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Sample records for rapidly implement seedling

  1. Buckwheat seedling flavonoids do not undergo rapid turnover

    International Nuclear Information System (INIS)

    Margna, U.; Vainjaerv, T.

    1981-01-01

    Pulse-labelling with exogenous [1- 14 C]-L-phenylalanine showed that of all flavonoids of buckwheat seedling cotyledons only anthocyanins underwent a slow turnover (not more than 6-8 per cent a day) whilst the major flavonoids, rutin and four C-glycosylflavones, remained metabolically stable within at least 7 days. From excised hypocotyls pulse-labelled flavonoids (anthocyanins and rutin) began to disappear gradually beginning with the second day of incubation. As hypocotyls, however, during prolonged incubation soon began to autolyse a considerable part of that loss was obviously due to abnormal shifts in cell metabolic activities with a possibility that some microbial process was also involved. In hypocotyls of intact seedlings pulse-labelled rutin, similar to rutin in cotyledons, showed no signs of turnover. (author)

  2. Rapid root extension during water pulses enhances establishment of shrub seedlings in the Atacama Desert

    NARCIS (Netherlands)

    Leon, M.F.; Squeo, F.A.; Gutierrez, J.R.; Holmgren, M.

    2011-01-01

    Questions: (1) What is the water threshold for shrub seedling establishment in arid scrubland? (2) How do seedling root growth morphological traits affect the water threshold required for seedling establishment? Location: Arid scrubland, Atacama Desert, north-central Chile. Methods: We conducted a

  3. Standard Operating Procedure (SOP) for Rapid and Efficient Production of Stevia Tissue Culture Seedlings

    International Nuclear Information System (INIS)

    Norazlina Noordin; Peng, C.S.; Rusli Ibrahim

    2015-01-01

    Stevia rebaudiana Bertoni is a non-caloric natural sweetener which is 300 times sweeter than cane sugar. Extracts from stevia leaves has vast application in food and beverages based industries, can be added to tea and coffee, cooked or baked goods, processed foods and confectionary goods. Recently, stevia attained awareness owing to its natural, non-caloric sweetness by diet/ health conscious and diabetic persons (Arpita et al., 2011). This natural sweetener has high commercial value in global market, it was estimated that global market value for stevia is be around USD11 billion by year 2015. Although stevia is being largely popularized in Malaysia and other countries but large-scale propagation procedures for the continuous supply of planting materials in commercial plantation has yet to be established, optimized and standardized. Furthermore, propagation through stevia seeds is often very difficult due to self-incompatibility which results in sterile seeds (Sakaguchi et al., 1982). Tissue culture is the only rapid process for the mass propagation of stevia and there have been few reports of in vitro growth of stevia (Miyagaya et al., 1986) and in vitro micropropagation from shoot tip and leaf (Uddin et al., 2006). Hence, study was carried out to establish a suitable protocol for in vitro propagation of S. rebaudiana Bertoni that can be further up-scaled for mass propagation of stevia seedlings. The established Standard Operating Procedure (SOP) will ensure rapid and efficient production of stevia tissue culture seedlings for continuous supply of planting materials for commercial stevia plantations in Malaysia. Preparation of growth medium, multiplication of shoots, rooting of plant lets and hardening of ex-vitro rooted plant lets is discussed in this paper. (author)

  4. A rapid and robust method of identifying transformed Arabidopsis thaliana seedlings following floral dip transformation

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    Gray John C

    2006-11-01

    Full Text Available Abstract Background The floral dip method of transformation by immersion of inflorescences in a suspension of Agrobacterium is the method of choice for Arabidopsis transformation. The presence of a marker, usually antibiotic- or herbicide-resistance, allows identification of transformed seedlings from untransformed seedlings. Seedling selection is a lengthy process which does not always lead to easily identifiable transformants. Selection for kanamycin-, phosphinothricin- and hygromycin B-resistance commonly takes 7–10 d and high seedling density and fungal contamination may result in failure to recover transformants. Results A method for identifying transformed seedlings in as little as 3.25 d has been developed. Arabidopsis T1 seeds obtained after floral dip transformation are plated on 1% agar containing MS medium and kanamycin, phosphinothricin or hygromycin B, as appropriate. After a 2-d stratification period, seeds are subjected to a regime of 4–6 h light, 48 h dark and 24 h light (3.25 d. Kanamycin-resistant and phosphinothricin-resistant seedlings are easily distinguished from non-resistant seedlings by green expanded cotyledons whereas non-resistant seedlings have pale unexpanded cotyledons. Seedlings grown on hygromycin B differ from those grown on kanamycin and phosphinothricin as both resistant and non-resistant seedlings are green. However, hygromycin B-resistant seedlings are easily identified as they have long hypocotyls (0.8–1.0 cm whereas non-resistant seedlings have short hypocotyls (0.2–0.4 cm. Conclusion The method presented here is an improvement on current selection methods as it allows quicker identification of transformed seedlings: transformed seedlings are easily discernable from non-transformants in as little as 3.25 d in comparison to the 7–10 d required for selection using current protocols.

  5. Arabidopsis seedling flood-inoculation technique: a rapid and reliable assay for studying plant-bacterial interactions

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    Uppalapati Srinivasa R

    2011-10-01

    Full Text Available Abstract Background The Arabidopsis thaliana-Pseudomonas syringae model pathosystem is one of the most widely used systems to understand the mechanisms of microbial pathogenesis and plant innate immunity. Several inoculation methods have been used to study plant-pathogen interactions in this model system. However, none of the methods reported to date are similar to those occurring in nature and amicable to large-scale mutant screens. Results In this study, we developed a rapid and reliable seedling flood-inoculation method based on young Arabidopsis seedlings grown on MS medium. This method has several advantages over conventional soil-grown plant inoculation assays, including a shorter growth and incubation period, ease of inoculation and handling, uniform infection and disease development, requires less growth chamber space and is suitable for high-throughput screens. In this study we demonstrated the efficacy of the Arabidopsis seedling assay to study 1 the virulence factors of P. syringae pv. tomato DC3000, including type III protein secretion system (TTSS and phytotoxin coronatine (COR; 2 the effector-triggered immunity; and 3 Arabidopsis mutants affected in salicylic acid (SA- and pathogen-associated molecular pattern (PAMPs-mediated pathways. Furthermore, we applied this technique to study nonhost resistance (NHR responses in Arabidopsis using nonhost pathogens, such as P. syringae pv. tabaci, pv. glycinea and pv. tomato T1, and confirmed the functional role of FLAGELLIN-SENSING 2 (FLS2 in NHR. Conclusions The Arabidopsis seedling flood-inoculation assay provides a rapid, efficient and economical method for studying Arabidopsis-Pseudomonas interactions with minimal growth chamber space and time. This assay could also provide an excellent system for investigating the virulence mechanisms of P. syringae. Using this method, we demonstrated that FLS2 plays a critical role in conferring NHR against nonhost pathovars of P. syringae, but not to

  6. Implementing RapidArc into clinical routine

    DEFF Research Database (Denmark)

    Van Esch, Ann; Huyskens, Dominique P; Behrens, Claus F

    2011-01-01

    With the increased commercial availability of intensity modulated arc therapy (IMAT) comes the need for comprehensive QA programs, covering the different aspects of this newly available technology. This manuscript proposes such a program for the RapidArc (RA) (Varian Medical Systems, Palo Alto...

  7. Calotropis procera seedlings could be used as a rapid cost effective bioindicator for measuring aluminum environmental pollution

    Science.gov (United States)

    Mosa, Kareem A.; El-Keblawy, Ali; Najar, Atyat

    2017-04-01

    Calotropis procera seedlings could be used as a rapid cost effective bioindicator for measuring aluminum environmental pollution Kareem A. Mosa, Ali El-Keblawy, Atyat Najar Department of Applied Biology, College of Sciences, University of Sharjah, UAE Rapid industrialization and urbanization processes has led to the incorporation of different heavy metals in natural resources like soil, water and air thus affecting their quality. Aluminum (Al) is a dominant heavy metal pollutant that causes serious toxic effects to living systems including plants. Therefore, it is critical to regularly monitor the changes in Al levels in natural resources. Living organisms could be used as bioindicators for monitoring and measuring the levels of heavy metals in environmental samples. The aim of this study was to develop a cost effective bioindicator for monitoring aluminum (Al) and assess the damage caused by Al bioaccumulation using the root system of Calotropis Procera seedlings. A hydroponic system was developed for growing C. Procera in four different concentrations of Al (20, 40, 60 and 80 ppm). Root length and shoot fresh and dry weights were assessed after 5, 10, 15 and 20 days of Al treatment. The results showed remarkable sensitivity of C. Procera seedlings for the different concentrations of Al. There was gradual but significant decrease in C. Procera root length with the increase in the Al concentrations. X-ray fluorescence microscopy (XRF) analysis indicated a significant increase in Al concentration in C. Procera roots with the increase of both Al concentration in the hydroponic solution and the growing period. Moreover, electrical conductivity analysis showed that Al induced damage to C. Procera root plasma membrane as indicated by the increase in electrolyte leakages. Randomly amplified polymorphic DNA (RAPD) PCR analysis confirmed the genotoxin effect of Al which induced C. Procera genomic DNA modification. Altogether, the result demonstrated that C. Procera could

  8. Reduction in Mortality Following Pediatric Rapid Response Team Implementation.

    Science.gov (United States)

    Kolovos, Nikoleta S; Gill, Jeff; Michelson, Peter H; Doctor, Allan; Hartman, Mary E

    2018-05-01

    To evaluate the effectiveness of a physician-led rapid response team program on morbidity and mortality following unplanned admission to the PICU. Before-after study. Single-center quaternary-referral PICU. All unplanned PICU admissions from the ward from 2005 to 2011. The dataset was divided into pre- and post-rapid response team groups for comparison. A Cox proportional hazards model was used to identify the patient characteristics associated with mortality following unplanned PICU admission. Following rapid response team implementation, Pediatric Risk of Mortality, version 3, illness severity was reduced (28.7%), PICU length of stay was less (19.0%), and mortality declined (22%). Relative risk of death following unplanned admission to the PICU after rapid response team implementation was 0.685. For children requiring unplanned admission to the PICU, rapid response team implementation is associated with reduced mortality, admission severity of illness, and length of stay. Rapid response team implementation led to more proximal capture and aggressive intervention in the trajectory of a decompensating pediatric ward patient.

  9. The limitations in implementing and operating a rapid response system.

    Science.gov (United States)

    Subramaniam, A; Botha, J; Tiruvoipati, R

    2016-10-01

    Despite the widespread introduction of rapid response systems (RRS)/medical emergency teams (MET), there is still controversy regarding how effective they are. While there are some observational studies showing improved outcomes with RRS, there are no data from randomised controlled trials to support the effectiveness. Nevertheless, the MET system has become a standard of care in many healthcare organisations. In this review, we present an overview of the limitations in implementing and operating a RRS in modern healthcare. © 2016 Royal Australasian College of Physicians.

  10. Organic Fertilizers Improves Trembesi Samanea Saman Seedling Growth A Case Study Of The Implementation Of Post-Mining Land Reclamation And Revegetation Within The Forest Cultivation Zone

    Directory of Open Access Journals (Sweden)

    Suria Darma

    2017-10-01

    Full Text Available This study aimed to 1 determine the effect of each organic fertilizer dosage a the growth variables of Trembesi seedlings and b the quality of planting media after 120 days planted Trembesi Seedlings. This study also aimed to 2 obtain the optimum dose of organic fertilizer to be applied to the implementation of post-mining land reclamation and revegetation within the Forest Cultivation Zone. This research used various manure Control without fertilizer NPK synthetic fertilizer control chicken manure cow manure and organic litter compost. Each of the organic fertilizer was given at doses of 125 250 and 375 gpolybag. The test plants used were Trembesi seedlings Samanea saman at 4 months of age.The experimental design was prepared using Randomized Block Design RAK with 5 replications in each test plant group. Data analysis was completed with Fisher LSD Test and Duncan Multiple Range Test DMRT as well as regression analysis.The treatment of organic fertilizer dosage showed significant in all variables of growth of trembesi seedlings except on average of Trembesi seedlings height at 90 days after planting DAP and on average stem diameter of Trembesi seed of 30 60 90 120 DAP. Effect of organic fertilizer dosage to planting medium after 120 days planted Trembesi seedling. All variations of fertilization dose increase the pH value organic C N-total CN ratio available P available K Ca Mg Na K and cation exchange rate CEC. Treatment dose of 375gpolybag of chicken manure was the best treatment dose with the highest number of twigs on Trembesi seedlings at the age of 30 DAP 21.00 twigs 60 DAP 36.40 twigs 90 DAP 63.60 twigs 120 DAP 106.60 twigs The Longest length of twig was found on Trembesi seedlings with age of 30 DAP 17.95 cm 60 DAP21.61 cm 90 DAP 28.49 cm 120 DAP 32.11 cm longest root length and heaviest biomass weight of Trembesi seedling wasfor the age of 120 DAP which were 58.80 cm and 487.22 g respectively.

  11. Implementation of a Rapid, Protocol-based TIA Management Pathway.

    Science.gov (United States)

    Jarhult, Susann J; Howell, Melissa L; Barnaure-Nachbar, Isabelle; Chang, Yuchiao; White, Benjamin A; Amatangelo, Mary; Brown, David F; Singhal, Aneesh B; Schwamm, Lee H; Silverman, Scott B; Goldstein, Joshua N

    2018-03-01

    Our goal was to assess whether use of a standardized clinical protocol improves efficiency for patients who present to the emergency department (ED) with symptoms of transient ischemic attack (TIA). We performed a structured, retrospective, cohort study at a large, urban, tertiary care academic center. In July 2012 this hospital implemented a standardized protocol for patients with suspected TIA. The protocol selected high-risk patients for admission and low/intermediate-risk patients to an ED observation unit for workup. Recommended workup included brain imaging, vascular imaging, cardiac monitoring, and observation. Patients were included if clinical providers determined the need for workup for TIA. We included consecutive patients presenting during a six-month period prior to protocol implementation, and those presenting between 6-12 months after implementation. Outcomes included ED length of stay (LOS), hospital LOS, use of neuroimaging, and 90-day risk of stroke or TIA. From 01/2012 to 06/2012, 130 patients were evaluated for TIA symptoms in the ED, and from 01/2013 to 06/2013, 150 patients. The final diagnosis was TIA or stroke in 45% before vs. 41% after (p=0.18). Following the intervention, the inpatient admission rate decreased from 62% to 24% (pTIA among those with final diagnosis of TIA was 3% for both periods. Implementation of a TIA protocol significantly reduced ED LOS and total hospital LOS.

  12. A rapid seedling resistance assay identifies wild tomato lines that are resistant to Psuedomonas syringe pv. tomato race 1

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    Bacterial speck caused by Pseudomonas syringae has historically been controlled by the Pto/Prf gene cluster. Emerging strains like P. syringae pv. tomato race 1 overcome resistance conferred by Pto/Prf, and can cause serious crop loss under appropriate environmental conditions. We developed a rapid ...

  13. Implementation of a Rapid, Protocol-based TIA Management Pathway

    Directory of Open Access Journals (Sweden)

    Susann J. Jarhult

    2018-02-01

    Full Text Available Introduction: Our goal was to assess whether use of a standardized clinical protocol improves efficiency for patients who present to the emergency department (ED with symptoms of transient ischemic attack (TIA. Methods: We performed a structured, retrospective, cohort study at a large, urban, tertiary care academic center. In July 2012 this hospital implemented a standardized protocol for patients with suspected TIA. The protocol selected high-risk patients for admission and low/intermediate-risk patients to an ED observation unit for workup. Recommended workup included brain imaging, vascular imaging, cardiac monitoring, and observation. Patients were included if clinical providers determined the need for workup for TIA. We included consecutive patients presenting during a six-month period prior to protocol implementation, and those presenting between 6–12 months after implementation. Outcomes included ED length of stay (LOS, hospital LOS, use of neuroimaging, and 90-day risk of stroke or TIA. Results: From 01/2012 to 06/2012, 130 patients were evaluated for TIA symptoms in the ED, and from 01/2013 to 06/2013, 150 patients. The final diagnosis was TIA or stroke in 45% before vs. 41% after (p=0.18. Following the intervention, the inpatient admission rate decreased from 62% to 24% (p<0.001, median ED LOS decreased by 1.2 hours (5.7 to 4.9 hours, p=0.027, and median total hospital LOS from 29.4 hours to 23.1 hours (p=0.019. The proportion of patients receiving head computed tomography (CT went from 68% to 58% (p=0.087; brain magnetic resonance (MR imaging from 83% to 88%, (p=0.44 neck CT angiography from 32% to 22% (p=0.039; and neck MR angiography from 61% to 72% (p=0.046. Ninety-day stroke or recurrent TIA among those with final diagnosis of TIA was 3% for both periods. Conclusion: Implementation of a TIA protocol significantly reduced ED LOS and total hospital LOS.

  14. Rapid research and implementation priority setting for wound care uncertainties.

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    Trish A Gray

    Full Text Available People with complex wounds are more likely to be elderly, living with multimorbidity and wound related symptoms. A variety of products are available for managing complex wounds and a range of healthcare professionals are involved in wound care, yet there is a lack of good evidence to guide practice and services. These factors create uncertainty for those who deliver and those who manage wound care. Formal priority setting for research and implementation topics is needed to more accurately target the gaps in treatment and services. We solicited practitioner and manager uncertainties in wound care and held a priority setting workshop to facilitate a collaborative approach to prioritising wound care-related uncertainties.We recruited healthcare professionals who regularly cared for patients with complex wounds, were wound care specialists or managed wound care services. Participants submitted up to five wound care uncertainties in consultation with their colleagues, via an on-line survey and attended a priority setting workshop. Submitted uncertainties were collated, sorted and categorised according professional group. On the day of the workshop, participants were divided into four groups depending on their profession. Uncertainties submitted by their professional group were viewed, discussed and amended, prior to the first of three individual voting rounds. Participants cast up to ten votes for the uncertainties they judged as being high priority. Continuing in the professional groups, the top 10 uncertainties from each group were displayed, and the process was repeated. Groups were then brought together for a plenary session in which the final priorities were individually scored on a scale of 0-10 by participants. Priorities were ranked and results presented. Nominal group technique was used for generating the final uncertainties, voting and discussions.Thirty-three participants attended the workshop comprising; 10 specialist nurses, 10 district

  15. Rapid research and implementation priority setting for wound care uncertainties

    Science.gov (United States)

    Dumville, Jo C.; Christie, Janice; Cullum, Nicky A.

    2017-01-01

    Introduction People with complex wounds are more likely to be elderly, living with multimorbidity and wound related symptoms. A variety of products are available for managing complex wounds and a range of healthcare professionals are involved in wound care, yet there is a lack of good evidence to guide practice and services. These factors create uncertainty for those who deliver and those who manage wound care. Formal priority setting for research and implementation topics is needed to more accurately target the gaps in treatment and services. We solicited practitioner and manager uncertainties in wound care and held a priority setting workshop to facilitate a collaborative approach to prioritising wound care-related uncertainties. Methods We recruited healthcare professionals who regularly cared for patients with complex wounds, were wound care specialists or managed wound care services. Participants submitted up to five wound care uncertainties in consultation with their colleagues, via an on-line survey and attended a priority setting workshop. Submitted uncertainties were collated, sorted and categorised according professional group. On the day of the workshop, participants were divided into four groups depending on their profession. Uncertainties submitted by their professional group were viewed, discussed and amended, prior to the first of three individual voting rounds. Participants cast up to ten votes for the uncertainties they judged as being high priority. Continuing in the professional groups, the top 10 uncertainties from each group were displayed, and the process was repeated. Groups were then brought together for a plenary session in which the final priorities were individually scored on a scale of 0–10 by participants. Priorities were ranked and results presented. Nominal group technique was used for generating the final uncertainties, voting and discussions. Results Thirty-three participants attended the workshop comprising; 10 specialist nurses

  16. State and Federal project development procedures for bus rapid transit : managing differences and reducing implementation delays

    Science.gov (United States)

    2011-08-01

    This report documents an investigation into the transportation project development process in the : context of the implementation of bus rapid transit systems on the State Highway System as well as such : systems being part of the Federal New Starts ...

  17. Long-term culture change related to rapid response system implementation.

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    Stevens, Jennifer; Johansson, Anna; Lennes, Inga; Hsu, Douglas; Tess, Anjala; Howell, Michael

    2014-12-01

    Increasing attention to patient safety in training hospitals may come at the expense of trainee autonomy and professional growth. This study sought to examine changes in medical trainees' self-reported behaviour after the institution-wide implementation of a rapid response system. We conducted a two-point cross-sectional survey of medical trainees in 2006, during the implementation of a rapid response system, and in 2010, in a single academic medical centre. A novel instrument was used to measure trainee likelihood of calling for supervisory assistance, perception of autonomy, and comfort in managing decompensating patients. Non-parametric tests to assess for change were used and year of training was evaluated as an effect modifier. Response rates were 38% in 2006 and 70% in 2010. After 5 years of the full implementation of the rapid response system, residents were significantly more likely to report calling their attending physicians for assistance (rising from 40% to 65% of relevant situations; p autonomy at 5 years after the implementation of the rapid response system. These changes were mirrored in the actual use of the rapid response system, which increased by 41% during the 5-year period after adjustment for patient volume (p < 0.0001). A primary team-focused implementation of a rapid response system was associated with durable changes in resident physicians' reported behaviour, including increased comfort with involving more experienced physicians and managing unstable patients. © 2014 John Wiley & Sons Ltd.

  18. Implementation of Rapid Molecular Infectious Disease Diagnostics: the Role of Diagnostic and Antimicrobial Stewardship.

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    Messacar, Kevin; Parker, Sarah K; Todd, James K; Dominguez, Samuel R

    2017-03-01

    New rapid molecular diagnostic technologies for infectious diseases enable expedited accurate microbiological diagnoses. However, diagnostic stewardship and antimicrobial stewardship are necessary to ensure that these technologies conserve, rather than consume, additional health care resources and optimally affect patient care. Diagnostic stewardship is needed to implement appropriate tests for the clinical setting and to direct testing toward appropriate patients. Antimicrobial stewardship is needed to ensure prompt appropriate clinical action to translate faster diagnostic test results in the laboratory into improved outcomes at the bedside. This minireview outlines the roles of diagnostic stewardship and antimicrobial stewardship in the implementation of rapid molecular infectious disease diagnostics. Copyright © 2017 American Society for Microbiology.

  19. The cost of implementing rapid HIV testing in sexually transmitted disease clinics in the United States.

    Science.gov (United States)

    Eggman, Ashley A; Feaster, Daniel J; Leff, Jared A; Golden, Matthew R; Castellon, Pedro C; Gooden, Lauren; Matheson, Tim; Colfax, Grant N; Metsch, Lisa R; Schackman, Bruce R

    2014-09-01

    Rapid HIV testing in high-risk populations can increase the number of persons who learn their HIV status and avoid spending clinic resources to locate persons identified as HIV infected. We determined the cost to sexually transmitted disease (STD) clinics of point-of-care rapid HIV testing using data from 7 public clinics that participated in a randomized trial of rapid testing with and without brief patient-centered risk reduction counseling in 2010. Costs included counselor and trainer time, supplies, and clinic overhead. We applied national labor rates and test costs. We calculated median clinic start-up costs and mean cost per patient tested, and projected incremental annual costs of implementing universal rapid HIV testing compared with current testing practices. Criteria for offering rapid HIV testing and methods for delivering nonrapid test results varied among clinics before the trial. Rapid HIV testing cost an average of US $22/patient without brief risk reduction counseling and US $46/patient with counseling in these 7 clinics. Median start-up costs per clinic were US $1100 and US $16,100 without and with counseling, respectively. Estimated incremental annual costs per clinic of implementing universal rapid HIV testing varied by whether or not brief counseling is conducted and by current clinic testing practices, ranging from a savings of US $19,500 to a cost of US $40,700 without counseling and a cost of US $98,000 to US $153,900 with counseling. Universal rapid HIV testing in STD clinics with same-day results can be implemented at relatively low cost to STD clinics, if brief risk reduction counseling is not offered.

  20. Using Rapid Ethnography to Support the Design and Implementation of Health Information Technologies.

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    Ackerman, Sara; Gleason, Nathaniel; Gonzales, Ralph

    2015-01-01

    Ethnography is the defining practice - and art - of anthropology. Among health information technology (IT) developers, however, ethnography remains a little used and undervalued mode of inquiry and representation. In this chapter we demonstrate that ethnography can make important contributions to the design and implementation of more user-oriented health IT devices and systems. In particular, we propose 'rapid ethnography' as a pragmatic strategy that draws on classic ethnographic methods, but emphasizes shorter periods of fieldwork and quick turnaround of findings to inform (re)design, programming and implementation efforts. Rapid ethnography is theoretically and empirically situated in science and technology studies' explorations of a) the entanglement of social and technical dimensions of technology use; b) how getting tools to 'work' requires aligning interests across a wide range of human and non-human actors; and c) the ways in which humans and technology transform each other as they interact. We provide two detailed case studies to illustrate the evolution and uses of rapid ethnography at a U.S. academic medical center. By providing deeper insights into the experiences of users, and the contexts and communities in which new tools are introduced, rapid ethnography can serve as a valuable component of Techno-Anthropology and health IT innovation.

