coefficient, seed vigor index and other germination indicators. Therefore, this test as a suitable method for determining the quality of various seed lot can be used in the water logging condition. In addition, among different cultivars characterized that Roshan cultivar was more resistant to oxygen deficit stress than Chamran, Flat and Star cultivars. Although Chamran cultivar is common cultivar in Khouzestan, but of look most germination indicators arranged as weak seed class. The highest correlation coefficients among the tested cultivars have been related to seed vigor with seedling length and dry weight of radicle with seedling with 0.92 and 0.90, respectively.

  10. Influence de quelques facteurs environnementaux sur la germination d'Euphorbia heterophylla L. (Euphorbiaceae

    Directory of Open Access Journals (Sweden)

    Ipou Ipou, J.

    2004-01-01

    Full Text Available Influence of some Environmental Factors on Euphorbia heterophylla L. (Euphorbiaceae Seeds Germination. In Ivory Coast, Euphorbia heterophylla appears as a weed in cotton fields. Effects of temperature, light and burying levels on its seed germination were tested. Temperature effects were monitored by means of 4 procedures, using a range of temperatures between 20 and 35 °C. The germination latency period can vary between 1 and 2 days, according to the temperature. After 4 days, germination rates were not longer related to temperature and were very similar. Germination can not happen without light. In order to measure the effect of burying levels, six series of 100 seeds were buried; the first at ground level, the others respectively 2, 4, 6, 8 and 9 cm deeper. Optimal germination rates were found for seeds that were buried between 0 and 6 cm.

  11. Environmental filtering drives the shape and breadth of the seed germination niche in coastal plant communities.

    Science.gov (United States)

    Fernández-Pascual, Eduardo; Pérez-Arcoiza, Adrián; Prieto, José Alberto; Díaz, Tomás E

    2017-05-01

    A phylogenetic comparative analysis of the seed germination niche was conducted in coastal plant communities of western Europe. Two hypotheses were tested, that (1) the germination niche shape (i.e. the preference for a set of germination cues as opposed to another) would differ between beaches and cliffs to prevent seedling emergence in the less favourable season (winter and summer, respectively); and (2) the germination niche breadth (i.e. the amplitude of germination cues) would be narrower in the seawards communities, where environmental filtering is stronger. Seeds of 30 specialist species of coastal plant communities were collected in natural populations of northern Spain. Their germination was measured in six laboratory treatments based on field temperatures. Germination niche shape was estimated as the best germination temperature. Germination niche breadth was calculated using Pielou's evenness index. Differences between plant communities in their germination niche shape and breadth were tested using phylogenetic generalized least squares regression (PGLS). Germination niche shape differed between communities, being warm-cued in beaches (best germination temperature = 20 °C) and cold-cued in cliffs (14 °C). Germination niche was narrowest in seawards beaches (Pielou's index = 0·89) and broadest in landwards beaches (0·99). Cliffs had an intermediate germination niche breadth (0·95). The relationship between niche and plant community had a positive phylogenetic signal for shape (Pagel's λ = 0·64) and a negative one for breadth (Pagel's λ = -1·71). Environmental filters shape the germination niche to prevent emergence in the season of highest threat for seedling establishment. The germination niche breadth is narrower in the communities with stronger environmental filters, but only in beaches. This study provides empirical support to a community-level generalization of the hypotheses about the environmental drivers of the germination

  12. [Detection method for the ability of hemp (Cannabis sativa L.) seed germination by the use of 2,3,5-triphenyl-2H-tetrazolium chloride (TTC)].

    Science.gov (United States)

    Ogata, Jun; Kikura-Hanajiri, Ruri; Yoshimatsu, Kayo; Kiuchi, Fumiyuki; Goda, Yukihiro

    2008-11-01

    Cannabis plants show a high Delta9-tetrahydrocannabinol content and are used as a psychoactive drug. Therefore the cultivation of hemp and its possession are prohibited by law in Japan. Meanwhile, Cannabis seeds have been used as a component of shichimi-togarashi (a Japanese spice), bird feed, or a crude drug (mashinin). To exclude the possibility of germination, it is officially noticed that hemp seeds must be killed. However, the number of violators has increased in recent years. To judge the ability of seed germination, a germination test is performed. However, the test requires several days and thus has not been used for on-site inspection. In this study, we developed a rapid detection method to determine the ability of Cannabis seeds to germinate using 2,3,5-triphenyl-2H-tetrazolium chloride (TTC). The principle of the assay is as follows. The endogenous respiratory enzymes in hemp seeds convert added colorless TTC into red 1,3,5-triphenylformazan. Consequently, a living embryo is stained red, while red does not appear in the dead seeds. The reaction was active over a pH range of 8.0-9.0, and the optimum activity was found from 40 to 50 degrees C. Under the optimum conditions, we were able to determine the ability of seeds to germinate based on the presence of color within 20 min. Since this method is rapid and simple, it is applicable to on-site inspections. In addition, it could be used as an alternative technique to the germination test, because erroneous decisions is cannot occur under the assay principle.

  13. Changes in vicine, con vicine and oligosaccharides contents during germination of broad bean

    International Nuclear Information System (INIS)

    Al-Kaisey, T. M.; Al-Hadithi, R. T.; Sahead, A. B.

    1997-01-01

    Seeds of three cultivars of broad beans were subjected to germination at 25 deg. for 24, 48 and 72 hours. Also, three sets of experiments were germinated for 48 hour se and each one was subjected to different concentrations of gibberellin (100), 200 ppm) as growth regulator. Significant levels of variation were found in the contents of vicine and con vicine during seeds germination. Meanwhile, a complete disappearance of raffinose, scythe's and verbascose (the flatus factors in broad beans) were observed. No significant differences were found in the non-flatulent sugars, protein, ash and oil in the un germinated and germinated seed. (authors). 19 refs., 3 tabs

  14. Allelopathic effect of Jatropha curcas (Lin) leachate on germination ...

    African Journals Online (AJOL)

    Laboratory study was conducted using sterilized petri dishes with double layer of Whatman filter paper at averagely 27oC and 70% humidity. An interval of 24, 48, 76 and 92 hours were recorded on germination studies while radicle and shoot lengths at 92nhours respectively. Decreased in germination percentage, shoot ...

  15. Tetrazolium chloride as an indicator of pine pollen germinability

    Science.gov (United States)

    Stanton A. Cook; Robert G. Stanley

    1960-01-01

    Controlled pollination in forest tree breeding requires pollen of known germination capacity. Methods of determining pollen viability include germination in a hanging drop, in a moist atmosphere, on agar gel, or in a sugar solution (DUFFIELD, 1954; DILLON et al., 1957). Errors commonly arise in the application of these techniques because maximum...

  16. The Cooperative and Interdependent Roles of GerA, GerK, and Ynd in Germination of Bacillus licheniformis Spores.

    Science.gov (United States)

    Borch-Pedersen, Kristina; Lindbäck, Toril; Madslien, Elisabeth H; Kidd, Shani W; O'Sullivan, Kristin; Granum, Per Einar; Aspholm, Marina

    2016-07-15

    When nutrients are scarce, Bacillus species form metabolically dormant and extremely resistant spores that enable survival over long periods of time under conditions not permitting growth. The presence of specific nutrients triggers spore germination through interaction with germinant receptors located in the spore's inner membrane. Bacillus licheniformis is a biotechnologically important species, but it is also associated with food spoilage and food-borne disease. The B. licheniformis ATCC 14580/DSM13 genome exhibits three gerA family operons (gerA, gerK, and ynd) encoding germinant receptors. We show that spores of B. licheniformis germinate efficiently in response to a range of different single l-amino acid germinants, in addition to a weak germination response seen with d-glucose. Mutational analyses revealed that the GerA and Ynd germination receptors function cooperatively in triggering an efficient germination response with single l-amino acid germinants, whereas the GerK germination receptor is essential for germination with d-glucose. Mutant spores expressing only GerA and GerK or only Ynd and GerK show reduced or severely impaired germination responses, respectively, with single l-amino acid germinants. Neither GerA nor Ynd could function alone in stimulating spore germination. Together, these results functionally characterize the germination receptor operons present in B. licheniformis We demonstrate the overlapping germinant recognition patterns of the GerA and Ynd germination receptors and the cooperative functionalities between GerA, Ynd, and GerK in inducing germination. To ensure safe food production and durable foods, there is an obvious need for more knowledge on spore-forming bacteria. It is the process of spore germination that ultimately leads to food spoilage and food poisoning. Bacillus licheniformis is a biotechnologically important species that is also associated with food spoilage and food-borne disease. Despite its importance, the

  17. DIFFERENT SUBSTRATA EFFECTS IN THE GERMINATION OF Ochroma pyramidale (CAV. EX LAM. URB. (BOMBACACEAE

    Directory of Open Access Journals (Sweden)

    Fabrízia de Oliveira Alvino

    2010-08-01

    Full Text Available The objective of this paper was to analyze the effect of different substrata in the germination of Ochroma pyramidale (Cav. ex Lam. Urb. (Bombacaceae. The experiment was conducted in delineation randomized with three treatments (substratum and four repetitions of 25 seeds. The following substrata had been tested: sand + vermiculite (1:1; vermiculite and, sand + shavings (1:1. The effect of substrata through the percentage of germination of the seeds, average time of germination and index of germination speed (IGS were evaluated. There had been significant difference between the treatments in of all the observed variable. The seeds, when conditioned in vermiculite, had presented the biggest tax of germination, greatest speed and lowest germination time.

  18. Improvised Media for In Vitro Pollen Germination of some Species of Apocynaceae

    Directory of Open Access Journals (Sweden)

    Reshmi Chatterjee

    2014-09-01

    Full Text Available Pollen germination forms one of the most important stage post pollination prior to fertilization. This is essential for proper seed setting and seed development. In vitro pollen germination test is the most reliable way of assessing the pollen viability. In the present study pollen grains of seven genera under Apocynaceae family namely, Allamanda, Alstonia, Catharanthus, Nerium, Plumeria, Thevetia and Tabernaemontana were tested in some basic cultural media, such as Brewbaker’s media, 6% Glucose solution, 4% Calcium Nitrate solution and 3% Boron solution. Alstonia pollen grains exhibited highest percentage of germination rate in all the cultural media. Glucose and Brewbaker’s media is found to be highly suitable for efficient pollen germination in all the genera. Boron solution is effective for germination of pollen grains of tree species. In vitro pollen germination can be easily carried out in laboratories. These results can be utilised in plant breeding programmes to improve cultivar and varieties. DOI: http://dx.doi.org/10.3126/ije.v3i3.11074 International Journal of Environment Vol.3(3 2014: 146-153

  19. Germination and seedling frost tolerance differ between the native and invasive range in common ragweed.

    Science.gov (United States)

    Leiblein-Wild, Marion Carmen; Kaviani, Rana; Tackenberg, Oliver

    2014-03-01

    Germination characteristics and frost tolerance of seedlings are crucial parameters for establishment and invasion success of plants. The characterization of differences between populations in native and invasive ranges may improve our understanding of range expansion and adaptation. Here, we investigated germination characteristics of Ambrosia artemisiifolia L., a successful invader in Europe, under a temperature gradient between 5 and 25 °C. Besides rate and speed of germination we determined optimal, minimal and maximal temperature for germination of ten North American and 17 European populations that were sampled along major latitudinal and longitudinal gradients. We furthermore investigated the frost tolerance of seedlings. Germination rate was highest at 15 °C and germination speed was highest at 25 °C. Germination rate, germination speed, frost tolerance of seedlings, and the temperature niche width for germination were significantly higher and broader, respectively, for European populations. This was partly due to a higher seed mass of these populations. Germination traits lacked evidence for adaptation to climatic variables at the point of origin for both provenances. Instead, in the native range, seedling frost tolerance was positively correlated with the risk of frosts which supports the assumption of local adaptation. The increased frost tolerance of European populations may allow germination earlier in the year which may subsequently lead to higher biomass allocation--due to a longer growing period--and result in higher pollen and seed production. The increase in germination rates, germination speed and seedling frost tolerance might result in a higher fitness of the European populations which may facilitate further successful invasion and enhance the existing public health problems associated with this species.

  20. Notable light-free catalytic activity for pollutant destruction over flower-like BiOI microspheres by a dual-reaction-center Fenton-like process.

    Science.gov (United States)

    Wang, Liang; Yan, Dengbiao; Lyu, Lai; Hu, Chun; Jiang, Ning; Zhang, Lili

    2018-10-01

    BiOI is widely used as photocatalysts for pollutant removal, water splitting, CO 2 reduction and organic transformation due to its excellent photoelectric properties. Here, we report for the first time that a light-free catalyst consisting of the flower-like BiOI microspheres (f-BiOI MSs) exposing (1 0 1) and (1 1 0) crystal planes prepared by a hydrothermal method in ethylene glycol environment can rapidly eliminate the refractory BPA within only ∼3 min through a Fenton-like process. The reaction activity is ∼190 times higher than that of the conventional Fenton catalyst Fe 2 O 3 . A series of characterizations and experiments reveal the formation of the dual reaction centers on f-BiOI MSs. The electron-rich O centers efficiently reduce H 2 O 2 to OH, while the electron-poor oxygen vacancies capture electrons from the adsorbed pollutants and divert them to the electron-rich area during the Fenton-like reactions. By these processes, pollutants are degraded and mineralized quickly in a wide pH range. Our findings address the problems of the classical Fenton reaction and are useful for the development of efficient Fenton-like catalysts through constructing dual reaction centers. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Differentiation inside multicelled macroconidia of Fusarium culmorum during early germination

    NARCIS (Netherlands)

    Chitarra, Gilma S; Breeuwer, Pieter; Rombouts, Frans M; Abee, Tjakko; Dijksterhuis, Jan

    Multicelled conidia are formed by many fungal species, but germination of these spores is scarcely studied. Here, the germination and the effects of antimicrobials on multicompartment macroconidia of Fusarium culmorum were investigated. Germ-tube formation was mostly from apical compartments. The

  2. Differentiation inside multicelled macroconidia of Fusarium culmorum during early germination

    NARCIS (Netherlands)

    Chitarra, G.S.; Breeuwer, P.; Rombouts, F.M.; Abee, T.; Dijksterhuis, J.

    2005-01-01

    Multicelled conidia are formed by many fungal species, but germination of these spores is scarcely studied. Here, the germination and the effects of antimicrobials on multicompartment macroconidia of Fusarium culmorum were investigated. Germ-tube formation was mostly from apical compartments. The

  3. Effects of crude oil pollution on the germination of Zea mays and Capsicum frutescens

    Energy Technology Data Exchange (ETDEWEB)

    Amakiri, J.O.; Onofeghara, F.A.

    1984-01-01

    The effects of crude oil pollution on the germination of Zea mays F7 and F27 and Capsicum frutescens were investigated. Crude oil was found to inhibit the germination of all the seed types used. The rate of germination decreased signficantly with increase in the length of the period of presoaking. The germination percentage of oil-soaked seeds of Zea mays also fell significantly with time. Seeds of Capsicum frutescens are most tolerant of crude oil in their germination response. The seeds were found to retain almost 100% viability after nearly 1 year of presoaking in crude oil. The lag phase preceding the germination of such seeds, however, increased threefold. Germination inhibition is attributed primarily to the physical surface characteristics of soil, which make it function as a physical barrier to water and oxygen. However, crude oil, where it penetrates, may be toxic to the embryos.

  4. Proteomic analysis of early phase of conidia germination in Aspergillus nidulans.

    Science.gov (United States)

    Oh, Young Taek; Ahn, Chun-Seob; Kim, Jeong Geun; Ro, Hyeon-Su; Lee, Chang-Won; Kim, Jae Won

    2010-03-01

    In order to investigate proteins involved in early phase of conidia germination, proteomic analysis was performed using two-dimensional gel electrophoresis (2D-GE) in conjunction with MALDI-TOF mass spectrometry (MS). The expression levels of 241 proteins varied quantitatively with statistical significance (Pproteomic analysis of early phase of conidia germination and will contribute to a better understanding of the molecular events involved in conidia germination process. Copyright (c) 2009 Elsevier Inc. All rights reserved.

  5. EFFECT OF DIFFERENT SUBSTRATES ON THE GERMINATION OF SEEDS CEDRELA FISSILIS VELLOZO (MELIACEAE

    Directory of Open Access Journals (Sweden)

    R. Marchezan

    2017-12-01

    Full Text Available The present study was to evaluate the Cedar seed germination and the handling of different substrates to elucidate what is the best condition for the species. The experiment was conducted in the laboratory, without control of incidence of light or temperature, leaving them as much as possible under natural conditions. Treatments consisted of four treatments and four repetitions, each repetition consisted of 10 subrepetitions, totaling 40 units (plastic cups per treatment. Seeds were sown with two seeds per cup. The characteristics evaluated were the percentage of germination and germination speed index (GSI. It is concluded this way that the seeds subjected to the earth and sand worked to conduct tests for germination cedar seeds were those that gave higher percentages of germination and IVG. While the substrates, commercial and land forest were considered unfavorable for conducting germination tests for cedar seeds.

  6. ABA, GA(3), and nitrate may control seed germination of Crithmum maritimum (Apiaceae) under saline conditions.

    Science.gov (United States)

    Atia, Abdallah; Debez, Ahmed; Barhoumi, Zouhaier; Smaoui, Abderrazak; Abdelly, Chedly

    2009-08-01

    Impaired germination is common among halophyte seeds exposed to salt stress, partly resulting from the salt-induced reduction of the growth regulator contents in seeds. Thus, the understanding of hormonal regulation during the germination process is a main key: (i) to overcome the mechanisms by which NaCl-salinity inhibit germination; and (ii) to improve the germination of these species when challenged with NaCl. In the present investigation, the effects of ABA, GA(3), NO(-)(3), and NH(+)(4) on the germination of the oilseed halophyte Crithmum maritimum (Apiaceae) were assessed under NaCl-salinity (up to 200 mM NaCl). Seeds were collected from Tabarka rocky coasts (N-W of Tunisia). The exogenous application of GA(3), nitrate (either as NaNO(3) or KNO(3)), and NH(4)Cl enhanced germination under NaCl salinity. The beneficial impact of KNO(3) on germination upon seed exposure to NaCl salinity was rather due to NO(-)(3) than to K(+), since KCl failed to significantly stimulate germination. Under optimal conditions for germination (0 mM NaCl), ABA inhibited germination over time in a dose dependent manner, but KNO(3) completely restored the germination parameters. Under NaCl salinity, the application of fluridone (FLU) an inhibitor of ABA biosynthesis, stimulated substantially seed germination. Taken together, our results point out that NO(-)(3) and GA(3) mitigate the NaCl-induced reduction of seed germination, and that NO(-)(3) counteracts the inhibitory effect of ABA on germination of C. maritimum.

  7. Effect of electron beam irradiation on seed germination

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seunghee; Bae, Youngmin [Changwon Univ., Changwon (Korea, Republic of)

    2013-07-01

    Effect of electron beam irradiation on seed germination was investigated in this research. Electron beam of 0.5, 1.0, 1.5 and 2.0 kGy was irradiated to the seeds of lettuce, green onion and cucumber, and the irradiated seeds were incubated at 25 .deg. Cn Nitsch medium solidified with 0.2% Phytagel. Germination percentage and the length of the sprouts were determined after 72 hours. Germination percentage of lettuce seeds was greatly reduced by the irradiation, and that of the green onion and cucumber were moderately reduced or unchanged by the irradiation. Although average length of the lettuce sprouts was reduced severely, that of the green onion and cucumber was unchanged or moderately reduced. Conclusively, electron beam irradiation might be a useful way of disinfecting some plant seeds including green onion and cucumber.

  8. Effect of electron beam irradiation on seed germination

    International Nuclear Information System (INIS)

    Han, Seunghee; Bae, Youngmin

    2013-01-01

    Effect of electron beam irradiation on seed germination was investigated in this research. Electron beam of 0.5, 1.0, 1.5 and 2.0 kGy was irradiated to the seeds of lettuce, green onion and cucumber, and the irradiated seeds were incubated at 25 .deg. Cn Nitsch medium solidified with 0.2% Phytagel. Germination percentage and the length of the sprouts were determined after 72 hours. Germination percentage of lettuce seeds was greatly reduced by the irradiation, and that of the green onion and cucumber were moderately reduced or unchanged by the irradiation. Although average length of the lettuce sprouts was reduced severely, that of the green onion and cucumber was unchanged or moderately reduced. Conclusively, electron beam irradiation might be a useful way of disinfecting some plant seeds including green onion and cucumber

  9. DEVELOPMENT OF AN EFFICIENT METHOD FOR in vitro GERMINATION OF SORGHUM POLLEN

    Directory of Open Access Journals (Sweden)

    José Luis Anaya-López

    2011-10-01

    Full Text Available The in vitro pollen germination of sorghum is useful in viability, physiology and genetic transformation studies of pollen. However, the media reported are not efficient. The aim of this study was to formulate an artificial medium, and to determine the optimal conditions for in vitro pollen germination of sorghum. We used a factorial arrangement of concentrations of sucrose, boric acid and calcium nitrate, also evaluated the effect of pH, relative humidity, the physical state of the medium and the stage of flower development over germination. The conditions described in this paper allowed to obtain up to 51% of in vitro pollen germination from 14 varieties of sorghum. These findings show that for increasing in vitro germination, optimal formulation of the medium is required, as well as control over relative humidity and phonological stage of pollen collection.

  10. Determination of Cardinal Temperatures and Germination Respond to Different Temperature for Five Lawns Cultivars

    Directory of Open Access Journals (Sweden)

    hadi khavari

    2017-08-01

    Full Text Available Introduction: Germination of every plant species respond to temperature variation in particular way. Germination is critical stage in plant life cycle. Seed germination is a complex biological process that is influenced by various environmental and genetic factors. The effects of temperature on plant development are the basis for models used to predict the timing of germination. Estimation of the cardinal temperatures, including base, optimum, and maximum, is essential because rate of development increases between base and optimum, decreases between optimum and maximum, and ceases above the maximum and below the base temperatures. Usually, a linear increase in germination rate is associated with an increase in temperature from base temperature (Tb to an optimum. An increase of temperature from the optimum will reduce the germination rate to zero. To determine the best planting date for plants, it is necessary to find the base (Tb, optimum (To and maximum temperatures (Tc for seed germination. These are known as cardinal temperatures. Modelling of seed germination is considered an effective approach to determining cardinal temperatures for most plant species, although these methods have some limitations due to unpredictable biological changes. The results of fitting mechanical models are useful for evaluating seed quality, germination rate, germination percentage, germination uniformity and seed performance under different environmental stresses such as salinity, drought, and freezing. Regression models incorporating more parameters can produce more precise estimates. Cardinal temperature was determined using segmented and logistic models in millet varieties and seedling emergence of wheat. In the dent-like model at lower-than-optimum temperature, a linear relationship holds between temperature and germination rate. This relationship remains linear at higher-than-optimum temperatures, but with a reducing trend. With increasing temperature

  11. Millipede damage to germinating acorns of northern red oak

    Science.gov (United States)

    Jimmy R. Galford; L. R. Auchmoody; Russell S. Walters; H. Clay. Smith; H. Clay. Smith

    1992-01-01

    Millipedes have not been reported as pests of germinating acorns. Studies in Pennsylvania on the impact of insects on northern red (Quercus rubra L. seedling establishment revealed that the millipede Ptyoiulus impressus (Say) damaged the radicles of germinating acorns. Up to 17 percent of the acorn radicles in areas with heavy acorn crops were damaged in 1'991....

  12. Variability of Germinative Potential among Pathogenic Species of Aspergillus

    OpenAIRE

    Araujo, Ricardo; Rodrigues, Acacio Gonçalves

    2004-01-01

    The objective of our study was to evaluate parameters influencing the germination of Aspergillus conidia. Inoculum concentration and age significantly influenced germination. Different incubation temperatures revealed significant differences among Aspergillus species. The internal human milieu provides the ideal conditions for the development of invasive disease by Aspergillus fumigatus but restricts invasion by Aspergillus flavus and Aspergillus niger.

  13. Interaction of prechilling, temperature, osmotic stress, and light in Picea abies seed germination

    International Nuclear Information System (INIS)

    Leinonen, K.; Rita, H.

    1995-01-01

    A multi-factor experimental approach and proportional odds model was used to study interactions between five environmental factors significant to Norway spruce seed germination: prechilling (at +4.5 °C), suboptimal temperatures (+12 and +16 °C), osmotically induced water stress (–0.3 Mpa and 0 Mpa), prolonged white light, and short-period far-red light. Temperature and osmotic stress interacted with one another in the germination of seeds: the effect of osmotic stress being stronger at +16 °C than at +12 °C. In natural conditions, this interaction may prevent germination early in the summer when soil dries and temperature increases. Prolonged white light prevented germination at low temperature and low osmotic potential. Inhibitory effect was less at higher temperatures and higher osmotic potential, as well as after prechilling. Short-period far-red light did not prevent germination of unchilled seeds in darkness. Prechilling tended to make seeds sensitive to short pulses of far-red light, an effect which depended on temperature: at +12 °C the effect on germination was promotive, but at +16 °C, inhibitory and partly reversible by white light. It seems that Norway spruce seeds may have adapted to germinate in canopy shade light rich in far-red. The seeds may also have evolved mechanisms to inhibit germination in prolonged light

  14. Low CXCL13 expression, splenic lymphoid tissue atrophy and germinal center disruption in severe canine visceral leishmaniasis.

    Directory of Open Access Journals (Sweden)

    Joselli S Silva

    Full Text Available Visceral leishmaniasis is associated with atrophy and histological disorganization of splenic compartments. In this paper, we compared organized and disorganized splenic lymphoid tissue from dogs naturally infected with Leishmania infantum assessing the size of the white pulp compartments, the distribution of T, B and S100+ dendritic cells, using immunohistochemistry and morphometry and the expression of CCR7 and the cytokines, CXCL13, lymphotoxin (LT-α, LT-β, CCL19, CCL21, TNF-α, IL-10, IFN-γ and TGF-β, using by real time RT-PCR. The lymphoid follicles and marginal zones were smaller (3.2 and 1.9 times, respectively; Mann-Whitney, P<0.02 in animals with disorganized splenic tissue in comparison to those with organized splenic lymphoid tissue. In spleens with disorganized lymphoid tissue, the numbers of T cells and S100+ dendritic cells were decreased in the follicles, and the numbers of B cells were reduced in both the follicles and marginal zones. CXCL13 mRNA expression was lower in animals with disorganized lymphoid tissue (0.5±0.4 compared to those with organized lymphoid tissue (2.7±2.9, both relative to 18S expression, P = 0.01. These changes in the spleen were associated with higher frequency of severe disease (7/12 in the animals with disorganized than in animals with organized (2/13, Chi-square, P = 0.01 splenic lymphoid tissue. The data presented herein suggest that natural infection with Leishmania infantum is associated with the impairment of follicular dendritic cells, CXCL13 expression, B cell migration and germinal center formation and associates these changes with severe clinical forms of visceral leishmaniasis. Furthermore the fact that this work uses dogs naturally infected with Leishmania infantum emphasizes the relevance of the data presented herein for the knowledge on the canine and human visceral leishmaniasis.

  15. The effect of cytokinins on flax seed germination at low temperature

    Directory of Open Access Journals (Sweden)

    Irena Niedźwiedź-Siegień

    2011-01-01

    Full Text Available Germination of flax seeds (Linum usitatissimum L., cv. Szafir at 5oC was enhanced by continuous white light, gibberellin A3 (GA3, kinetin and benzylaminopurine. GA3 and kinetin at physiological concentrations (10-8-10-6 M improved significantly germination in darkness. Stimulatory effect of benzylaminopurine was visible only in the light. Almost no effect of zeatin and isopentenyladenine (2iP on germination was observed. Possible causes of this differences were suggested.

  16. Évaluation du potentiel de germination de Moringa oleifera dans la ...

    African Journals Online (AJOL)

    SARAH

    28 févr. 2014 ... graines. Au regard des résultats des travaux de. Quashie et al., (2009) in vitro ou en serre, la présence de la lumière raccourcit le temps de germination tout en réduisant de 10 à 20%, les taux cumulés de germination. Ces résultats expliqueraient le faible taux de germination ainsi que la durée du délai de ...

  17. germination of seeds from earlier fruits of bitter and sweet african

    African Journals Online (AJOL)

    ACSS

    2014-11-18

    Nov 18, 2014 ... Seed germination speed significantly depended on the drying level and the germination system (sunshine versus covered condition). .... the West African forest block) is characterised ..... tropical and subtropical America.

  18. Germination biology of Hibiscus tridactylites in Australia and the implications for weed management

    Science.gov (United States)

    Chauhan, Bhagirath Singh

    2016-05-01

    Hibiscus tridactylites is a problematic broadleaf weed in many crops in Australia; however, very limited information is available on seed germination biology of Australian populations. Experiments were conducted to evaluate the effect of environmental factors on germination and emergence of H. tridactylites. Germination was stimulated by seed scarification, suggesting the inhibition of germination in this species is mainly due to the hard seed coat. Germination was not affected by light conditions, suggesting that seeds of this species are not photoblastic. Germination was higher at alternating day/night temperatures of 30/20 °C (74%) and 35/25 °C (69%) than at 25/15 °C (63%). Moderate salinity and water stress did not inhibit germination of H. tridactylites. Seedling emergence of H. tridactylites was highest (57%) for the seeds buried at a 2 cm depth in the soil; 18% of seedlings emerged from seeds buried at 8 cm but no seedlings emerged below this depth. Soil inversion by tillage to bury weed seeds below their maximum depth of emergence could serve an important tool for managing H. tridactylites.

  19. Post-X-irradiation effects on petunia pollen germinating in vitro and in vivo

    International Nuclear Information System (INIS)

    Gilissen, L.J.W.

    1978-01-01

    The germination of Petunia hybrida L. pollen grains in germination medium, containing 10% sucrose and 0.01 % H 3 BO 3 , was linearly related to relative humidity (RH): being minimal at 0 % RH and maximal at 100 % RH. The low germination at 0 % RH was completely restored after transfer to 100 % RH. Germination in medium decreased with increasing X-ray exposures between O and 400 kR. This decrease was caused by pollen rupture. No in vitro germination occurred at exposures of 400 kR and more. The radiosensitivity of pollen in vitro was minimal at 80 % RH. Transfer of pollen to the stigma post-X-irradiation resulted in resistance to much higher exposures of irradiation (<750 kR). The differences in radiosensitivity of the pollen germinated in vitro and in vivo are due possibly to the differences in composition of the germination medium and the stigmatic exudate. Pollen tube growth of irradiated pollen after compatible or incompatible pollination at first showed retarded then normal tube growth. A conclusion is that X-irradiation of pollen cannot influence the characteristics of pollen tube growth after compatible or incompatible pollination. (author)

  20. On the nature of organic and inorganic centers that bifurcate electrons, coupling exergonic and endergonic oxidation-reduction reactions.

    Science.gov (United States)

    Peters, John W; Beratan, David N; Schut, Gerrit J; Adams, Michael W W

    2018-04-19

    Bifurcating electrons to couple endergonic and exergonic electron-transfer reactions has been shown to have a key role in energy conserving redox enzymes. Bifurcating enzymes require a redox center that is capable of directing electron transport along two spatially separate pathways. Research into the nature of electron bifurcating sites indicates that one of the keys is the formation of a low potential oxidation state to satisfy the energetics required of the endergonic half reaction, indicating that any redox center (organic or inorganic) that can exist in multiple oxidation states with sufficiently separated redox potentials should be capable of electron bifurcation. In this Feature Article, we explore a paradigm for bifurcating electrons down independent high and low potential pathways, and describe redox cofactors that have been demonstrated or implicated in driving this unique biochemistry.

  1. Role of the gerA operon in L-alanine germination of Bacillus licheniformis spores

    Directory of Open Access Journals (Sweden)

    Løvdal Irene S

    2012-03-01

    Full Text Available Abstract Background The genome of Bacillus licheniformis DSM 13 harbours three neighbouring open reading frames showing protein sequence similarities to the proteins encoded from the Bacillus subtilis subsp. subtilis 168 gerA operon, GerAA, GerAB and GerAC. In B. subtilis, these proteins are assumed to form a germinant receptor involved in spore germination induced by the amino acid L-alanine. Results In this study we show that disruption of the gerAA gene in B. licheniformis MW3 hamper L-alanine and casein hydrolysate-triggered spore germination, measured by absorbance at 600 nm and confirmed by phase contrast microscopy. This ability was restored by complementation with a plasmid-borne copy of the gerA locus. Addition of D-alanine in the casein hydrolysate germination assay abolished germination of both B. licheniformis MW3 and the complementation mutant. Germination of both B. licheniformis MW3 and the gerA disruption mutant was induced by the non-nutrient germinant Ca2+-Dipicolinic acid. Conclusions These results demonstrate that the B. licheniformis MW3 gerA locus is involved in germination induced by L-alanine and potentially other components present in casein hydrolysate.

  2. Role of the gerA operon in L-alanine germination of Bacillus licheniformis spores

    Science.gov (United States)

    2012-01-01

    Background The genome of Bacillus licheniformis DSM 13 harbours three neighbouring open reading frames showing protein sequence similarities to the proteins encoded from the Bacillus subtilis subsp. subtilis 168 gerA operon, GerAA, GerAB and GerAC. In B. subtilis, these proteins are assumed to form a germinant receptor involved in spore germination induced by the amino acid L-alanine. Results In this study we show that disruption of the gerAA gene in B. licheniformis MW3 hamper L-alanine and casein hydrolysate-triggered spore germination, measured by absorbance at 600 nm and confirmed by phase contrast microscopy. This ability was restored by complementation with a plasmid-borne copy of the gerA locus. Addition of D-alanine in the casein hydrolysate germination assay abolished germination of both B. licheniformis MW3 and the complementation mutant. Germination of both B. licheniformis MW3 and the gerA disruption mutant was induced by the non-nutrient germinant Ca2+-Dipicolinic acid. Conclusions These results demonstrate that the B. licheniformis MW3 gerA locus is involved in germination induced by L-alanine and potentially other components present in casein hydrolysate. PMID:22420404

  3. Environmental and genetic effects on tomato seed metabolic balance and its association with germination vigor.

    Science.gov (United States)

    Rosental, Leah; Perelman, Adi; Nevo, Noa; Toubiana, David; Samani, Talya; Batushansky, Albert; Sikron, Noga; Saranga, Yehoshua; Fait, Aaron

    2016-12-19

    The metabolite content of a seed and its ability to germinate are determined by genetic makeup and environmental effects during development. The interaction between genetics, environment and seed metabolism and germination was studied in 72 tomato homozygous introgression lines (IL) derived from Solanum pennelli and S. esculentum M82 cultivar. Plants were grown in the field under saline and fresh water irrigation during two consecutive seasons, and collected seeds were subjected to morphological analysis, gas chromatograph-mass spectrometry (GC-MS) metabolic profiling and germination tests. Seed weight was under tight genetic regulation, but it was not related to germination vigor. Salinity significantly reduced seed number but had little influence on seed metabolites, affecting only 1% of the statistical comparisons. The metabolites negatively correlated to germination were simple sugars and most amino acids, while positive correlations were found for several organic acids and the N metabolites urea and dopamine. Germination tests identified putative loci for improved germination as compared to M82 and in response to salinity, which were also characterized by defined metabolic changes in the seed. An integrative analysis of the metabolite and germination data revealed metabolite levels unambiguously associated with germination percentage and rate, mostly conserved in the different tested seed development environments. Such consistent relations suggest the potential for developing a method of germination vigor prediction by metabolic profiling, as well as add to our understanding of the importance of primary metabolic processes in germination.

  4. Role of Ethylene in Lactuca sativa cv ;Grand Rapids' Seed Germination.

    Science.gov (United States)

    Abeles, F B

    1986-07-01

    Promotion of thermoinhibited (30 degrees C) lettuce (Lactuca sativa cv ;Grand Rapids') seed germination by ethylene is similar to the action of the gas in other hormonal systems. Ethylene was more active than propylene and ethane was inactive. An inhibitor of ethylene production, aminoethoxy-vinylglycine, reduced ethylene evolution and germination. Inhibitors of ethylene action such as, 5-methyl-7-chloro-4-ethoxycarbonylmethoxy-2,1,3-benzothiadiazole, 2,5-norbornadiene, and silver thiosulfate inhibited germination and the effect was reversed by the addition of ethylene to the gas phase. The action of ethylene appears to be due to the promotion of radial cell expansion in the embryonic hypocotyl. The action of N6-benzyladenine and fusiccocin, which also overcome thermoinhibition, appears to be due to a promotion of hypocotyl elongation. None of the germination promoters studied appeared to function by lowering the mechanical resistance of the endosperm to embryonic growth. Data presented here are consistent with the view that ethylene plays a role in lettuce seed germination under thermoinhibited and normal conditions.