  1. Implementation of universal rapid human immunodeficiency virus screening on labor and delivery.

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    Crochet, Stacia; Huang, Chun-Chih; Fries, Melissa; Scott, Rachel K

    2018-03-01

    A case of mother to child transmission (MTCT) of HIV at a medical center in Washington, DC, resulted in the implementation of universal opt-out rapid testing of patients admitted for delivery. This article evaluates the policy's efficacy and implementation. We evaluated the implementation using the Reach, Efficacy, Adoption, Implementation, and Maintenance (RE-AIM) framework. We could not evaluate decrease in MTCT rate secondary to low sample size ( n  = 3324) and no true-positive results. Patients not tested ( n  = 458) were predominately secondary to physician omission (93.7%) and were more likely to be White ( p  < 0.01) and older ( p  < 0.01). There was a negative relationship with physician omission over time. The policy was successfully implemented with decreasing proportions of patients not tested. Earlier inclusion of testing into standard admission orders and nurse-based approach may have expedited adoption. Given the low incidence of new HIV diagnosis in labor, we were unable to assess decrease in MTCT.

  2. Implementation of broad screening with Ebola rapid diagnostic tests in Forécariah, Guinea

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    Frantz Jean Louis

    2017-03-01

    Full Text Available Background: Laboratory-enhanced surveillance is critical for rapidly detecting the potential re-emergence of Ebola virus disease. Rapid diagnostic tests (RDT for Ebola antigens could expand diagnostic capacity for Ebola virus disease. Objectives: The Guinean National Coordination for Ebola Response conducted a pilot implementation to determine the feasibility of broad screening of patients and corpses with the OraQuick® Ebola RDT. Methods: The implementation team developed protocols and trained healthcare workers to screen patients and corpses in Forécariah prefecture, Guinea, from 15 October to 30 November 2015. Data collected included number of consultations, number of fevers reported or measured, number of tests performed for patients or corpses and results of confirmatory RT-PCR testing. Data on malaria RDT results were collected for comparison. Feedback from Ebola RDT users was collected informally during supervision visits and forums. Results: There were 3738 consultations at the 15 selected healthcare facilities; 74.6% of consultations were for febrile illness. Among 2787 eligible febrile patients, 2633 were tested for malaria and 1628 OraQuick® Ebola RDTs were performed. A total of 322 OraQuick® Ebola RDTs were conducted on corpses. All Ebola tests on eligible patients were negative. Conclusions: Access to Ebola testing was expanded by the implementation of RDTs in an emergency situation. Feedback from Ebola RDT users and lessons learned will contribute to improving quality for RDT expansion.

  3. Implementation of a Multichannel Serial Data Streaming Algorithm using the Xilinx Serial RapidIO Solution

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    Doxley, Charles A.

    2016-01-01

    In the current world of applications that use reconfigurable technology implemented on field programmable gate arrays (FPGAs), there is a need for flexible architectures that can grow as the systems evolve. A project has limited resources and a fixed set of requirements that development efforts are tasked to meet. Designers must develop robust solutions that practically meet the current customer demands and also have the ability to grow for future performance. This paper describes the development of a high speed serial data streaming algorithm that allows for transmission of multiple data channels over a single serial link. The technique has the ability to change to meet new applications developed for future design considerations. This approach uses the Xilinx Serial RapidIO LOGICORE Solution to implement a flexible infrastructure to meet the current project requirements with the ability to adapt future system designs.

  4. Seedling root targets

    Science.gov (United States)

    Diane L. Haase

    2011-01-01

    Roots are critical to seedling performance after outplanting. Although root quality is not as quick and simple to measure as shoot quality, target root characteristics should be included in any seedling quality assessment program. This paper provides a brief review of root characteristics most commonly targeted for operational seedling production. These are: root mass...

  5. A cross sectional survey of the barriers for implementing rapid HIV testing among French general practitioners.

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    Fraisse, Thibaut; Fourcade, Camille; Brazes-Sanz, Julie; Koumar, Yatrika; Lavigne, Jean Philippe; Sotto, Albert; Laureillard, Didier

    2016-10-01

    In France, almost 30,000 people are unaware of their HIV-positive status. Innovative screening strategies are essential to reach this population. The aim of this study was to describe the acceptability of rapid HIV testing (RHT) among French general practitioners (GPs) working in the south of France and barriers for implementing this strategy. We analysed an anonymous questionnaire sent by mail to GPs about demographic data, routine practice, knowledge of RHT and barriers to its use. Between 1 April and 30 September 2013, out of the 165 GPs contacted, 78 returned the questionnaires. The GPs' mean age was 52 years; 49 were men. Fifty-one GPs reported that their registered patients included at least one HIV-infected person and 70 GPs reported taking care of high-risk patients. Sixty-three percent of GPs reported being interested in using RHT in their daily practice. The main reasons reported by uninterested GPs were: greater confidence in standard HIV testing, difficulties including RHT during the routine consultation, difficulties to screen for other sexually transmitted infections simultaneously, and difficulties to deliver a positive result. French National Authorities for Health propose to screen the population at least once in their lifetime and high-risk people at least once a year. In order to achieve this aim, RHT should be included in the GPs' arsenal for HIV testing. We showed a high acceptability of RHT by GPs. If specific and adapted training is developed, and if solutions to barriers reported by GPs are found, RHT could be implemented in to their routine activity. © The Author(s) 2016.

  6. Labelling of rice seedlings and rice plants with 32P

    International Nuclear Information System (INIS)

    Achmad Nasroh, K.

    1989-01-01

    Labelling of rice seedlings and rice plants with 32 P. Labelled rice seedlings can be used to tag insect pests that feed on. Radioactivity counting of 32 P in the endosperm and in the shoot of rice seeds that soaked for 72 hours in KH 2 32 PO 4 solution of 1 μCi/ml were 29,300 and 9,500 cpm respectively. When these labelled seedlings were grown in unlabelled medium the radioactivity in the shoot increased. It was due to the 32 P that was translocated to the shoot from the endosperm. The 32 P translocation reached maximum about one week after the seedling were grown in the unlabelled medium. Labelled seedlings could also be produced by growing 5, 10 and 15 days old seedlings hydroponically in Kimura B solution containing 32 P. Ten days after growing, the radioactivity concentration of the seedlings stem reached about 115,000; 85,000 and 170,000 cpm/mg dry weight for the 5, 10 and 15 days old seedlings respectively. For the implementation of this method, 20 ml labelled Kimura B was needed for labelling of one seedling. The seedlings should be prepared in tap water. During the growth the 32 P in the labelled seedlings was distributed throughout the plant, so that new leaves and tillers became also radioactive. (author). 5 refs

  7. Rapid implementation of evidence-based guidelines for imaging after first urinary tract infection.

    Science.gov (United States)

    Jerardi, Karen E; Elkeeb, Dena; Weiser, Jason; Brinkman, William B

    2013-09-01

    The American Academy of Pediatrics published a new guideline for management of first urinary tract infection (UTI) in children aged 2 to 24 months in September 2011. The imaging evaluation changed from the previous guideline to recommend voiding cystourethrogram (VCUG) only for patients with an abnormal renal and bladder ultrasound (RBUS). The objective was to decrease the proportion of guideline-eligible children with a normal RBUS who underwent VCUG from median of 92% for patients treated as inpatients and 100% for patients treated in the emergency department to 5% in both settings. This was a quality improvement implementation study in a large academic medical center. Key drivers included: appropriate guideline knowledge, timely identification of guideline eligible patients, and effective communication with the community-based primary care provider. A multidisciplinary team developed and tested interventions. Impact was assessed with annotated run charts. Statistical comparisons were made with χ(2) analysis and Fisher's exact test. The proportion of children with first UTI and normal RBUS who underwent VCUG decreased from a median of 92% to 0% within 1 month of initiating the project among those hospitalized and from 100% to 40% within 4 months among those diagnosed in the emergency department. Rates have been sustained for 12 months and 8 months, respectively. Interventions using the electronic medical record and ordering system were most impactful. Rapid adoption of evidence-based UTI care across multiple settings is achievable. Practice change occurred faster and to a greater magnitude in the inpatient setting compared with the outpatient setting.

  8. UMTS rapid response real-time seismic networks: implementation and strategies at INGV

    Science.gov (United States)

    Govoni, Aladino; Margheriti, Lucia; Moretti, Milena; Lauciani, Valentino; Sensale, Gianpaolo; Bucci, Augusto; Criscuoli, Fabio

    2015-04-01

    The benefits of portable real-time seismic networks are several and well known. During the management of a temporary experiment from the real-time data it is possible to detect and fix rapidly problems with power supply, time synchronization, disk failures and, most important, seismic signal quality degradation due to unexpected noise sources or sensor alignment/tampering. This usually minimizes field maintenance trips and maximizes both the quantity and the quality of the acquired data. When the area of the temporary experiment is not well monitored by the local permanent network, the real-time data from the temporary experiment can be fed to the permanent network monitoring system improving greatly both the real-time hypocentral locations and the final revised bulletin. All these benefits apply also in case of seismic crises when rapid deployment stations can significantly contribute to the aftershock analysis. Nowadays data transmission using meshed radio networks or satellite systems is not a big technological problem for a permanent seismic network where each site is optimized for the device power consumption and is usually installed by properly specialized technicians that can configure transmission devices and align antennas. This is not usually practical for temporary networks and especially for rapid response networks where the installation time is the main concern. These difficulties are substantially lowered using the now widespread UMTS technology for data transmission. A small (but sometimes power hungry) properly configured device with an omnidirectional antenna must be added to the station assembly. All setups are usually configured before deployment and this allows for an easy installation also by untrained personnel. We describe here the implementation of a UMTS based portable seismic network for both temporary experiments and rapid response applications developed at INGV. The first field experimentation of this approach dates back to the 2009 L

  9. Eastern Redcedar Seedling Assessment

    Data.gov (United States)

    U.S. Environmental Protection Agency — Eastern redcedar tree seedling growth in response to various soil, nitrogen, and photosynthetic radiation characteristics. This dataset is associated with the...

  10. Shared care in mental illness: A rapid review to inform implementation

    Directory of Open Access Journals (Sweden)

    Kelly Brian J

    2011-11-01

    Full Text Available Abstract Background While integrated primary healthcare for the management of depression has been well researched, appropriate models of primary care for people with severe and persistent psychotic disorders are poorly understood. In 2010 the NSW (Australia Health Department commissioned a review of the evidence on "shared care" models of ambulatory mental health services. This focussed on critical factors in the implementation of these models in clinical practice, with a view to providing policy direction. The review excluded evidence about dementia, substance use and personality disorders. Methods A rapid review involving a search for systematic reviews on The Cochrane Database of Systematic Reviews and Database of Abstracts of Reviews of Effects (DARE. This was followed by a search for papers published since these systematic reviews on Medline and supplemented by limited iterative searching from reference lists. Results Shared care trials report improved mental and physical health outcomes in some clinical settings with improved social function, self management skills, service acceptability and reduced hospitalisation. Other benefits include improved access to specialist care, better engagement with and acceptability of mental health services. Limited economic evaluation shows significant set up costs, reduced patient costs and service savings often realised by other providers. Nevertheless these findings are not evident across all clinical groups. Gains require substantial cross-organisational commitment, carefully designed and consistently delivered interventions, with attention to staff selection, training and supervision. Effective models incorporated linkages across various service levels, clinical monitoring within agreed treatment protocols, improved continuity and comprehensiveness of services. Conclusions "Shared Care" models of mental health service delivery require attention to multiple levels (from organisational to individual

  11. Characterization of a rapid, blue light-mediated change in detectable phosphorylation of a plasma membrane protein from etiolated pea (Pisum sativum L.) seedlings

    International Nuclear Information System (INIS)

    Short, T.W.; Briggs, W.R.

    1990-01-01

    When crude microsomal membranes from apical stem segments of etiolated Pisum sativum L. cv Alaska are mixed in vitro with γ-[ 32 P]ATP, a phosphorylated band of apparent molecular mass 120 kilodaltons can be detected on autoradiographs of sodium dodecyl sulfate electrophoresis gels. If the stem sections are exposed to blue light immediately prior to membrane isolation, this band is not evident. Comparisons of the kinetics, tissue distribution, and dark recovery of the phosphorylation response with those published for blue light mediated phototropism or rapid growth inhibition indicate that the phosphorylation could be linked to one or both of the reactions described. However, the fluence-response relationships for the change in detectable phosphorylation match quite closely those reported for phototropism but not those for growth inhibition. Blue light has also been found to regulate the capacity for in vitro phosphorylation of a second protein. It has an apparent molecular mass of 84 kilodaltons and is localized primarily in basal stem sections

  12. Critical water stress levels in Pinus patula seedlings and their ...

    African Journals Online (AJOL)

    Critical water stress levels in Pinus patula seedlings and their relation to measures of seedling morphology. ... Southern Forests: a Journal of Forest Science ... A pot trial was implemented to determine the effect of soil water stress following transplanting on shoot water potential and stomatal conductance of Pinus patula ...

  13. UMTS rapid response real-time seismic networks: implementation and strategies at INGV

    Science.gov (United States)

    Govoni, A.; Margheriti, L.; Moretti, M.; Lauciani, V.; Sensale, G.; Bucci, A.; Criscuoli, F.

    2015-12-01

    Universal Mobile Telecommunications System (UMTS) and its evolutions are nowadays the most affordable and widespread data communication infrastructure available almost world wide. Moreover the always growing cellular phone market is pushing the development of new devices with higher performances and lower power consumption. All these characteristics make UMTS really useful for the implementation of an "easy to deploy" temporary real-time seismic station. Despite these remarkable features, there are many drawbacks that must be properly taken in account to effectively transmit the seismic data: Internet security, signal and service availability, power consumption. - Internet security: exposing seismological data services and seismic stations to the Internet is dangerous, attack prone and can lead to downtimes in the services, so we setup a dedicated Virtual Private Network (VPN) service to protect all the connected devices. - Signal and service availability: while for temporary experiment a carefull planning and an accurate site selection can minimize the problem, this is not always the case with rapid response networks. Moreover, as with any other leased line, the availability of the UMTS service during a seismic crisis is basically unpredictable. Nowadays in Italy during a major national emergency a Committee of the Italian Civil Defense ensures unified management and coordination of emergency activities. Inside it the telecom companies are committed to give support to the crisis management improving the standards in their communication networks. - Power consumption: it is at least of the order of that of the seismic station and, being related to data flow and signal quality is largely unpredictable. While the most secure option consists in adding a second independent solar power supply to the seismic station, this is not always a very convenient solution since it doubles the cost and doubles the equipment on site. We found that an acceptable trade-off is to add an

  14. Countermeasures for electrolytic corrosion - Part II: Implementation of a rapid potential-controlled rectifier

    Energy Technology Data Exchange (ETDEWEB)

    Ha, Tae-Hyun; Kim, Dae-Kyeong; Lee, Hyun-Goo; Ha, Yoon-Cheol; Bae, Jeong-Hyo [Underground Systems Group, Korea Electrotechnology Research Institute, 28-1 Sungju-dong, Changwon, 641-120 (Korea)

    2004-07-01

    In electrolytic interference circumstances such as underground pipelines in the vicinity of DC electrified railroads, drainage method or impressed current cathodic protection method has been widely used as a countermeasure for the electrolytic corrosion. In the former method, forced or polarized drainage is commonly adopted and in the latter, the phase-controlled rectifier with thyristor is in common use. Both methods, however, does not show as the optimal measure for the integrity of the pipeline, since the pipe-to-soil potential fluctuates highly positive to the cathodic protection criterion. In particular, as the potential of the pipeline near the railroad varies rapidly, a new rapidly responding countermeasure is necessary. In this paper, we introduce a new rapid potential controlled rectifier and report the result in field tests. Comparison with the existing forced drainage method is also made. The pipe-to-soil potential data show the effectiveness of the rapid potential-controlled rectifier. (authors)

  15. Psi4NumPy: An Interactive Quantum Chemistry Programming Environment for Reference Implementations and Rapid Development.

    Science.gov (United States)

    Smith, Daniel G A; Burns, Lori A; Sirianni, Dominic A; Nascimento, Daniel R; Kumar, Ashutosh; James, Andrew M; Schriber, Jeffrey B; Zhang, Tianyuan; Zhang, Boyi; Abbott, Adam S; Berquist, Eric J; Lechner, Marvin H; Cunha, Leonardo A; Heide, Alexander G; Waldrop, Jonathan M; Takeshita, Tyler Y; Alenaizan, Asem; Neuhauser, Daniel; King, Rollin A; Simmonett, Andrew C; Turney, Justin M; Schaefer, Henry F; Evangelista, Francesco A; DePrince, A Eugene; Crawford, T Daniel; Patkowski, Konrad; Sherrill, C David

    2018-06-11

    Psi4NumPy demonstrates the use of efficient computational kernels from the open-source Psi4 program through the popular NumPy library for linear algebra in Python to facilitate the rapid development of clear, understandable Python computer code for new quantum chemical methods, while maintaining a relatively low execution time. Using these tools, reference implementations have been created for a number of methods, including self-consistent field (SCF), SCF response, many-body perturbation theory, coupled-cluster theory, configuration interaction, and symmetry-adapted perturbation theory. Furthermore, several reference codes have been integrated into Jupyter notebooks, allowing background, underlying theory, and formula information to be associated with the implementation. Psi4NumPy tools and associated reference implementations can lower the barrier for future development of quantum chemistry methods. These implementations also demonstrate the power of the hybrid C++/Python programming approach employed by the Psi4 program.

  16. Using the Consolidated Framework for Implementation Research (CFIR) to produce actionable findings: a rapid-cycle evaluation approach to improving implementation.

    Science.gov (United States)

    Keith, Rosalind E; Crosson, Jesse C; O'Malley, Ann S; Cromp, DeAnn; Taylor, Erin Fries

    2017-02-10

    Much research does not address the practical needs of stakeholders responsible for introducing health care delivery interventions into organizations working to achieve better outcomes. In this article, we present an approach to using the Consolidated Framework for Implementation Research (CFIR) to guide systematic research that supports rapid-cycle evaluation of the implementation of health care delivery interventions and produces actionable evaluation findings intended to improve implementation in a timely manner. To present our approach, we describe a formative cross-case qualitative investigation of 21 primary care practices participating in the Comprehensive Primary Care (CPC) initiative, a multi-payer supported primary care practice transformation intervention led by the Centers for Medicare and Medicaid Services. Qualitative data include observational field notes and semi-structured interviews with primary care practice leadership, clinicians, and administrative and medical support staff. We use intervention-specific codes, and CFIR constructs to reduce and organize the data to support cross-case analysis of patterns of barriers and facilitators relating to different CPC components. Using the CFIR to guide data collection, coding, analysis, and reporting of findings supported a systematic, comprehensive, and timely understanding of barriers and facilitators to practice transformation. Our approach to using the CFIR produced actionable findings for improving implementation effectiveness during this initiative and for identifying improvements to implementation strategies for future practice transformation efforts. The CFIR is a useful tool for guiding rapid-cycle evaluation of the implementation of practice transformation initiatives. Using the approach described here, we systematically identified where adjustments and refinements to the intervention could be made in the second year of the 4-year intervention. We think the approach we describe has broad

  17. Rapid, low-cost prototyping of centrifugal microfluidic devices for effective implementation of various microfluidic operations

    CSIR Research Space (South Africa)

    Hugo, S

    2013-10-01

    Full Text Available can be achieved. This work provides a complete centrifugal microfluidic platform and the building blocks on which to develop a variety of microfluidic applications and potential products rapidly and at a low cost. ... stream_source_info Hugo_2015_ABSTRACT.pdf.txt stream_content_type text/plain stream_size 1281 Content-Encoding UTF-8 stream_name Hugo_2015_ABSTRACT.pdf.txt Content-Type text/plain; charset=UTF-8 Rapid Product Development...

  18. Implementation of a rapid chest pain protocol in the emergency department: A quality improvement project.

    Science.gov (United States)

    Bunch, Azalea Marie; Leasure, A Renee; Carithers, Cathrin; Burnette, Robert E; Berryman, Michael Scott

    2016-02-01

    The purpose of this quality improvement (QI) project is to compare the effectiveness of a rapid 90-min chest pain screening and evaluation protocol to a 120-min screening and evaluation protocol in determining patient readiness for hospital admission or discharge home. The existing chest pain protocol utilized in the emergency department (ED) was revised based on a review of current research changing initial screening and reevaluation times from 120 to 90 min. A prospective comparative study of patients presenting to the ED with chest pain was performed comparing the existing chest pain protocol of 120 min (standard care) with a rapid screening evaluation protocol of 90 min. A total of 128 patients presenting to an ED in Texas with chest pain comprised the sample for this study. There was a significant difference in the number of minutes between the groups for readiness for disposition. The average time from chest pain evaluation to readiness for disposition home, observation, or admission decreased from an average of 191 min in the standard care group to an average of 118 min in the rapid screening group. Use of the rapid screening and evaluation protocol decreased the time to disposition by an average of 73 min, which enhanced ED flow without influencing disposition and patient safety. ©2015 American Association of Nurse Practitioners.

  19. Analysis of readmission rates to the intensive care unit after implementation of a rapid response team in a University Hospital.

    Science.gov (United States)

    Bergamasco E Paula, R; Tanita, M T; Festti, J; Queiroz Cardoso, L T; Carvalho Grion, C M

    2017-10-01

    To compare readmission rates to the intensive care unit (ICU) before and after the implementation of a rapid response team (RRT), and to identify risk factors for readmission. A quasi-experimental before-after study was carried out. A University Hospital. All patients discharged from the ICU from January to December 2008 (control group) and from January 2010 to December 2012 (intervention group). Implementation of an RRT. The data included demographic parameters, diagnoses upon admission, ICU readmission, APACHE II, SOFA, and TISS 28 scores, and routine daily assessment by an RRT of patients discharged from the ICU. During the study interval, 380 patients were analyzed in the period prior to the implementation of the RRT and 1361 after implementation. There was a tendency toward decreased readmission rates one year after RRT implementation. The APACHE II score and SOFA score at ICU discharge were independent factors associated to readmission, as well as clinical referral to the ICU. The RRT intervention resulted in a sustained decrease in readmission rates one year after implementation of this service. The use of a specialized team in health institutions can be recommended for ICU survivors. Copyright © 2016 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  20. Implementation of a gel dosimeter for dosimetric verification of treatments with RapidArcTM

    International Nuclear Information System (INIS)

    Cortes, H.; Vasquez, J.; Plazas, M.

    2014-08-01

    The gel dosimetry represents advantages on other dosimetric systems for its potential of analyzing information in third dimension (3D). This work seeks to find another alternative for the verification of treatments of high complexity like the RapidArc TM . A gel type Magic was prepared and characterized, which was irradiated with base in a plan of RapidArc TM calculated in the Treatment Planning System (Tps) Eclipse, using the Anisotropic Analytic Algorithm (Aaa) for a beam with an acceleration potential of 6 MV. The dosimeter was characterized using Magnetic Resonance Images starting from the correlation between the T2 and the dose. The dose distribution curves were analyzed in second dimension (2D) using the program Omni Pro-I mrT and were compared with the curves obtained for the Tps under the approach gamma 2D. The comparison showed that the Gel represents a valid option inside the acceptable ranges for Quality Assurance in radiotherapy. (Author)

  1. Low-Cost Rapid Usability Testing: Its Application in Both Product Development and System Implementation.

    Science.gov (United States)

    Kushniruk, Andre; Borycki, Elizabeth

    2017-01-01

    In recent years there has been considerable discussion around the need for certification and regulation of healthcare information technology (IT). In particular, the usability of the products being developed needs to be evaluated. This has included the application of standards designed to ensure the process of system development is user-centered and takes usability into consideration while a product is being developed. In addition to this, in healthcare, organizations in the United States and Europe have also addressed the need and requirement for product certification. However, despite these efforts there are continued reports of unusable and unsafe implementations. In this paper we discuss the need to not only include (and require) usability testing in the one-time development process of health IT products (such as EHRs), but we also argue for the need to additionally develop specific usability standards and requirements for usability testing during the implementation of vendor products (i.e. post product development) in healthcare settings. It is further argued that health IT products that may have been certified regarding their development process will still require application of usability testing in the process of implementing them in real hospital settings in order to ensure usability and safety. This is needed in order to ensure that the final result of both product development and implementation processes take into account and apply the latest usability principles and methods.