  5. Iron and zinc absorption from weaning foods prepared from germinated cereals and legumes

    International Nuclear Information System (INIS)

    Kuizon, M.D.

    1992-01-01

    Iron deficiency anaemia is a public health problem in the Philippines especially in infants, children and pregnant women. The immediate cause is inadequate intake of available iron to meet increased iron requirements. Iron supplementation studies on pregnant women showed improvement in haemoglobin level and reduction of prevalence of anaemia. A project on iron fortification of rice with ferrous sulphate is going on. It is proposed to study iron and zinc absorption from weaning food prepared from germinated rice: mungbean, germinated rice: cowpea, and germinated corn:mungbean to support the finding that these formulations will alleviate not only protein-energy malnutrition but contribute to improvement of iron status as well since iron contents are higher and anti-nutritional factors (phytates and tannin) are either reduced or eliminated. This study aims to measure the iron and zinc absorption from weaning foods prepared from germinated rice-mungbean, germinated rice-cowpea, and germinated corn-mungbean and to indicate usefullness of modifying local foods to improve iron absorption. 24 refs, 4 figs

  6. Germination and development of pecan cultivar seedlings by seed stratification

    Directory of Open Access Journals (Sweden)

    Igor Poletto

    2015-12-01

    Full Text Available Abstract: The objective of this work was to evaluate the effect of seed stratification on germination rate, germination speed, and initial development of seedlings of six pecan (Carya illinoinensis cultivars under subtropical climatic conditions in southern Brazil. For stratification, the seeds were placed in boxes with moist sand, in a cold chamber at 4°C, for 90 days. In the fourteenth week after sowing, the emergence speed index, total emergence, plant height, stem diameter, and number of leaves were evaluated. Seed stratification significantly improves the germination potential and morphological traits of the evaluated cultivars.

  7. Fluridone: a combination germination stimulant and herbicide for problem fields?

    Science.gov (United States)

    Goggin, Danica E; Powles, Stephen B

    2014-09-01

    Problem weeds in agriculture, such as Lolium rigidum Gaud., owe some of their success to their large and dormant seed banks, which permit germination throughout a crop-growing season. Dormant weed seed banks could be greatly depleted by application of a chemical that stimulates early-season germination and then kills the young seedlings. Fluridone, a phytoene desaturase-inhibiting herbicide that can also break seed dormancy, was assessed for its efficacy in this regard. The germination of fluridone-treated Lolium rigidum seeds was stimulated on soils with low organic matter, and almost 100% seedling mortality was observed, while the treatment was only moderately effective on a high-organic-matter potting mix. Seedlings from wheat, canola, common bean and chickpea seeds sown on fluridone-treated sandy loam were bleached and did not survive, but lupins and field peas grew normally. This proof-of-concept study with fluridone suggests that it may be possible to design safe and effective molecules that act as germination stimulants plus herbicides in a range of crop and soil types: a potentially novel way of utilising herbicides to stimulate seed bank germination and a valuable addition to an integrated weed management system. © 2014 Society of Chemical Industry.

  8. Effect of Temperature Regimes on Seed Germination Asafoetida (Ferula Assafoetida L.

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    Zangoie M.

    2014-12-01

    Full Text Available Asafoetida is a medicinal plant belonging to the Apiaceae family. Gum obtained from the lower part of the stem and roots of this plant has many industrial and pharmaceutical applications. This plant is subject to extinction in its natural habitats due to over-utilization. Understanding the biology of seed germination can help to restore such degradation by implementing agricultural development programs. The present study is an attempt to determine the germination responses to two temperature regimes (constant and fluctuating during the course of the study. The experiment was planned based on a factorial-completely randomized design with two factors (constant and fluctuating temperature regimes at 3 levels each (15, 20 and 25°C with 4 replications. The results showed that the characteristics of germination in asafoetida were significantly improved under the fluctuating temperature as compared with the constant regime. It showed a mean germination time of 1.88 days for the fluctuating regime, while it was 4.88 days for the constant regime. The same results were found on germination rates in favor of fluctuating (0.62 per day in comparison with constant regime (0.33 per day. Under the fluctuating regime, the lowest level of imposed temperature (daily application of 10 and 20 degree during the first and the second 12 hours, respectively was the best for seed germination in this experiment.

  9. Proteolytic and Trypsin Inhibitor Activity in Germinating Jojoba Seeds (Simmondsia chinensis).

    Science.gov (United States)

    Samac, D; Storey, R

    1981-12-01

    Changes in proteolytic activity (aminopeptidase, carboxypeptidase, endopeptidase) were followed during germination (imbibition through seedling development) in extracts from cotyledons of jojoba seeds (Simmondsia chinensis). After imbibition, the cotyledons contained high levels of sulfhydryl aminopeptidase activity (APA) but low levels of serine carboxypeptidase activity (CPA). CPA increased with germination through the apparent loss of a CPA inhibitor substance in the seed. Curves showing changes in endopeptidase activity (EPA) assayed at pH 4, 5, 6, 7, and 8 during germination were distinctly different. EPA at pH 4, 5, 6, and 7 showed characteristics of sulfhydryl enzymes while activity at pH 8 was probably due to a serine type enzyme. EPA at pH 6 was inhibited early in germination by one or more substances in the seed. Activities at pH 5 and later at pH 6 were the highest of all EPA throughout germination and increases in these activities were associated with a rapid loss of protein from the cotyledons of the developing seedling.Jojoba cotyledonary extracts were found to inhibit the enzymic activity of trypsin, chymotrypsin, and pepsin but not the protease from Aspergillus saotoi. The heat-labile trypsin inhibitor substance(s) was found in commercially processed jojoba seed meal and the albumin fraction of seed proteins. Trypsin inhibitor activity decreased with germination.

  10. Irradiation and germination effects on phytate, protein and amino acids of soybean

    International Nuclear Information System (INIS)

    Sattar, A.; Neelofar; Akhtar, M.A.

    1990-01-01

    Influence of irradiation (0.05–0.20 kGy) and germination (24–120 hours) in distilled and tap water on phytate, protein and amino acids of soybean, was studied. Phytate values significantly decreased with increasing germination period and irradiation dose (P<0.01). Irradiation independently decreased the original phytate (212.0 mg/100 g) to a range value of 205.0–190.0 mg/100 g depending upon dose level. Germination of unirradiated seeds for 120 hours in distilled and tap water lowered the phytate to 55.0 and 94.9 mg/100 g (74.1 and 55.2% reduction) respectively. Maximum destruction of phytate to levels of 20.5 and 50.9 mg/100 g (90.3 and 76.0% reduction) occurred during germination of 0.20 kGy samples for 120 hours in distilled and tap water respectively. Total protein content significantly increased during germination (P<0.05) and the increase was more in tap than distilled water. Germination for 120 hours of untreated seeds in tap water increased the essential and decreased non-essential amino acids while in the 0.10 kGy sample, increases in both cases were observed

  11. Germination Behaviour of Lawsonia inermis L. as Influenced by Polyethylene Glycol (PEG

    Directory of Open Access Journals (Sweden)

    Enneb Hanen

    2016-11-01

    Full Text Available Tunisian Flora is well known for its richness and diversity of medicinal plants such as henna plant (Lawsonia inermis L. a flowering plant belongs to the family of Lyteraceae, distributed in dry tropical and subtropical zones including North Africa. This plant pertains to continental oases where water shortage, constitute the essential limiting factor of agricultural production. The present study was carried out to evaluate the impact of water stress on the germination of the henna plant (Lawsonia inermis L.. Seeds were germinated under stress of aqueous Polyethylene Glycol (PEG solutions blended to create water potentials of 0, -0.2, -0.4, -0.6, - 0.8 and -1 MPa. Results showed that seeds germinated in PEG solutions exhibited significantly lower cumulative germination rate (CGR than control especially when water potential fell below -0.6 MPa. Mean germination time (MGT was delayed by increasing PEG concentrations, while germination stress tolerance index (GSTI was decreased with the increase in PEG concentrations. The highest percentage of GSTI in stressed condition was 84.13% for PEG (-0.2MPa whereas, the lowest value was 8.37% for PEG (-1MPa.

  12. EASTERN DODDER (CUSCUTA MONOGYNA VAHL.) SEED GERMINATION AFFECTED BY SOME HERBACEOUS DISTILLATES.

    Science.gov (United States)

    Movassaghi, M; Hassannejad, S

    2015-01-01

    Eastern dodder (Cuscuta monogyna Vahl.) is one of the noxious parasitic weeds that infected many ornamental trees in green spaces and gardens. Our purpose is to find natural inhibitors for prevention of its seed germination. In order to reach this aim, laboratory studies were conducted by using of herbaceous distillates of Dracocephalum moldavica, Nasturtium officinalis, Malva neglecta, Mentha piperita, Mentha pulegium, Rosa damascene, Ziziphora tenuior, and Urtica dioica on seed germination of C. monogyna. Z. tenuior distillate stimulated C. monogyna seed germination, whereas others reduced this parasitic weed's seed germination. D. moldavica caused maximum inhibition on weed seed germination. Seedling growth of C. monogyna was more affected than its seed germination. All of these herbaceous distillates reduced C. monogyna seedling length so that the latter decreased from 28.2 mm in distilled water to 4.5, 3.97, 3.85, 3.67, 3.1, 2.87, 2.57, 1.9, and 1.17 in M. pulegium, M. piperita, F. officinalis, Z. tenuior, N. officinalis, M. neglecta, R. damascene, U. dioica and D. moldavica, respectively. By using these medicinal plants distillates instead of herbicides, the parasitic weed seedling length and host plant infection will reduce.

  13. Lab and Field Warming Similarly Advance Germination Date and Limit Germination Rate for High and Low Elevation Provenances of Two Widespread Subalpine Conifers

    Directory of Open Access Journals (Sweden)

    Lara M. Kueppers

    2017-11-01

    Full Text Available Accurately predicting upslope shifts in subalpine tree ranges with warming requires understanding how future forest populations will be affected by climate change, as these are the seed sources for new tree line and alpine populations. Early life history stages are particularly sensitive to climate and are also influenced by genetic variation among populations. We tested the climate sensitivity of germination and initial development for two widely distributed subalpine conifers, using controlled-environment growth chambers with one temperature regime from subalpine forest in the Colorado Rocky Mountains and one 5 °C warmer, and two soil moisture levels. We tracked germination rate and timing, rate of seedling development, and seedling morphology for two seed provenances separated by ~300 m elevation. Warming advanced germination timing and initial seedling development by a total of ~2 weeks, advances comparable to mean differences between provenances. Advances were similar for both provenances and species; however, warming reduced the overall germination rate, as did low soil moisture, only for Picea engelmannii. A three-year field warming and watering experiment planted with the same species and provenances yielded responses qualitatively consistent with the lab trials. Together these experiments indicate that in a warmer, drier climate, P. engelmannii germination, and thus regeneration, could decline, which could lead to declining subalpine forest populations, while Pinus flexilis forest populations could remain robust as a seed source for upslope range shifts.

  14. [On the influence of local molecular environment on the redox potential of electron transfer cofactors in bacterial photosynthetic reaction centers].

    Science.gov (United States)

    Krasil'nikov, P M; Noks, P P; Rubin, A B

    2011-01-01

    The addition of cryosolvents (glycerol, dimethylsulfoxide) to a water solution containing bacterial photosynthetic reaction centers changes the redox potential of the bacteriochlorophyll dimer, but does not affect the redox potential of the quinone primary acceptor. It has been shown that the change in redox potential can be produced by changes of the electrostatic interactions between cofactors and the local molecular environment modified by additives entered into the solution. The degree of influence of a solvent on the redox potential of various cofactors is determined by degree of availability of these cofactors for molecules of solvent, which depends on the arrangement of cofactors in the structure of reaction centers.

  15. The evolutionary pathway from anoxygenic to oxygenic photosynthesis examined by comparison of the properties of photosystem II and bacterial reaction centers.

    Science.gov (United States)

    Allen, J P; Williams, J C

    2011-01-01

    In photosynthetic organisms, such as purple bacteria, cyanobacteria, and plants, light is captured and converted into energy to create energy-rich compounds. The primary process of energy conversion involves the transfer of electrons from an excited donor molecule to a series of electron acceptors in pigment-protein complexes. Two of these complexes, the bacterial reaction center and photosystem II, are evolutionarily related and structurally similar. However, only photosystem II is capable of performing the unique reaction of water oxidation. An understanding of the evolutionary process that lead to the development of oxygenic photosynthesis can be found by comparison of these two complexes. In this review, we summarize how insight is being gained by examination of the differences in critical functional properties of these complexes and by experimental efforts to alter pigment-protein interactions of the bacterial reaction center in order to enable it to perform reactions, such as amino acid and metal oxidation, observable in photosystem II.

  16. Effect of population, collection year, after-ripening and incubation condition on seed germination of Stipa bungeana.

    Science.gov (United States)

    Zhang, Rui; Baskin, J M; Baskin, C C; Mo, Qing; Chen, Lijun; Hu, Xiaowen; Wang, Yanrong

    2017-10-24

    Knowledge of the germination behavior of different populations of a species can be useful in the selection of appropriate seed sources for restoration. The aim of this study was to test the effect of seed population, collection year, after-ripening and incubation conditions on seed dormancy and germination of Stipa bungeana, a perennial grass used for revegetation of degraded grasslands on the Loess Plateau, China. Fresh S. bungeana seeds were collected from eight locally-adapted populations in 2015 and 2016. Dormancy and germination characteristics of fresh and 6-month-old dry-stored seeds were determined by incubating them over a range of alternating temperature regimes in light. Effect of water stress on germination was tested for fresh and 6-month-old dry-stored seeds. Seed dormancy and germination of S. bungeana differed with population and collection year. Six months of dry storage broke seed dormancy, broadened the temperature range for germination and increased among-population differences in germination percentage. The rank order of germination was not consistent in all germination tests, and it varied among populations. Thus, studies on comparing seed dormancy and germination among populations must consider year of collection, seed dormancy states and germination test conditions when selecting seeds for grassland restoration and management.

  17. Repeated Stand-Replacing Crown Fires Affect Seed Morphology and Germination in Aleppo pine

    Directory of Open Access Journals (Sweden)

    Antonio Saracino

    2017-06-01

    Full Text Available Post-fire reproductive niche of Aleppo pine (Pinus halepensis is deeply interlaced with fire products. Indeed, the high pH and low osmotic potentials of ash beds under burnt crowns constitute the main constraints to seed germination. In this study, we aim to investigate whether fire recurrence, through the physico-chemical constraints imposed by the ash beds, affects the reproduction ability of P. halepensis at the germination stage. To this aim, Aleppo pine seeds were collected in neighboring even-aged stands subjected to 0, 1, or 2 fires (namely fire cohorts, and seed morphology and germination performance, in terms of cumulative germination and germination kinetics, were studied under increasing osmotic potentials (from 0.0 to −1.2 MPa and pH (from 6 to 11. Besides fire history, the role of ontogenetic age of mother plants on seed morphology and germination was also investigated. Differences in seed morphology among the three cohorts have been highlighted in a multivariate context, with anisotropic enlargement of the seeds produced by pine stands experiencing repeated fires. The patterns of seed germination varied primarily in relation to the fire cohort, with seeds from the pine stand experiencing repeated fires exhibiting enhanced tolerance to pH stress. Conversely, germination performances under osmotic constraints mainly depends on tree ontogenetic stage, with an involvement of fire history especially in the timing of seed germination. Our results suggest that, at least in the short term, fire recurrence does not constrain the reproduction ability of Aleppo pine. These results highlight the need for further research to elucidate the mechanisms behind these responses to recurrent fires.

  18. Repeated Stand-Replacing Crown Fires Affect Seed Morphology and Germination in Aleppo pine

    Science.gov (United States)

    Saracino, Antonio; Bellino, Alessandro; Allevato, Emilia; Mingo, Antonio; Conti, Stefano; Rossi, Sergio; Bonanomi, Giuliano; Carputo, Domenico; Mazzoleni, Stefano

    2017-01-01

    Post-fire reproductive niche of Aleppo pine (Pinus halepensis) is deeply interlaced with fire products. Indeed, the high pH and low osmotic potentials of ash beds under burnt crowns constitute the main constraints to seed germination. In this study, we aim to investigate whether fire recurrence, through the physico-chemical constraints imposed by the ash beds, affects the reproduction ability of P. halepensis at the germination stage. To this aim, Aleppo pine seeds were collected in neighboring even-aged stands subjected to 0, 1, or 2 fires (namely fire cohorts), and seed morphology and germination performance, in terms of cumulative germination and germination kinetics, were studied under increasing osmotic potentials (from 0.0 to −1.2 MPa) and pH (from 6 to 11). Besides fire history, the role of ontogenetic age of mother plants on seed morphology and germination was also investigated. Differences in seed morphology among the three cohorts have been highlighted in a multivariate context, with anisotropic enlargement of the seeds produced by pine stands experiencing repeated fires. The patterns of seed germination varied primarily in relation to the fire cohort, with seeds from the pine stand experiencing repeated fires exhibiting enhanced tolerance to pH stress. Conversely, germination performances under osmotic constraints mainly depends on tree ontogenetic stage, with an involvement of fire history especially in the timing of seed germination. Our results suggest that, at least in the short term, fire recurrence does not constrain the reproduction ability of Aleppo pine. These results highlight the need for further research to elucidate the mechanisms behind these responses to recurrent fires. PMID:28713415

  19. Effect of gamma ray irradiation on seed germination of Ardisia crenata

    International Nuclear Information System (INIS)

    Huang Donghua; Xu Hong; Huang Yanping; Song Xiaomin

    2011-01-01

    The seeds of Ardisia crenata were used as experimental material and treated with gamma ray under the irradiative doses ranging from 50 to 500 Gy. The results showed that the seed germination rates were not affected under the irradiative dose of 150 Gy and below. The germination potentiality turned to reduce while the irradiative dose was higher than 250 Gy. And in the range of 300 to 500 Gy the germination rates were decreased with the increase of the irradiative dose. (authors)

  20. Using hyperspectral imaging to determine germination of native Australian plant seeds.

    Science.gov (United States)

    Nansen, Christian; Zhao, Genpin; Dakin, Nicole; Zhao, Chunhui; Turner, Shane R

    2015-04-01

    We investigated the ability to accurately and non-destructively determine the germination of three native Australian tree species, Acacia cowleana Tate (Fabaceae), Banksia prionotes L.F. (Proteaceae), and Corymbia calophylla (Lindl.) K.D. Hill & L.A.S. Johnson (Myrtaceae) based on hyperspectral imaging data. While similar studies have been conducted on agricultural and horticultural seeds, we are unaware of any published studies involving reflectance-based assessments of the germination of tree seeds. Hyperspectral imaging data (110 narrow spectral bands from 423.6nm to 878.9nm) were acquired of individual seeds after 0, 1, 2, 5, 10, 20, 30, and 50days of standardized rapid ageing. At each time point, seeds were subjected to hyperspectral imaging to obtain reflectance profiles from individual seeds. A standard germination test was performed, and we predicted that loss of germination was associated with a significant change in seed coat reflectance profiles. Forward linear discriminant analysis (LDA) was used to select the 10 spectral bands with the highest contribution to classifications of the three species. In all species, germination decreased from over 90% to below 20% in about 10-30days of experimental ageing. P50 values (equal to 50% germination) for each species were 19.3 (A. cowleana), 7.0 (B. prionotes) and 22.9 (C. calophylla) days. Based on independent validation of classifications of hyperspectral imaging data, we found that germination of Acacia and Corymbia seeds could be classified with over 85% accuracy, while it was about 80% for Banksia seeds. The selected spectral bands in each LDA-based classification were located near known pigment peaks involved in photosynthesis and/or near spectral bands used in published indices to predict chlorophyll or nitrogen content in leaves. The results suggested that seed germination may be successfully classified (predicted) based on reflectance in narrow spectral bands associated with the primary metabolism

  1. A germination test: an easy approach to know the irradiation

    International Nuclear Information System (INIS)

    Khawar, A.; Bhatti, I.A.; Bhatti, H.N.