  2. Design and implementation of a rapid-mixer flow cell for time-resolved infrared microspectroscopy

    International Nuclear Information System (INIS)

    Marinkovic, Nebojsa S.; Adzic, Aleksandar R.; Sullivan, Michael; Kovacs, Kevin; Miller, Lisa M.; Rousseau, Denis L.; Yeh, Syun-Ru; Chance, Mark R.

    2000-01-01

    A rapid mixer for the analysis of reactions in the millisecond and submillisecond time domains by Fourier-transform infrared microspectroscopy has been constructed. The cell was tested by examination of cytochrome-c folding kinetics. The device allows collection of full infrared spectral data on millisecond and faster time scales subsequent to chemical jump reaction initiation. The data quality is sufficiently good such that spectral fitting techniques could be applied to analysis of the data. Thus, this method provides an advantage over kinetic measurements at single wavelengths using infrared laser or diode sources, particularly where band overlap exists

  3. A Rapid Selection Procedure for Simple Commercial Implementation of omega-Transaminase Reactions

    DEFF Research Database (Denmark)

    Gundersen Deslauriers, Maria; Tufvesson, Pär; Rackham, Emma J.

    2016-01-01

    A stepwise selection procedure is presented to quickly evaluate whether a given omega-transaminase reaction is suitable for a so-called "simple" scale-up for fast industrial implementation. Here "simple" is defined as a system without the need for extensive process development or specialized......, and (3) determination of product inhibition. The method is exemplified with experimental work focused on two products: 1-(4-bromophenyl)ethylamine and (S)-(+)3-amino-1-Boc-piperidine, synthesized from their corresponding pro-chiral ketones each with two alternative amine donors, propan-2-amine, and 1......-phenylethylamine. Each step of the method has a threshold value, which must be surpassed to allow "simple" implementation, helping select suitable combinations of substrates, enzymes, and donors. One reaction pair, 1-Boc-3-piperidone with propan-2-amine, met the criteria of the three-step selection procedure...

  4. Implementation of the rapid cross section adjustment approach at General Electric

    International Nuclear Information System (INIS)

    Cowan, C.L.; Kujawski, E.; Protsik, R.

    1978-01-01

    The General Electric rapid cross section adjustment approach was developed to use the shielding factor method for formulating multigroup cross sections. In this approach, space- and composition-dependent cross sections for a particular reactor or shield design are prepared from a generalized cross section library by the use of resonance self-shielding factors, and by the adjustment of elastic scattering cross sections for the local neutron flux spectra. The principal tool in the cross section adjustment package is the data processing code TDOWN. This code was specified to give the user a high degree of flexibility in the analysis of advanced reactor designs. Of particular interest in the analysis of critical experiments is the ability to carry out cell heterogeneity self-shielding calculations using a multiregion equivalence relationship, and the homogenization of the cross sections over the specified cell with the flux weighting obtained from transport theory calculations. Extensive testing of the rapid cross section adjustment approach, including comparisons with Monte Carlo methods, indicated that this approach can be utilized with a high degree of confidence in the design analysis of complex fast reactor systems. 2 figures, 1 table

  5. Implementation of Bus Rapid Transit in Copenhagen: A Mesoscopic Model Approach

    DEFF Research Database (Denmark)

    Ingvardson, Jesper Bláfoss; Kornerup Jensen, Jonas

    2012-01-01

    Bus Rapid Transit(BRT) has shown to be an efficient and cost-effective mode of public transport, and has gained popularity in many cities around the world.To optimise the operations and infrastructure it is advantageous to deploy transportmodels. However, microscopic models are very inefficient...... upgrades (busways and enhanced stations) ensure a reduction to traveltime whereas no improvements to reliability occur. Upgrades to technology and serviceplanning (pre-paid fare collection, boarding and alighting from all doors, special BRT vehicles, ITS, and active bus control) ensure an increase...... in service reliability whereas only small reductions to travel time are observed. By combining all BRT elements it is possible to obtain synergies where the improved reliability due to planning and technology elements makes it possible to utilise the infrastructure optimally. Hence, it is possible...

  6. [Physiological responses of mycorrhizal Pinus massoniana seedlings to drought stress and drought resistance evaluation].

    Science.gov (United States)

    Wang, Yi; Ding, Gui-jie

    2013-03-01

    A greenhouse pot experiment was conducted to study the effects of inoculating Pisolithus tinctorius, Cenococcum geophilum, Cantharellus cibarius, and Suillus luteus on the physiological characteristics of Pinus massoniana seedlings under the conditions of drought stress and re-watering, with the drought resistance of the mycorrhizal seedlings evaluated. Under drought stress, the MDA content and membrane' s relative permeability of P. massoniana seedlings increased, but these two indices in the inoculated (mycorrhizal) seedlings were significantly lower than these in the un-inoculated (control) seedlings. After re-watering, the MDA content and membrane's relative permeability of mycorrhizal seedlings had a rapid decrease, as compared with the control. In the first 21 days of drought stress, the production rate of superoxide radical of the seedlings increased, and the SOD, POD and NR activities of mycorrhizal seedlings increased significantly. With the extending of drought stress, the seedlings after re-watering had different recovery ability. Under the re-watering after 14 days drought stress, the SOD, POD and NR activities recovered. The drought resistance of the mycorrhizal seedlings was in the order of Suillus luteus 1 > Suillus luteus 7 > Cantharellus cibarius > Cenococcum geophilum > Pisolithus tinctorius. The SOD and MDA activities had a greater correlation with the mycorrhizal seedlings drought resistance, being able to be used as the indicators to evaluate the drought resistance of mycorrhizal seedlings.

  7. Challenges with implementing malaria rapid diagnostic tests at primary care facilities in a Ghanaian district: a qualitative study.

    Science.gov (United States)

    Boadu, Nana Yaa; Amuasi, John; Ansong, Daniel; Einsiedel, Edna; Menon, Devidas; Yanow, Stephanie K

    2016-02-27

    Rapid diagnostic Tests (RDTs) for malaria enable diagnostic testing at primary care facilities in resource-limited settings, where weak infrastructure limits the use of microscopy. In 2010, Ghana adopted a test-before-treat guideline for malaria, with RDT use promoted to facilitate diagnosis. Yet healthcare practitioners still treat febrile patients without testing, or despite negative malaria test results. Few studies have explored RDT implementation beyond the notions of provider or patient acceptability. The aim of this study was to identify the factors directly influencing malaria RDT implementation at primary care facilities in a Ghanaian district. Qualitative interviews, focus groups and direct observations were conducted with 50 providers at six purposively selected primary care facilities in the Atwima-Nwabiagya district. Data were analysed thematically. RDT implementation was hampered by: (1) healthcare delivery constraints (weak supply chain, limited quality assurance and control, inadequate guideline emphasis, staffing limitations); (2) provider perceptions (entrenched case-management paradigms, limited preparedness for change); (3) social dynamics of care delivery (expected norms of provider-patient interaction, test affordability); and (4) limited provider engagement in policy processes leading to fragmented implementation of health sector reform. Limited health system capacity, socio-economic, political, and historical factors hampered malaria RDT implementation at primary care facilities in the study district. For effective RDT implementation providers must be: (1) adequately enabled through efficient allocation and management of essential healthcare commodities; (2) appropriately empowered with the requisite knowledge and skill through ongoing, effective professional development; and (3) actively engaged in policy dialogue to demystify socio-political misconceptions that hinder health sector reform policies from improving care delivery. Clear

  8. Rapid expansion and pseudo spectral implementation for reverse time migration in VTI media

    KAUST Repository

    Pestana, Reynam C; Ursin, Bjø rn; Stoffa, Paul L

    2012-01-01

    In isotropic media, we use the scalar acoustic wave equation to perform reverse time migration (RTM) of the recorded pressure wavefield data. In anisotropic media, P- and SV-waves are coupled, and the elastic wave equation should be used for RTM. For computational efficiency, a pseudo-acoustic wave equation is often used. This may be solved using a coupled system of second-order partial differential equations. We solve these using a pseudo spectral method and the rapid expansion method (REM) for the explicit time marching. This method generates a degenerate SV-wave in addition to the P-wave arrivals of interest. To avoid this problem, the elastic wave equation for vertical transversely isotropic (VTI) media can be split into separate wave equations for P- and SV-waves. These separate wave equations are stable, and they can be effectively used to model and migrate seismic data in VTI media where |ε- δ| is small. The artifact for the SV-wave has also been removed. The independent pseudo-differential wave equations can be solved one for each mode using the pseudo spectral method for the spatial derivatives and the REM for the explicit time advance of the wavefield. We show numerically stable and high-resolution modeling and RTM results for the pure P-wave mode in VTI media. © 2012 Sinopec Geophysical Research Institute.

  9. Rapid expansion and pseudo spectral implementation for reverse time migration in VTI media

    KAUST Repository

    Pestana, Reynam C

    2012-04-24

    In isotropic media, we use the scalar acoustic wave equation to perform reverse time migration (RTM) of the recorded pressure wavefield data. In anisotropic media, P- and SV-waves are coupled, and the elastic wave equation should be used for RTM. For computational efficiency, a pseudo-acoustic wave equation is often used. This may be solved using a coupled system of second-order partial differential equations. We solve these using a pseudo spectral method and the rapid expansion method (REM) for the explicit time marching. This method generates a degenerate SV-wave in addition to the P-wave arrivals of interest. To avoid this problem, the elastic wave equation for vertical transversely isotropic (VTI) media can be split into separate wave equations for P- and SV-waves. These separate wave equations are stable, and they can be effectively used to model and migrate seismic data in VTI media where |ε- δ| is small. The artifact for the SV-wave has also been removed. The independent pseudo-differential wave equations can be solved one for each mode using the pseudo spectral method for the spatial derivatives and the REM for the explicit time advance of the wavefield. We show numerically stable and high-resolution modeling and RTM results for the pure P-wave mode in VTI media. © 2012 Sinopec Geophysical Research Institute.

  10. Implementing the strategy of multileveled PI activities to promote rapid nuclear power development

    International Nuclear Information System (INIS)

    Chen Gang

    2005-01-01

    The first two decades of the 21st century is the golden time for nuclear power development in China. According to the nuclear power development program laid down by the State Development and Reform Commission, nearly 30 units of 1000MW will be built in the next 15 years, so as to meet fastgrowing energy demand, to optimize energy mix and to alleviate environmental pollution. Under such a new situation, based on the public information practice and experience during the construction and operation of Qinshan Nuclear Power Complex where the first commercial NPP originated in the Mainland of China, this paper emphasizes on the necessity of establishment of an active and open strategy of multileveled nuclear energy public information activities and implementation of the strategy with adoption of various forms of nuclear energy popularization means, including seminars, contests, exhibitions, site tour to nuclear power plants, reports by mass media, hosting questions-answering dialogue by experts via Internet, TV and radio programs, newspapers and journals , etc.. Thus through the nuclear energy public information activity the recognition and confidence of the public, especially the local community and the public in vicinity of new nuclear power sites on the nuclear energy can be enhanced, and the nuclear power program can gain their support. Furthermore, the fine social environment for nuclear power development can be fostered. (authors)

  11. On the impact of dose rate variation upon RapidArc implementation of volumetric modulated arc therapy

    International Nuclear Information System (INIS)

    Nicolini, Giorgia; Clivio, Alessandro; Cozzi, Luca; Fogliata, Antonella; Vanetti, Eugenio

    2011-01-01

    Purpose: A study was carried out to evaluate the robustness and mutual interplay of two variables concurring to generate modulation patterns of the RapidArc (RapidArc) implementation of volumetric modulated arc therapy. Dose rate (DR) and gantry speed (GS) are free parameters optimized alongside field aperture shape by the RapidArc engine; however, they are limited by machine constraints and mutually compensate in order to deliver the proper MU/deg during the gantry rotation. Methods: Four test cases (one geometrical and three clinical) were selected and RapidArc plans were optimized using maximum allowed dose rates from 100 to 600 MU/min. The maximum gantry speed was fixed at 4.8 deg/s. Qualitative analysis of DR and GS patterns from these cases was summarized together with quantitative assessment of delivery parameters. Pretreatment quality assurance measurements and scoring of plan quality aimed to determine whether preferable initial conditions might be identified or the optimization engine might be invariant to those variables and capable of providing adequate plans independently from the limits applied. Results: The results of the study were: (i) High dynamic range in MU/deg is achievable across all dose rates by means of gantry speed modulation; (ii) there is a robust compensation mechanism between the two variables; (iii) from a machine delivery point-of-view, slightly improved accuracy is achieved when lower DRs are applied; however, this does not have practical consequences since measurements and plan evaluation showed a lack of clinically relevant deviation; and (iv) reduced total treatment time is a major advantage of high DR. Conclusions: A trend toward improved plan quality for clinical cases was observed with high DR but cannot be generalized, due to the limited amount of cases investigated and the consequent limited significance of the observed differences. As a minimum benefit, the reduced total treatment time should be considered as well.

  12. Feasibility of implementing rapid oral fluid HIV testing in an urban University Dental Clinic: a qualitative study

    Directory of Open Access Journals (Sweden)

    Hutchinson M

    2012-05-01

    Full Text Available Abstract Background More than 1 million individuals in the U.S. are infected with HIV; approximately 20% of whom do not know they are infected. Early diagnosis of HIV infection results in earlier access to treatment and reductions in HIV transmission. In 2006, the CDC recommended that health care providers offer routine HIV screening to all adolescent and adult patients, regardless of community seroprevalence or patient lifestyle. Dental providers are uniquely positioned to implement these recommendations using rapid oral fluid HIV screening technology. However, thus far, uptake into dental practice has been very limited. Methods The study utilized a qualitative descriptive approach with convenience samples of dental faculty and students. Six in-depth one-on-one interviews were conducted with dental faculty and three focus groups were conducted with fifteen dental students. Results Results were fairly consistent and indicated relatively high levels of acceptability. Barriers and facilitators of oral fluid HIV screening were identified in four primary areas: scope of practice/practice enhancement, skills/knowledge/training, patient service/patient reactions and logistical issues. Conclusions Oral fluid HIV screening was described as having benefits for patients, dental practitioners and the public good. Many of the barriers to implementation that were identified in the study could be addressed through training and interdisciplinary collaborations.

  13. Helical Tomotherapy-Based STAT RT: Dosimetric Evaluation for Clinical Implementation of a Rapid Radiation Palliation Program

    International Nuclear Information System (INIS)

    McIntosh, Alyson; Dunlap, Neal; Sheng, Ke; Geezey, Constance; Turner, Benton; Blackhall, Leslie; Weiss, Geoffrey; Lappinen, Eric; Larner, James M.; Read, Paul W.

    2010-01-01

    Helical tomotherapy-based STAT radiation therapy (RT) uses an efficient software algorithm for rapid intensity-modulated treatment planning, enabling conformal radiation treatment plans to be generated on megavoltage computed tomography (MVCT) scans for CT simulation, treatment planning, and treatment delivery in one session. We compared helical tomotherapy-based STAT RT dosimetry with standard linac-based 3D conformal plans and standard helical tomotherapy-based intensity-modulated radiation therapy (IMRT) dosimetry for palliative treatments of whole brain, a central obstructive lung mass, multilevel spine disease, and a hip metastasis. Specifically, we compared the conformality, homogeneity, and dose with regional organs at risk (OARs) for each plan as an initial step in the clinical implementation of a STAT RT rapid radiation palliation program. Hypothetical planning target volumes (PTVs) were contoured on an anthropomorphic phantom in the lung, spine, brain, and hip. Treatment plans were created using three planning techniques: 3D conformal on Pinnacle 3 , helical tomotherapy, and helical tomotherapy-based STAT RT. Plan homogeneity, conformality, and dose to OARs were analyzed and compared. STAT RT and tomotherapy improved conformality indices for spine and lung plans (CI spine = 1.21, 1.17; CI lung = 1.20, 1.07, respectively) in comparison with standard palliative anteroposterior/posteroanterior (AP/PA) treatment plans (CI spine = 7.01, CI lung = 7.30), with better sparing of heart, esophagus, and spinal cord. For palliative whole-brain radiotherapy, STAT RT and tomotherapy reduced maximum and mean doses to the orbits and lens (maximum/mean lens dose: STAT RT = 2.94/2.65 Gy, tomotherapy = 3.13/2.80 Gy, Lateral opposed fields = 7.02/3.65 Gy), with an increased dose to the scalp (mean scalp dose: STAT RT = 16.19 Gy, tomotherapy = 15.61 Gy, lateral opposed fields = 14.01 Gy). For bony metastatic hip lesions, conformality with both tomotherapy techniques (CI = 1

  14. Meaningful use in the safety net: a rapid ethnography of patient portal implementation at five community health centers in California.

    Science.gov (United States)

    Ackerman, Sara L; Sarkar, Urmimala; Tieu, Lina; Handley, Margaret A; Schillinger, Dean; Hahn, Kenneth; Hoskote, Mekhala; Gourley, Gato; Lyles, Courtney

    2017-09-01

    US health care institutions are implementing secure websites (patient portals) to achieve federal Meaningful Use (MU) certification. We sought to understand efforts to implement portals in "safety net" health care systems that provide services for low-income populations. Our rapid ethnography involved visits at 4 California safety net health systems and in-depth interviews at a fifth. Visits included interviews with clinicians and executives ( n  = 12), informal focus groups with front-line staff ( n  = 35), observations of patient portal sign-up procedures and clinic work, review of marketing materials and portal use data, and a brief survey ( n  = 45). Our findings demonstrate that the health systems devoted considerable effort to enlisting staff support for portal adoption and integrating portal-related work into clinic routines. Although all health systems had achieved, or were close to achieving, MU benchmarks, patients faced numerous barriers to portal use and our participants were uncertain how to achieve and sustain "meaningful use" as defined by and for their patients. Health systems' efforts to achieve MU certification united clinic staff under a shared ethos of improved quality of care. However, MU's assumptions about patients' demand for electronic access to health information and ability to make use of it directed clinics' attention to enrollment and message routing rather than to the relevance and usability of a tool that is minimally adaptable to the safety net context. We found a mismatch between MU-based metrics of patient engagement and the priorities and needs of safety net patient populations. © The Author 2017. Published by Oxford University Press on behalf of the American Medical Informatics Association. All rights reserved. For Permissions, please email: journals.permissions@oup.com

  15. Molecular biology of Ganoderma pathogenicity and diagnosis in coconut seedlings.

    Science.gov (United States)

    Kandan, A; Radjacommare, R; Ramanathan, A; Raguchander, T; Balasubramanian, P; Samiyappan, R

    2009-01-01

    The pathogenicity of Ganoderma boninense was tested on coconut seedlings under greenhouse conditions and infection confirmed by using immunological and molecular diagnostic tools. Desiccation of older leaves and the emergence of sporophores were observed from pathogen-inoculated seedlings, whereas a control seedling does not show any pathogenic symptoms. Mature sporophores were formed within 10-13 weeks after inoculation. Polyclonal antibodies raised against mycelial proteins of Ganoderma were used for detection of Ganoderma in infected field palm and seedlings through indirect enzyme-linked immunosorbent assay technique. We adopted dot-immunobinding assay for the detection of Ganoderma from greenhouse and field samples. Under nucleic-acid-based diagnosis, G. boninense (167 bp) was detected from artificially inoculated seedlings and infected field palms by polymerase chain reaction. Apart from these, histopathological studies also support the Ganoderma pathogenicity in coconut seedlings. The pathogenicity test and combination of all the three diagnostic methods for Ganoderma could be highly reliable, rapid, sensitive and effective screening of resistance in planting material in the future.

  16. Undertaking a Collaborative Rapid Realist Review to Investigate What Works in the Successful Implementation of a Frail Older Person's Pathway.

    LENUS (Irish Health Repository)

    2018-01-25

    We addressed the research question "what factors enable the successful development and implementation of a frail older person\\'s pathway within the acute setting". A rapid realist review (RRR) was conducted by adopting the RAMESES standards. We began with a sample of 232 articles via database searches supplemented with 94 additional records including inputs from a twitter chat and a hospital site visit. Our final sample consisted of 18 documents. Following review and consensus by an expert panel we identified a conceptual model of context-mechanism-(resources)-outcomes. There was overall agreement frailty should be identified at the front door of the acute hospital. Significant challenges identified related to organisational boundaries both within the acute setting and externally, the need to shift outcomes to patient orientated ones, to support staff to sustain the pathway by providing ongoing education and by providing role clarity. RRRs can support research such as the systematic approach to improving care for frail older adults (SAFE) study by producing accounts of what works based on a wide range of sources and innovative engagement with stakeholders. It is evident from our provisional model that numerous factors need to combine and interact to enable and sustain a successful frail older person\\'s pathway.

  17. Development of rapid, continuous calibration techniques and implementation as a prototype system for civil engineering materials evaluation

    International Nuclear Information System (INIS)

    Scott, M. L.; Gagarin, N.; Mekemson, J. R.; Chintakunta, S. R.

    2011-01-01

    Until recently, civil engineering material calibration data could only be obtained from material sample cores or via time consuming, stationary calibration measurements in a limited number of locations. Calibration data are used to determine material propagation velocities of electromagnetic waves in test materials for use in layer thickness measurements and subsurface imaging. Limitations these calibration methods impose have been a significant impediment to broader use of nondestructive evaluation methods such as ground-penetrating radar (GPR). In 2006, a new rapid, continuous calibration approach was designed using simulation software to address these measurement limitations during a Federal Highway Administration (FHWA) research and development effort. This continuous calibration method combines a digitally-synthesized step-frequency (SF)-GPR array and a data collection protocol sequence for the common midpoint (CMP) method. Modeling and laboratory test results for various data collection protocols and materials are presented in this paper. The continuous-CMP concept was finally implemented for FHWA in a prototype demonstration system called the Advanced Pavement Evaluation (APE) system in 2009. Data from the continuous-CMP protocol is processed using a semblance/coherency analysis to determine material propagation velocities. Continuously calibrated pavement thicknesses measured with the APE system in 2009 are presented. This method is efficient, accurate, and cost-effective.

  18. Introducing rapid diagnostic tests for malaria into drug shops in Uganda: design and implementation of a cluster randomized trial.

    Science.gov (United States)

    Mbonye, Anthony K; Magnussen, Pascal; Chandler, Clare I R; Hansen, Kristian S; Lal, Sham; Cundill, Bonnie; Lynch, Caroline A; Clarke, Siân E

    2014-07-29

    An intervention was designed to introduce rapid diagnostics tests for malaria (mRDTs) into registered drug shops in Uganda to encourage rational and appropriate treatment of malaria with artemisinin-based combination therapy (ACT). We conducted participatory training of drug shop vendors and implemented supporting interventions to orientate local communities (patients) and the public sector (health facility staff and district officials) to the behavioral changes in diagnosis, treatment and referral being introduced in drug shops. The intervention was designed to be evaluated through a cluster randomized trial. In this paper, we present detailed design, implementation and evaluation experiences in order to help inform future studies of a complex nature. Three preparatory studies (formative, baseline and willingness-to-pay) were conducted to explore perceptions on diagnosis and treatment of malaria at drug shops, and affordable prices for mRDTs and ACTs in order to inform the design of the intervention and implementation modalities. The intervention required careful design with the intention to be acceptable, sustainable and effective. Critical components of intervention were: community sensitization and creating awareness, training of drug shop vendors to diagnose malaria with mRDTs, treat and refer customers to formal health facilities, giving pre-referral rectal artesunate and improved record-keeping. The primary outcome was the proportion of patients receiving appropriately-targeted treatment with ACT, evaluated against microscopy on a research blood slide. Introducing mRDTs in drug shops may seem simple, but our experience of intervention design, conduct and evaluation showed this to be a complex process requiring multiple interventions and evaluation components drawing from a combination of epidemiological, social science and health economics methodologies. The trial was conducted in phases sequenced such that each benefited from the other. The main challenges

  19. Comparative study of drought and salt stress effects on germination and seedling growth of pea

    Directory of Open Access Journals (Sweden)

    Petrović Gordana

    2016-01-01

    Full Text Available Seed germination is first critical and the most sensitive stage in the life cycle of plants compromise the seedlings establishment. Salt and drought tolerance testing in initial stages of plant development is of vital importance, because the seed with more rapid germination under salt or water deficit conditions may be expected to achieve a rapid seedling establishment, resulting in higher yields. The aim of this study was to determine whether the pea seed germination and seedling growth were inhibited by the salt toxicity and osmotic effect during the seedling development, and also identification of the sensitive seedling growth parameters in response to those stresses. Based on the obtained results, pea has been presented to be more tolerant to salt than water stress during germination and early embryo growth. Investigated cultivars showed greater susceptibility to both abiotic stresses when it comes growth parameters compared to seed germination. [Projekat Ministarstva nauke Republike Srbije, br. TR-31024 i br. TR-31022

  20. Health co-benefits in mortality avoidance from implementation of the mass rapid transit (MRT) system in Kuala Lumpur, Malaysia.