    2010-01-01

    Food irradiation is an evolving preserving technique that provides a shield against the spoilage and might have a potential to ensure the food safety and security world wide. In the present study, feasibility to apply germination test to distinguish an un-irradiated and irradiated samples of wheat, maize, chickpea and black eye beans was checked. Samples were irradiated to the absorbed doses ranging from 0-10 kGy using Co-60 gamma irradiator and were germinated in plant growth chamber. Root and shoot lengths were measured at 7th day after gamma radiation treatment. In all the irradiated samples root and shoot lengths were decreased with the increase in radiation absorbed doses. The seeds irradiated to the absorbed doses more than 2 kGy were not germinated. Germination test proved as an easy and simple method to detect irradiation in wheat, maize, chickpea and black eye beans irradiated even at low absorbed doses. (author)

  2. The Effect of Temperature and Water Potential on Seed Germination of Asian spiderflower (Cleome viscose L.: As Invasive Weed in Soybean Fields in Golestan Province

    Directory of Open Access Journals (Sweden)

    M. Shirdel

    2016-09-01

    Full Text Available Introduction: Cleome viscose Linn. with a common name as “Asian spiderflower”, belongs to the Capparidacea family. It is an annual, sticky herb found as a common weed all over the tropical regions of the world. It is a very competitive weed of annual crops. This plant is currently introduced as an invasive plant in soybean fields of Golestan province. There is no management recommendation to control Asian spider flower. Thus large quantities of soybean destroyed by this weed every year. Germination and emergence are the two most important stages in the life cycle of plants. Environmental factors such as temperature, light, pH, planting depth and soil moisture are known to affect seed germination and emergence of weeds. An understanding of the germination biology of Asian spider flower would facilitate the development of better management strategies for this weed. Therefore, the purposes of this research were to study the effects of temperature and water potential on Asian spider flower seed germination. Material and Methods: To evaluate the effect of temperature and water potential on seed germination and determination of seed germination cardinal temperatures of Asian spider flower, an experiment was conducted as Factorial Experiment in Completely Randomized Design with 4 replications in Agricultural Research and Natural Resources Center of Golestan Province during 2013. Treatments were included temperatures with seven levels (15, 20, 25, 30, 35, 38 and 400C and water potentials with six levels (0, -2, -4, -6, -8 and -10 bar. Germination was monitored daily until germination discontinued and the number of the germinated seeds was recorded. Seeds were observed twice daily and considered germinated when the radical was approximately >2mm long. To quantify the response of germination rate to temperature and to determine the cardinal temperatures for germination original beta, and modified beta, segmented and dent models were used. Water

  3. Cytokinins and urea derivatives stimulate seed germination in Lotus corniculatus L.

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    Nikolić Radomirka

    2007-01-01

    Full Text Available We studied the effects of various cytokinins and urea derivatives on germination of aged seeds of in Lotus corniculatus L. The following substances were applied: N6-isoprenoid cytokinins (isopentenyl adenine and zeatin, adenine sulfate, N6-aromatic cytokinins (kinetin, benzyladenine and their N9-ribosides, N-benzyl-9-(2- tetrahydropyranyladenine, and urea derivatives (diphenylurea, thidiazuron, and chloro-pyridyl phenylurea. With the exception of adenine sulfate, all cytokinins increased the percentage of seed germination up to twofold, depending on their kind and concentration. It is concluded that cytokinins may be among the missing factors in aged seeds of L. corniculatus contributing to the implementation of their full germination potential. They could be used to improve germination of both freshly harvested and aged seed samples, if necessary. .

  4. Regulatory-associated protein of TOR (RAPTOR) alters the hormonal and metabolic composition of Arabidopsis seeds, controlling seed morphology, viability and germination potential.

    Science.gov (United States)

    Salem, Mohamed A; Li, Yan; Wiszniewski, Andrew; Giavalisco, Patrick

    2017-11-01

    Target of Rapamycin (TOR) is a positive regulator of growth and development in all eukaryotes, which positively regulates anabolic processes like protein synthesis, while repressing catabolic processes, including autophagy. To better understand TOR function we decided to analyze its role in seed development and germination. We therefore performed a detailed phenotypic analysis using mutants of the REGULATORY-ASSOCIATED PROTEIN OF TOR 1B (RAPTOR1B), a conserved TOR interactor, acting as a scaffold protein, which recruits substrates for the TOR kinase. Our results show that raptor1b plants produced seeds that were delayed in germination and less resistant to stresses, leading to decreased viability. These physiological phenotypes were accompanied by morphological changes including decreased seed-coat pigmentation and reduced production of seed-coat mucilage. A detailed molecular analysis revealed that many of these morphological changes were associated with significant changes of the metabolic content of raptor1b seeds, including elevated levels of free amino acids, as well as reduced levels of protective secondary metabolites and storage proteins. Most of these observed changes were accompanied by significantly altered phytohormone levels in the raptor1b seeds, with increases in abscisic acid, auxin and jasmonic acid, which are known to inhibit germination. Delayed germination and seedling growth, observed in the raptor1b seeds, could be partially restored by the exogenous supply of gibberellic acid, indicating that TOR is at the center of a regulatory hub controlling seed metabolism, maturation and germination. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  5. Incorporation of 15N-inorganic nitrogen into free-amino acids in germinating corn

    International Nuclear Information System (INIS)

    Samukawa, Kisaburo; Yamaguchi, Masuro

    1979-01-01

    Incorporation of 15 N-labeled compounds, (K 15 NO 3 ) and ( 15 NH 4 ) 2 SO 4 , into free-amino acids was measured in germinating corn. Sterilized seeds of sweet corn (Choko No. 865) were sown on the filter papers soaked in 10 ml of the solution containing one of the labeled compounds (40 ppm N, 99 atom % excess) in petri dishes and germinated at 30 deg C. After 48 hours and 72 hours, 15 N-incorporation was measured in 5 seedlings selected owing to uniform growth. A GC-MS was used for measuring the ratio of 15 N isotopes present in free-amino acids. 15 N incorporation into free-amino acids hardly occurred when corn was germinated in the solution containing K 15 NO 3 , which suggested that endogenous nitrogen was used during the early germination stage of corn when nitrate is present. Incorporation into amino acids was greater when corn was germinated in the medium containing ( 15 NH 4 ) 2 SO 4 , than the case of the solution containing K 15 NO 3 . When corn was germinated in the solution containing ( 15 NH 4 ) 2 SO 4 , assimilation of 15 N into asparagine or aspartic acid was comparatively higher than that into the other amino acids, though the incorporation rate was low. Thus, in intact germinating corn, the hydrolyzed product of protein was utilized for germination with priority, and dependence on exogenous nitrogen was low. (Kaihara, S.)

  6. Effect of NaCl on seed germination in some Centaurium Hill. Species (Gentianaceae

    Directory of Open Access Journals (Sweden)

    Živković S.

    2007-01-01

    Full Text Available The influence of high NaCl concentrations on seed germination in both light and darkness was examined in the species Centaurium pulchellum, C. erythraea, C. littorale, C. spicatum, and C. tenuiflorum. Salt tolerance was found to depend on the life history of the seeds. To be specific, seeds of all five species failed to complete germination when exposed to continuous white light if kept all the time in the presence of 100-200 mM and greater NaCl concentrations. However, when after two weeks NaCl was rinsed from the seeds and the seeds were left in distilled water under white light for an additional two weeks, all species completed germination to a certain extent. The percent of germination not only depended on NaCl concentration in the prior medium, but was also species specific. Thus, seeds of C. pulchellum, C. erythraea, and C. littorale completed germination well almost irrespective of the salt concentration previously experienced. On the other hand, seeds of C. tenuiflorum completed germination poorly if NaCl concentrations in the prior media were greater than 200 mM. When seeds after washing were transferred to darkness for an additional 14 days, they failed to complete germination if previously imbibed on media containing NaCl concentrations greater than 400 mM. However, the seeds of all species, even if previously imbibed at 800 mM NaCl, could be induced to complete germination in darkness by 1 mM gibberellic acid. .

  7. Seed dormancy and germination of Halophila ovalis mediated by simulated seasonal temperature changes

    Science.gov (United States)

    Statton, John; Sellers, Robert; Dixon, Kingsley W.; Kilminster, Kieryn; Merritt, David J.; Kendrick, Gary A.

    2017-11-01

    The seagrass, Halophila ovalis plays an important ecological and sediment stability role in estuarine systems in Australia with the species in decline in many sites. Halophila ovalis is a facultative annual, relying mainly on recruitment from the sediment seed bank for the annual regeneration of meadows. Despite this, there is little understanding of seed dormancy releasing mechanisms and germination cues. Using H. ovalis seed from the warm temperate Swan River Estuary in Western Australia, the germination ecology of H. ovalis was investigated by simulating the natural seasonal variation in water temperatures. The proportion of germinating seeds was found to be significantly different among temperature treatments (p < 0.001). The treatment with the longest period of cold exposure at 15 °C followed by an increase in temperature to 20-25 °C (i.e. cold stratification) had the highest final mean germination of 32% and the fastest germination rate. Seeds exposed to constant mean winter temperatures of 15 °C had the slowest germination rate with less than two seeds germinating over 118 days. Thus temperature is a key germination cue for H. ovalis seeds and these data infer that cold stratification is an important dormancy releasing mechanism. This finding has implications for recruitment in facultative annual species like H. ovalis under global warming since the trend for increasing water temperatures in the region may limit seed-based recruitment in the future.

  8. 7 CFR 201.29 - Germination of vegetable seed in containers of 1 pound or less.

    Science.gov (United States)

    2010-01-01

    ... the percentage of germination and date of test. Each variety of vegetable seed which has a germination... 7 Agriculture 3 2010-01-01 2010-01-01 false Germination of vegetable seed in containers of 1 pound... (CONTINUED) FEDERAL SEED ACT FEDERAL SEED ACT REGULATIONS Labeling Vegetable Seeds § 201.29 Germination of...

  9. Engineered Photosystem II reaction centers optimize photochemistry versus photoprotection at different solar intensities.

    Science.gov (United States)

    Vinyard, David J; Gimpel, Javier; Ananyev, Gennady M; Mayfield, Stephen P; Dismukes, G Charles

    2014-03-12

    The D1 protein of Photosystem II (PSII) provides most of the ligating amino acid residues for the Mn4CaO5 water-oxidizing complex (WOC) and half of the reaction center cofactors, and it is present as two isoforms in the cyanobacterium Synechococcus elongatus PCC 7942. These isoforms, D1:1 and D1:2, confer functional advantages for photosynthetic growth at low and high light intensities, respectively. D1:1, D1:2, and seven point mutations in the D1:2 background that are native to D1:1 were expressed in the green alga Chlamydomonas reinhardtii. We used these nine strains to show that those strains that confer a higher yield of PSII charge separation under light-limiting conditions (where charge recombination is significant) have less efficient photochemical turnover, measured in terms of both a lower WOC turnover probability and a longer WOC cycle period. Conversely, these same strains under light saturation (where charge recombination does not compete) confer a correspondingly faster O2 evolution rate and greater protection against photoinhibition. Taken together, the data clearly establish that PSII primary charge separation is a trade-off between photochemical productivity (water oxidation and plastoquinone reduction) and charge recombination (photoprotection). These trade-offs add up to a significant growth advantage for the two natural isoforms. These insights provide fundamental design principles for engineering of PSII reaction centers with optimal photochemical efficiencies for growth at low versus high light intensities.

  10. Natural variation in germination responses of Arabidopsis to seasonal cues and their associated physiological mechanisms

    Science.gov (United States)

    Barua, Deepak; Butler, Colleen; Tisdale, Tracy E.; Donohue, Kathleen

    2012-01-01

    Background and Aims Despite the intense interest in phenological adaptation to environmental change, the fundamental character of natural variation in germination is almost entirely unknown. Specifically, it is not known whether different genotypes within a species are germination specialists to particular conditions, nor is it known what physiological mechanisms of germination regulation vary in natural populations and how they are associated with responses to particular environmental factors. Methods We used a set of recombinant inbred genotypes of Arabidopsis thaliana, in which linkage disequilibrium has been disrupted over seven generations, to test for genetic variation and covariation in germination responses to distinct environmental factors. We then examined physiological mechanisms associated with those responses, including seed-coat permeability and sensitivity to the phytohormones gibberellic acid (GA) and abscisic acid (ABA). Key Results Genetic variation for germination was environment-dependent, but no evidence for specialization of germination to different conditions was found. Hormonal sensitivities also exhibited significant genetic variation, but seed-coat properties did not. GA sensitivity was associated with germination responses to multiple environmental factors, but seed-coat permeability and ABA sensitivity were associated with specific germination responses, suggesting that an evolutionary change in GA sensitivity could affect germination in multiple environments, but that of ABA sensitivity may affect germination under more restricted conditions. Conclusions The physiological mechanisms of germination responses to specific environmental factors therefore can influence the ability to adapt to diverse seasonal environments encountered during colonization of new habitats or with future predicted climate change. PMID:22012958

  11. Role of seed germination in adaptation and reproductive isolation in Arabidopsis lyrata.

    Science.gov (United States)

    Hämälä, Tuomas; Mattila, Tiina M; Leinonen, Päivi H; Kuittinen, Helmi; Savolainen, Outi

    2017-07-01

    Seed germination is an important developmental and life history stage. Yet, the evolutionary impact of germination has mainly been studied in the context of dormancy, or for its role in reproductive isolation between species. Here, we aim to examine multiple consequences of genetic divergence on germination traits between two Arabidopsis lyrata subspecies: ssp. petraea (Eurasia) and ssp. lyrata (North America). Postdormancy germination time, a potentially adaptive trait, showed differentiation between the populations, and quantitative trait loci (QTL) mapping revealed that the trait variation is mainly controlled by two antagonistic loci. These QTL areas contain several candidate genes with known function in postdormancy germination in A. thaliana. The sequence variation of three genes was consistent with differential selection, and they also included fixed nonsynonymous substitutions with potential to account for the phenotypic differentiation. We further show that the divergence between the subspecies has led to a slight but significant reduction in hybrid germination proportions, indicating incipient reproductive isolation. Comparison of reciprocal F 1 and F 2 progenies suggests that Bateson-Dobzhansky-Muller incompatibilities likely act through uniparentally inherited factors. Examination of genomewide transmission ratio distortion further revealed that cytonuclear interactions cause substantial pregermination inviability in the hybrids. These results confirm that seed germination has adaptive potential beyond the dormancy stage and that hybrid seed inviability can be one of the first reproductive barriers to arise during divergence. © 2017 John Wiley & Sons Ltd.

  12. Partial inhibition of in vitro pollen germination by simulated solar ultraviolet-B radiation

    International Nuclear Information System (INIS)

    Flint, S.D.; Caldwell, M.M.

    1984-01-01

    Pollen from four temperate-latitude taxa were treated with UV radiation in a portion of the UV-B (280-320 nm) waveband during in vitro germination. Inhibition of germination was noted in this pollen compared to samples treated identically except for the exclusion of the UV-B portion of the spectrum. Levels similar to maximum solar UV-B found in temperate-latitude areas failed to inhibit pollen germination significantly, while levels similar to maximum solar UV-B found in equatorial alpine locations caused partial inhibition of germination in three of the four taxa examined

  13. Germination phenology of some Great Basin native annual forb species

    Science.gov (United States)

    Tara A. Forbis

    2010-01-01

    Great Basin native plant communities are being replaced by the annual invasive cheatgrass Bromus tectorum. Cheatgrass exhibits a germination syndrome that is characteristic of facultative winter annuals. Although perennials dominate these communities, native annuals are present at many sites. Germination timing is often an important predictor of competitive...

  14. Full Length Research Paper Seed germination and in vitro plant ...

    African Journals Online (AJOL)

    Parkia biglobosa is an important leguminous forest species which is being threatened of going into extinction in Senegal. To preserve this genetic resource of great economic value, studies on germination were carried out and in vitro conservation option through tissue culture technique was adopted. 100% of germination ...

  15. Effect of pre-sowing treatments on seed germination and seedling ...

    African Journals Online (AJOL)

    Pre-sowing treatments were evaluated for Tetracarpidium conophorum. Mechanically scarified T. conophorum seeds soaked in indole acetic acid for 24 h yielded 90% seed germination. Smoked- and sun-dried seeds for 14 days yielded 73 and 33.3% seed germination, respectively. Poorest values were obtained from acid ...