    Science.gov (United States)

    Kwan, Soo Chen; Tainio, Marko; Woodcock, James; Hashim, Jamal Hisham

    2016-03-01

    The mass rapid transit (MRT) is the largest transport infrastructure project under the national key economic area (NKEA) in Malaysia. As urban rail is anticipated to be the future spine of public transport network in the Greater Kuala Lumpur city, it is important to mainstream climate change mitigation and public health benefits in the local transport development. This study quantifies the health co-benefits in terms of mortality among the urbanites when the first line of the 150 km MRT system in Kuala Lumpur commences by 2017. Using comparative health risk assessment, we estimated the potential health co-benefits from the establishment of the MRT system. We estimated the reduced CO2 emissions and air pollution (PM2.5) exposure reduction among the general population from the reduced use of motorized vehicles. Mortality avoided from traffic incidents involving motorcycles and passenger cars, and from increased physical activity from walking while using the MRT system was also estimated. A total of 363,130 tonnes of CO2 emissions could be reduced annually from the modal shift from cars and motorcycles to the MRT system. Atmospheric PM2.5 concentration could be reduced 0.61 μg/m3 annually (2%). This could avoid a total of 12 deaths, mostly from cardio-respiratory diseases among the city residents. For traffic injuries, 37 deaths could be avoided annually from motorcycle and passenger cars accidents especially among the younger age categories (aged 15-30). One additional death was attributed to pedestrian walking. The additional daily physical activity to access the MRT system could avoid 21 deaths among its riders. Most of the mortality avoided comes from cardiovascular diseases. Overall, a total of 70 deaths could be avoided annually among both the general population and the MRT users in the city. The implementation of the MRT system in Greater Kuala Lumpur could bring substantial health co-benefits to both the general population and the MRT users mainly from the

  1. Genetic improvement of Eucalyptus grandis using breeding seedling ...

    African Journals Online (AJOL)

    Eucalyptus grandis is commercially important in Zimbabwe and a breeding program has been in progress since 1962. A classical breeding strategy was used initially but, in 1981, the Multiple Population Breeding Strategy (MPBS) was implemented and the concept of the Breeding Seedling Orchard (BSO) became central to ...

  2. AVSynDEx: A Rapid Prototyping Process Dedicated to the Implementation of Digital Image Processing Applications on Multi-DSP and FPGA Architectures

    Directory of Open Access Journals (Sweden)

    Fresse Virginie

    2002-01-01

    Full Text Available We present AVSynDEx (concatenation of AVS SynDEx, a rapid prototyping process aiming to the implementation of digital signal processing applications on mixed architectures (multi-DSP FPGA. This process is based on the use of widely available and efficient CAD tools established along the design process so that most of the implementation tasks become automatic. These tools and architectures are judiciously selected and integrated during the implementation process to help a signal processing specialist without relevant hardware experience. We have automated the translation between the different levels of the process to increase and secure it. One main advantage is that only a signal processing designer is needed, all the other specialized manual tasks being transparent in this prototyping methodology, hereby reducing the implementation time.

  3. Rapid Reconstitution Packages (RRPs) implemented by integration of computational fluid dynamics (CFD) and 3D printed microfluidics.

    Science.gov (United States)

    Chi, Albert; Curi, Sebastian; Clayton, Kevin; Luciano, David; Klauber, Kameron; Alexander-Katz, Alfredo; D'hers, Sebastian; Elman, Noel M

    2014-08-01

    Rapid Reconstitution Packages (RRPs) are portable platforms that integrate microfluidics for rapid reconstitution of lyophilized drugs. Rapid reconstitution of lyophilized drugs using standard vials and syringes is an error-prone process. RRPs were designed using computational fluid dynamics (CFD) techniques to optimize fluidic structures for rapid mixing and integrating physical properties of targeted drugs and diluents. Devices were manufactured using stereo lithography 3D printing for micrometer structural precision and rapid prototyping. Tissue plasminogen activator (tPA) was selected as the initial model drug to test the RRPs as it is unstable in solution. tPA is a thrombolytic drug, stored in lyophilized form, required in emergency settings for which rapid reconstitution is of critical importance. RRP performance and drug stability were evaluated by high-performance liquid chromatography (HPLC) to characterize release kinetics. In addition, enzyme-linked immunosorbent assays (ELISAs) were performed to test for drug activity after the RRPs were exposed to various controlled temperature conditions. Experimental results showed that RRPs provided effective reconstitution of tPA that strongly correlated with CFD results. Simulation and experimental results show that release kinetics can be adjusted by tuning the device structural dimensions and diluent drug physical parameters. The design of RRPs can be tailored for a number of applications by taking into account physical parameters of the active pharmaceutical ingredients (APIs), excipients, and diluents. RRPs are portable platforms that can be utilized for reconstitution of emergency drugs in time-critical therapies.

  4. Study on tissue culture for Gelidium seedling

    Science.gov (United States)

    Pei, Lu-Qing; Luo, Qi-Jun; Fei, Zhi-Qing; Ma, Bin

    1996-06-01

    As seedling culture is a crucial factor for successful cultivation of Gelidium, the authors researched tissue culture technology for producing seedlings. The morphogeny and experimental ecology were observed and studied fully in 2 5 mm isolated tissue fragments. Regeneration, appearance of branching creepers and attaching structure and new erect seedlings production and development were studied. Fragments were sown on bamboo slice and vinylon rope. The seedlings were cultured 20 30 days indoor, then cultured in the sea, where the density of erect seedlings was 3 19 seedlings/cm2, growth rate was 3.84% day. The frond arising from seedlings directly was up to 10 cm per year. The ecological conditions for regenerated seedlings are similar to the natural ones. The regenerated seedlings are suitable for raft culture in various sea areas.

  5. Modular Rapid E-Learning Framework (MORELF) in Desktop Virtualization Environment: An Effective Hybrid Implementation in Nurse Education

    Science.gov (United States)

    Parlakkilic, Alattin

    2015-01-01

    Generally it is not easy for an instructor to prepare and deliver electronic courses via e-learning. Therefore it is necessary to work and develop an easy system. In this context module technology was used to for provide modularity in conducting educational development of e-learning course. Then, rapid e-learning was used for more quick and easy…

  6. Potential production of Aspidosperma cylindrocarpon seedlings viarescue seedlings

    Directory of Open Access Journals (Sweden)

    Nathália Ferreira e Silva

    Full Text Available ABSTRACT: Translocation of rare populations is regarded as the last resort for the conservation of species whose habitat destruction is imminent. The objective of the present study was to evaluate the effect of two height classes and three leaf reduction intensities on growth and increases in height, stem diameter, survival, and new leaf production in seedlings of Aspidosperma cylindrocarpon (peroba obtained via rescue seedlings in a remnant of tropical semi deciduous forest. We recovered 240 individuals that were divided into two height classes (Class I-5 to 15cm and Class II-20 to 35cm and subjected to three leaf reduction intensities (0%, 50%, and 100%, which were then transported to a shade house with 50% light reduction. Measurements of height, stem diameter, and new leaf production were collected 8 times at 0, 15, 60, 75, 90, 105, 120, and 135 days, and survival rate was measured at day 135. The average survival rate was 82.9%; 77.5% for one Class I (5-15cm and 88.3% for Class II (20-35cm. Higher seedling growth was observed for the 0% leaf reduction treatment in both height classes. The leaves insertion were greater in the 100% cuts, with a decrease observed over time. It is advisable to restore A. cylindrocarpon seedlings in two height classes owing to the high survival rate, leaf appearance, and growth reported in the present study. The no-leaf reduction treatment (0% is the most viable alternative for the production of A. cylindrocarpon seedlings, via rescue seedlings.

  7. Machine vision system for measuring conifer seedling morphology

    Science.gov (United States)

    Rigney, Michael P.; Kranzler, Glenn A.

    1995-01-01

    A PC-based machine vision system providing rapid measurement of bare-root tree seedling morphological features has been designed. The system uses backlighting and a 2048-pixel line- scan camera to acquire images with transverse resolutions as high as 0.05 mm for precise measurement of stem diameter. Individual seedlings are manually loaded on a conveyor belt and inspected by the vision system in less than 0.25 seconds. Designed for quality control and morphological data acquisition by nursery personnel, the system provides a user-friendly, menu-driven graphical interface. The system automatically locates the seedling root collar and measures stem diameter, shoot height, sturdiness ratio, root mass length, projected shoot and root area, shoot-root area ratio, and percent fine roots. Sample statistics are computed for each measured feature. Measurements for each seedling may be stored for later analysis. Feature measurements may be compared with multi-class quality criteria to determine sample quality or to perform multi-class sorting. Statistical summary and classification reports may be printed to facilitate the communication of quality concerns with grading personnel. Tests were conducted at a commercial forest nursery to evaluate measurement precision. Four quality control personnel measured root collar diameter, stem height, and root mass length on each of 200 conifer seedlings. The same seedlings were inspected four times by the machine vision system. Machine stem diameter measurement precision was four times greater than that of manual measurements. Machine and manual measurements had comparable precision for shoot height and root mass length.

  8. Barriers and Facilitators to Implementing the HEADS-ED: A Rapid Screening Tool for Pediatric Patients in Emergency Departments.

    Science.gov (United States)

    MacWilliams, Kate; Curran, Janet; Racek, Jakub; Cloutier, Paula; Cappelli, Mario

    2017-12-01

    This study sought to identify barriers and facilitators to the implementation of the HEADS-ED, a screening tool appropriate for use in the emergency department (ED) that facilitates standardized assessments, discharge planning, charting, and linking pediatric mental health patients to appropriate community resources. A qualitative theory-based design was used to identify barriers and facilitators to implementing the HEADS-ED tool. Focus groups were conducted with participants recruited from 6 different ED settings across 2 provinces (Ontario and Nova Scotia). The Theoretical Domains Framework was used as a conceptual framework to guide data collection and to identify themes from focus group discussions. The following themes spanning 12 domains were identified as reflective of participants' beliefs about the barriers and facilitators to implementing the HEADS-ED tool: knowledge, skills, beliefs about capabilities, social professional role and identity, optimism, beliefs about consequences, reinforcement, environmental context and resources, social influences, emotion, behavioral regulation and memory, and attention and decision process. The HEADS-ED has the potential to address the need for better discharge planning, complete charting, and standardized assessments for the increasing population of pediatric mental health patients who present to EDs. This study has identified potential barriers and facilitators, which should be considered when developing an implementation plan for adopting the HEADS-ED tool into practice within EDs.

  9. Methods for Rapid Screening in Woody Plant Herbicide Development

    Directory of Open Access Journals (Sweden)

    William Stanley

    2014-07-01

    Full Text Available Methods for woody plant herbicide screening were assayed with the goal of reducing resources and time required to conduct preliminary screenings for new products. Rapid screening methods tested included greenhouse seedling screening, germinal screening, and seed screening. Triclopyr and eight experimental herbicides from Dow AgroSciences (DAS 313, 402, 534, 548, 602, 729, 779, and 896 were tested on black locust, loblolly pine, red maple, sweetgum, and water oak. Screening results detected differences in herbicide and species in all experiments in much less time (days to weeks than traditional field screenings and consumed significantly less resources (<500 mg acid equivalent per herbicide per screening. Using regression analysis, various rapid screening methods were linked into a system capable of rapidly and inexpensively assessing herbicide efficacy and spectrum of activity. Implementation of such a system could streamline early-stage herbicide development leading to field trials, potentially freeing resources for use in development of beneficial new herbicide products.

  10. Design and implementation of a radiation hardened silicon on sapphire (SOS) embedded signal conditioning unit controller (SCUC) for the RAPID instrument on the Cluster satellites

    International Nuclear Information System (INIS)

    Ersland, L.

    1992-07-01

    The Cluster mission consistens of four spacecrafts equipped with instruments capable of making comprehensive measurements of plasma particles and electromagnetic fields. The RAPID (Research with Adaptive Particle Imaging Detectors) spectrometer is one of many instruments on board the Cluster satellites. It is designed for fast analysis of energetic electrons and ions with a complete coverage of the unit sphere in phase space. This thesis describes the development and testing of an embedded controller for the Spectroscopic Camera for Electrons, Neutral and Ion Compositions (SCENIC), which is a part of the RAPID instrument. The design is implemented in two different CMOS circuit technologies, namely Actel's Field Programmable Gate Arrays and GEC Plessey's CMOS Silicon On Sapphire (SOS) gate array. The prototypes of the SOS gate array have been verified and characterized. This includes measurements of DC and AC parameters under different conditions, including total dose of gamma irradiation. 42 refs., 92 figs., 44 tabs

  11. Seedling vigor and genetic variability for rice seed, seedling emergence and seedling traits

    International Nuclear Information System (INIS)

    Ali, S.S.; Jafri, S.J.H.; Jamil, M.; Ijaz, M.

    1994-01-01

    Eleven local rice cultivars including Basmati 370 were evaluated for seedling vigor. Three groups of traits were evaluated viz; seed traits (Seed density, seed volume see weight, paddy length and grain length), seed emergence traits (emergence %, emergence index and emergence rate index), and seedling traits (fresh root length, dry root weight, emergence percentage, root length, dry root weight, seed weight and relative root weight were observed significant, respectively. Seed density, relative root weight, emergence rate index and root to shoot ratio were relatively more amenable to improvement. Relative expected genetic advance was the function of heritability and coefficient of phenotypic variability, latter being more important. (author)

  12. Growing container seedlings: Three considerations

    Science.gov (United States)

    Kas Dumroese; Thomas D. Landis

    2015-01-01

    The science of growing reforestation and conservation plants in containers has continually evolved, and three simple observations may greatly improve seedling quality. First, retaining stock in its original container for more than one growing season should be avoided. Second, strongly taprooted species now being grown as bareroot stock may be good candidates...

  13. Light affects the chloroplast ultrastructure and post-storage photosynthetic performance of watermelon (Citrullus lanatus) plug seedlings.

    Science.gov (United States)

    Duan, Qingqing; Jiang, Wu; Ding, Ming; Lin, Ye; Huang, Danfeng

    2014-01-01

    Watermelon [Citrullus lanatus (Thunb.) Matsum. and Nakai] plug seedlings were stored at 15°C in the light at a photosynthetic photon flux density of 15 µmol·m(-2)·s(-1) or in darkness for 6 days, to evaluate their chloroplast ultrastructure, and associated photosynthetic characteristics. Storage in the dark caused swelling, disordered granal arrangement, and starch grain disappearance in the chloroplasts. In contrast, the chloroplasts stored in the light were relatively normal. As a result, the light-stored seedlings had a significantly higher chlorophyll content, Fv/Fm, and Pn than did dark-stored seedlings. Regardless of whether the seedlings were stored in light or darkness, the Gs and Ls of the seedlings significantly decreased, while the Ci obviously increased when the Pn decreased after 6 days of storage. This result suggests that the decreased Pn is not solely a stomatal effect, as the effects on the chloroplasts contributed to this photosynthetic inhibition. Six days after transplanting, seedlings that were stored in the light or darkness for 2 or 4 days showed complete recovery of chloroplast ultrastructure, chlorophyll content, Fv/Fm, Gs and Pn. When the storage period increased to 6 days, the dark-stored seedlings had a significantly lower Fv/Fm and Pn than the light-stored and control seedlings 6 days after transplanting, which was mainly ascribed to incomplete recovery of chloroplast ultrastructure. Furthermore, the light-stored seedlings exhibited a significantly higher shoot dry weight during storage and a higher percentage dry weight increase after transplanting than the dark-stored seedlings. These effects were enhanced by prolonged storage (4 to 6 days). This study demonstrated that dim light during storage is beneficial for maintaining chloroplast ultrastructure as well as photosynthetic efficiency in watermelon seedlings, thus contributing to the rapid recovery of post-storage photosynthetic performance, which ensures the transplant quality

  14. The use of SMIRP for the rapid design and implementation of pedagogical constructs: Case study of a question-answer-reference framework

    Directory of Open Access Journals (Sweden)

    Jeremy Boecker,

    2003-01-01

    Full Text Available The use of SMIRP, a web-based collaborative tool, for an application in an undergraduate and a graduate class is described. SMIRP was used to rapidly construct a collaborative space where students could work on their assignment, request assistance and view their grades. The pedagogical construct was based on a question-answer-reference model where students were required to answer a series of questions based only on the material present in references they selected from the open literature. The answers and grades of all students were visible to all students in real time, although pseudonyms were used to respect student privacy. Email alerts were provided to the teacher, teaching assistants and in the second class also to the students and a librarian. Based on the analysis of log files, overall student performance in the class was found to correlate positively with curiosity and negatively with procrastination. Student expectations of turnaround times for grades and general queries were also analyzed and compared to actual performance. At the end of both classes a questionnaire module was created and an analysis of student satisfaction and preferences is reported. The successful implementation of SMIRP in these two classes supports the contention that this collaborative tool is flexible enough for the rapid design and implementation of relatively complex pedagogical constructs, with the possibility of obtaining detailed metrics.

  15. Feasibility of distributing rapid diagnostic tests for malaria in the retail sector: evidence from an implementation study in Uganda.

    Science.gov (United States)

    Cohen, Jessica; Fink, Günther; Berg, Katrina; Aber, Flavia; Jordan, Matthew; Maloney, Kathleen; Dickens, William

    2012-01-01

    Despite the benefits of malaria diagnosis, most presumed malaria episodes are never tested. A primary reason is the absence of diagnostic tests in retail establishments, where many patients seek care. Malaria rapid diagnostic tests (RDTs) in drug shops hold promise for guiding appropriate treatment. However, retail providers generally lack awareness of RDTs and training to administer them. Further, unsubsidized RDTs may be unaffordable to patients and unattractive to retailers. This paper reports results from an intervention study testing the feasibility of RDT distribution in Ugandan drug shops. 92 drug shops in 58 villages were offered subsidized RDTs for sale after completing training. Data on RDT purchases, storage, administration and disposal were collected, and samples were sent for quality testing. Household surveys were conducted to capture treatment outcomes. Estimated daily RDT sales varied substantially across shops, from zero to 8.46 RDTs per days. Overall compliance with storage, treatment and disposal guidelines was excellent. All RDTs (100%) collected from shops passed quality testing. The median price charged for RDTs was 1000USH ($0.40), corresponding to a 100% markup, and the same price as blood slides in local health clinics. RDTs affected treatment decisions. RDT-positive patients were 23 percentage points more likely to buy Artemisinin Combination Therapies (ACTs) (p = .005) and 33.1 percentage points more likely to buy other antimalarials (ppercentage points more likely to buy ACTs (p = .05) and 31.4 percentage points more likely to buy other antimalarials (p<.001) than those not tested at all. Despite some heterogeneity, shops demonstrated a desire to stock RDTs and use them to guide treatment recommendations. Most shops stored, administered and disposed of RDTs properly and charged mark-ups similar to those charged on common medicines. Results from this study suggest that distributing RDTs through the retail sector is feasible and

  16. Rapid EHR development and implementation using web and cloud-based architecture in a large home health and hospice organization.

    Science.gov (United States)

    Weaver, Charlotte A; Teenier, Pamela

    2014-01-01

    Health care organizations have long been limited to a small number of major vendors in their selection of an electronic health record (EHR) system in the national and international marketplace. These major EHR vendors have in common base systems that are decades old, are built in antiquated programming languages, use outdated server architecture, and are based on inflexible data models [1,2]. The option to upgrade their technology to keep pace with the power of new web-based architecture, programming tools and cloud servers is not easily undertaken due to large client bases, development costs and risk [3]. This paper presents the decade-long efforts of a large national provider of home health and hospice care to select an EHR product, failing that to build their own and failing that initiative to go back into the market in 2012. The decade time delay had allowed new technologies and more nimble vendors to enter the market. Partnering with a new start-up company doing web and cloud based architecture for the home health and hospice market, made it possible to build, test and implement an operational and point of care system in 264 home health locations across 40 states and three time zones in the United States. This option of "starting over" with the new web and cloud technologies may be posing a next generation of new EHR vendors that retells the Blackberry replacement by iPhone story in healthcare.

  17. Retardation of hypocotyl elongation of ornamental and vegetable seedlings by ultraviolet irradiation

    International Nuclear Information System (INIS)

    Bae, E.; Inamoto, K.; Doi, M.; Imanishi, H.

    1998-01-01

    Seedlings of cosmos (Cosmos bipinnatus Cav.), lettuce (Lactuca sativa L.), sunflower (Helianthus annuus L), ornamental kale (Brassica oleracea L. var. acephara), tomato (Lycopersicon esculentum Mill.), bell pepper (Capsicum annuum L.), and cucumber (Cucumis sativus L.) were irradiated by a UV-B lamp (fluorescent sun lamp) or a three-band fluorescent lamp (control) for 72 hr just after sowing. Hypocotyl elongation was repressed by all species during the irradiation with UV-B. The retarding effects of UV-B persisted when these seedlings were placed in dark or a greenhouse with 30% shade after irradiation. The most effective timing of UV-B irradiation for cosmos and ornamental kale seedlings was from 48 hr to 72 hr after sowing, when the seedlings were rapidly increasing their surface area to UV-B

  18. Feasibility of distributing rapid diagnostic tests for malaria in the retail sector: evidence from an implementation study in Uganda.

    Directory of Open Access Journals (Sweden)

    Jessica Cohen

    Full Text Available BACKGROUND: Despite the benefits of malaria diagnosis, most presumed malaria episodes are never tested. A primary reason is the absence of diagnostic tests in retail establishments, where many patients seek care. Malaria rapid diagnostic tests (RDTs in drug shops hold promise for guiding appropriate treatment. However, retail providers generally lack awareness of RDTs and training to administer them. Further, unsubsidized RDTs may be unaffordable to patients and unattractive to retailers. This paper reports results from an intervention study testing the feasibility of RDT distribution in Ugandan drug shops. METHODS AND FINDINGS: 92 drug shops in 58 villages were offered subsidized RDTs for sale after completing training. Data on RDT purchases, storage, administration and disposal were collected, and samples were sent for quality testing. Household surveys were conducted to capture treatment outcomes. Estimated daily RDT sales varied substantially across shops, from zero to 8.46 RDTs per days. Overall compliance with storage, treatment and disposal guidelines was excellent. All RDTs (100% collected from shops passed quality testing. The median price charged for RDTs was 1000USH ($0.40, corresponding to a 100% markup, and the same price as blood slides in local health clinics. RDTs affected treatment decisions. RDT-positive patients were 23 percentage points more likely to buy Artemisinin Combination Therapies (ACTs (p = .005 and 33.1 percentage points more likely to buy other antimalarials (p<.001 than RDT-negative patients, and were 5.6 percentage points more likely to buy ACTs (p = .05 and 31.4 percentage points more likely to buy other antimalarials (p<.001 than those not tested at all. CONCLUSIONS: Despite some heterogeneity, shops demonstrated a desire to stock RDTs and use them to guide treatment recommendations. Most shops stored, administered and disposed of RDTs properly and charged mark-ups similar to those charged on common

  19. Implementation of a rapid HIT immunoassay at a university hospital - Retrospective analysis of HIT laboratory orders in patients with thrombocytopenia.

    Science.gov (United States)

    Black, Anne; Heimerl, Susanne; Oertli, Linnéa; Wilczek, Wolf; Greinacher, Andreas; Spannagl, Michael; Herr, Wolfgang; Hart, Christina

    2017-10-01

    Heparin-induced thrombocytopenia (HIT) is a rare cause of thrombocytopenia and a potentially life-threatening adverse drug reaction. Clinical overdiagnosis of HIT results in costly laboratory tests and anticoagulation. Criteria and algorithms for diagnosis are established, but their translation into clinical practice is still challenging. In a retrospective approach we studied all HIT related laboratory test requests within four years and evaluated data before (1st period, 24month) and after (2nd period, 24month) replacing particle gel immunoassay (PaGIA) and enzyme-linked immunosorbent assay (ELISA) by a chemiluminescent immunoassay (CLIA). HIT was confirmed by heparin-induced platelet activation (HIPA) test. Clinical pretest probability for HIT using an implemented simplified 4Ts score and platelet count were evaluated. Costs for laboratory tests and alternative anticoagulation were calculated. In 1850 patients with suspected HIT, 2327 laboratory orders were performed. In 87.2% of these orders an intermediate/high simplified 4Ts score was found. Thrombocytopenia was present in 87.1%. After replacing PaGIA and ELISA by CLIA the number of immunological and functional laboratory tests was reduced by 38.2%. The number of positive HIT immunoassays declined from 22.6% to 6.0%, while the number of positive HIPA tests among positive immunological tests increased by 19%. Altogether, acute HIT was confirmed in 59 patients. A decline in the use of alternative anticoagulants was observed in the 2nd period. Our study shows that in a university hospital setting HIT is well-known, but diagnosis requires a precise laboratory confirmation. Replacing PaGIA and ELISA by CLIA did not influence laboratory order behavior but results in reduced overall costs for laboratory diagnostics and alternative anticoagulation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Clinician Perspectives of Barriers to Effective Implementation of a Rapid Response System in an Academic Health Centre: A Focus Group Study

    Directory of Open Access Journals (Sweden)

    John Rihari-Thomas

    2017-08-01

    Full Text Available Background Systemic and structural issues of rapid response system (RRS models can hinder implementation. This study sought to understand the ways in which acute care clinicians (physicians and nurses experience and negotiate care for deteriorating patients within the RRS. Methods Physicians and nurses working within an Australian academic health centre within a jurisdictional-based model of clinical governance participated in focus group interviews. Verbatim transcripts were analysed using thematic content analysis. Results Thirty-four participants (21 physicians and 13 registered nurses [RNs] participated in six focus groups over five weeks in 2014. Implementing the RRS in daily practice was a process of informal communication and negotiation in spite of standardised protocols. Themes highlighted several systems or organisational-level barriers to an effective RRS, including (1 responsibility is inversely proportional to clinical experience; (2 actions around system flexibility contribute to deviation from protocol; (3 misdistribution of resources leads to perceptions of inadequate staffing levels inhibiting full optimisation of the RRS; and (4 poor communication and documentation of RRS increases clinician workloads. Conclusion Implementing a RRS is complex and multifactorial, influenced by various inter- and intra-professional factors, staffing models and organisational culture. The RRS is not a static model; it is both reflexive and iterative, perpetually transforming to meet healthcare consumer and provider demands and local unit contexts and needs. Requiring more than just a strong initial implementation phase, new models of care such as a RRS demand good governance processes, ongoing support and regular evaluation and refinement. Cultural, organizational and professional factors, as well as systems-based processes, require consideration if RRSs are to achieve their intended outcomes in dynamic healthcare settings.