  16. Effects of animal's rumen juice on seed germination of Vicia ...

    African Journals Online (AJOL)

    To help understand the effects of grazing on seed germination characteristics of Vicia angustifolia L., we conducted a laboratory germination experiment of V. angustifolia L., which is a main companion species of Leguminosae family in alpine grassland of the Qinghai-Tibetan Plateau, using Yak and Tibetan sheep rumen ...

  17. Effects of hydropriming on seed germination and seedling growth in ...

    African Journals Online (AJOL)

    The germination of Salvia officinalis L. (sage) seeds is a problem of great concern that may be overcome by employing seed priming techniques. Seed priming is an efficient technique for improvement of seed vigor, increasing germination and seedling growth. Little information has been reported on seedling development ...

  18. The role of seed priming in improving seed germination and ...

    African Journals Online (AJOL)

    Salinity is considered as a major abiotic stress affecting germination, seedling growth and crop production in arid and semi-arid regions. Many techniques are used to improve tolerance to salinity. Priming is believed to be an effective technique that increases germination, plant growth and improve yield of several ...

  19. Sulfinylated Azadecalins act as functional mimics of a pollen germination stimulant in Arabidopsis pistils

    Science.gov (United States)

    Qin, Yuan; Wysocki, Ronald J; Somogyi, Arpad; Feinstein, Yelena; Franco, Jessica Y; Tsukamoto, Tatsuya; Dunatunga, Damayanthi; Levy, Clara; Smith, Steven; Simpson, Robert; Gang, David; Johnson, Mark A; Palanivelu, Ravishankar

    2011-01-01

    SUMMARY Polarized cell elongation is triggered by small molecule cues during development of diverse organisms. During plant reproduction, pollen interactions with the stigma result in the polar outgrowth of a pollen tube, which delivers sperm cells to the female gametophyte to effect double fertilization. In many plants, pistils stimulate pollen germination. However, in Arabidopsis, the effect of pistils on pollen germination and the pistil factors that stimulate pollen germination remain poorly characterized. Here, we demonstrate that stigma, style, and ovules in Arabidopsis pistils stimulate pollen germination. We isolated an Arabidopsis pistil extract fraction that stimulates Arabidopsis pollen germination, and employed ultrahigh resolution ESI FT-ICR and MS/MS techniques to accurately determine the mass (202.126 daltons) of a compound that is specifically present in this pistil extract fraction. Using the molecular formula (C10H19NOS) and tandem mass spectral fragmentation patterns of the m/z (mass to charge ratio) 202.126 ion, we postulated chemical structures, devised protocols, synthesized N-Methanesulfinyl 1- and 2-azadecalins that are close structural mimics of the m/z 202.126 ion, and showed that they are sufficient to stimulate Arabidopsis pollen germination in vitro (30 µM stimulated ~50% germination) and elicit accession-specific response. Although N-Methanesulfinyl 2-azadecalin stimulated pollen germination in three species of Lineage I of Brassicaceae, it did not induce a germination response in Sisymbrium irio (Lineage II of Brassicaceae) and tobacco, indicating that activity of the compound is not random. Our results show that Arabidopsis pistils promote germination by producing azadecalin-like molecules to ensure rapid fertilization by the appropriate pollen. PMID:21801250

  20. Germination and Seedling Development of Seeds from Different Parkia biglobosa (Jacq G. Don Trees

    Directory of Open Access Journals (Sweden)

    Christiana O. ADEYEMI

    2013-02-01

    Full Text Available The effect of daylight, continuous illumination and acid scarification on the seed germination and seedling vegetative growth (epicotyl and hypocotyl lengths, and number of secondary roots of different Parkia biglobosawere investigated in the Plant Physiology Laboratory University of Ilorin, Ilorin Kwara State Nigeria. Seeds from two out of the twenty six Parkia tree samples (trees B and T germinated within 24 hours of planting in the daylight germination study while seeds from another tree (Q did not germinate until the third week after planting (3WAP. Some seeds have higher germination percentage both in the daylight (preliminary germination study and in the continuous light (illuminated study. The treatment with concentrated Sulphric acid (conc. H2SO4was effective in breaking the seed dormancy as seeds from eight (8 trees produced one hundred percent (100% germination. At p= 0.05 the length of epicotyl and hypocoty1 lengths were significantly different as seedling vegetative growth were long in the seedlings from the daylight experiment than the continuous light experiment. The vegetative growths of the seedlings from the scarified seed were longer at 15min of scarification in all except in trees F and Z. It was observed that the time of scarification affect the both seed germination and seedling development.

  1. Enhanced tocopherol levels during early germination events in Chamaerops humilis var. humilis seeds.

    Science.gov (United States)

    Siles, Laura; Alegre, Leonor; Tijero, Verónica; Munné-Bosch, Sergi

    2015-10-01

    Most angiosperms accumulate vitamin E in the form of tocopherols in seeds, exerting a protective antioxidant role. However, several palm trees principally accumulate tocotrienols, rather than tocopherols, in seeds, as it occurs in other monocots. To unravel the protective role of either tocopherols or tocotrienols against lipid peroxidation during seed germination in Chamaerops humilis var. humilis; seed viability, natural and induced germination capacity, seed water content, malondialdehyde levels (as an indicator of the extent of lipid peroxidation) and vitamin E levels (including both tocopherols and tocotrienols) were examined at various germination phases in a simulated, natural seed bank. At the very early stages of germination (operculum removal), malondialdehyde levels increased 2.8-fold, to decrease later up to 74%, thus indicating a transient lipid peroxidation at early stages of germination. Tocopherol levels were absent in quiescent seeds and did not increase during operculum removal, but increased later presumably dampening malondialdehyde accumulation. Thereafter, tocopherols continued increasing, while lipid peroxidation levels decreased. By contrast, tocotrienols levels remained constant or even decreased as germination progressed, showing no correlation with lipid peroxidation levels. We hypothesize that despite their high tocotrienol content, seeds synthesize tocopherols during germination to protect lipids from peroxidation events. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Ameliorating influence of sulfur on germination attributes of canola (brassica napus l.) under chromium stress

    International Nuclear Information System (INIS)

    Jahan, S.; Iqbal, S.; Jabeen, K.; Sadaf, S.

    2015-01-01

    An experiment was performed to evaluate the role of sulfur to induce tolerance in Brassica napus L. against chromium stress by estimating the changes in germination parameters. Petriplates were assembled in Randomized Complete Block Design. A total 9 sets of treatments viz., control, chromium treated (40 and 160ppm), sulfur treated (50 and 150ppm) and sulfur (50 and 150ppm) combined with chromium (40 and 160ppm) with three replicates was used. Chromium under both concentrations was responsible for significant decline in germination parameters i.e. germination percentage, germination rate, seedling vigor index, shoot and root length, fresh weight and dry weight of seedlings. Sulfur application under chromium stress resulted in improvement of germination parameters such as germination percentage, germination rate, seedling vigor index, shoot and root length, fresh weight and dry weight of seedlings in contrast to chromium treatment. So, it can be concluded that sulfur in appropriate dose can be used to ameliorate the negative effects of chromium by increasing the germination potential of canola. (author)

  3. Precocious germination and its regulation in embryos of triticale caryopses

    Directory of Open Access Journals (Sweden)

    Stanisław Weidner

    2014-01-01

    Full Text Available Triticale var. Lasko embryos, isolated from grain gathered at milk ripeness, the beginning of wax ripeness and at full ripeness, were allowed to germinate for 48 h on agar with glucose. The highest incorporation of tritiated adenosine into polyribosomal RNA during germination was found in the ribosome fractions from embryos of grain gathered at full ripeness, lower incorporation was in preparations from embryos of milk ripe grain and the lowest in preparations from embryos of wax ripe grain. Different tendencies were observed in respect to the synthesis of ribosomal proteins. The highest incorporation of 14C-amino acids into ribosomal proteins was found in preparations of ribosome fractions from embryos of milk ripe grain, lower in preparations of embryos from fully ripe grain, the lowest in preparations of embryos from wax ripe grain. ABA (10-4 M completely inhibited the external symptoms of germination of immature embryos, while its inhibition of the synthesis of polyribosomal RNA and ribosomal proteins was greater the more mature the embryos that were germinated. The greatest stimulation of precocious germination by exogenous BA and GA3 was demonstrated in the least mature embryos isolated from milk ripe grain. Under the influence of both stimulators, an increase of the proportion of polyribosomes in the total ribosome fraction occurred in this sample, as did a rise in the intensity of ribosomal protein synthesis. The incorporation of 3H-adenosine into polyribosomal RNA, however, was lower than in the control sample. The results obtained suggest that the regulation of precocious germination of triticale embryos by phyto-hormones is not directly related to transcription.

  4. Report compiled by Research Center for Carbonaceous Resources, Institute for Chemical Reaction Science, Tohoku University; Tohoku Daigaku Hanno Kagaku Kenkyusho tanso shigen hanno kenkyu center hokokusho

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1994-04-01

    The Research Center for Carbonaceous Resources was established in April 1991 for the purpose of developing a comprehensive process for converting carbonaceous resources into clean fuels or into materials equipped with advanced functions. In this report, the track records etc. of the center are introduced. Under study in the conversion process research department is the organization of a comprehensive coal conversion process which will be a combination of solvent extraction, catalytic decomposition, and catalytic gasification, whose goal is to convert coal in a clean way at high efficiency. Under study in the conversion catalyst research department are the development of a coal denitrogenation method, development of a low-temperature gasification method by use of inexpensive catalysts, synthesis of C{sub 2} hydrocarbons in a methane/carbon dioxide reaction, etc. Other endeavors under way involve the designing and development of new organic materials such as new carbon materials and a study of the foundation on which such efforts stand, that is, the study of the control of reactions between solids. Furthermore, in the study of interfacial reaction control, the contact gasification of coal, brown coal ion exchange capacity and surface conditions, carbonization of cation exchanged brown coal, etc., are being developed. (NEDO)

  5. Sugar apple (Annona squamosa L., Annonaceae seed germination: morphological and anatomical changes

    Directory of Open Access Journals (Sweden)

    Fabio Ernesto Martínez-Maldonado

    2013-08-01

    Full Text Available The anon or sugar apple is a species of the Annona genus, widely distributed in the world and in Colombia and a fruit with great potential in domestic and international markets. However, the technical information related to the aspects of propagation and production is limited. In the present study, the morphological and anatomical changes during seed germination of the sugar apple were determined using histological techniques and photographic records. The results show that seed germination is a process that takes place in two stages: testa rupture and endosperm rupture-radicle protrusion. In the post-germination stages, the induction and formation of lateral roots that were endogenously produced from the primary root from the pericycle were seen. The endosperm underwent morphological changes that increased its volume during imbibition and degraded in the final stages of germination, which could be indicative of endosperm weakening and reduction of mechanical strength imposed by embryo growth, which was required to complete germination in A. squamosa

  6. Winery wastewater inhibits seed germination and vegetative growth of common crop species.

    Science.gov (United States)

    Mosse, Kim P M; Patti, Antonio F; Christen, Evan W; Cavagnaro, Timothy R

    2010-08-15

    The ability to reuse winery wastewater would be of significant benefit to the wine industry, as it could potentially be a cost-effective method of wastewater management, whilst at the same time providing a valuable water resource. This study investigated the effects of different dilutions of a semi-synthetic winery wastewater on the growth and germination of four common crop species in a glasshouse study; barley (Hordeum vulgare), millet (Pennisetum glaucum), lucerne (Medicago sativa) and phalaris (Phalaris aquatica). The wastewater caused a significant delay in the germination of lucerne, millet and phalaris, although overall germination percentage of all species was not affected. Vegetative growth was significantly reduced in all species, with millet being the most severely affected. The germination index of barley correlated very highly (r(2)=0.99) with barley biomass, indicating that barley seed germination bioassays are highly relevant to plant growth, and therefore may be of use as a bioassay for winery wastewater toxicity. Copyright 2010 Elsevier B.V. All rights reserved.

  7. Germination of red alder (Alnus rubra) seed from several locations in its natural range

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, D.M.; Taylor, I.E.P.

    1981-01-01

    Tests were carried out on stratified, pre-soaked or untreated seeds. Germination of all provenances and treatments was more than 90%, except for one provenance showing physiological dormancy in which germination was low, but increased significantly with stratification and presoaking; dormancy could be broken completely by chilling at 0 degrees C for 5 days. Significant interactions were found between provenances and treatments for both germination % and seed vigour (as measured by germination value).

  8. Effect of priming with potassium nitrate and dehusking on seed germination of gladiolus (gladiolus alatus)

    International Nuclear Information System (INIS)

    Ramzan, A.; Hafiz, I.A.; Ahmad, T.; Abbasi, N.A.

    2010-01-01

    Gladiolus (Gladiolus alatus), belonging to the family Iridaceae is rated as the most popular flower in the world at commercial scale. The effect of different concentrations of KNO/sub 3/ (1, 2, 3, 4, 5 and 0 %) on seed germination percentage, time required for 50% germination and on mean germination time (MGT) was studied under controlled conditions. Best germination rate of 92% was achieved in T6 (distilled water) followed by 80% in T1 (1% KNO/sub 3/) and 70% in T2 (2% KNO/sub 3/). Minimum time required for 50% germination i.e., 8 days was obtained with T6 (distilled water) and in the same way shortest mean germination time required by seeds was 15 days in T6. Bulb gained maximum weight (0.6467 g) and diameter (9.49 mm) in T3 (3% KNO/sub 3)/. Likewise, this treatment also resulted in an acquisition of 14 cm seedling length and a positive correlation was found between seedling length and growth parameters of bulb i.e., weight and diameter. In another experiment, effect of de husking on seed germination was tested. Seed without husk gave the promising outcome of 74% germination while seeds with husk merely acquired 63% germination after 30 days. (author)

  9. Generalist dispersers promote germination of an alien fleshy-fruited tree invading natural grasslands.

    Directory of Open Access Journals (Sweden)

    Martín Raúl Amodeo

    Full Text Available Plants with animal-dispersed fruits seem to overcome the barriers that limit their spread into new habitats more easily than other invasive plants and, at the same time, they pose special difficulties for containment, control or eradication. The effects of animals on plant propagules can be very diverse, with positive, neutral or negative consequences for germination and recruitment. Moreover, the environmental conditions where the seeds are deposited and where the post-dispersal processes take place can be crucial for their fate. Prunus mahaleb is a fleshy-fruited tree invading natural grasslands in the Argentine Pampas. In this study, we analyzed the importance of pulp removal, endocarp scarification and the effects of vectors on its germination response, by means of germination experiments both in the laboratory and under semi-natural conditions. Our laboratory results demonstrated that endocarp scarification enhances germination and suggests that vestiges of pulp on the stones have inhibitory effects. Frugivores exert a variety of effects on germination responses and this variation can be explained by their differing influence on pulp removal and endocarp scarification. Most frugivores produced a positive effect on germination under laboratory conditions, in comparison to intact fruits and hand-peeled stones. We observed different degrees of pulp removal from the surface of the stones by the dispersers which was directly correlated to the germination response. On the other hand, all the treatments showed high germination responses under semi-natural conditions suggesting that post-dispersal processes, like seed burial, and the exposure to natural conditions might exert a positive effect on germination response, attenuating the plant's dependence on the dispersers' gut treatment. Our results highlight the need to consider the whole seed dispersal process and the value of combining laboratory and field tests.

  10. Effects of seed fermentation method on seed germination and vigor ...

    African Journals Online (AJOL)

    The present study was conducted to examine the influence of Lagenaria siceraria seed fermentation method on seed germination and vigor. Three seed fermentation methods (fermented in ambient air, plastic bag stored in ambient or in plastic bag buried) were tested on two cultivars during two years. Seed germination and ...

  11. Soybean mother plant exposure to temperature stress and its effect on germination under osmotic stress

    International Nuclear Information System (INIS)

    Khalil, S.K.; Rehman, A.; Khan, A.Z.; Mexal, J.G.; Zubair, M.; Wahab, S.; Khalil, I.H.; Mohammad, F.

    2010-01-01

    High temperature reduces quality of soybean seed developed at different positions on the plant. The objective of this research was to study the quality of seed produced under different temperature regimes located at different position in the canopy. Soybean plants grown in pots were transferred at first pod stage to three growth chambers fixed at 18/10, 25/15 and 32/20 deg. C day/night temperature having 13/11 hrs day/night length. The plants remained in growth chambers until physiological maturity. Seeds harvested from each growth chamber were exposed to osmotic stress having osmotic potential of -0.5 MPa and unstressed control. Both stressed and control treatments were germinated in three growth chambers fixed at 18, 25 and 35 deg. C. Seed developed at lowest temperature (18/10 deg. C day/night) had maximum germination. Germination decreased linearly with increased day/night temperature and lowest germination was recorded at highest temperature of 32/20 deg. C (day/night). Seed developed at bottom position was heaviest and had better germination compared with seed developed at middle and top position. Seed germination was highest at 25 deg. C and took fewer days to 50% germination than 18 and 25 deg. C. Osmotic stress decreased germination and delayed days to 50% germination than control. It can be concluded that optimum temperature for seed development was 18/10 deg. C (day/night) whereas best germination temperature was 25 deg. C. (author)

  12. Effect of different doses of gamma rays on seed germination of Carthamus L

    International Nuclear Information System (INIS)

    Malik, Anjali; Srivastava, A.K.

    2010-01-01

    Genetic variability is essential for any crop improvement programme. Experimentally induced mutation provides an important source of variability. The ionizing radiation treatment would be useful on account of the total randomness of action of radiation on genetic material as also the fact that an optimal dose radiation produces effect both through gene mutation and chromosomal mutations. The most commonly used ionizing radiation in plant improvement program are γ-rays. The control sets of different accessions/species showed significant variability in the germination pattern. γ-ray alteration in the mean total seed germination frequency of Carthamus accessions/species presently explored, was genotype dependent. However, these could also modify substantially the temporal patterns of the germination as compared to corresponding control sets. The seed lots of different accessions could be supposed to be a mixture of seeds showing differences in the time of induction of germination. That is, seed lots differed in their temporal seed germination pattern. On the basis of the present study it can be inferred that the temporal seed germination could be decided at genotypic and/or biochemical levels. (author)

  13. NITRIC OXIDE IMPLICATION IN THE CONTROL OF SEED DORMANCY AND GERMINATION

    Directory of Open Access Journals (Sweden)

    Erwann eArc

    2013-09-01

    Full Text Available Germination ability is regulated by a combination of environmental and endogenous signals with both synergistic and antagonistic effects. Nitric oxide (NO is a potent dormancy-releasing agent in many species, including Arabidopsis, and has been suggested to behave as an endogenous regulator of this physiological blockage. Distinct reports have also highlighted a positive impact of NO on seed germination under sub-optimal conditions. However, its molecular mode of action in the context of seed biology remains poorly documented. This review aims to focus on the implications of this radical in the control of seed dormancy and germination. The consequences of NO chemistry on the investigations on both its signaling and its targets in seeds are discussed. NO-dependant protein post-translational modifications are proposed as a key mechanism underlying NO signalling during early seed germination.