  1. Management of unscheduled tetanus prophylaxis in Emergency Departments: Point-of-Care implementation as a rapid tool for the evaluation of anti-tetanus antibodies

    Directory of Open Access Journals (Sweden)

    Andrea Rocchetti

    2016-03-01

    Full Text Available Background and aim: Each analytical activity, including those carried out in Point of Care (POCT must be, at law, under the control of Laboratory Medicine. Before the implementation of the rapid tetanus quick stick (TQS test for the evaluation of the specific tetanus immunisation, a multi-disciplinary and multi-professional group was created. The aim of this study was to evaluate the ability of Emergency Department (ED staff to manage and correctly understand the result of TQS test in POCT. Materials and Methods: This analysis took into consideration 152 patients admitted to ED with traumatic wounds; information on the state of tetanus immunisation at their arrival wasn’t recorded. Blood sample analysis was performed twice. The Laboratory confirmed a 100% concordance between their results and ELISA test (standard criterion. Study design consisted of 2 phases: the first one (50 test to preliminarily evaluate if any corrective action or improvement of procedures is required, and the second one (102 tests to confirm the quality of corrective actions. Results: The concordance of results between TQS test in Laboratory and POCT test in ED was 80% in the first phase and 95% in the second one.Conclusions: The use of the rapid TQS test is a valuable tool; however, to avoid serious mistakes of interpretation, periodic checks on the quality of the results must be arranged.

  2. Natural Homologous Triploidization and DNA Methylation in SARII-628, a Twin-seedling Line of Rice (Oryza sativa

    Directory of Open Access Journals (Sweden)

    Hai PENG

    2007-12-01

    Full Text Available A total of five pairs of diploid-triploid twin-seedlings (a diploid seedling and a triploid seedling emerged from a grain were selected out from 4500 pairs of seedlings from SARII-628, a twin-seedling rice line. SSR analysis indicated that no difference between the diploid seedling and corresponding triploid seedling in a twin-seedling was found at the 310 loci, indicating that there was no obvious change in DNA primary structure. A modified AFLP technique ‘MSAP (methylation-sensitive AFLP’ was used to analyze methylation mutation. Although no methylation mutation was noted among the five diploids, 29 methylation mutation loci were found from the corresponding triploids. This suggested that methylation mutation happened rapidly on M0 generation after natural homologous triploidization. The mutations were classified into 10 types, including 3 increased types, 3 decreased types and 4 undecided types of methylation-degrees. The bands of 22 loci were sequenced and then those sequences were searched through website. The result showed that the methylation mutation involved into the whole rice genome and the 12 pairs of chromosomes. The mutation trend was site-related and there were different mutation loci for different triploids, which foretold that SARII-628 would have different evolution fates after natural homologous triploidization.

  3. Seedling recruitment of Colophospermum mopane on the Highveld ...

    African Journals Online (AJOL)

    Seedling recruitment of Colophospermum mopane on the Highveld of Zimbabwe: research note. ... Open areas with bare ground or sparse grass cover were favourable sites for seedling recruitment. Seedlings ... AJOL African Journals Online.

  4. Diversity of seedling responses to drought

    NARCIS (Netherlands)

    Slot, M.; Poorter, L.

    2007-01-01

    Drought is an important seedling mortality agent in dry and moist tropical forests, and more severe and frequent droughts are predicted in the future. The effect of drought on leaf gas exchange and seedling survival was tested in a dry-down experiment with four tree species from dry and moist

  5. Reduction of anti-malarial consumption after rapid diagnostic tests implementation in Dar es Salaam: a before-after and cluster randomized controlled study

    Directory of Open Access Journals (Sweden)

    Swai Ndeniria

    2011-04-01

    Full Text Available Abstract Background Presumptive treatment of all febrile patients with anti-malarials leads to massive over-treatment. The aim was to assess the effect of implementing malaria rapid diagnostic tests (mRDTs on prescription of anti-malarials in urban Tanzania. Methods The design was a prospective collection of routine statistics from ledger books and cross-sectional surveys before and after intervention in randomly selected health facilities (HF in Dar es Salaam, Tanzania. The participants were all clinicians and their patients in the above health facilities. The intervention consisted of training and introduction of mRDTs in all three hospitals and in six HF. Three HF without mRDTs were selected as matched controls. The use of routine mRDT and treatment upon result was advised for all patients complaining of fever, including children under five years of age. The main outcome measures were: (1 anti-malarial consumption recorded from routine statistics in ledger books of all HF before and after intervention; (2 anti-malarial prescription recorded during observed consultations in cross-sectional surveys conducted in all HF before and 18 months after mRDT implementation. Results Based on routine statistics, the amount of artemether-lumefantrine blisters used post-intervention was reduced by 68% (95%CI 57-80 in intervention and 32% (9-54 in control HF. For quinine vials, the reduction was 63% (54-72 in intervention and an increase of 2.49 times (1.62-3.35 in control HF. Before-and-after cross-sectional surveys showed a similar decrease from 75% to 20% in the proportion of patients receiving anti-malarial treatment (Risk ratio 0.23, 95%CI 0.20-0.26. The cluster randomized analysis showed a considerable difference of anti-malarial prescription between intervention HF (22% and control HF (60% (Risk ratio 0.30, 95%CI 0.14-0.70. Adherence to test result was excellent since only 7% of negative patients received an anti-malarial. However, antibiotic

  6. Effects of genetics, management intensity, and seedling density on early stocking in loblolly pine

    Science.gov (United States)

    Scott D. Roberts; Randall J. Rousseau; B. Landis Herrin

    2015-01-01

    Rapid establishment and early tree growth can be key factors in successful plantation management. This generally entails planting good quality planting stock at a seedling density appropriate for the management objectives and then managing at an appropriate intensity with a goal of fully occupying the site as quickly as possible within the context of those objectives....

  7. Remnant Trees in Enrichment Planted Gaps in Quintana Roo, Mexico: Reasons for Retention and Effects on Seedlings

    Directory of Open Access Journals (Sweden)

    Angélica Navarro-Martínez

    2017-07-01

    Full Text Available Natural forest management in the tropics is often impeded by scarcity of advanced regeneration of commercial species. To supplement natural regeneration in a forest managed by a community in the Selva Maya of Mexico, nursery-grown Swietenia macrophylla seedlings were planted in multiple-tree felling gaps, known as bosquetes. Remnant trees are often left standing in gaps for cultural and economic reasons or due to their official protected status. We focus on these purposefully retained trees and their impacts on planted seedlings. Sampled bosquetes were 400–1800 m2, of which remnant trees covered a mean of 29%. Seedling height growth rates over the first 18 months after out-planting more than doubled with increased canopy openness from 0.09 m year−1 under medium cover to 0.22 m year−1 in full sun. Liana infestations and shoot tip damage were most frequent on seedlings in the open, but, contrary to our expectations, height growth rates were 0.14 m year−1 faster for liana-infested seedlings than non-infested and did not differ between damaged and undamaged seedlings. Apparently the more rapid height growth of well-illuminated seedlings more than compensated for the effects of lianas or shoot tip damage. Despite the abundance of remnant trees and their negative effects on seedling growth, enrichment planting in bosquetes has potential for community-based natural forest management in the tropics in supplementing natural regeneration of commercial species. One obvious recommendation is to leave fewer remnant trees, especially those of commercial species that are non-merchantable due to stem defects and trees retained for no apparent reason, which together constituted half of the remnant crown cover in the sampled bosquetes. Finally, given the rapid growth of lianas and understory palms in large canopy gaps, at least the most vigorous of the planted seedlings should be tended for at least two years.

  8. Undertaking a Collaborative Rapid Realist Review to Investigate What Works in the Successful Implementation of a Frail Older Person’s Pathway

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    Éidín Ní Shé

    2018-01-01

    Full Text Available We addressed the research question “what factors enable the successful development and implementation of a frail older person’s pathway within the acute setting”. A rapid realist review (RRR was conducted by adopting the RAMESES standards. We began with a sample of 232 articles via database searches supplemented with 94 additional records including inputs from a twitter chat and a hospital site visit. Our final sample consisted of 18 documents. Following review and consensus by an expert panel we identified a conceptual model of context-mechanism-(resources-outcomes. There was overall agreement frailty should be identified at the front door of the acute hospital. Significant challenges identified related to organisational boundaries both within the acute setting and externally, the need to shift outcomes to patient orientated ones, to support staff to sustain the pathway by providing ongoing education and by providing role clarity. RRRs can support research such as the systematic approach to improving care for frail older adults (SAFE study by producing accounts of what works based on a wide range of sources and innovative engagement with stakeholders. It is evident from our provisional model that numerous factors need to combine and interact to enable and sustain a successful frail older person’s pathway.

  9. A Prototype Regional GSI-based EnKF-Variational Hybrid Data Assimilation System for the Rapid Refresh Forecasting System: Dual-Resolution Implementation and Testing Results

    Science.gov (United States)

    Pan, Yujie; Xue, Ming; Zhu, Kefeng; Wang, Mingjun

    2018-05-01

    A dual-resolution (DR) version of a regional ensemble Kalman filter (EnKF)-3D ensemble variational (3DEnVar) coupled hybrid data assimilation system is implemented as a prototype for the operational Rapid Refresh forecasting system. The DR 3DEnVar system combines a high-resolution (HR) deterministic background forecast with lower-resolution (LR) EnKF ensemble perturbations used for flow-dependent background error covariance to produce a HR analysis. The computational cost is substantially reduced by running the ensemble forecasts and EnKF analyses at LR. The DR 3DEnVar system is tested with 3-h cycles over a 9-day period using a 40/˜13-km grid spacing combination. The HR forecasts from the DR hybrid analyses are compared with forecasts launched from HR Gridpoint Statistical Interpolation (GSI) 3D variational (3DVar) analyses, and single LR hybrid analyses interpolated to the HR grid. With the DR 3DEnVar system, a 90% weight for the ensemble covariance yields the lowest forecast errors and the DR hybrid system clearly outperforms the HR GSI 3DVar. Humidity and wind forecasts are also better than those launched from interpolated LR hybrid analyses, but the temperature forecasts are slightly worse. The humidity forecasts are improved most. For precipitation forecasts, the DR 3DEnVar always outperforms HR GSI 3DVar. It also outperforms the LR 3DEnVar, except for the initial forecast period and lower thresholds.

  10. Synthesis of Pisolithus Ectomycorrhizae on Pecan Seedlings in Fumigated Soil

    Science.gov (United States)

    Donald H. Marx

    1979-01-01

    Curtis variety of pecan (Carya illinoensis) seedlings were grown for 8 months in fumigated soil infested at sowing with mycelial inoculum of Pisolithus tinctorius. Pisolithus ectomycorrhizae were formed on all inoculated seedlings and significantly improved their growth over control seedlings. Inoculated and control seedlings also formed ectomycorrhizae with naturally...

  11. Red fox ( Vulpes vulpes L.) favour seed dispersal, germination and seedling survival of Mediterranean Hackberry ( Celtis australis L.)

    Science.gov (United States)

    Juan, Traba; Sagrario, Arrieta; Jesús, Herranz; Cristina, Clamagirand M.

    2006-07-01

    Seeds of the Mediterranean Hackberry Celtis australis are often encountered in fox faeces. In order to evaluate the effect of gut transit on the size of seeds selected, the rates and speed of germination and on the survival of the seedlings, Mediterranean Hackberry seeds from fox faeces were germinated in a greenhouse. The results were compared with those of seeds taken from ripe, uneaten fruits. Fox-dispersed seeds were smaller and lighter than the control ones and had higher (74% vs. 57%) and more rapid germination (74.5 days vs. 99.2 days). Seedlings from fox-dispersed seeds showed significantly greater survival by the end of the study period (74.1% vs. 43.6%) than the control ones. Survival in seedlings from fox-dispersed seeds was related to germination date, late seedlings showing poorer survival. This relationship was not observed away in the control seedlings. Seed mass did not affect seedling survival. Seedling arising from fox-dispersed seeds grew faster than control ones. These results suggest that fox can play a relevant role as seed disperser of Mediterranean Hackberry.

  12. Short dry spells in the wet season increase mortality of tropical pioneer seedlings.

    Science.gov (United States)

    Engelbrecht, Bettina M J; Dalling, James W; Pearson, Timothy R H; Wolf, Robert L; Gálvez, David A; Koehler, Tobias; Tyree, Melvin T; Kursar, Thomas A

    2006-06-01

    Variation in plant species performance in response to water availability offers a potential axis for temporal and spatial habitat partitioning and may therefore affect community composition in tropical forests. We hypothesized that short dry spells during the wet season are a significant source of mortality for the newly emerging seedlings of pioneer species that recruit in treefall gaps in tropical forests. An analysis of a 49-year rainfall record for three forests across a rainfall gradient in central Panama confirmed that dry spells of > or = 10 days during the wet season occur on average once a year in a deciduous forest, and once every other year in a semi-deciduous moist and an evergreen wet forest. The effect of wet season dry spells on the recruitment of pioneers was investigated by comparing seedling survival in rain-protected dry plots and irrigated control plots in four large artificially created treefall gaps in a semi-deciduous tropical forest. In rain-protected plots surface soil layers dried rapidly, leading to a strong gradient in water potential within the upper 10 cm of soil. Seedling survival for six pioneer species was significantly lower in rain-protected than in irrigated control plots after only 4 days. The strength of the irrigation effect differed among species, and first became apparent 3-10 days after treatments started. Root allocation patterns were significantly, or marginally significantly, different between species and between two groups of larger and smaller seeded species. However, they were not correlated with seedling drought sensitivity, suggesting allocation is not a key trait for drought sensitivity in pioneer seedlings. Our data provide strong evidence that short dry spells in the wet season differentially affect seedling survivorship of pioneer species, and may therefore have important implications to seedling demography and community dynamics.

  13. Effect of accelerating growth on flowering in lodgepole pine seedlings and grafts

    Energy Technology Data Exchange (ETDEWEB)

    Wheeler, N.C.; Ying, C.C.; Murphy, J.C.

    1982-09-01

    Seedlings and grafts from lodgepole pine (Pinus contorta var. latifolia Dougl.) plus-tree selections in British Columbia were established and maintained in the greenhouse under 24-hour photoperiod for 6 months. Subsequently, seedlings were outplanted in the nursery and grafts in a breeding orchard at Red Rock Research Centre. In the 5th year from seed (1980), the proportion of flowering trees and the average number of seed cones per flowering tree were roughly six times greater for accelerated growth seedlings (81%, 18 flowers/tree) than for controls (12%, 3.6 flowers/tree). Differences in pollen cone production were of similar magnitude. Flower enhancement in seedlings carried over into the next year. Grafted trees were considerably less productive than seedlings. At age 5 a mean of four female strobili were produced on 77% of treated grafts compared with 1.6 strobili on 36% of untreated controls. These values decreased slightly in 1981. Pollen production was yet to be observed on grafted materials. While the superiority in height of accelerated seedlings relative to controls has steadily decreased since time of establishment, large differences in number of branches per tree and biomass remain. Root systems of accelerated seedlings generally were excessively pot-bound, resulting in considerable root grafting after outplanting. The possible causes of increased flower production in accelerated growth trees are briefly discussed. The production of both pollen and seed cones in numbers large enough to support a modest breeding scheme greatly increases the opportunity for rapid generation turnover in forest trees such as logepole pine and permits greater flexibility in planning a long-term tree improvement program.

  14. Implementation of 3D spatial indexing and compression in a large-scale molecular dynamics simulation database for rapid atomic contact detection.

    Science.gov (United States)

    Toofanny, Rudesh D; Simms, Andrew M; Beck, David A C; Daggett, Valerie

    2011-08-10

    Molecular dynamics (MD) simulations offer the ability to observe the dynamics and interactions of both whole macromolecules and individual atoms as a function of time. Taken in context with experimental data, atomic interactions from simulation provide insight into the mechanics of protein folding, dynamics, and function. The calculation of atomic interactions or contacts from an MD trajectory is computationally demanding and the work required grows exponentially with the size of the simulation system. We describe the implementation of a spatial indexing algorithm in our multi-terabyte MD simulation database that significantly reduces the run-time required for discovery of contacts. The approach is applied to the Dynameomics project data. Spatial indexing, also known as spatial hashing, is a method that divides the simulation space into regular sized bins and attributes an index to each bin. Since, the calculation of contacts is widely employed in the simulation field, we also use this as the basis for testing compression of data tables. We investigate the effects of compression of the trajectory coordinate tables with different options of data and index compression within MS SQL SERVER 2008. Our implementation of spatial indexing speeds up the calculation of contacts over a 1 nanosecond (ns) simulation window by between 14% and 90% (i.e., 1.2 and 10.3 times faster). For a 'full' simulation trajectory (51 ns) spatial indexing reduces the calculation run-time between 31 and 81% (between 1.4 and 5.3 times faster). Compression resulted in reduced table sizes but resulted in no significant difference in the total execution time for neighbour discovery. The greatest compression (~36%) was achieved using page level compression on both the data and indexes. The spatial indexing scheme significantly decreases the time taken to calculate atomic contacts and could be applied to other multidimensional neighbor discovery problems. The speed up enables on-the-fly calculation

  15. Implementation of 3D spatial indexing and compression in a large-scale molecular dynamics simulation database for rapid atomic contact detection

    Directory of Open Access Journals (Sweden)

    Toofanny Rudesh D

    2011-08-01

    Full Text Available Abstract Background Molecular dynamics (MD simulations offer the ability to observe the dynamics and interactions of both whole macromolecules and individual atoms as a function of time. Taken in context with experimental data, atomic interactions from simulation provide insight into the mechanics of protein folding, dynamics, and function. The calculation of atomic interactions or contacts from an MD trajectory is computationally demanding and the work required grows exponentially with the size of the simulation system. We describe the implementation of a spatial indexing algorithm in our multi-terabyte MD simulation database that significantly reduces the run-time required for discovery of contacts. The approach is applied to the Dynameomics project data. Spatial indexing, also known as spatial hashing, is a method that divides the simulation space into regular sized bins and attributes an index to each bin. Since, the calculation of contacts is widely employed in the simulation field, we also use this as the basis for testing compression of data tables. We investigate the effects of compression of the trajectory coordinate tables with different options of data and index compression within MS SQL SERVER 2008. Results Our implementation of spatial indexing speeds up the calculation of contacts over a 1 nanosecond (ns simulation window by between 14% and 90% (i.e., 1.2 and 10.3 times faster. For a 'full' simulation trajectory (51 ns spatial indexing reduces the calculation run-time between 31 and 81% (between 1.4 and 5.3 times faster. Compression resulted in reduced table sizes but resulted in no significant difference in the total execution time for neighbour discovery. The greatest compression (~36% was achieved using page level compression on both the data and indexes. Conclusions The spatial indexing scheme significantly decreases the time taken to calculate atomic contacts and could be applied to other multidimensional neighbor discovery

  16. Ferulic acid depletion by cultured soybean seedlings under action of glucose and methionine

    Directory of Open Access Journals (Sweden)

    Herrig Vanessa

    2000-01-01

    Full Text Available Cultured soybean seedlings were used to investigate how glucose or methionine influenced depletion of ferulic acid. Three-day-old seedlings were grown in hydroponic solution containing ferulic acid plus glucose or methionine, and the level of the phenolic acid were monitored in the nutrient culture. The results showed that ferulic acid depletion was more rapid in the presence of those compounds. After 6 h, the increase caused by glucose (0.01 and 0.05 mM was more pronounced than methionine in the same concentrations. On the other hand, methionine (0.1 and 0.2 mM increased depletion more significantly than glucose. Results suggested that both compounds might to increase the allelopathic effects of ferulic acid in the seedlings.

  17. Rice Seedling Substrate Produced by Coal Gangue

    Directory of Open Access Journals (Sweden)

    SHAO Yu-fei

    2017-10-01

    Full Text Available Peats are the mostly used material in making rice seedling substrate. However, mining peats could cause environmental problems. In order to reduce or replace peats in rice seedling substrate industry, this paper studied suitable way to configure rice seedling. The coal gangue was used to experiment cultivating rice. Four rice seeding experiments were carried out based on physical and chemical properties of materials attributes. The results showed:(1 Coal gangue was feasible for rice seedling; (2 The maximum adding amount of coal gangue was 80%(volume ratio though the coal gangue need to be activated; (3 In the case of no activated treatment only 38%(volume ratio of coal gangue could be added to the substrate.

  18. 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, ...

  19. Growth and nutrition of eucalyptus clones seedlings inoculated with mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    Francisco de Sousa Lima

    2014-06-01

    Full Text Available Eucalyptus is one of the most planted forest species, in Brazil, due to its rapid growth and high economic yield. Arbuscular mycorrhizal fungi improve the seedlings nutritional and phytosanitary status, besides increasing their resistance to biotic and abiotic stress. This study aimed to evaluate the effect of inoculation with arbuscular mycorrhizal fungi species on the growth and nutrition of different eucalyptus clones seedlings. The experiment was conducted under greenhouse conditions, in a randomized blocks design and a 5x5 factorial scheme (five fungal species and five eucalyptus clones, with five replications. In general, the mycorrhizal symbiosis significantly increased the growth and nutrition of eucalyptus seedlings, when compared to the non-inoculated seedlings. The most efficient interaction occured between the 2361 clone and the Entrophospora infrequens fungus, with increases of 107.3% and 120.6%, for the shoot and root dry biomass yield, and 107.7%, 94.1% and 103.3%, respectively for the accumulation of N, P and K in the seedlings shoots. All the fungal species studied showed a high absolute compatibility index with eucalyptus clones. The Glomus manihots and E. infrequens fungi presented a higher functional compatibility index with the clones tested. The 5204 clone showed 75% of compatibility with the fungi evaluated.

  20. Genetic variation of seedling traits in a random mating population of sunflower

    International Nuclear Information System (INIS)

    Habib, S.

    2004-01-01

    Forty S/sub 1/ families obtained from a random mating population of sunflower were evaluated in the laboratory for various seedling traits. The objectives of this study were to investigate the extent and nature of genetic variability and to determine the estimates of genotypic and phenotypic correlations among ten seedling traits prevailing in a random mating population of sunflower. The results indicated that significant differences existed among the 40 S/sub 1/ families for all the traits evaluated. Genotypic and phenotypic coefficients of variation were comparatively high for emergence rate index, root/shoot ratio, dry root weight, fresh root weight and fresh shoot weight. The estimates of broad-sense heritability were high and significant for all the traits. The study of genotypic and phenotypic correlations among these traits revealed that generally, the seedlings which took more time to emerge were vigorous for most of the traits except fresh shoot length. However, rapidly emerging seedlings had higher emergence percentage. The root traits appeared to be better indicators of seedling vigour compared to other traits as these traits exhibited strong and positive genotypic and phenotypic correlations among them. (author)

  1. Line-scan inspection of conifer seedlings

    Science.gov (United States)

    Rigney, Michael P.; Kranzler, Glenn A.