  14. Enzyme activity and reserve mobilization during Macaw palm ( Acrocomia aculeata seed germination

    Directory of Open Access Journals (Sweden)

    Elisa Monteze Bicalho

    2016-01-01

    Full Text Available ABSTRACT Reserve mobilization in seeds occurs after visible germination, which is marked by the protrusion of the radicle or cotyledonary petiole, as in species of Arecaceae. Acrocomia aculeata (macaw palm, usually produces hard seeds whose endosperm has mannan-rich cell walls. We investigated the composition of storage compounds in macaw palm seed and the roles of two enzymes (endo-β-mannanase, α-galactosidase during and after germination. The seeds were firstly submitted to pre-established protocol to overcome dormancy and promote germination. Enzyme activity in both embryo and endosperm were assayed from the initiation of germinative activities until leaf sheath appearance, and the status of seed structures and reserve compounds were evaluated. Protein content of the embryo decreased with the initiation of imbibition while the lipid content began decreasing six days after removal of the operculum. Increases in enzyme activity and starch content were both observed after visible germination. We suggest that endo-β-mannanase and α-galactosidase become active immediately at germination, facilitating haustorium expansion and providing carbohydrates for initial seedling development. Protein is the first storage compound mobilized during early imbibition, and the observed increase in the starch content of the haustorium was related to lipid degradation in that organ and mannan degradation in the adjacent endosperm.

  15. Re-induction of desiccation tolerance after germination of Cedrela fissilis Vell. seeds.

    Science.gov (United States)

    Masetto, Tathiana E; Faria, Jose M; Fraiz, Ana C R

    2014-09-01

    This work aimed to characterize the re-induction of desiccation tolerance (DT) in germinated seeds, using polyethylene glycol (PEG 8000). Cell changes were investigated through cytological assays (cell viability and transmission electronic microscopy) as well as DNA integrity during loss and re-establishment of DT. The loss of DT was characterized by drying germinated seeds with different radicle lengths (1, 2, 3, 4 and 5 mm) in silica gel, decreasing the moisture content to ten percentage points intervals, followed by pre-humidification (100% RH / 24 h) and rehydration. To re-induce DT, germinated seeds were treated for 72 h with PEG (-2.04 MPa) and PEG (-2.04 MPa) + ABA (100 µM) before dehydration. Germinated seeds did not tolerate desiccation to 10% moisture content, irrespectively of the radicle length. However, when incubated in PEG, those with 1 and 2 mm long radicle attained 71% and 29% survival, respectively. The PEG+ABA treatment was efficient to re-establish DT in seeds with 1 mm long radicles (100% survival). The ultrastructural assays of the cells of germinated seeds with 2 and 5 mm length confirmed the obtained physiological results. Germinated seeds of C. fissilis constitute a useful tool for desiccation tolerance investigations.

  16. Re-induction of desiccation tolerance after germination of Cedrela fissilis Vell. seeds

    Directory of Open Access Journals (Sweden)

    TATHIANA E. MASETTO

    2014-09-01

    Full Text Available This work aimed to characterize the re-induction of desiccation tolerance (DT in germinated seeds, using polyethylene glycol (PEG 8000. Cell changes were investigated through cytological assays (cell viability and transmission electronic microscopy as well as DNA integrity during loss and re-establishment of DT. The loss of DT was characterized by drying germinated seeds with different radicle lengths (1, 2, 3, 4 and 5 mm in silica gel, decreasing the moisture content to ten percentage points intervals, followed by pre-humidification (100% RH / 24 h and rehydration. To re-induce DT, germinated seeds were treated for 72 h with PEG (-2.04 MPa and PEG (-2.04 MPa + ABA (100 µM before dehydration. Germinated seeds did not tolerate desiccation to 10% moisture content, irrespectively of the radicle length. However, when incubated in PEG, those with 1 and 2 mm long radicle attained 71% and 29% survival, respectively. The PEG+ABA treatment was efficient to re-establish DT in seeds with 1 mm long radicles (100% survival. The ultrastructural assays of the cells of germinated seeds with 2 and 5 mm length confirmed the obtained physiological results. Germinated seeds of C. fissilis constitute a useful tool for desiccation tolerance investigations.

  17. Germination of some important weeds influenced by red light and nitrogenous compounds

    International Nuclear Information System (INIS)

    Tanfg, Dong-Seng; Hamayun, M.; Khan, A.L.; Shinwari, Z.K.; Kim, H.A.; Yoon-Ha; Kang, Sang-Mo; Lee, Joon-Hee; Chae-In; Nawaz, Y.; Kang, Kee-Kyung; Lee, In-Jung

    2010-01-01

    Seed dormancy is a major constraint in the eradication of weeds from agriculture fields. Seeds of Amaranthus retroflexus, Echinocloa crus-galli and Digitaria adscendens were collected from cultivated fields, dried and then treated with different nitrogen containing compounds i.e., potassium nitrate, ammonium chloride, ammonium nitrate and sodium nitrite. Some seeds were kept under dark while others were irradiated with red light for 10 min., after 12 hr of inhibition. The N-compounds were applied at the rate of 1, 5, 10, 25 and 50 mM, while the strength of red light pulse was maintained at 80 mu mols/sup -2/m/sup -1/. It was observed that red light significantly improved germination rates of A. retroflexus, E. crus-galli and D. adscendens. Nitrogenous compounds significantly improved germination of weeds and maximum germination was induced by ammonium nitrate. However, exposure of seeds to both red light and N-compounds provided significantly higher germination as compared to singular application of either of them. E. crusgalli recorded highest germination rates in response to red light and N-compounds, while D. adscendens provided least values for the same treatments. Application of N-compounds in conjunction with red light significantly improves germination rates of selected weed species by breaking their dormancy. (author)

  18. Effect of osmotic stress and post-stress recovery on the content of phenolics and properties of antioxidants in germinating seeds of grapevine Vitis californica

    Directory of Open Access Journals (Sweden)

    Stanisław Weidner

    2011-05-01

    antioxidizing enzymes in germinating grapevine seeds. Thus, the antioxidative defence system is largely blocked under osmotic stress. It seems that a very high oxidoreductive potential in grapevine tissues prior to occurrence of osmotic stress is essential for maintaining proper homeostasis of oxidation and reduction reactions.

  19. Effects of seed priming and water potential on seed germination and ...

    African Journals Online (AJOL)

    Administrator

    2011-05-23

    May 23, 2011 ... (without seed drying), primed and 12 h drying on seed germination of wheat .... completely with the lower half and the paper were rolled and placed ..... water stress and control of germination: a review. Plant Cell Environ.

  20. Incidence of transfusion reactions: a multi-center study utilizing systematic active surveillance and expert adjudication

    Science.gov (United States)

    Hendrickson, Jeanne E.; Roubinian, Nareg H.; Chowdhury, Dhuly; Brambilla, Don; Murphy, Edward L.; Wu, Yanyun; Ness, Paul M.; Gehrie, Eric A.; Snyder, Edward L.; Hauser, R. George; Gottschall, Jerome L.; Kleinman, Steve; Kakaiya, Ram; Strauss, Ronald G.

    2017-01-01

    Background Prevalence estimates of serious hazards of transfusion vary widely. We hypothesized that the current reporting infrastructure in the United States fails to capture many transfusion reactions, and undertook a multi-center study utilizing active surveillance, data review, and adjudication to test this hypothesis. Study Design and Methods A retrospective record review was completed for a random sample of 17% of all inpatient transfusion episodes over 6 months at 4 academic tertiary care hospitals, with an episode defined as all blood products released to a patient in 6 hours. Data were recorded by trained clinical research nurses, and serious reactions were adjudicated by a panel of transfusion medicine experts. Results Of 4857 transfusion episodes investigated, 1.1% were associated with a serious reaction. Transfusion associated circulatory overload (TACO) was the most frequent serious reaction noted, being identified in 1% of transfusion episodes. Despite clinical notes describing a potential transfusion association in 59% of these cases, only 5.1% were reported to the transfusion service. Suspected transfusion related acute lung injury (TRALI/possible TRALI), anaphylactic, and hypotensive reactions were noted in 0.08%, 0.02%, and 0.02% of transfusion episodes. Minor reactions, including febrile non-hemolytic and allergic, were noted in 0.62% and 0.29% of transfusion episodes, with 30–50% reported to the transfusion service. Conclusion Underreporting of cardiopulmonary transfusion reactions is striking among academic, tertiary care hospitals. Complete and accurate reporting is essential to identify, define, establish pathogenesis, and mitigate/treat transfusion reactions. A better understanding of the failure to report may improve the accuracy of passive reporting systems. PMID:27460200

  1. Application of germination inhibitors in organic solvents to conifer seeds. Information report No. 0-X-371

    Energy Technology Data Exchange (ETDEWEB)

    Groot, A.

    1985-12-31

    Study to determine whether the germination inhibitors abscisic acid and coumarin could be applied to black spruce and jack pine seed with organic solvents to delay germination. If successful, the treatment would delay field germination of seeds sown in mid to late summer until the following spring, thus reducing the risk of immature plants being affected by late fall frosts. Results were expressed in germination value, peak day, and germination capacity on the basis of a 28-day germination period. Effects of treatment on the variables were examined by means of one-way or two-way analysis of variance with completely randomized designs.

  2. Thermal buffering capacity of the germination phenotype across the environmental envelope of the Cactaceae.

    Science.gov (United States)

    Seal, Charlotte E; Daws, Matthew I; Flores, Joel; Ortega-Baes, Pablo; Galíndez, Guadalupe; León-Lobos, Pedro; Sandoval, Ana; Ceroni Stuva, Aldo; Ramírez Bullón, Natali; Dávila-Aranda, Patricia; Ordoñez-Salanueva, Cesar A; Yáñez-Espinosa, Laura; Ulian, Tiziana; Amosso, Cecilia; Zubani, Lino; Torres Bilbao, Alberto; Pritchard, Hugh W

    2017-12-01

    Recruitment from seeds is among the most vulnerable stage for plants as global temperatures change. While germination is the means by which the vast majority of the world's flora regenerate naturally, a framework for accurately predicting which species are at greatest risk of germination failure during environmental perturbation is lacking. Taking a physiological approach, we assess how one family, the Cactaceae, may respond to global temperature change based on the thermal buffering capacity of the germination phenotype. We selected 55 cactus species from the Americas, all geo-referenced seed collections, reflecting the broad environmental envelope of the family across 70° of latitude and 3700 m of altitude. We then generated empirical data of the thermal germination response from which we estimated the minimum (T b ), optimum (T o ) and ceiling (T c ) temperature for germination and the thermal time (θ 50 ) for each species based on the linearity of germination rate with temperature. Species with the highest T b and lowest T c germinated fastest, and the interspecific sensitivity of the germination rate to temperature, as assessed through θ 50 , varied tenfold. A left-skewed asymmetry in the germination rate with temperature was relatively common but the unimodal pattern typical of crop species failed for nearly half of the species due to insensitivity to temperature change at T o . For 32 fully characterized species, seed thermal parameters correlated strongly with the mean temperature of the wettest quarter of the seed collection sites. By projecting the mean temperature of the wettest quarter under two climate change scenarios, we predict under the least conservative scenario (+3.7°C) that 25% of cactus species will have reduced germination performance, whilst the remainder will have an efficiency gain, by the end of the 21st century. © 2017 John Wiley & Sons Ltd.

  3. Modelling the effect of temperature on seed germination in some ...

    African Journals Online (AJOL)

    The prediction of germination percentage (GP) and germination speed (GS) of the seeds for some cucurbits (watermelon, melon, cucumber, summer squash, pumpkin and winter squash) was investigated by mathematical model based on temperature. The model, D = [a - (b x T) + (c x T2)] of Uzun et al. (2001), was adapted ...

  4. Effects of Sowing Media and Sowing Depth on Germination and ...

    African Journals Online (AJOL)

    This study examines the effect of sowing media and sowing depth on the germination and growth of Lecanodiscus cupanoides (Planch.Ex Benth). The germination of L. cupanoides seed was significantly affected by sowing depth and sowing medium at p=0.05. The result of various sowing media and sowing depth showed ...

  5. Habitat specialization through germination cueing

    DEFF Research Database (Denmark)

    Ten Brink, Dirk-Jan; Hendriksma, Harmen; Bruun, Hans Henrik

    2013-01-01

    This study examined the adaptive association between seed germination ecology and specialization to either forest or open habitats across a range of evolutionary lineages of seed plants, in order to test the hypotheses that (1) species' specialization to open vs. shaded habitats is consistently...

  6. Purification and spectroscopic characterization of photosystem II reaction center complexes isolated with or without Triton X-100.

    NARCIS (Netherlands)

    Eijckelhoff, C.; van Roon, H.; Groot, M.L.; van Grondelle, R.; Dekker, J.P.

    1996-01-01

    The pigment composition of the isolated photosystem II reaction center complex in its most stable and pure form currently is a matter of considerable debate. In this contribution, we present a new method based on a combination of gel filtration chromatography and diode array detection to analyze the

  7. Comparative study of the germination of Ulva prolifera gametes on various substrates

    Science.gov (United States)

    Geng, Huixia; Yan, Tian; Zhou, Mingjiang; Liu, Qing

    2015-09-01

    Since 2007, massive green tides have occurred every summer in the southern Yellow Sea (YS), China. They have caused severe ecological consequences and huge economic losses. Ulva prolifera originated from Subei Shoal of the YS was confirmed as causative species of the green tides. The Porphyra yezoensis aquaculture rafts in the Subei Shoal have been highly suspected to be the "seed bed" of the green tides, because U. prolifera abundantly fouled the Porphyra yezoensis aquaculture facilities. Besides, various habitats of aquaculture ponds along the Jiangsu coastline and mudflat in the Subei Shoal were proposed to be possible sources of green tides. To understand the "seed" of the green tides in the southern YS and mitigate the original biomass of the green tide, various materials used as substrates for the germination of U. prolifera gametes were tested in this study. Culture experiments showed the following: 1) materials used in the P. yezoensis rafts (plastic, bamboo, jute rope, plastic rope, nylon netting, and plastic netting) displayed a significantly higher germination rate than those associated with mudflats and aquaculture ponds (mud, sand and rock); 2) plastics were the best substrates for the germination of U. prolifera gametes; 3) poor germination was found on old fronds of U. prolifera,, and rubber showed inhibitory effect on germination. The success in germination on P. yezoensis rafts related materials supports the notion that these mariculture structures may be involved in acting as a seed bed for green tide macroalgae. The lack of germination on rubber surfaces may suggest one way to limit the proliferation of early stages of U. prolifera.

  8. Stereoselective synthesis of organosulfur compounds incorporating N-aromatic heterocyclic motifs and quaternary carbon centers via a sulfa-Michael triggered tandem reaction.

    Science.gov (United States)

    Qin, Tianyou; Cheng, Lu; Zhang, Sean Xiao-An; Liao, Weiwei

    2015-06-14

    A novel sulfa-Michael addition (SMA)-triggered tandem reaction was developed by combining a SMA reaction with a simultaneous rearomatization process utilizing a less reactive carbonyl group as an intramolecular electrophile partner, which provided a unique synthetic route to access various organosulfur compounds incorporating an N-aromatic heterocyclic motif and quaternary carbon centers.

  9. Menaquinone-7 in the reaction center complex of the green sulfur bacterium Chlorobium vibrioforme functions as the electron acceptor A1

    DEFF Research Database (Denmark)

    Kjaer, B; Frigaard, N-U; Yang, F

    1998-01-01

    Photosynthetically active reaction center complexes were prepared from the green sulfur bacterium Chlorobium vibrioforme NCIMB 8327, and the content of quinones was determined by extraction and high-performance liquid chromatography. The analysis showed a stoichiometry of 1.7 molecules of menaqui......Photosynthetically active reaction center complexes were prepared from the green sulfur bacterium Chlorobium vibrioforme NCIMB 8327, and the content of quinones was determined by extraction and high-performance liquid chromatography. The analysis showed a stoichiometry of 1.7 molecules...

  10. Induction of seed germination in Orobanche spp. by extracts of traditional Chinese medicinal herbs.

    Science.gov (United States)

    Ma, YongQing; Zhang, Wei; Dong, ShuQi; Ren, XiangXiang; An, Yu; Lang, Ming

    2012-03-01

    The co-evolution of Orobanche spp. and their hosts within the same environment has resulted in a high degree of adaptation and effective parasitism whereby the host releases parasite germination stimulants, which are likely to be unstable in the soil. Our objective was to investigate whether extracts from non-host plants, specifically, Chinese medicinal plants, could stimulate germination of Orobanche spp. Samples of 606 Chinese medicinal herb species were extracted with deionized water and methanol. The extracts were used to induce germination of three Orobanche species; Orobanche minor, Orobanche cumana, and Orobanche aegyptiaca. O. minor exhibited a wide range of germination responses to the various herbal extracts. O. cumana and O. aegyptiaca exhibited an intermediate germination response to the herbal extracts. O. minor, which has a narrow host spectrum, showed higher germination rates in response to different herbal extracts compared with those of O. cumana and O. aegyptiaca, which have a broader host spectrum. Methanolic extracts of many Chinese herbal species effectively stimulated seed germination among the Orobanche spp., even though they were not the typical hosts. The effective herbs represent interesting examples of potential trap crops. Different countries can also screen extracts from indigenous herbaceous plants for their ability to induce germination of Orobanche spp. seeds. The use of such species as trap plants could diminish the global soil seed bank of Orobanche.