    1993-05-01

    Almost two billion conifer seedlings are produced in the U.S. each year to support reforestation efforts. Seedlings are graded manually to improve viability after transplanting. Manual grading is labor-intensive and subject to human variability. Our previous research demonstrated the feasibility of automated tree seedling inspection with machine vision. Here we describe a system based on line-scan imaging, providing a three-fold increase in resolution and inspection rate. A key aspect of the system is automatic recognition of the seedling root collar. Root collar diameter, shoot height, and projected shoot and root areas are measured. Sturdiness ratio and shoot/root ratio are computed. Grade is determined by comparing measured features with pre-defined set points. Seedlings are automatically sorted. The precision of machine vision and manual measurements was determined in tests at a commercial forest nursery. Manual measurements of stem diameter, shoot height, and sturdiness ratio had standard deviations three times those of machine vision measurements. Projected shoot area was highly correlated (r2 equals 0.90) with shoot volume. Projected root area had good correlation (r2 equals 0.80) with root volume. Seedlings were inspected at rates as high as ten per second.

  2. Programme level implementation of malaria rapid diagnostic tests (RDTs) use: outcomes and cost of training health workers at lower level health care facilities in Uganda.

    Science.gov (United States)

    Kyabayinze, Daniel J; Asiimwe, Caroline; Nakanjako, Damalie; Nabakooza, Jane; Bajabaite, Moses; Strachan, Clare; Tibenderana, James K; Van Geetruyden, Jean Pierre

    2012-04-20

    The training of health workers in the use of malaria rapid diagnostic tests (RDTs) is an important component of a wider strategy to improve parasite-based malaria diagnosis at lower level health care facilities (LLHFs) where microscopy is not readily available for all patients with suspected malaria. This study describes the process and cost of training to attain competence of lower level health workers to perform malaria RDTs in a public health system setting in eastern Uganda. Health workers from 21 health facilities in Uganda were given a one-day central training on the use of RDTs in malaria case management, including practical skills on how to perform read and interpret the test results. Successful trainees subsequently integrated the use of RDTs into their routine care for febrile patients at their LLHFs and transferred their acquired skills to colleagues (cascade training model). A cross-sectional evaluation of the health workers' competence in performing RDTs was conducted six weeks following the training, incorporating observation, in-depth interviews with health workers and the review of health facility records relating to tests offered and antimalarial drug (AMD) prescriptions pre and post training. The direct costs relating to the training processes were also documented. Overall, 135 health workers were trained including 63 (47%) nursing assistants, a group of care providers without formal medical training. All trainees passed the post-training concordance test with ≥ 80% except 12 that required re-training. Six weeks after the one-day training, 51/64 (80%) of the health workers accurately performed the critical steps in performing the RDT. The performance was similar among the 10 (16%) participants who were peer-trained by their trained colleagues. Only 9 (14%) did not draw the appropriate amount of blood using pipette. The average cost of the one-day training was US$ 101 (range $92-$112), with the main cost drivers being trainee travel and per

  3. Programme level implementation of malaria rapid diagnostic tests (RDTs use: outcomes and cost of training health workers at lower level health care facilities in Uganda

    Directory of Open Access Journals (Sweden)

    Kyabayinze Daniel J

    2012-04-01

    Full Text Available Abstract Background The training of health workers in the use of malaria rapid diagnostic tests (RDTs is an important component of a wider strategy to improve parasite-based malaria diagnosis at lower level health care facilities (LLHFs where microscopy is not readily available for all patients with suspected malaria. This study describes the process and cost of training to attain competence of lower level health workers to perform malaria RDTs in a public health system setting in eastern Uganda. Methods Health workers from 21 health facilities in Uganda were given a one-day central training on the use of RDTs in malaria case management, including practical skills on how to perform read and interpret the test results. Successful trainees subsequently integrated the use of RDTs into their routine care for febrile patients at their LLHFs and transferred their acquired skills to colleagues (cascade training model. A cross-sectional evaluation of the health workers’ competence in performing RDTs was conducted six weeks following the training, incorporating observation, in-depth interviews with health workers and the review of health facility records relating to tests offered and antimalarial drug (AMD prescriptions pre and post training. The direct costs relating to the training processes were also documented. Results Overall, 135 health workers were trained including 63 (47% nursing assistants, a group of care providers without formal medical training. All trainees passed the post-training concordance test with ≥ 80% except 12 that required re-training. Six weeks after the one-day training, 51/64 (80% of the health workers accurately performed the critical steps in performing the RDT. The performance was similar among the 10 (16% participants who were peer-trained by their trained colleagues. Only 9 (14% did not draw the appropriate amount of blood using pipette. The average cost of the one-day training was US$ 101 (range $92-$112, with the

  4. Effects of seed and seedling predation by small mammals on ...

    African Journals Online (AJOL)

    Seed predation reduced seedling recruitment from seeds planted in March 1986 in mature fynbos, but ... Seed predation did not significantly reduce seedling recruitment from seed planted in July, August and ... AJOL African Journals Online.

  5. 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 ...

  6. IMPROVED METHODS OF OBTAINING PEPPER SEEDLINGS

    OpenAIRE

    Florina Uleanu

    2012-01-01

    This paper refers to the effect of different types of pots on the level of growth and development of the pepper seedlings in order to clarify the influences caused by use of different recipes transplanters pots. Different biocomposites from renewable resources biodegradable nutritive support were studied. Seedlings were grown in 4 variants of pots M1 (V1), M2 (V2), M3 (V3) and jiffy- pots (V4). The height of the aerial part varied from 14.5 (V1) to 17.4 cm (V4), whereas the root length varied...

  7. The fungi causin damping-off of carrot seedlings

    Directory of Open Access Journals (Sweden)

    Bogdan Nowicki

    2013-12-01

    Full Text Available When 136 samples of dying carrot seedlings from several fields were analyzed Alternaria rudicina proved to be the most common seedling pathogen (41%, followed by some Fusarium species (27%, mostly F. avenaceum.The less common seedling pathogens were Pythium spp. (13%, Phoma spp.(2,5% and Botrytis cinerea (1,4%. Some other fungi (Bipolaris sorokiniana, Sclerotinia sclerotiorum, Stemphylium botryosym and Ulocladium consortiale were found in less than 1% of seedlings examined.

  8. Grazing on Regeneration Sites Encourages Pine Seedling Growth

    Science.gov (United States)

    Raymond D. Ratliff; Renee G. Denton

    1995-01-01

    Effects of season-long, deferred-rotation, and rest-rotation grazing, on ponderosa pine (Pinus ponderosa Dougl. ex Laws.) seedling growth and herbaceous vegetation control were studied in regeneration sites at Boyd Hill, Modoc National Forest, California. Seedlings were planted in 1989. Pine seedling survival and damage did not differ, but the...

  9. Containers of Attalea funifera fibers to produce eucalyptus seedlings

    Directory of Open Access Journals (Sweden)

    Andrea Vita Reis Mendonça

    2016-09-01

    Full Text Available The aim of this study was to assess the technical feasibility of using biodegradable containers made of fiber waste of Attalea funifera Martius to produce seedling of Eucalyptus camaldulensis Dehnh. The work was carried out in three stages: manufacture of piassava fiber containers, seedling production and field simulation. The experiment of seedling production was in completely randomized design, with two treatments (polyethylene tube and biodegradable container and 10 repetitions, with 64 seedlings per repetition. After 93 days, seedlings were evaluated based on quality variables. The simuation of initial growth of seedlings in the field consisted in planting seedlings in containers of 11L, in completely randomized design, with three treatments: seedlings produced in polyethylene tubes; seedlings produced in biodegradable containers, without removal of the container during planting; and seedlings produced in biodegradable containers, with removal of the container at planting, with ten repetitions, with one seedling by repetition. The biodegradable container withstood the production cycle and resulted in seedlings within acceptable standards quality. The use of biodegradable container, made of palm fibers, waived the removal of this vessel in the final planting.

  10. Production of cell wall enzymes in pepper seedlings, inoculated with ...

    African Journals Online (AJOL)

    Pepper seedlings inoculated with arbuscular mycorrhizal AM fungus, Glomus etunicatum, produced cellulase, polygal-acturonase and pectin methylestrase enzymes. The activities of the enzymes increased as the pepper seedlings matured in age, showing that the activity of the enzymes in the seedlings was age mediated.

  11. Cotyledon persistence and seedling growth in fluted Pumpkin ...

    African Journals Online (AJOL)

    Photosynthetic activity of exposed cotyledons of Telfairia occidentalis during seed germination and the growth of seedlings with removed or attached cotyledons were investigated. The experiment investigated how early cotyledon removal affects seedling growth. Seedlings from seeds germinated in light and those ...

  12. Tree seedling response to LED spectra: Implications for forest restoration

    Science.gov (United States)

    Antonio Montagnoli; R. Kasten Dumroese; Mattia Terzaghi; Jeremiah R. Pinto; Nicoletta Fulgaro; Gabriella Stefania Scippa; Donato Chiatante

    2018-01-01

    We found that different spectra, provided by light-emitting diodes or a fluorescent lamp, caused different photomorphological responses depending on tree seedling type (coniferous or broad-leaved), species, seedling development stage, and seedling fraction (shoot or root). For two conifers (Picea abies and Pinus sylvestris) soon after germination (≤40 days), more...

  13. Purification and characterization of amine oxidase from soybean seedlings.

    Science.gov (United States)

    Vianello, F; Di Paolo, M L; Stevanato, R; Gasparini, R; Rigo, A

    1993-11-15

    A simple and rapid procedure for purification of soybean seedling amine oxidase is reported. The crude enzyme, obtained by ammonium sulfate fractionation was purified by ion-exchange chromatography on a cellulose phosphate column and batch affinity chromatography on 6-aminohexyl-Sepharose. Cyclohexylamine, a competitive inhibitor, was utilized to elute the enzyme. A homogeneous enzyme was obtained with a yield higher than 25%, the content of minor components being lauryl sulfate-polyacrylamide gel electrophoresis. The enzyme is a dimer and contains two Cu2+ ion per molecule. Its EPR spectrum is typical of Cu2+ in a tetragonal symmetry. The enzyme oxidizes cadaverine at high rate, the specific activity being 4.3 mukat/mg. Molecular, spectroscopic, and kinetic properties of this enzyme are reported.

  14. Implementation of a gel dosimeter for dosimetric verification of treatments with RapidArc{sup TM}; Implementacion de un dosimetro en gel para verificacion dosimetrica de tratamientos con RapidArc{sup TM}

    Energy Technology Data Exchange (ETDEWEB)

    Cortes, H.; Vasquez, J. [Centro de Control de Cancer Ltda., Carrera 16A No. 83 A-11, 110911 Bogota (Colombia); Plazas, M., E-mail: hhcortess@unal.edu.co [Universidad Nacional de Colombia, Av. Carrera 30 No. 45, 110911 Bogota (Colombia)

    2014-08-15

    The gel dosimetry represents advantages on other dosimetric systems for its potential of analyzing information in third dimension (3D). This work seeks to find another alternative for the verification of treatments of high complexity like the RapidArc{sup TM}. A gel type Magic was prepared and characterized, which was irradiated with base in a plan of RapidArc{sup TM} calculated in the Treatment Planning System (Tps) Eclipse, using the Anisotropic Analytic Algorithm (Aaa) for a beam with an acceleration potential of 6 MV. The dosimeter was characterized using Magnetic Resonance Images starting from the correlation between the T2 and the dose. The dose distribution curves were analyzed in second dimension (2D) using the program Omni Pro-I mrT and were compared with the curves obtained for the Tps under the approach gamma 2D. The comparison showed that the Gel represents a valid option inside the acceptable ranges for Quality Assurance in radiotherapy. (Author)

  15. 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 ...

  16. Direct-seedling pines in the south

    Science.gov (United States)

    Harold J. Derr; William F. Mann

    1971-01-01

    Direct seeding of the southern pines is a versatile reforestation technique that is being widely accepted by land managers. On many sites it is more economical than planting nursery-grown seedlings or waiting for natural reproduction. It is applicable on some sites where access, terrain, or drainage conditions make planting difficult. Commercial trials have proved it...

  17. Genotype X Fertility Interactions in Seedling Sweetgum

    Science.gov (United States)

    Scott X. Chang; Daniel J. Robison

    2002-01-01

    Genotype x fertility interactions may affect the suitability of sweetgum (Liquidambar styraciflua L.) for specific sites or the efficiency of nutrient use. To gain a better understanding of these interactions, 2-year-old sweetgum seedlings from two half-sib families were tested for growth response to N (0 and 100 kg/ha equivalent) and P (0 and 50 kg...

  18. Evaluation of the Implementation of a Rapid Response Treatment Protocol for Patients with Acute Onset Stroke: Can We Increase the Number of Patients Treated and Shorten the Time Needed

    Directory of Open Access Journals (Sweden)

    Rajiv Advani

    2014-06-01

    Full Text Available Aims: This study aims to evaluate the implementation of a rapid response treatment protocol for patients presenting with acute onset ischemic stroke. Improvements of routines surrounding the admission and treatment of patients with intravenous thrombolysis (IVT, such as door-to-needle (DTN times, and increasing the numbers of patients treated are discussed. Methods: We conducted a retrospective analysis of all patients (n = 320 treated with IVT for acute onset ischemic stroke at the Stavanger University Hospital, Norway, between 2003 and 2012. In 2009, a succession of changes to pre- and intra-hospital routines were made as well as an improvement in the education of primary health care physicians, nurses and paramedics involved in the treatment of acute onset stroke patients (rapid response treatment protocol. Analyses of DTN times, onset-to-needle times and the number of patients treated per year were carried out to ascertain the effect of the changes made. The primary aim was to analyze DTN times to look for any changes, and the secondary aim was to analyze changes in the number of patients treated per year. Results: In the years after the implementation of the rapid treatment protocol, we saw an improvement in the median DTN time with a decrease from 73 to 50 min in the first year (p = 0.03, a decrease of 45 min in the second year (p = 0.01 and a decrease of 31 min in the third year (p Conclusions: The implementation of the rapid treatment protocol for acute onset ischemic stroke patients led to a significant decrease in the DTN time at our center. These improvements also produced an increase in the number of patients treated per year. The extension of the therapeutic window from 3 to 4.5 h for the use of intravenous recombinant tissue plasminogen activator also played a role in the increased treatment numbers.

  19. The First Six Years of Building and Implementing a Return-to-Work Service for Patients with Acquired Brain Injury. The Rapid-Return-to-Work-Cohort-Study.

    Science.gov (United States)

    Haveraaen, L; Brouwers, E P M; Sveen, U; Skarpaas, L S; Sagvaag, H; Aas, R W

    2017-12-01

    Background and objective Despite large activity worldwide in building and implementing new return-to-work (RTW) services, few studies have focused on how such implementation processes develop. The aim of this study was to examine the development in patient and service characteristics the first six years of implementing a RTW service for persons with acquired brain injury (ABI). Methods The study was designed as a cohort study (n=189). Data were collected by questionnaires, filled out by the service providers. The material was divided into, and analyzed with, two implementation phases. Non-parametrical statistical methods and hierarchical regression analyses were applied on the material. Results The number of patients increased significantly, and the patient group became more homogeneous. Both the duration of the service, and the number of consultations and group session days were significantly reduced. Conclusion The patient group became more homogenous, but also significantly larger during the first six years of building the RTW service. At the same time, the duration of the service decreased. This study therefore questions if there is a lack of consensus on the intensity of work rehabilitation for this group.

  20. Assessment of risk factors for musculoskeletal disorders using the Rapid Office Strain Assessment (ROSA Method and implementing ergonomics intervention programs in Sepah Bank

    Directory of Open Access Journals (Sweden)

    I. Nasiri

    2015-07-01

    .Conclusion: Using the ROSA technique was seemed to be beneficialto assess the ergonomic risk factors of office works, and the deficiencies in the workstation can be identified through this method. Moreover,by design and implementation of an educational intervention program along with engineering interventions which comply with the elements of this technique, the defects can be eliminated.

  1. Development-specific responses to drought stress in Aleppo pine (Pinus halepensis Mill.) seedlings.

    Science.gov (United States)

    Alexou, Maria

    2013-10-01

    Aleppo pine (Pinus halepensis Mill.) is a pioneer species, highly competitive due to exceptional resistance to drought. To investigate the stress resistance in the first and second year of development, a steady-state drought experiment was implemented. Photosynthesis (A(net)), stomatal conductance and transpiration (E) were measured on three different sampling dates together with phloem soluble sugars, amino acids and non-structural proteins. Needle ascorbic acid (AsA) and reactive oxygen species were measured to evaluate the seedlings' drought stress condition in the final sampling. Drought impaired A(net) and E by 35 and 31%, respectively, and increased AsA levels up to 10-fold, without significant impact on the phloem metabolites. Phloem sugars related to temperature fluctuations rather than soil moisture and did not relate closely to A(net) levels. Sugars and proteins decreased between the second and third sampling date by 56 and 61%, respectively, and the ratio of sugars to amino acids decreased between the first and third sampling by 81%, while A(net) and water-use efficiency (A(net)/E) decreased only in the older seedlings. Although gas exchange was higher in the older seedlings, ascorbic acid and phloem metabolites were higher in the younger seedlings. It was concluded that the drought stress responses depended significantly on developmental stage, and research on the physiology of Aleppo pine regeneration should focus more on temperature conditions and the duration of drought than its severity.

  2. Exogenous nitric oxide improves salt tolerance during establishment of Jatropha curcas seedlings by ameliorating oxidative damage and toxic ion accumulation.

    Science.gov (United States)

    Gadelha, Cibelle Gomes; Miranda, Rafael de Souza; Alencar, Nara Lídia M; Costa, José Hélio; Prisco, José Tarquinio; Gomes-Filho, Enéas

    2017-05-01

    Jatropha curcas is an oilseed species that is considered an excellent alternative energy source for fossil-based fuels for growing in arid and semiarid regions, where salinity is becoming a stringent problem to crop production. Our working hypothesis was that nitric oxide (NO) priming enhances salt tolerance of J. curcas during early seedling development. Under NaCl stress, seedlings arising from NO-treated seeds showed lower accumulation of Na + and Cl - than those salinized seedlings only, which was consistent with a better growth for all analyzed time points. Also, although salinity promoted a significant increase in hydrogen peroxide (H 2 O 2 ) content and membrane damage, the harmful effects were less aggressive in NO-primed seedlings. The lower oxidative damage in NO-primed stressed seedlings was attributed to operation of a powerful antioxidant system, including greater glutathione (GSH) and ascorbate (AsA) contents as well as catalase (CAT) and glutathione reductase (GR) enzyme activities in both endosperm and embryo axis. Priming with NO also was found to rapidly up-regulate the JcCAT1, JcCAT2, JcGR1 and JcGR2 gene expression in embryo axis, suggesting that NO-induced salt responses include functional and transcriptional regulations. Thus, NO almost completely abolished the deleterious salinity effects on reserve mobilization and seedling growth. In conclusion, NO priming improves salt tolerance of J. curcas during seedling establishment by inducing an effective antioxidant system and limiting toxic ion and reactive oxygen species (ROS) accumulation. Copyright © 2017 Elsevier GmbH. All rights reserved.

  3. Characteristics of injury and recovery of net NO3- transport of barley seedlings from treatments of NaCl

    Science.gov (United States)

    Klobus, G.; Ward, M. R.; Huffaker, R. C.

    1988-01-01

    The nature of the injury and recovery of nitrate uptake (net uptake) from NaCl stress in young barley (Hordeum vulgare L, var CM 72) seedlings was investigated. Nitrate uptake was inhibited rapidly by NaCl, within 1 minute after exposure to 200 millimolar NaCl. The duration of exposure to saline conditions determined the time of recovery of NO3- uptake from NaCl stress. Recovery was dependent on the presence of NO3- and was inhibited by cycloheximide, 6-methylpurine, and cerulenin, respective inhibitors of protein, RNA, and sterol/fatty acid synthesis. These inhibitors also prevented the induction of the NO3- uptake system in uninduced seedlings. Uninduced seedlings exhibited endogenous NO3- transport activity that appeared to be constitutive. This constitutive activity was also inhibited by NaCl. Recovery of constitutive NO3- uptake did not require the presence of NO3-.

  4. Maximizing growth of vegetable seedlings in controlled environments at elevated temperature, light and CO/sub 2/

    Energy Technology Data Exchange (ETDEWEB)

    Krizek, D.T.; Bailey, W.A.; Klueter, H.; Liu, R.C.

    1974-01-01

    Seedlings of cucumber Burpee Hybrid, tomato Michigan-Ohio and lettuce Grand Rapids were germinated in the greenhouse for 5, 8, and 11 days respectively, and then grown for 15 days at elevated temperature (30/24/sup 0/C), light (43.1 klx), and CO/sub 2/ (2000 ppm) a 16-hr photoperiod, 65% relative humidity, and fertilized 4 times daily. At the end of this time, they weighed 2 to 4.6 times those grown at standard environmental conditions in the growth chamber (24/18/sup 0/C, 21.5 klx, and 400 ppm CO/sub 2/) and 10 to 25 times those of greenhouse controls kept on natural days (24/18/sup 0/C, 350 ppm CO/sub 2/, and ca 12-hr photoperiod). Leaf expansion of seedlings grown under elevated growth chamber conditions was double that of seedlings in standard growth chamber conditions, and 6 to 7 times greater than under natural days in the greenhouse. Temperature was the most limiting factor for seedling growth. At the levels of light and CO/sub 2/ used in the experiment, CO/sub 2/ was more limiting than light intensity. In general, optimum seedling growth was obtained when temperature, light, and CO/sub 2/ were increased simultaneously. The most striking effects of CO/sub 2/ enrichment were precocious flower bud formation in tomato and cucumber and extensive growth of the lateral buds in all three species.

  5. The transition from a maternal to external nitrogen source in maize seedlings

    KAUST Repository

    Sabermanesh, Kasra

    2017-02-07

    Maximising NO3 - uptake during seedling development is important as it has a major influence on plant growth and yield. However, little is known about the processes leading to, and involved in, the initiation of root NO3 - uptake capacity in developing seedlings. This study examines the physiological processes involved in root NO3 - uptake and metabolism, to gain an understanding of how the NO3 - uptake system responds to meet demand as maize seedlings transition from seed N use to external N capture. The concentrations of seed-derived free amino acids within root and shoot tissues are initially high, but decrease rapidly until stabilising eight days after imbibition (DAI). Similarly, shoot N% decreases, but does not stabilise until 12-13 DAI. Following the decrease in free amino acid concentrations, root NO3 - uptake capacity increases until shoot N% stabilises. The increase in root NO3 uptake capacity corresponds with a rapid rise in transcript levels of putative NO3 - transporters, ZmNRT2.1 and ZmNRT2.2. The processes underlying the increase in root NO3 - uptake capacity to meet N demand provide an insight into the processes controlling N uptake.

  6. IMPROVED METHODS OF OBTAINING PEPPER SEEDLINGS

    Directory of Open Access Journals (Sweden)

    Florina Uleanu

    2012-12-01

    Full Text Available This paper refers to the effect of different types of pots on the level of growth and development of the pepper seedlings in order to clarify the influences caused by use of different recipes transplanters pots. Different biocomposites from renewable resources biodegradable nutritive support were studied. Seedlings were grown in 4 variants of pots M1 (V1, M2 (V2, M3 (V3 and jiffy- pots (V4. The height of the aerial part varied from 14.5 (V1 to 17.4 cm (V4, whereas the root length varied from 5.4 (V1 to 12.6 cm (V4. The number of leaves ranged from 7 (V2 to 12 (V4. The total volume was lowest for V2 (1.5 cm3 and highest for V4 (2.5 cm3, but the root volume was lowest for V2 (0.5 cm3 and highest for V1 (1 cm3. V2 also resulted in the smallest total seedling mass (1.6 g aerial part mass (1.1 g and root mass (0.5 g. Excepting the root volume V4 had the greatest values for the studied indicators.

  7. ECOTOXICITY AND PHYTOTOXICITY OF PLANT PROTECTION PRODUCTS TO RHIZOSPHERE FUNGI AND WINTER WHEAT SEEDLINGS

    Directory of Open Access Journals (Sweden)

    Anna Daria Stasiulewicz-Paluch

    2015-11-01

    Full Text Available Registration of plant protection products involves the analysis of their effects on soil microorganisms. The residues of plant protection products penetrate the soil, but their impact on fungi remains scarcely researched. In this study, the influence of selected plant protection products on the abundance of rhizosphere-dwelling fungi and the growth of winter wheat seedlings was evaluated under greenhouse conditions. The analysed plant protection products had an inhibitory effect on the growth of filamentous fungi in the rhizosphere, whereas yeasts were resistant to those products applied to soil. Tebuconazole exerted the strongest suppressive effect on the growth of filamentous fungi, and propiconazole was characterized by the greatest phytotoxic activity against winter wheat seedlings. Azoxystrobin had the weakest ecotoxic and phytotoxic effects, and its application to soil usually led to a rapid increase in the counts of fungi of the genus Acremonium.

  8. Transformation of Medicago truncatula via infiltration of seedlings or flowering plants with Agrobacterium

    DEFF Research Database (Denmark)

    Trieu, A.T.; Burleigh, S.H.; Kardailsky, I.V.

    2000-01-01

    Two rapid and simple in planta transformation methods have been developed for the model legume Medicago truncatula. The first approach is based on a method developed for transformation of Arabidopsis thaliana and involves infiltration of flowering plants with a suspension of Agrobacterium....... The second method involves infiltration of young seedlings with Agrobacterium. In both cases a proportion of the progeny of the infiltrated plants is transformed. The transformation frequency ranges from 4.7 to 76% for the flower infiltration method, and from 2.9 to 27.6% for the seedling infiltration method....... Both procedures resulted in a mixture of independent transformants and sibling transformants. The transformants were genetically stable, and analysis of the T-2 generation indicates that the transgenes are inherited in a Mendelian fashion. These transformation systems will increase the utility of M...

  9. Distinct genecological patterns in seedlings of Norway spruce and silver fir from a mountainous landscape.

    Science.gov (United States)

    Frank, Aline; Sperisen, Christoph; Howe, Glenn Thomas; Brang, Peter; Walthert, Lorenz; St Clair, John Bradley; Heiri, Caroline

    2017-01-01

    Understanding the genecology of forest trees is critical for gene conservation, for predicting the effects of climate change and climate change adaptation, and for successful reforestation. Although common genecological patterns have emerged, species-specific details are also important. Which species are most vulnerable to climate change? Which are the most important adaptive traits and environmental drivers of natural selection? Even though species have been classified as adaptive specialists vs. adaptive generalists, large-scale studies comparing different species in the same experiment are rare. We studied the genecology of Norway spruce (Picea abies) and silver fir (Abies alba), two co-occurring but ecologically distinct European conifers in Central Europe. For each species, we collected seed from more than 90 populations across Switzerland, established a seedling common-garden test, and developed genecological models that associate population variation in seedling growth and phenology to climate, soil properties, and site water balance. Population differentiation and associations between seedling traits and environmental variables were much stronger for Norway spruce than for silver fir, and stronger for seedling height growth than for bud phenology. In Norway spruce, height growth and second flushing were strongly associated with temperature and elevation, with seedlings from the lowlands being taller and more prone to second flush than seedlings from the Alps. In silver fir, height growth was more weakly associated with temperature and elevation, but also associated with water availability. Soil characteristics explained little population variation in both species. We conclude that Norway spruce has become an adaptive specialist because trade-offs between rapid juvenile growth and frost avoidance have subjected it to strong diversifying natural selection based on temperature. In contrast, because silver fir has a more conservative growth habit, it has

  10. [Effect of ectomycorrhizae on the growth of Picea koraiensis seedlings].

    Science.gov (United States)

    Song, Rui-Qing; Wu, Ke

    2005-12-01

    Basidioscarps of Agaricales in different Picea koraiensis forest plantations were collected during August-October, 2000. 36 isolaters of species of Agaricales were obtained by isolating and culturing to the basidioscarps. Through indoor inoculation test on seedlings of Picea koraiensis, 6 ectomycorrhizae fungi cultures were obtained from 36 isolaters. The inoculation results show that the period for ectomycorrhizae inoculation to 1-year seedlings of Picea koraiensis should be about 30 days after seedlings emerging, the suitable temperature for ectomycorrhizae forming is about 20 degrees C. 6 ectomycorrhizae strains all have growth-promoting effect to the seedlings of Picea koraiensis. The contents of chlorophyll a of the seedlings inoculated strains of Agaricus silvaticus, 031 and L15 were significantly higher than other strains and control. The contents of chlorophyll b in the seedlings inoculated strains 009, 004, Agaricus silvaticus and L15 were significantly higher than other strains and control. The weights of seedlings which inoculated strains 009, 025, 031, Agaricus silvaticus and L15 were significantly different to control, the weight of seedlings inoculated strains of Agaricus silvaticus and L15 are 19.23% and 23.08% more than control; The heights of the seedlings inoculated 6 strains all have significant difference to control, the weight of seedlings inoculated strains of Agaricus silvaticus and L15 are 17.83% and 16.37% more than control. The results of outdoor inoculation show that the seedlings inoculated Agaricus silvaticus grow best on height, 9.25% more than control after inoculated 70 days; the seedlings inoculated strain L15 grow best on collar diameter, 9.92% more than control after inoculated 70 days; the lateral root numbers of seedlings inoculated strain 009 is largest, 51.91% more than control after inoculated 70 days; the main roots of seedlings inoculated strain 009 are longest, 3.36% more than control after inoculated 70 days; the

  11. Using Real Time Workshop for rapid and reliable control implementation in the Frascati Tokamak Upgrade Feedback Control System running under RTAI-GNU/Linux

    International Nuclear Information System (INIS)

    Centioli, C.; Iannone, F.; Ledauphin, M.; Panella, M.; Pangione, L.; Podda, S.; Vitale, V.; Zaccarian, L.

    2005-01-01

    The Feedback Control System running at FTU has been recently ported from a commercial platform (based on LynxOS) to an open-source GNU/Linux-based RTAI-LXRT platform, thereby, obtaining significant performance and cost improvements. Based on the new open-source platform, it is now possible to experiment novel control strategies aimed at improving the robustness and accuracy of the feedback control. Nevertheless, the implementation of control ideas still requires a great deal of coding of the control algorithms that, if carried out manually, may be prone to coding errors, therefore time consuming both in the development phase and in the subsequent validation tests consisting of dedicated experiments carried out on FTU. In this paper, we report on recent developments based on Mathworks' Simulink and Real Time Workshop (RTW) packages to obtain a user-friendly environment where the real time code implementing novel control algorithms can be easily generated, tested and validated. Thanks to this new tool, the control designer only needs to specify the block diagram of the control task (namely, a high level and functional description of the new algorithm under consideration) and the corresponding real time code generation and testing is completely automated without any need of dedicated experiments. In the paper, the necessary work carried out to adapt the Real Time Workshop to our RTAI-LXRT context will be illustrated. A necessary re-organization of the previous real time software, aimed at incorporating the code coming from the adapted RTW, will also be discussed. Moreover, we will report on a performance comparison between the code obtained using the automated RTW-based procedure and the hand-written C code, appropriately optimised; at the moment, a preliminary performance comparison consisting of dummy algorithms has shown that the code automatically generated from RTW is faster (about 30% up) than the manually written one. This preliminary result combined with the

  12. Effect of ethephon on hardening of Pachystroma longifolium seedlings

    Directory of Open Access Journals (Sweden)

    João Alexandre Lopes Dranski

    2013-06-01

    Full Text Available Immediately after planting, tree seedlings face adverse environmental and biotic stresses that must be overcome to ensure survival and to yield a desirable growth. Hardening practices in the nursery may help improve seedling stress resistance through reduction of aboveground plant tissues and increased root volume and biomass. We conducted an assay to quantify changes in the morphogenesis following application of ethephon on seedlings of Pachystroma longifolium (Ness I. M. Johnst.during hardening. The results showed no effect of the ethephon treatments on the number of leaves but a reduction of up to 50% in seedling height increment, and an increase in stem diameter increment of up to 44% with the 600 mg L-1 ethephon treatment, which consequently altered seedling Dickson Quality Index. Our results indicate that ethephon may help to promote desired morphological changes that occur during seedling hardening in nurseries.

  13. Biodegradable bags for the production of plant seedlings

    OpenAIRE

    Bilck,Ana Paula; Olivato,Juliana Bonametti; Yamashita,Fabio; Souza,José Roberto Pinto de

    2014-01-01

    The production of plant seedlings has traditionally used polyethylene bags, which are thrown out in the soil or burned after transplant because the large amount of organic material attached to the bags makes recycling difficult. Additionally, when a seedling is taken from the bag for transplant, there is the risk of root damage, which compromises the plant’s development. In this study, we developed biodegradable bags to be used in seedling production, and we verify their influence on the deve...

  14. Longleaf pine bud development: influence of seedling nutrition

    Science.gov (United States)

    J. P. Barnett; D. P. Jackson; R. K. Dumroese

    2010-01-01

    A subset of seedlings from a larger study (Jackson and others 2006, 2007) were selected and evaluated for two growing seasons to relate bud development, and root-collar diameter (RCD), and height growth with three nursery fertilization rates. We chose seedlings in the 0.5 (lowest), 2.0 (mid-range), and 4.0 (highest) mg of nitrogen per seedling treatments. Buds moved...

  15. SU-F-303-11: Implementation and Applications of Rapid, SIFT-Based Cine MR Image Binning and Region Tracking

    Energy Technology Data Exchange (ETDEWEB)

    Mazur, T; Wang, Y; Fischer-Valuck, B; Acharya, S; Kashani, R; Li, H; Yang, D; Zoberi, I; Thomas, M; Mutic, S; Li, H [Washington University School of Medicine, St. Louis, MO (United States)

    2015-06-15

    Purpose: To develop a novel and rapid, SIFT-based algorithm for assessing feature motion on cine MR images acquired during MRI-guided radiotherapy treatments. In particular, we apply SIFT descriptors toward both partitioning cine images into respiratory states and tracking regions across frames. Methods: Among a training set of images acquired during a fraction, we densely assign SIFT descriptors to pixels within the images. We cluster these descriptors across all frames in order to produce a dictionary of trackable features. Associating the best-matching descriptors at every frame among the training images to these features, we construct motion traces for the features. We use these traces to define respiratory bins for sorting images in order to facilitate robust pixel-by-pixel tracking. Instead of applying conventional methods for identifying pixel correspondences across frames we utilize a recently-developed algorithm that derives correspondences via a matching objective for SIFT descriptors. Results: We apply these methods to a collection of lung, abdominal, and breast patients. We evaluate the procedure for respiratory binning using target sites exhibiting high-amplitude motion among 20 lung and abdominal patients. In particular, we investigate whether these methods yield minimal variation between images within a bin by perturbing the resulting image distributions among bins. Moreover, we compare the motion between averaged images across respiratory states to 4DCT data for these patients. We evaluate the algorithm for obtaining pixel correspondences between frames by tracking contours among a set of breast patients. As an initial case, we track easily-identifiable edges of lumpectomy cavities that show minimal motion over treatment. Conclusions: These SIFT-based methods reliably extract motion information from cine MR images acquired during patient treatments. While we performed our analysis retrospectively, the algorithm lends itself to prospective motion

  16. Factors affecting acorn production and germination and early growth of seedlings and seedling sprouts

    Science.gov (United States)

    David F. Olson; Stephen G. Boyce

    1971-01-01

    Acorn production is extremely variable and unpredictable. Flowering is copious, but many climatic factors influence acorn development from initiation of flowers to acorn maturity. Acorns are consumed by birds, animals, insects, and microorganisms. The establishment of seedlings is more closely related to favorable site factors than to size of crops. A majority of oaks...

  17. Planting and care of fine hardwood seedlings: Nursery production of hardwood seedlings

    Science.gov (United States)

    Douglass F. Jacobs

    2003-01-01

    Access to quality tree seedlings is an essential component of a successful hardwood reforestation project. Hardwood plantations may be established by sowing seed directly to a field site, but the success of direct seeding operations has been inconsistent for many species, which indicates that more research is needed before this practice can be recommended. For...

  18. Seed-vectored endophytic bacteria modulate development of rice seedlings.

    Science.gov (United States)

    Verma, S K; Kingsley, K; Irizarry, I; Bergen, M; Kharwar, R N; White, J F

    2017-06-01

    The aim of the present study was to evaluate the effects of the removal of indigenous bacteria from rice seeds on seedling growth and development. Here we report the presence of three indigenous endophytic bacteria in rice seeds that play important roles in modulating seedling development (shoot and root lengths, and formation of root hairs and secondary roots) and defence against pathogens. Seed-associated bacteria were removed using surface sterilization with NaOCl (bleach) followed by antibiotic treatment. When bacteria were absent, growth of seedlings in terms of root hair development and overall seedling size was less than that of seedlings that contained bacteria. Reactive oxygen staining of seedlings showed that endophytic bacteria became intracellular in root parenchyma cells and root hairs. Roots containing endophytic bacteria were seen to stain densely for reactive oxygen, while roots free of bacteria stained lightly for reactive oxygen. Bacteria were isolated and identified as Enterobacter asburiae (VWB1), Pantoea dispersa (VWB2) and Pseudomonas putida (VWB3) by 16S rDNA sequencing. Bacteria were found to produce indole acetic acid (auxins), inhibited the pathogen Fusarium oxysporum and solubilized phosphate. Reinoculation of bacteria onto seedlings derived from surface-disinfected rice and Bermuda grass seeds significantly restored seedling growth and development. Rice seeds harbour indigenous bacterial endophytes that greatly influence seedling growth and development, including root and shoot lengths, root hair formation and disease susceptibility of rice seedlings. This study shows that seeds of rice naturally harbour bacterial endophytes that play key roles in modulation of seedling development. © 2017 The Society for Applied Microbiology.

  19. Plasticity and stress tolerance override local adaptation in the responses of Mediterranean holm oak seedlings to drought and cold.

    Science.gov (United States)

    Gimeno, Teresa E; Pías, Beatriz; Lemos-Filho, José P; Valladares, Fernando

    2009-01-01

    Plant populations of widely distributed species experience a broad range of environmental conditions that can be faced by phenotypic plasticity or ecotypic differentiation and local adaptation. The strategy chosen will determine a population's ability to respond to climate change. To explore this, we grew Quercus ilex (L.) seedlings from acorns collected at six selected populations from climatically contrasting localities and evaluated their response to drought and late season cold events. Maximum photosynthetic rate (A(max)), instantaneous water use efficiency (iWUE), and thermal tolerance to freeze and heat (estimated from chlorophyll fluorescence versus temperature curves) were measured in 5-month-old seedlings in control (no stress), drought (water-stressed), and cold (low suboptimal temperature) conditions. The observed responses were similar for the six populations: drought decreased A(max) and increased iWUE, and cold reduced A(max) and iWUE. All the seedlings maintained photosynthetic activity under adverse conditions (drought and cold), and rapidly increased their iWUE by closing stomata when exposed to drought. Heat and freeze tolerances were similarly high for seedlings from all the populations, and they were significantly increased by drought and cold, respectively; and were positively related to each other. Differences in seedling performance across populations were primarily induced by maternal effects mediated by seed size and to a lesser extent by idiosyncratic physiologic responses to drought and low temperatures. Tolerance to multiple stresses together with the capacity to physiologically acclimate to heat waves and cold snaps may allow Q. ilex to cope with the increasingly stressful conditions imposed by climate change. Lack of evidence of physiologic seedling adaptation to local climate may reflect opposing selection pressures to complex, multidimensional environmental conditions operating within the distribution range of this species.

  20. Characterization of copper toxicity in letttuce seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Mukherji, S; Gupta, B D

    1972-01-01

    Information on the effects of toxic concentration of cupric sulphate on the growth of lettuce (Lactuca sativa) seedlings is provided. Root growth is completely inhibited at 5 x 10/sup -2/ M and germination stops altogether at 10/sup -1/ M. The relative inhibition of root growth is stronger than that of hypocotyl growth. Various metabolites and hormones are partially capable of relieving copper inhibition. Catalase, peroxidase and IAA-oxidase activity shows increments directly proportional to the concentration of copper. It is obvious that growth is inversely proportional to enzyme activity. The increased level of these enzymes is probably due to an accelerated protein synthesis.

  1. Radiation effects on Brassica seeds and seedlings

    Science.gov (United States)

    Deoli, Naresh; Hasenstein, Karl H.

    2016-07-01

    Space radiation consists of high energy charged particles and affects biological systems, but because of its stochastic, non-directional nature is difficult to replicate on Earth. Radiation damages biological systems acutely at high doses or cumulatively at low doses through progressive changes in DNA organization. These damages lead to death or cause of mutations. While radiation biology typically focuses on mammalian or human systems, little is known as to how radiation affects plants. In addition, energetic ion beams are widely used to generate new mutants in plants considering their high-LET (Linear Energy Transfer) as compared to gamma rays and X-rays. Understanding the effect of ionizing radiation on plant provides a basis for studying effects of radiation on biological systems and will help mitigate (space) radiation damage in plants. We exposed dry and imbibed Brassica rapa seeds and seedling roots to proton beams of varying qualities and compared the theoretical penetration range of different energy levels with observable growth response. We used 1, 2 and 3 MeV protons in air at the varying fluences to investigate the effect of direct irradiation on the seeds (1012 - 1015 ions/cm2) and seedlings (1013 ions/cm2). The range of protons in the tissue was calculated using Monte-Carlo based SRIM (Stopping and Range of Ions in Matter) software. The simulation and biological results indicate that ions did not penetrate the tissue of dry or hydrated seeds at all used ion energies. Therefore the entire energy was transferred to the treated tissue. Irradiated seeds were germinated vertically under dim light and roots growth was observed for two days after imbibition. The LD50 of the germination was about 2×1014 ions/cm2 and about 5×1014 ions/cm2 for imbibed and dry seeds, respectively. Since seedlings are most sensitive to gravity, the change in gravitropic behavior is a convenient means to assess radiation damage on physiological responses other than direct tissue

  2. Asymmetric distribution of glucose and indole-3-acetyl-myo-inositol in geostimulated Zea mays seedlings

    Science.gov (United States)

    Momonoki, Y. S.; Bandurski, R. S. (Principal Investigator)

    1988-01-01

    Indole-3-acetyl-myo-inositol occurs in both the kernel and vegetative shoot of germinating Zea mays seedlings. The effect of a gravitational stimulus on the transport of [3H]-5-indole-3-acetyl-myo-inositol and [U-14C]-D-glucose from the kernel to the seedling shoot was studied. Both labeled glucose and labeled indole-3-acetyl-myo-inositol become asymmetrically distributed in the mesocotyl cortex of the shoot with more radioactivity occurring in the bottom half of a horizontally placed seedling. Asymmetric distribution of [3H]indole-3-acetic acid, derived from the applied [3H]indole-3-acetyl-myo-inositol, occurred more rapidly than distribution of total 3H-radioactivity. These findings demonstrate that the gravitational stimulus can induce an asymmetric distribution of substances being transported from kernel to shoot. They also indicate that, in addition to the transport asymmetry, gravity affects the steady state amount of indole-3-acetic acid derived from indole-3-acetyl-myo-inositol.

  3. Sugar maple and yellow birch seedling growth after simulated browsing.

    Science.gov (United States)

    Frederick T. Metzger

    1977-01-01

    Simulating natural damage to leaders of forest-grown seedlings of yellow birch and sugar maple resulted in no loss of vigor but a loss in net height growth. Leader elongation depended upon seedling, shoot, and bud characteristics rather than on the extent of damage.

  4. Asymbiotic seed germination and in vitro seedling development of ...

    African Journals Online (AJOL)

    Within two weeks of culture, spherules emerged out due to cracking of the seed coat. The spherules developed into protocorms with a leaf primordium at apical portion after 3 to 4 weeks and gradually produced complete seedlings. Strong and stout root system was induced in in vitro seedlings on transferring in half strength ...

  5. Grass defoliation affecting survival and growth of seedlings of ...

    African Journals Online (AJOL)

    Two experiments were conducted, one in the field and the other in the greenhouse, to investigate the effects of the intensity and frequency of grass defoliation on the survival and growth of Acacia karroo seedlings. In the greenhouse, seedlings growing with heavily clipped grasses had higher biomass production than those ...

  6. Effects of Mulching, Fertilizer, Seeding and Seedling Treatments on ...

    African Journals Online (AJOL)

    Effects of Mulching, Fertilizer, Seeding and Seedling Treatments on Plant Species Recovery in Kondoa Irangi Hills, Tanzania. ... There were high significant correlations of 0.85 and 0.87 between seedling recruitment and mortality in both sites, indicating that other factors, probably aridity, rather than prevailing site conditions ...

  7. 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 ...

  8. (GPx) activity in young barley seedlings enriched with selenium

    African Journals Online (AJOL)

    AJB_YOMI

    2011-09-21

    Sep 21, 2011 ... E-mail: guzx@njau.edu.cn. Tel/Fax: +86. 25 84396293. have been used for animal feeds and beer malts. Recently, young barley seedlings have been used as food material for people in Asian countries such as China,. Japan, and Korea. Young barley seedlings are rich in dietary fiber, chlorophyll, carotene ...

  9. Seedling characters at different temperatures in pearl millet ...

    African Journals Online (AJOL)

    The effect of six temperatures ranging from 20 to 45°C on the germination and seedling length of six grain pearl millet genotypes (KS, AM, HG, EC, ZZ and D) was determined. There was significant variation in germination and seedling length across temperatures and among genotypes. As a result, significant temperature ...

  10. The growth of Balanites aegyptiaca (L.) seedlings under varied ...

    African Journals Online (AJOL)

    Drought and soil fertility are the major factors that influence seedling survival and growth in arid areas, thus it is of paramount importance to establish optimum water requirements for ... Two weeks old seedlings in polythene bag (2kg) containing the standard potting mixture as growing media were used for the experiments.

  11. Seedling growth of Adenanthera pavonina L. in polluted soils of ...

    African Journals Online (AJOL)

    The seedling growth performance of Adenanthera pavonina L. in polluted soils of different railway tracks viz. Karachi Cantt. Station, Malir Halt, Malir 15, Landhi Junction and University Campus (control) was studied under in pots under natural field conditions. The results showed that the root, shoot and seedling size, number ...

  12. Response of fenugreek ( Trigonella foenum-graecum L.) seedlings ...

    African Journals Online (AJOL)

    In the present investigation, the impact of drought and heavy metal in fenugreek was critically monitored. Fenugreek seedlings were exposed to 1- bar polyethylene glycol (PEG) solution (osmotic stress) and 10 ppm solution of HgCl2 (heavy metal). Within 3 days of seedling growth, mercury exposure induced relatively high ...

  13. Analysis on Factors Affecting Seedling Establishment in Rice

    Directory of Open Access Journals (Sweden)

    Ju LUO

    2007-03-01

    Full Text Available Elongations of coleoptile and mesocotyl are related directly to rice seedling establishment in soil and height of plant is related to lodging in rice production. Twelve typical rice cultivars with different lengths of coleoptile and mesocotyl (long, medium and short were selected by screening the lengths of coleoptile and mesocotyl in 1500 accessions. The seedling establishments of these typical cultivars were compared under the combinations of different sowing depths and flooding durations, and two semi-dwarf varieties (G140, Zhong 96–21 with good seedling establishments and optimum mesocotyl lengths were found. The length of mesocotyl was completely fitted negative binomial distribution and the length of coleoptile was nearly fitted lognormal distribution. Analysis of the relationships among mesocotyl, coleoptile, seeding depth, flooding duration, and their interactions to seedling establishment percentage showed that there existed significant relations among mesocotyl, coleoptile, mesocotyl × coleoptile, seeding depth, flooding duration and mesocotyl × sowing depth in the experiment for seedling establishment.

  14. Responses of endogenous proline in rice seedlings under chromium exposure

    Directory of Open Access Journals (Sweden)

    X.Z. Yu

    2016-12-01

    Full Text Available Hydroponic experiments were performed to exam the dynamic change of endogenous proline in rice seedlings exposed to potassium chromate chromium (VI or chromium nitrate chromium (III. Although accumulation of both chromium species in rice seedlings was obvious, more chromium was detected in plant tissues of rice seedlings exposed to chromium (III than those in chromium (VI, majority being in roots rather than shoots. Results also showed that the accumulation capacity of chromium by rice seedlings was positively correlated to chromium concentrations supplied in both chromium variants and the accumulation curve depicted an exponential trend in both chromium treatments over the entire period of exposure. Proline assays showed that both chromium variants induced the change of endogenous proline in shoots and roots of rice seedlings. Chromium (VI of 12.8 mg/L increased proline content significantly (p

  15. 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.

  16. Screening cotton genotypes for seedling drought tolerance

    Directory of Open Access Journals (Sweden)

    Penna Julio C. Viglioni

    1998-01-01

    Full Text Available The objectives of this study were to adapt a screening method previously used to assess seedling drought tolerance in cereals for use in cotton (Gossypium hirsutum L. and to identify tolerant accessions among a wide range of genotypes. Ninety genotypes were screened in seven growth chamber experiments. Fifteen-day-old seedlings were subjected to four 4-day drought cycles, and plant survival was evaluated after each cycle. Three cycles are probably the minimum required in cotton work. Significant differences (at the 0.05 level or lower among entries were obtained in four of the seven experiments. A "confirmation test" with entries previously evaluated as "tolerant" (high survival and "susceptible" (low survival was run. A number of entries duplicated their earlier performance, but others did not, which indicates the need to reevaluate selections. Germplasms considered tolerant included: `IAC-13-1', `IAC-RM4-SM5', `Minas Sertaneja', `Acala 1517E-1' and `4521'. In general, the technique is simple, though time-consuming, with practical value for screening a large number of genotypes. Results from the screening tests generally agreed with field information. The screening procedure is suitable to select tolerant accessions from among a large number of entries in germplasm collections as a preliminary step in breeding for drought tolerance. This research also demonstrated the need to characterize the internal lack of uniformity in growth chambers to allow for adequate designs of experiments.