  11. Effect of Aqueous Extracts from Weed Species on Germination and Initial Growth in Raphanus sativus L.

    Directory of Open Access Journals (Sweden)

    Anisoara STRATU

    2015-12-01

    Full Text Available The current paper presents the results of a study on the effects of aqueous extracts from five weed species (Amaranthus retroflexus, Cirsium arvense, Convolvulus arvensis, Echinochloa crus-galii, Setaria verticillata on germination and initial growth in Raphanus sativus L. The following indicators have been analyzed: indices of germination (the germination percentage; the speed of germination; the speed of accumulated germination and the coefficient of germination rate, the length of the root and hypocotyls, the pH of aqueous extracts, the UV-Vis absorption spectra of aqueous extracts. The results of the investigations showed the following aspects: the aqueous extracts reduced the values of calculated germination indices and root growth in the first ontogenetic stages of the test species; the pH of the extracts was slightly acid to neutral. Qualitative spectrophotometric analysis indicated the possible presence of phenolic and organic compounds in the extracts. C. arvense, S. verticillata and E. crus-galii presented the most pronounced effect on germination and growth processes.

  12. Barley Seed Germination/Root Elongation Toxicity Test For Evaluation Of Sludge Pre-Treatment

    DEFF Research Database (Denmark)

    Eriksson, Eva; Kusk, Kresten Ole; Barrett Sørensen, Mie

    Application of sludge from wastewater treatment plants (WWTPs) on agricultural land is an approach for nutrient recycling that rise challenges due to recalcitrant and harmful pollutants. In this study we assessed the feasibility of a seed germination test to evaluate sludge ecotoxicity and compared...... germination responses from two test parameters, root elongation and seed germination (sprouts elongation) of the barley (Hordeum vulgare). 2nd objective was to evaluate sewage sludge pre-treatments at batch-scale of sludge samples from two WWTPs using anaerobic digestion, and thermal and ozonation pre......-treatments. Glyphosate and eco-labelled soil were used as references. Inhibition of germination of seeds exposed to the glyphosate and sludge was registered and thus germination was successfully applied for sludge ecotoxicity assessment, and using the root elongation as the end-point was both faster and more precise...

  13. Inhibitory effect of marine green algal extracts on germination of Lactuca sativa seeds.

    Science.gov (United States)

    Choi, Jae-Suk; Choi, In Soon

    2016-03-01

    The allelopathic potential of nine green seaweed species was examined based on germination and seedling growth of lettuce (Lactuca sativa L.). Out of nine methanol extracts, Capsosiphon fulvescens and Monostroma nitidum extracts completely inhibited germination of L. sativa at 4 mg/filter paper after 24 hr of treatment. Water extracts of these seaweeds generally showed low anti-germination activities than methanol extracts. Of the nine water extracts, Enteromorpha linza extract completely inhibited L. sativa germination at 16 mg/filter paper after 24 hrs. To identify the primary active compounds, C. fulvescens. powder was successively fractionated according to polarity, and the main active agents against L. sativa were determined to be lipids (0.0% germination at 0.5 mg of lipids/paper disc). According to these results, extracts of C. fulvescens can be used to develop natural herbicidal agents and manage terrestrial weeds.

  14. Effects of salinity, temperature, light and dormancy regulating chemicals on seed germination of salsola drummondii ulbr

    International Nuclear Information System (INIS)

    Rasheed, A.; Hameed, A.; Khan, M.A.; Gul, B.

    2015-01-01

    Salsola drummondii Ulbr. is a perennial halophyte found in salt deserts of southern Balochistan, Pakistan. Experiments were conducted to study the effects of salinity (0, 200, 400, 600, 800 and 1000 mM NaCl), thermoperiod (10/20, 15/25, 20/30 and 25/35 degree C), light (12-h photoperiod and dark) and dormancy regulating chemicals (DRCs) on germination, recovery and viability of the seeds of S. drummondii. Seeds of S. drummondii germinated quickly in distilled water at different temperature regimes and increases in salinity decreased seed germination. Interestingly, few seeds could even germinate in 1000 mM NaCl treatment, which is about twice as high as seawater salinity. Seeds were partially photoblastic and showed relatively higher germination under 12-h photoperiod than in dark. Seeds showed poor recovery of germination from salinity and particularly when germinated in dark. Germination inhibition at high salinity (800 mM NaCl) under 12-h photoperiod was partially alleviated by the exogenous application of different DRCs, particularly fusicoccin. Moreover, all the DRCs, except GA4+7, ameliorated germination of salt stressed seeds under complete darkness and GA4 and fusicoccin were most effective. Our study shows that seeds of S. drummondii are highly tolerant to salinity and variation in temperature but partially photoblastic nature indicate that seeds will not germinate if buried under the soil. Seed germination under saline conditions can be improved by the use of DRCs particularly by application of fusicoccin. (author)

  15. Spectroscopic properties of reaction center pigments in photosystem II core complexes: revision of the multimer model.

    Science.gov (United States)

    Raszewski, Grzegorz; Diner, Bruce A; Schlodder, Eberhard; Renger, Thomas

    2008-07-01

    Absorbance difference spectra associated with the light-induced formation of functional states in photosystem II core complexes from Thermosynechococcus elongatus and Synechocystis sp. PCC 6803 (e.g., P(+)Pheo(-),P(+)Q(A)(-),(3)P) are described quantitatively in the framework of exciton theory. In addition, effects are analyzed of site-directed mutations of D1-His(198), the axial ligand of the special-pair chlorophyll P(D1), and D1-Thr(179), an amino-acid residue nearest to the accessory chlorophyll Chl(D1), on the spectral properties of the reaction center pigments. Using pigment transition energies (site energies) determined previously from independent experiments on D1-D2-cytb559 complexes, good agreement between calculated and experimental spectra is obtained. The only difference in site energies of the reaction center pigments in D1-D2-cytb559 and photosystem II core complexes concerns Chl(D1). Compared to isolated reaction centers, the site energy of Chl(D1) is red-shifted by 4 nm and less inhomogeneously distributed in core complexes. The site energies cause primary electron transfer at cryogenic temperatures to be initiated by an excited state that is strongly localized on Chl(D1) rather than from a delocalized state as assumed in the previously described multimer model. This result is consistent with earlier experimental data on special-pair mutants and with our previous calculations on D1-D2-cytb559 complexes. The calculations show that at 5 K the lowest excited state of the reaction center is lower by approximately 10 nm than the low-energy exciton state of the two special-pair chlorophylls P(D1) and P(D2) which form an excitonic dimer. The experimental temperature dependence of the wild-type difference spectra can only be understood in this model if temperature-dependent site energies are assumed for Chl(D1) and P(D1), reducing the above energy gap from 10 to 6 nm upon increasing the temperature from 5 to 300 K. At physiological temperature, there are

  16. Label-free in situ imaging of oil body dynamics and chemistry in germination.

    Science.gov (United States)

    Waschatko, Gustav; Billecke, Nils; Schwendy, Sascha; Jaurich, Henriette; Bonn, Mischa; Vilgis, Thomas A; Parekh, Sapun H

    2016-10-01

    Plant oleosomes are uniquely emulsified lipid reservoirs that serve as the primary energy source during seed germination. These oil bodies undergo significant changes regarding their size, composition and structure during normal seedling development; however, a detailed characterization of these oil body dynamics, which critically affect oil body extractability and nutritional value, has remained challenging because of a limited ability to monitor oil body location and composition during germination in situ Here, we demonstrate via in situ, label-free imaging that oil bodies are highly dynamic intracellular organelles that are morphologically and biochemically remodelled extensively during germination. Label-free, coherent Raman microscopy (CRM) combined with bulk biochemical measurements revealed the temporal and spatial regulation of oil bodies in native soya bean cotyledons during the first eight days of germination. Oil bodies undergo a cycle of growth and shrinkage that is paralleled by lipid and protein compositional changes. Specifically, the total protein concentration associated with oil bodies increases in the first phase of germination and subsequently decreases. Lipids contained within the oil bodies change in saturation and chain length during germination. Our results show that CRM is a well-suited platform to monitor in situ lipid dynamics and local chemistry and that oil bodies are actively remodelled during germination. This underscores the dynamic role of lipid reservoirs in plant development. © 2016 The Authors.

  17. Proanthocyanidins in seed coat tegmen and endospermic cap inhibit seed germination in Sapium sebiferum.

    Science.gov (United States)

    Shah, Faheem Afzal; Ni, Jun; Chen, Jing; Wang, Qiaojian; Liu, Wenbo; Chen, Xue; Tang, Caiguo; Fu, Songling; Wu, Lifang

    2018-01-01

    Sapium sebiferum , an ornamental and bio-energetic plant, is propagated by seed. Its seed coat contains germination inhibitors and takes a long time to stratify for germination. In this study, we discovered that the S. sebiferum seed coat (especially the tegmen) and endospermic cap (ESC) contained high levels of proanthocyanidins (PAs). Seed coat and ESC removal induced seed germination, whereas exogenous application with seed coat extract (SCE) or PAs significantly inhibited this process, suggesting that PAs in the seed coat played a major role in regulating seed germination in S. sebiferum . We further investigated how SCE affected the expression of the seed-germination-related genes. The results showed that treatment with SCE upregulated the transcription level of the dormancy-related gene, gibberellins (GAs) suppressing genes, abscisic acid (ABA) biosynthesis and signalling genes. SCE decreased the transcript levels of ABA catabolic genes, GAs biosynthesis genes, reactive oxygen species genes and nitrates-signalling genes. Exogenous application of nordihydroguaiaretic acid, gibberellic acid, hydrogen peroxide and potassium nitrate recovered seed germination in seed-coat-extract supplemented medium. In this study, we highlighted the role of PAs, and their interactions with the other germination regulators, in the regulation of seed dormancy in S. sebiferum .

  18. Changes of phenolic profiles and antioxidant activity in canaryseed (Phalaris canariensis L.) during germination.

    Science.gov (United States)

    Chen, Zhijie; Yu, Lilei; Wang, Xinkun; Gu, Zhenxin; Beta, Trust

    2016-03-01

    Canaryseed is an important cereal crop in western Canada. The changes of the total phenolic content (TPC), antioxidant activities, phenolic acid profiles (free and bound) of canaryseed during germination were investigated in the present study. The growth properties also were investigated. Fresh weight, shoot length and root length increased, whereas dry mass of canaryseed decreased during germination. A 22.3% loss of dry matter was observed at 120h of germination. The total phenolic content and antioxidant activities of free and bound extracts showed a general trend of germinated seeds>raw seeds>soaked seeds. Free, bound and total phenolic content significantly increased 1042%, 120% and 741% at the end of germination as compared to raw seeds (pphenolic content and antioxidant activities. TPC and ORAC values showed the highest correlation (r=0.9984). Six phenolic acids in free phenolic extracts and seven phenolic acids in bound phenolic extracts were detected, respectively. Bound ferulic acid, the dominant phenolic acid in canaryseed, significantly increased during germination (p<0.05). Study showed that germination provided a new approach to further develop canaryseed as a functional food for human consumption. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Imbibition, germination and lipid mobilization response by sunflower subjected to salt stress

    International Nuclear Information System (INIS)

    Achakzai, A.K.K.

    2014-01-01

    Salinity is one of the most important abiotic stresses in arid and semi-arid regions that substantially reduce the germination, growth and average yield of major crops. The study was mainly aimed to select the most salt tolerant cultivar of sunflower. Therefore, a pot culture experiment was conducted to study the effects of four different salinity levels having electrical conductivity viz., 1.19, 9.54, 16.48 and 22.38 mS/cm on the imbibition (water uptake), germination and lipid mobilization of seedlings of 4 varieties of sunflower (Helianthus annuus L.) i.e., DO-728, DO-730, Hysun-33 and Suncross-843. Salinity levels were prepared by dissolving calculated amount of NaCl, Na/sub 2/SO/sub 4/, CaCl/sub 2/ and MgCl/sub 2/ (4:10:5:1) in half strength Hoagland culture solution. Imbibition was studied using plastic glasses at an interval of 12 and 24 hours. While germination studies were separately carried out in plastic pots and noted after every 12 hours till 20 days. Whereas, lipid contents of the salt stress germinating seeds were determined at three time intervals viz., 48, 96 and 144 hours of germination. Results showed that there was a linear decrease in imbibition, germination and lipid mobilization as the level of salinity progressively intensifies. Maximum significant reduction in imbibition (12.88%), germination (31.03%) and lipid mobilization (38.62%) is recorded in highest dose of applied salts (22.38 mS/cm). Results further exhibited that maximum significant reduction in imbibition (17.95%) and germination (43.05%) is recorded for variety Suncross-843. While minimum for the same attributes is recorded for variety DO-728. Therefore, in term of imbibitions and germination, DO-728 could be ranked as salt tolerant. Similarly maximum reduction (14.85%) in mobilized lipids is noted for DO-728 and minimum (40.89%) for DO-730. Therefore, in term of lipid mobilization, variety DO-730 could be ranked as salt tolerant and DO-728 as salt sensitive. While remaining 2

  20. Effects of seed cryopreservation, stratification and scarification on germination for five rare species of pitcher plants.

    Science.gov (United States)

    Khanna, Sruti; Jenkins, Heather; Bucalo, Kylie; Determann, Ron O; Cruse-Sanders, Jennifer M; Pullman, Gerald S

    2014-01-01

    Habitat loss and over collection have caused North American pitcher plants to become rare, including U.S. federally endangered Sarracenia alabamensis and S. oreophila, and S. leucophylla, S. psittacina and S. purpurea spp. venosa, endangered in several states. To develop reliable seed cryopreservation protocols for endangered Sarracenia species enabling similar germination percentages before and after storage in liquid nitrogen (LN) either in vivo or using in vitro tools. Seed germination pre- and post-cryopreservation were compared following seed drying with germination in soil, aseptic environment with wet filter paper or enriched medium, and using scarification or stratification for dormancy removal. After cryostorage, germination in vitro (1/6- or 1/3-strength MS medium) increased compared to germination on peat moss. Germination pre- and post-cryopreservation was similar for S. alabamensis and S. oreophila when seeds were stratified and grown in vitro. S. leucophylla and S. psittacina also showed high germination after cryopreservation when germinated on medium following stratification. Rapid liquid nitrogen exposure and rewarming induced seed coat cracking that damaged seeds, likely allowing internal damage during acid scarification and microbial entry during germination in non-sterile environments.

  1. Recurrent selection increases the seed germination of little bluestem (Schizachyrium scoparium)

    Science.gov (United States)

    Rainfall is often inadequate for satisfactory seed germination and emergence under field conditions. This research was designed to improve the seed germination of six experimental lines of little bluestem [Schizachyrium scoparium (Michx.) Nash]. Two cycle of recurrent selection were used to develo...

  2. Mechanism of endocarp-imposed constraints of germination of Lannea microcarpa seeds

    NARCIS (Netherlands)

    Neya, O.; Hoekstra, F.A.; Golovina, E.A.

    2008-01-01

    Lannea microcarpa, a multipurpose tree species from the dry African savanna, sheds seeds that often display inhibition of germination. The underlying mechanism was investigated using seeds processed from fully matured fruits collected from natural stands in Burkina Faso. Germination of fresh seeds

  3. Impact of germination on nutritional and physicochemical properties of adlay seed (Coixlachryma-jobi L.).

    Science.gov (United States)

    Xu, Lei; Chen, Long; Ali, Barkat; Yang, Na; Chen, Yisheng; Wu, Fengfeng; Jin, Zhengyu; Xu, Xueming

    2017-08-15

    Adlay has garnered a great deal of research attentions in recent years as a highly nutritious food material and herbal medicine. This study characterized the changes of nutritional and physicochemical properties of adlay seeds during a 60-h germination. The results showed that the 60-h germination brought about a 3.4-fold increase in γ-aminobutyric acid (GABA) and 3.6-fold increase in coixol compared to ungerminated adlay seeds, while the triolein content slightly decreased. Some high molecular proteins were hydrolyzed into smaller proteins, peptides and amino acids after germination. Scanning electron micrographs (SEM) showed that the germination process destroyed the continuous matrix structure of adlay flour and created pits and holes on the surface of some starch granules. Germination resulted to changes in the pasting and gelatinization properties of adlay flour. The results of present study suggest that germination efficiently enhances the nutritional compounds while altering the physicochemical characteristics of adlay seeds. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. L-alanine-induced germination in Bacillus licheniformis -the impact of native gerA sequences.

    Science.gov (United States)

    Madslien, Elisabeth H; Granum, Per Einar; Blatny, Janet M; Lindbäck, Toril

    2014-04-22

    L-alanine, acting through the GerA receptor, was recently found to be an efficient germinant in Bacillus licheniformis ATCC14580/DSM13. In this study, we show that several of 46 examined B. licheniformis strains germinate remarkably slower than the type strain when exposed to L-alanine. These strains are not necessarily closely related, as determined by MLST (multi-locus sequence typing). Three of the slow-germinating strains were further examined in order to see whether nucleotide substitutions in the gerA sequences were responsible for the slow L-alanine germination. This was performed by complementing the transformable type strain derivate MW3ΔgerAA with gerA variants from the three slow-germinating strains; NVH1032, NVH1112 and NVH800. A wide selection of B. licheniformis strains was evaluated for L-alanine-induced germination efficiency. Our results show that gerA substitutions could only partially explain why spores of some B. licheniformis strains responded slower than others in the presence of L-alanine.

  5. Phyotoxicity of diesel soil contamination on the germination of Lactuca sativa and Ipomoea batatas.

    Science.gov (United States)

    Fatokun, Kayode; Lewu, Francis Bayo; Zharare, Godfrey Elijah

    2015-11-01

    Phytotoxic effect of diesel contaminated soil on germination rate of Lactuca sativa and Ipomoea batatas, at two concentrations ranges (0-6ml and 0-30ml), were investigated and compared. Diesel soil contamination was simulated and soil samples were taken from contaminated soil at 1, 5,10, 15, 25, 50, 75 and 100 days should be after planting. The result showed that in both plant species, diesel inhibited germination in a concentration dependent manner, Also, the influence of diesel contamination diminished with increased time duration; suggesting possible reduction in diesel toxicity over time. However, germination of lettuce was significant and negatively correlated (r2 = -0.941) with diesel contamination as compared to sweet potato (r2 = -0.638).Critical concentration of diesel in relation to seed germination of L. sativa was lower than vegetative germination of I. batatas, indicating that germination of I. batatas was less sensitive to diesel contamination as compared to L. sativa.

  6. Report on the consultants` meeting on technical aspects of the co-operation of nuclear reaction data centers

    Energy Technology Data Exchange (ETDEWEB)

    Lemmel, H D; Schwerer, O; Wienke, H [eds.

    1995-10-01

    The IAEA Nuclear Data Section convenes in annual intervals coordination meetings of the Network of the Nuclear Reaction Data Center. The present meeting dealt with technical matters of the nuclear data compilation and exchange by means of the jointly operated computerized systems CINDA, EXFOR, ENDF and others. Refs, figs and tabs.

  7. Report on the consultants' meeting on technical aspects of the co-operation of nuclear reaction data centers

    International Nuclear Information System (INIS)

    Lemmel, H.D.; Schwerer, O.; Wienke, H.

    1995-10-01

    The IAEA Nuclear Data Section convenes in annual intervals coordination meetings of the Network of the Nuclear Reaction Data Center. The present meeting dealt with technical matters of the nuclear data compilation and exchange by means of the jointly operated computerized systems CINDA, EXFOR, ENDF and others. Refs, figs and tabs

  8. Oilfield water treatment by electrocoagulation-reverse osmosis for agricultural use: effects on germination and early growth characteristics of sunflower.

    Science.gov (United States)

    de Souza, Paulo S A; Cerqueira, Alexandre A; Rigo, Michelle M; de Paiva, Julieta L; Couto, Rafael S P; Merçon, Fábio; Perez, Daniel V; Marques, Monica R C

    2017-05-01

    This study aims to evaluate the effects of oilfield water (OW), treated by a hybrid process of electrocoagulation and reverse osmosis (EC-RO), on seed germination and early growth characteristics of sunflower (Heliantus annus L.). In the EC step, tests were conducted with 28.6 A m -2 current density and 4 min. reaction time. In the RO step, the system was operated with 1 L min -1 constant flow and 2 MPa, 2.5 MPa and 3 MPa feed pressures. In all feed pressures, RO polymeric membranes achieved very high removals of chemical oxygen demand (up to 89%) and oils and greases (100%) from EC-treated effluent. In best feed pressure (2.5 MPa), turbidity, total dissolved salts, electrical conductivity, salinity, toxic ions and sodium adsorption ratio values attained internationally recognized standards for irrigation water. Using EC-RO (feed pressure:2.5 MPa) treated OW, germinated sunflower seeds percentage (86 ± 6%), speed of germination (30 ± 2) and biomass production (49 ± 5 mg) were statistically similar to control (distilled water) results. Vigor index average values obtained using OW treated by EC-RO (3871)were higher than that obtained by OW water treated by EC (3300). The results of this study indicate that EC-RO seems to be a promising alternative for treatment of OW aiming sunflower crops irrigation, since the use of this treated effluent did not affect adversely seed germination and seedling development, and improved seedling vigor. Furthermore, OW treatment by EC-RO reduces sodium levels into acceptable standards values avoiding soil degradation.

  9. Gibberellic and kaurenoic hybrid strigolactone mimics for seed germination of parasitic weeds.

    Science.gov (United States)

    Pereira, Rondinelle G; Cala, Antonio; Fernández-Aparicio, Mónica; Molinillo, José Mg; Boaventura, Maria Ad; Macías, Francisco A

    2017-12-01

    Parasitic weeds are widespread and cause significant losses in important crops. Their germination requires the detection of crop-derived molecules such as strigolactones. Strigolactone mimics are germination-inducing molecules with the potential to apply a suicidal germination strategy for seed bank control of parasitic weeds. The D-ring, which is instrumental in the germination process of seeds of parasitic weeds, was attached to gibberellin (GA 3 ) and kaurenoic acid as the scaffold. It was shown that indeed strigolactone mimics prepared from GA 3 and kaurenoic acid are active as stimulants when a D-ring is present; some of the mimics are as active as GR24. The starting molecules were plant hormones that had previous growth-regulating activity in other organisms and the products showed enhanced activity towards parasitic weeds. The information generated may contribute to a better understanding of the germination biochemistry of the weed species used. Further research is required in this area but it is clear that the results are promising. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  10. Membrane damage and solute leakage from germinating pea seed under cadmium stress

    Energy Technology Data Exchange (ETDEWEB)

    Rahoui, Sondes, E-mail: rahoui.sondes@yahoo.fr [Bio-Physiologie Cellulaires, Departement des Sciences de la Vie, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia); Chaoui, Abdelilah, E-mail: cabdelilah1@yahoo.fr [Bio-Physiologie Cellulaires, Departement des Sciences de la Vie, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia); El Ferjani, Ezzeddine, E-mail: ezzferjani2002@yahoo.fr [Bio-Physiologie Cellulaires, Departement des Sciences de la Vie, Faculte des Sciences de Bizerte, 7021 Zarzouna (Tunisia)

    2010-06-15

    Seed germination represents a limiting stage of plant life cycle under heavy metal stress situation. Delay in germination can be associated with disorders in the event chain of germinative metabolism which is a highly complex multistage process, but one of underlying metabolic activities following imbibition of seed is the storage mobilization. The influence of cadmium on carbohydrates and aminoacids export from cotyledon to embryonic axis during germination of pea seed was investigated. Compared to the control, Cd caused a restriction in reserve mobilization as evidenced by the pronounced increase in cotyledon/embryo ratios of total soluble sugars, glucose, fructose and aminoacids. Moreover, the nutrient concentrations, as well as the electrical conductivity of germination medium were determined to quantify the extent of solute leakage. Such nutrients were lost into the imbibition medium at the expense of suitable mobilization to the growing embryonic axis. This was concomitant with an over-accumulation of lipid peroxidation products in Cd-poisoned embryonic tissues. However, the impairment of membrane integrity cannot be due to a stimulation in lipoxygenase activity, since the later was markedly inhibited after Cd exposure.

  11. Membrane damage and solute leakage from germinating pea seed under cadmium stress

    International Nuclear Information System (INIS)

    Rahoui, Sondes; Chaoui, Abdelilah; El Ferjani, Ezzeddine

    2010-01-01

    Seed germination represents a limiting stage of plant life cycle under heavy metal stress situation. Delay in germination can be associated with disorders in the event chain of germinative metabolism which is a highly complex multistage process, but one of underlying metabolic activities following imbibition of seed is the storage mobilization. The influence of cadmium on carbohydrates and aminoacids export from cotyledon to embryonic axis during germination of pea seed was investigated. Compared to the control, Cd caused a restriction in reserve mobilization as evidenced by the pronounced increase in cotyledon/embryo ratios of total soluble sugars, glucose, fructose and aminoacids. Moreover, the nutrient concentrations, as well as the electrical conductivity of germination medium were determined to quantify the extent of solute leakage. Such nutrients were lost into the imbibition medium at the expense of suitable mobilization to the growing embryonic axis. This was concomitant with an over-accumulation of lipid peroxidation products in Cd-poisoned embryonic tissues. However, the impairment of membrane integrity cannot be due to a stimulation in lipoxygenase activity, since the later was markedly inhibited after Cd exposure.

  12. Germination of several groundnut cultivars in relation to incidence of ...

    African Journals Online (AJOL)

    This experiment is concerned with the germination of nine cultivars of groundnut grown in Nigeria in relation to incidence of fungi. The cultivars were NHK 5V8, NUTII 288, Samnut 10, 11, 21, 22, 23, 24 and MK 373. Germination potential was assessed after 10 days of planting in petri-dishes. Parameters such as seedling ...

  13. ESTs analysis reveals putative genes involved in symbiotic seed germination in Dendrobium officinale.

    Science.gov (United States)

    Zhao, Ming-Ming; Zhang, Gang; Zhang, Da-Wei; Hsiao, Yu-Yun; Guo, Shun-Xing

    2013-01-01

    Dendrobiumofficinale (Orchidaceae) is one of the world's most endangered plants with great medicinal value. In nature, D. officinale seeds must establish symbiotic relationships with fungi to germinate. However, the molecular events involved in the interaction between fungus and plant during this process are poorly understood. To isolate the genes involved in symbiotic germination, a suppression subtractive hybridization (SSH) cDNA library of symbiotically germinated D. officinale seeds was constructed. From this library, 1437 expressed sequence tags (ESTs) were clustered to 1074 Unigenes (including 902 singletons and 172 contigs), which were searched against the NCBI non-redundant (NR) protein database (E-value cutoff, e(-5)). Based on sequence similarity with known proteins, 579 differentially expressed genes in D. officinale were identified and classified into different functional categories by Gene Ontology (GO), Clusters of orthologous Groups of proteins (COGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The expression levels of 15 selected genes emblematic of symbiotic germination were confirmed via real-time quantitative PCR. These genes were classified into various categories, including defense and stress response, metabolism, transcriptional regulation, transport process and signal transduction pathways. All transcripts were upregulated in the symbiotically germinated seeds (SGS). The functions of these genes in symbiotic germination were predicted. Furthermore, two fungus-induced calcium-dependent protein kinases (CDPKs), which were upregulated 6.76- and 26.69-fold in SGS compared with un-germinated seeds (UGS), were cloned from D. officinale and characterized for the first time. This study provides the first global overview of genes putatively involved in D. officinale symbiotic seed germination and provides a foundation for further functional research regarding symbiotic relationships in orchids.

  14. ESTs analysis reveals putative genes involved in symbiotic seed germination in Dendrobium officinale.

    Directory of Open Access Journals (Sweden)

    Ming-Ming Zhao

    Full Text Available Dendrobiumofficinale (Orchidaceae is one of the world's most endangered plants with great medicinal value. In nature, D. officinale seeds must establish symbiotic relationships with fungi to germinate. However, the molecular events involved in the interaction between fungus and plant during this process are poorly understood. To isolate the genes involved in symbiotic germination, a suppression subtractive hybridization (SSH cDNA library of symbiotically germinated D. officinale seeds was constructed. From this library, 1437 expressed sequence tags (ESTs were clustered to 1074 Unigenes (including 902 singletons and 172 contigs, which were searched against the NCBI non-redundant (NR protein database (E-value cutoff, e(-5. Based on sequence similarity with known proteins, 579 differentially expressed genes in D. officinale were identified and classified into different functional categories by Gene Ontology (GO, Clusters of orthologous Groups of proteins (COGs and Kyoto Encyclopedia of Genes and Genomes (KEGG pathways. The expression levels of 15 selected genes emblematic of symbiotic germination were confirmed via real-time quantitative PCR. These genes were classified into various categories, including defense and stress response, metabolism, transcriptional regulation, transport process and signal transduction pathways. All transcripts were upregulated in the symbiotically germinated seeds (SGS. The functions of these genes in symbiotic germination were predicted. Furthermore, two fungus-induced calcium-dependent protein kinases (CDPKs, which were upregulated 6.76- and 26.69-fold in SGS compared with un-germinated seeds (UGS, were cloned from D. officinale and characterized for the first time. This study provides the first global overview of genes putatively involved in D. officinale symbiotic seed germination and provides a foundation for further functional research regarding symbiotic relationships in orchids.

  15. ESTs Analysis Reveals Putative Genes Involved in Symbiotic Seed Germination in Dendrobium officinale

    Science.gov (United States)

    Zhao, Ming-Ming; Zhang, Gang; Zhang, Da-Wei; Hsiao, Yu-Yun; Guo, Shun-Xing

    2013-01-01

    Dendrobium officinale (Orchidaceae) is one of the world’s most endangered plants with great medicinal value. In nature, D . officinale seeds must establish symbiotic relationships with fungi to germinate. However, the molecular events involved in the interaction between fungus and plant during this process are poorly understood. To isolate the genes involved in symbiotic germination, a suppression subtractive hybridization (SSH) cDNA library of symbiotically germinated D . officinale seeds was constructed. From this library, 1437 expressed sequence tags (ESTs) were clustered to 1074 Unigenes (including 902 singletons and 172 contigs), which were searched against the NCBI non-redundant (NR) protein database (E-value cutoff, e-5). Based on sequence similarity with known proteins, 579 differentially expressed genes in D . officinale were identified and classified into different functional categories by Gene Ontology (GO), Clusters of orthologous Groups of proteins (COGs) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways. The expression levels of 15 selected genes emblematic of symbiotic germination were confirmed via real-time quantitative PCR. These genes were classified into various categories, including defense and stress response, metabolism, transcriptional regulation, transport process and signal transduction pathways. All transcripts were upregulated in the symbiotically germinated seeds (SGS). The functions of these genes in symbiotic germination were predicted. Furthermore, two fungus-induced calcium-dependent protein kinases (CDPKs), which were upregulated 6.76- and 26.69-fold in SGS compared with un-germinated seeds (UGS), were cloned from D . officinale and characterized for the first time. This study provides the first global overview of genes putatively involved in D . officinale symbiotic seed germination and provides a foundation for further functional research regarding symbiotic relationships in orchids. PMID:23967335

  16. The Effects of Storage on Germination Characteristics and Enzyme Activity of Sorghum Seeds

    Directory of Open Access Journals (Sweden)

    Azadi M.S.

    2013-11-01

    Full Text Available Seed moisture content (MC and storage temperature are the most important factors affecting seed longevity and vigor. Exposure to warm, moist air is principally responsible for this. Proper storage and optimum seed moisture content can affect the grain quality significantly. The purpose of this study was to evaluate the different storage treatments on seed quality of sorghum. The seed materials were fresh without any storage period. For storage treatments, 3 seed moisture contents (6, 10, 14 % were stored for 8 month in 0.5 L capacity sealed aluminum foil packet in 0.3 bar inside incubators set at 4 temperatures (5, 15, 25, 35 °C. After storage time, the higher the storage temperature, the lower was the grain quality of sorghum. The highest germination percentage, germination index, normal seedling percentage were achieved in control conditions (0 day of storage. Our results showed that increasing storage duration resulted higher reduction in germination characteristics. Also our results showed that, germination percentage, means time to germination, germination index, normal seedling percentage decrease significantly by storage. Enzyme activity decrease significantly by increased in storage.

  17. Quantifying cardinal temperatures and thermal time required for germination of Silybum marianum seed

    Directory of Open Access Journals (Sweden)

    Ghasem Parmoon

    2015-04-01

    Full Text Available The response of seed germination to environmental factors can be estimated by nonlinear regression. The present study was performed to compare four nonlinear regression models (segmented, beta, beta modified, and dent-like to describe the germination rate–temperature relationships of milk thistle (Silybum marianum L. at six constant temperatures, with the aim of identifying the cardinal temperatures and thermal times required to reach different germination percentiles. Models and statistical indices were calibrated using an iterative optimization method and their performance was compared by root mean square error (RMSE, coefficient of determination (R2 and Akaike information criterion correction (AICc. The beta model was found to be the best model for predicting the required time to reach 50% germination (D50, (R2 = 0.99; RMSE = 0.004; AICc = − 276.97. Based on the model outputs, the base, optimum, and maximum temperatures of seed germination were 5.19 ± 0.79, 24.01 ± 0.11, and 34.32 ± 0.36 °C, respectively. The thermal times required for 50% and 90% germination were 4.99 and 7.38 degree-days, respectively.

  18. A Waking Review: Old and Novel Insights into the Spore Germination in Streptomyces

    Directory of Open Access Journals (Sweden)

    Jan Bobek

    2017-11-01

    Full Text Available The complex development undergone by Streptomyces encompasses transitions from vegetative mycelial forms to reproductive aerial hyphae that differentiate into chains of single-celled spores. Whereas their mycelial life – connected with spore formation and antibiotic production – is deeply investigated, spore germination as the counterpoint in their life cycle has received much less attention. Still, germination represents a system of transformation from metabolic zero point to a new living lap. There are several aspects of germination that may attract our attention: (1 Dormant spores are strikingly well-prepared for the future metabolic restart; they possess stable transcriptome, hydrolytic enzymes, chaperones, and other required macromolecules stabilized in a trehalose milieu; (2 Germination itself is a specific sequence of events leading to a complete morphological remodeling that include spore swelling, cell wall reconstruction, and eventually germ tube emergences; (3 Still not fully unveiled are the strategies that enable the process, including a single cell’s signal transduction and gene expression control, as well as intercellular communication and the probability of germination across the whole population. This review summarizes our current knowledge about the germination process in Streptomyces, while focusing on the aforementioned points.

  19. Germination and biochemical changes in ‘Formosa’ papaya seeds treated with plant hormones

    Directory of Open Access Journals (Sweden)

    Rafael Fonsêca Zanotti

    2014-04-01

    Full Text Available This study aimed to investigate the effects of growth regulators on germination rates and biochemical compound concentrations in Carica papaya L. seeds (‘Formosa’ group. The seeds were harvested from fruits at maturation stages 3 and 5 (50 and 75% yellow fruit skin, respectively. The effects of 2-chloroethylphosphonic acid (CEPA, KNO3 and gibberellic acid (GA3on seed germination, germination index speed, soluble sugars, starch, lipids, soluble proteins and total proteins of the papaya seeds were evaluated. The seeds from stage 5 showed a higher rate of germination 30 days after sowing than did the seeds from stage 3. Treatment with CEPA decreased seed germination, apparently due to decreased starch mobilization; the opposite response was observed following KNO3 treatment. GA3, alone or in combination with KNO3, stimulated an increase in lipid mobilization. In general, with the exception of CEPA, all growth regulators tested were effective in overcoming seed dormancy, and KNO3 was the most effective. The seeds from stage 3 fruits treated with KNO3 or KNO3 + GA3 had higher rates of germination at 14 days.

  20. A Waking Review: Old and Novel Insights into the Spore Germination in Streptomyces.

    Science.gov (United States)

    Bobek, Jan; Šmídová, Klára; Čihák, Matouš

    2017-01-01

    The complex development undergone by Streptomyces encompasses transitions from vegetative mycelial forms to reproductive aerial hyphae that differentiate into chains of single-celled spores. Whereas their mycelial life - connected with spore formation and antibiotic production - is deeply investigated, spore germination as the counterpoint in their life cycle has received much less attention. Still, germination represents a system of transformation from metabolic zero point to a new living lap. There are several aspects of germination that may attract our attention: (1) Dormant spores are strikingly well-prepared for the future metabolic restart; they possess stable transcriptome, hydrolytic enzymes, chaperones, and other required macromolecules stabilized in a trehalose milieu; (2) Germination itself is a specific sequence of events leading to a complete morphological remodeling that include spore swelling, cell wall reconstruction, and eventually germ tube emergences; (3) Still not fully unveiled are the strategies that enable the process, including a single cell's signal transduction and gene expression control, as well as intercellular communication and the probability of germination across the whole population. This review summarizes our current knowledge about the germination process in Streptomyces , while focusing on the aforementioned points.