  17. Culturable bacterial endophytes isolated from Mangrove tree (Rhizophora apiculata Blume) enhance seedling growth in Rice.

    Science.gov (United States)

    Deivanai, Subramanian; Bindusara, Amitraghata Santhanam; Prabhakaran, Guruswamy; Bhore, Subhash Janardhan

    2014-07-01

    Endophytic bacteria do have several potential applications in medicine and in other various sectors of biotechnology including agriculture. Bacterial endophytes need to be explored for their potential applications in agricultural biotechnology. One of the potential applications of bacterial endophytes in agricultural is to enhance the growth of the agricultural crops. Hence, this study was undertaken to explore the plant growth promoting potential application of bacterial endophytes. The objective of this study was to examine the effect of endophytic bacteria from mangrove tree (Rhizophora apiculata Blume) for their efficacy in promoting seedling growth in rice. Eight endophytic bacterial isolates (EBIs) isolated from twig and petiole tissues of the mangrove were identified based on their 16S ribosomal ribonucleic acid (rRNA) gene sequence homology. Separately, surface sterilized paddy seeds were treated with cell-free broth and cell suspension of the EBIs. Rice seedlings were analyzed by various bioassays and data was recorded. The gene sequences of the isolates were closely related to two genera namely, Bacillus and Pantoea. Inoculation of EBIs from R. apiculata with rice seeds resulted in accelerated root and shoot growth with significant increase in chlorophyll content. Among the isolates, Pantoea ananatis (1MSE1) and Bacillus amyloliquefaciens (3MPE1) had shown predominance of activity. Endophytic invasion was recognized by the non-host by rapid accumulation of reactive oxygen species (ROS) and was counteracted by the production of hydrogen peroxide (H2O2) and lipid peroxide. The results demonstrated that EBIs from mangrove tree can increase the fitness of the rice seedlings under controlled conditions. These research findings could be useful to enhance the seedling growth and could serve as foundation in further research on enhancing the growth of the rice crop using endophytic bacteria.

  18. Branching of the PIF3 regulatory network in Arabidopsis: roles of PIF3-regulated MIDAs in seedling development in the dark and in response to light.

    Science.gov (United States)

    Sentandreu, Maria; Leivar, Pablo; Martín, Guiomar; Monte, Elena

    2012-04-01

    Plants need to accurately adjust their development after germination in the underground darkness to ensure survival of the seedling, both in the dark and in the light upon reaching the soil surface. Recent studies have established that the photoreceptors phytochromes and the bHLH phytochrome interacting factors PIFs regulate seedling development to adjust it to the prevailing light environment during post-germinative growth. However, complete understanding of the downstream regulatory network implementing these developmental responses is still lacking. In a recent work, published in The Plant Cell, we report a subset of PIF3-regulated genes in dark-grown seedlings that we have named MIDAs (MISREGULATED IN DARK). Analysis of their functional relevance using mutants showed that four of them present phenotypic alterations in the dark, and that each affected a particular facet of seedling development, suggesting organ-specific branching in the signal that PIF3 relays downstream. Furthermore, our results also showed an altered response to light in seedlings with an impaired PIF3/MIDA regulatory network, indicating that these factors might also be essential to initiate and optimize the developmental adjustment of the seedling to the light environment.

  19. 2-D Clinostat for Simulated Microgravity Experiments with Arabidopsis Seedlings

    Science.gov (United States)

    Wang, Hui; Li, Xugang; Krause, Lars; Görög, Mark; Schüler, Oliver; Hauslage, Jens; Hemmersbach, Ruth; Kircher, Stefan; Lasok, Hanna; Haser, Thomas; Rapp, Katja; Schmidt, Jürgen; Yu, Xin; Pasternak, Taras; Aubry-Hivet, Dorothée; Tietz, Olaf; Dovzhenko, Alexander; Palme, Klaus; Ditengou, Franck Anicet

    2016-04-01

    Ground-based simulators of microgravity such as fast rotating 2-D clinostats are valuable tools to study gravity related processes. We describe here a versatile g-value-adjustable 2-D clinostat that is suitable for plant analysis. To avoid seedling adaptation to 1 g after clinorotation, we designed chambers that allow rapid fixation. A detailed protocol for fixation, RNA isolation and the analysis of selected genes is described. Using this clinostat we show that mRNA levels of LONG HYPOCOTYL 5 (HY5), MIZU-KUSSEI 1 (MIZ1) and microRNA MIR163 are down-regulated in 5-day-old Arabidopsis thaliana roots after 3 min and 6 min of clinorotation using a maximal reduced g-force of 0.02 g, hence demonstrating that this 2-D clinostat enables the characterization of early transcriptomic events during root response to microgravity. We further show that this 2-D clinostat is able to compensate the action of gravitational force as both gravitropic-dependent statolith sedimentation and subsequent auxin redistribution (monitoring D R5 r e v :: G F P reporter) are abolished when plants are clinorotated. Our results demonstrate that 2-D clinostats equipped with interchangeable growth chambers and tunable rotation velocity are suitable for studying how plants perceive and respond to simulated microgravity.

  20. First report of alfalfa (Medicago sativa L.) seed rot, seedling root rot, and damping off caused by Pythium spp. in Sudanese soil

    Science.gov (United States)

    Alfalfa is an important forage crop in Sudan but has relatively low biomass yields. In September 2016 soil samples were collected from three commercial alfalfa production fields near Khartoum, Sudan with poor seedling establishment and rapid stand decline. Soil samples from each field were evaluated...

  1. Effect of seedling stock on the early stand development and physiology of improved loblolly pine (Pinus taeda L.) seedlings

    Science.gov (United States)

    Shakuntala Sharma; Joshua P. Adams; Jamie L. Schuler; Robert L. Ficklin; Don C. Bragg

    2016-01-01

    This study assessed the effects of spacing and genotype on the growth and physiology of improved loblolly pine (Pinus taeda L.) seedlings from three distinct genotypes planted in Drew County, Arkansas (USA). Genotype had a significant effect on survival and height. Clone CF Var 1 showed greater height and survival compared to other seedlings....

  2. Rapid improvement teams.

    Science.gov (United States)

    Alemi, F; Moore, S; Headrick, L; Neuhauser, D; Hekelman, F; Kizys, N

    1998-03-01

    Suggestions, most of which are supported by empirical studies, are provided on how total quality management (TQM) teams can be used to bring about faster organizationwide improvements. Ideas are offered on how to identify the right problem, have rapid meetings, plan rapidly, collect data rapidly, and make rapid whole-system changes. Suggestions for identifying the right problem include (1) postpone benchmarking when problems are obvious, (2) define the problem in terms of customer experience so as not to blame employees nor embed a solution in the problem statement, (3) communicate with the rest of the organization from the start, (4) state the problem from different perspectives, and (5) break large problems into smaller units. Suggestions for having rapid meetings include (1) choose a nonparticipating facilitator to expedite meetings, (2) meet with each team member before the team meeting, (3) postpone evaluation of ideas, and (4) rethink conclusions of a meeting before acting on them. Suggestions for rapid planning include reducing time spent on flowcharting by focusing on the future, not the present. Suggestions for rapid data collection include (1) sample patients for surveys, (2) rely on numerical estimates by process owners, and (3) plan for rapid data collection. Suggestions for rapid organizationwide implementation include (1) change membership on cross-functional teams, (2) get outside perspectives, (3) use unfolding storyboards, and (4) go beyond self-interest to motivate lasting change in the organization. Additional empirical investigations of time saved as a consequence of the strategies provided are needed. If organizations solve their problems rapidly, fewer unresolved problems may remain.

  3. Rapid response systems.

    Science.gov (United States)

    Lyons, Patrick G; Edelson, Dana P; Churpek, Matthew M

    2018-07-01

    Rapid response systems are commonly employed by hospitals to identify and respond to deteriorating patients outside of the intensive care unit. Controversy exists about the benefits of rapid response systems. We aimed to review the current state of the rapid response literature, including evolving aspects of afferent (risk detection) and efferent (intervention) arms, outcome measurement, process improvement, and implementation. Articles written in English and published in PubMed. Rapid response systems are heterogeneous, with important differences among afferent and efferent arms. Clinically meaningful outcomes may include unexpected mortality, in-hospital cardiac arrest, length of stay, cost, and processes of care at end of life. Both positive and negative interventional studies have been published, although the two largest randomized trials involving rapid response systems - the Medical Early Response and Intervention Trial (MERIT) and the Effect of a Pediatric Early Warning System on All-Cause Mortality in Hospitalized Pediatric Patients (EPOCH) trial - did not find a mortality benefit with these systems, albeit with important limitations. Advances in monitoring technologies, risk assessment strategies, and behavioral ergonomics may offer opportunities for improvement. Rapid responses may improve some meaningful outcomes, although these findings remain controversial. These systems may also improve care for patients at the end of life. Rapid response systems are expected to continue evolving with novel developments in monitoring technologies, risk prediction informatics, and work in human factors. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Jasmonate inhibits COP1 activity to suppress hypocotyl elongation and promote cotyledon opening in etiolated Arabidopsis seedlings.

    Science.gov (United States)

    Zheng, Yuyu; Cui, Xuefei; Su, Liang; Fang, Shuang; Chu, Jinfang; Gong, Qingqiu; Yang, Jianping; Zhu, Ziqiang

    2017-06-01

    A germinating seedling undergoes skotomorphogenesis to emerge from the soil and reach for light. During this phase, the cotyledons are closed, and the hypocotyl elongates. Upon exposure to light, the seedling rapidly switches to photomorphogenesis by opening its cotyledons and suppressing hypocotyl elongation. The E3 ubiquitin ligase CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1) is critical for maintaining skotomorphogenesis. Here, we report that jasmonate (JA) suppresses hypocotyl elongation and stimulates cotyledon opening in etiolated seedlings, partially phenocopying cop1 mutants in the dark. We also find that JA stabilizes several COP1-targeted transcription factors in a COP1-dependent manner. RNA-seq analysis further defines a JA-light co-modulated and cop1-dependent transcriptome, which is enriched for auxin-responsive genes and genes participating in cell wall modification. JA suppresses COP1 activity through at least two distinct mechanisms: decreasing COP1 protein accumulation in the nucleus; and reducing the physical interaction between COP1 and its activator, SUPPRESSOR OF PHYTOCHROME A-105 1 (SPA1). Our work reveals that JA suppresses COP1 activity to stabilize COP1 targets, thereby inhibiting hypocotyl elongation and stimulating cotyledon unfolding in etiolated Arabidopsis seedlings. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  5. Increased nitrogen input enhances Kandelia obovata seedling growth in the presence of invasive Spartina alterniflora in subtropical regions of China.

    Science.gov (United States)

    Cui, Xiaowei; Song, Weimin; Feng, Jianxiang; Jia, Dai; Guo, Jiemin; Wang, Zhonglei; Wu, Hao; Qi, Fei; Liang, Jie; Lin, Guanghui

    2017-01-01

    Mangroves in China are severely affected by the rapid invasion of the non-native species Spartina alterniflora Although many studies have addressed the possible impacts of S. alterniflora on the performance of mangrove seedlings, how excessive nitrogen (N) input due to eutrophication affects the interactions between mangrove species and S. alterniflora remains unknown. Here, we report the results from a mesocosm experiment using seedlings of the native mangrove species Kandelia obovata and the exotic S. alterniflora grown in monoculture and mixed culture under no nitrogen addition and nitrogen (N) addition treatments for 18 months. Without N addition, the presence of S. alterniflora inhibited the growth of K. obovata seedlings. Excessive N addition significantly increased the growth rate of K. obovata in both cultures. However, the positive and significantly increasing relative interaction intensity index under excessive N input suggested that the invasion of S. alterniflora could favour the growth of K. obovata under eutrophication conditions. Our results imply that excessive N input in southeastern China can increase the competitive ability of mangrove seedlings against invasive S. alterniflora. © 2017 The Author(s).

  6. The impact of birch seedlings on evapotranspiration from a mined peatland: an experimental study in southern Quebec, Canada

    Directory of Open Access Journals (Sweden)

    E. Fay

    2009-03-01

    Full Text Available Dense stands of birch (Betula spp. on abandoned peat workings have often been identified as potential barriers to site restoration, but little research has been conducted to evaluate their impact on water resources. The objective of this experimental study was to determine whether birch seedlings established on an abandoned mined peatland in eastern Canada had a significant impact on evapotranspiration. Transpiration rates from birch seedlings planted in containers filled with Sphagnum compost were measured gravimetrically. Unplanted containers were used to similarly measure evaporation rates from bare peat. On average, the measured rates of evaporation (per unit area from peat were 2.5 times the rates of transpiration from birch leaves. However, if the total leaf area of a dense birch population established on an abandoned mined peatland is considered, the total amount of water lost through birch transpiration could be higher than that lost by evaporation from the peat surface. This study provides a rough estimate of potential water losses due to birch seedling transpiration, and indicates that a dense population of birch on a mined peatland may influence site hydrology even at the early establishment phase (seedlings. Consequently, recently abandoned mined peatlands should be restored rapidly to prevent the establishment of birch trees.

  7. Machine Vision Implementation in Rapid PCB Prototyping

    Directory of Open Access Journals (Sweden)

    Yosafat Surya Murijanto

    2012-03-01

    Full Text Available Image processing, the heart of machine vision, has proven itself to be an essential part of the industries today. Its application has opened new doorways, making more concepts in manufacturing processes viable. This paper presents an application of machine vision in designing a module with the ability to extract drills and route coordinates from an un-mounted or mounted printed circuit board (PCB. The algorithm comprises pre-capturing processes, image segmentation and filtering, edge and contour detection, coordinate extraction, and G-code creation. OpenCV libraries and Qt IDE are the main tools used. Throughout some testing and experiments, it is concluded that the algorithm is able to deliver acceptable results. The drilling and routing coordinate extraction algorithm can extract in average 90% and 82% of the whole drills and routes available on the scanned PCB in a total processing time of less than 3 seconds. This is achievable through proper lighting condition, good PCB surface condition and good webcam quality. 

  8. Production of desert rose seedlings in different potting media

    Directory of Open Access Journals (Sweden)

    Ronan Carlos Colombo

    2017-09-01

    Full Text Available Over the past decade the desert rose received fame in the flower market due to its striking and sculptural forms; however, the commercial production of these species is quite recent and little is known about its crop management, including substrates recommendation. The objectives of this study were to investigate the effect of different substrates on desert rose seed germination and production of its seedlings. Experiment I: freshly harvested seeds of desert rose were sown in different substrates e.g. sand, coconut fiber, semi-composted pine bark, sand + coconut fiber, semi-composted pine bark + sand and coconut fiber + semicomposted pine bark. These substrates were evaluated to study the emergence percentage of seeds, initial growth of seedlings and seedling emergence speed index (ESI. Experiment II: desert rose from the experiment I were transferred to plastic pots filled with the same substrates as in experiment I. The pH and electrical conductivity (EC of the substrates were noted every 30 days while the growth parameters of seedlings were recorded after 240 days. Results from experiment I showed higher germination rate and seedling growth in substrates containing semi-composted pine bark. Similarly, in experiment II, better quality seedlings were observed in substrates containing semi-composted pine bark. Thus, for desert rose seed germination and seedling growth, it is recommended to use substrates containing semi-composted pine bark.

  9. Urban solid waste in the production of Lafoensia pacari seedlings

    Directory of Open Access Journals (Sweden)

    Alan H. M. de Abreu

    Full Text Available ABSTRACT This study aimed to verify the potential of urban solid wastes as substrate for production of seedlings of Lafoensia pacari. Five treatments were tested, four with solid wastes and one standard substrate, namely: sewage sludge from Alegria Wastewater Treatment Plant (WTP; sewage sludge from Ilha do Governador WTP; sewage sludge from Sarapuí WTP; domestic garbage compost (Fertlurb; and a commercial substrate made of biostabilized pine bark (standard substrate. The wastes received 20% (in volume of shredded coconut fiber. At 105 days after sowing, the seedlings were evaluated for different quality parameters. Seedlings produced with Sarapuí WTP sewage sludge showed the best results in all the parameters, followed by seedlings produced with sewage sludge from Alegria and Ilha do Governador WTPs, which did not differ. Seedlings produced with domestic garbage compost showed satisfactory results, higher than the ones observed for seedlings produced with commercial substrate. The urban solid wastes with 20% of coconut fiber showed high potential and can be recommended for the composition of substrate in the production of Lafoensia pacari seedlings.

  10. Effects of benzoic acid and cadmium toxicity on wheat seedlings

    Directory of Open Access Journals (Sweden)

    Kavita Yadav

    2013-06-01

    Full Text Available Benzoic acid (BA and Cd exhibit cumulative effects on plants due to their accumulation in the soil. The present study reports the effects of BA an allelochemical, Cd and their combinations on seed germination, seedling growth, biochemical parameters, and response of antioxidant enzymes in Triticum aestivum L. The experiment was conducted in sand supplemented with Hoagland nutrient solution. Benzoic acid was applied at concentrations of 0.5, 1.0, and 1.5 mM with or without Cd (7 mg L-1 to observe effects of allelochemical and Cd alone and in combination on wheat. Both stresses exhibited inhibitory effect on growth and metabolism of wheat seedlings. The allelochemical in single and combined treatments with Cd decreased seedling growth as compared to Cd stress. The two stresses significantly enhanced malondialdehyde content of wheat seedlings. The activity of other antioxidant enzymes, viz. superoxide dismutase (SOD, catalase (CAT, ascorbate peroxidase (APX, and guaiacol peroxidase (POX were also recorded. SOD increased in seedlings under the two stresses. CAT more prominently ameliorates the toxic effects of H2O2 as compared with APX and POX and protected wheat seedlings from oxidative stress. Allelochemical buttressed the toxic effect of Cd on wheat seedlings.

  11. Germination and initial development of aroeira (Myracrodruon urundeuva seedlings

    Directory of Open Access Journals (Sweden)

    Silvana de Paula Quintão Scalon

    2012-12-01

    Full Text Available Aroeira has great economic importance due to its wood useful, tannins extraction and use in the pharmacology. The aim of this work was to evaluate the germination aspects and initial seedlings development of aroeira, under gibberellins, substrata and shading effects, and for that two experiments were led out. In the first one, seeds were previously soaked for 24 hours in water and in 100 mg.L-1 gibberellin solution and were sowed directly in cells trays in the following substrata: land and sand (1:1 and 1:2 and Plantmax . In the second experiment, 15 cm length seedlings were transplanted to polyethylene sacks filled out land+sand+poultry manure (1:1:1 partly decomposed and they were maintained at greenhouse for 15 days. Soon after, seedlings were transferred for the following conditions: shading (50% and full sun and they were 50 mg.L-1 and 150 mg.L-1 gibberellins solutions pulverized, as control seedlings water pulverized. Aroeira seeds should not be previously water or gibberellins imbibed before being sowed. The best substrata for aroeira seeds germination was Plantmax without germinative treatments to reach higher than 80% of seedlings survival. The seedlings developed better at full sun light and the gibberellin. It was observed increment in height, diameter, foliar area and fresh and dry mass from aerial and root part when compared to shading situation. The gibberellins applications did not influence the aroeira seedlings initial growth characteristics.

  12. Rapid world modeling

    International Nuclear Information System (INIS)

    Little, Charles; Jensen, Ken

    2002-01-01

    Sandia National Laboratories has designed and developed systems capable of large-scale, three-dimensional mapping of unstructured environments in near real time. This mapping technique is called rapid world modeling and has proven invaluable when used by prototype systems consisting of sensory detection devices mounted on mobile platforms. These systems can be deployed into previously unmapped environments and transmit real-time 3-D visual images to operators located remotely. This paper covers a brief history of the rapid world modeling system, its implementation on mobile platforms, and the current state of the technology. Applications to the nuclear power industry are discussed. (author)

  13. Winter survival of Scots pine seedlings under different snow conditions.

    Science.gov (United States)

    Domisch, Timo; Martz, Françoise; Repo, Tapani; Rautio, Pasi

    2018-04-01

    Future climate scenarios predict increased air temperatures and precipitation, particularly at high latitudes, and especially so during winter. Soil temperatures, however, are more difficult to predict, since they depend strongly on the fate of the insulating snow cover. 'Rain-on-snow' events and warm spells during winter can lead to thaw-freeze cycles, compacted snow and ice encasement, as well as local flooding. These adverse conditions could counteract the otherwise positive effects of climatic changes on forest seedling growth. In order to study the effects of different winter and snow conditions on young Scots pine (Pinus sylvestris L.) seedlings, we conducted a laboratory experiment in which 80 1-year-old Scots pine seedlings were distributed between four winter treatments in dasotrons: ambient snow cover (SNOW), compressed snow and ice encasement (ICE), flooded and frozen soil (FLOOD) and no snow (NO SNOW). During the winter treatment period and a 1.5-month simulated spring/early summer phase, we monitored the needle, stem and root biomass of the seedlings, and determined their starch and soluble sugar concentrations. In addition, we assessed the stress experienced by the seedlings by measuring chlorophyll fluorescence, electric impedance and photosynthesis of the previous-year needles. Compared with the SNOW treatment, carbohydrate concentrations were lower in the FLOOD and NO SNOW treatments where the seedlings had almost died before the end of the experiment, presumably due to frost desiccation of aboveground parts during the winter treatments. The seedlings of the ICE treatment showed dead needles and stems only above the snow and ice cover. The results emphasize the importance of an insulating and protecting snow cover for small forest tree seedlings, and that future winters with changed snow patterns might affect the survival of tree seedlings and thus forest productivity.

  14. Photomodulation of strigolactone biosynthesis and accumulation during sunflower seedling growth

    Science.gov (United States)

    Bharti, Niharika; Tripathi, Smita; Bhatla, Satish Chander

    2015-01-01

    Present investigations report the presence of strigolactones (SLs) and photomodulation of their biosynthesis in sunflower seedlings (roots, cotyledons and first pair of leaves) during early phase of seedling development. Qualitative analyses and characterization by HPLC, ESI-MS and FT-IR revealed the presence of more than one type of SLs. Orobanchyl acetate was detected both in roots and leaves. Five-deoxystrigol, sorgolactone and orobanchol were exclusively detected in seedling roots. Sorgomol was detectable only in leaves. HPLC eluted fraction from seedling roots and leaves co-chromatographing with GR24 (a synthetic SL) could also bring about germination in Orobanche cernua (a weed) seeds, which are established to exhibit SL – mediated germination, thereby indicating the SL identity of the eluates using this bioassay. SLs accumulation was always more in the roots of light-grown seedlings, it being maximum at 4 d stage. Although significant activity of carotenoid cleavage dioxygenase (CCD, the enzyme critical for SL biosynthesis) was detected in 2 d old seedling roots, SLs remained undetectable in cotyledons at all stages of development and also in the roots of 2 d old light and dark-grown seedlings. Roots of light-grown seedlings showed maximum CCD activity during early (2 d) stage of development, thereby confirming photomodulation of enzyme activity. These observations indicate the migration of a probable light-sensitized signaling molecule (yet to be identified) or a SL precursor from light exposed aerial parts to the seedling roots maintained in dark. Thus, a photomodulation and migration of SL precursor/s is evident from the present work. PMID:26252191

  15. Dawn and Dusk Set States of the Circadian Oscillator in Sprouting Barley (Hordeum vulgare Seedlings.

    Directory of Open Access Journals (Sweden)

    Weiwei Deng

    Full Text Available The plant circadian clock is an internal timekeeper that coordinates biological processes with daily changes in the external environment. The transcript levels of clock genes, which oscillate to control circadian outputs, were examined during early seedling development in barley (Hordeum vulgare, a model for temperate cereal crops. Oscillations of clock gene transcript levels do not occur in barley seedlings grown in darkness or constant light but were observed with day-night cycles. A dark-to-light transition influenced transcript levels of some clock genes but triggered only weak oscillations of gene expression, whereas a light-to-dark transition triggered robust oscillations. Single light pulses of 6, 12 or 18 hours induced robust oscillations. The light-to-dark transition was the primary determinant of the timing of subsequent peaks of clock gene expression. After the light-to-dark transition the timing of peak transcript levels of clock gene also varied depending on the length of the preceding light pulse. Thus, a single photoperiod can trigger initiation of photoperiod-dependent circadian rhythms in barley seedlings. Photoperiod-specific rhythms of clock gene expression were observed in two week old barley plants. Changing the timing of dusk altered clock gene expression patterns within a single day, showing that alteration of circadian oscillator behaviour is amongst the most rapid molecular responses to changing photoperiod in barley. A barley EARLY FLOWERING3 mutant, which exhibits rapid photoperiod-insensitive flowering behaviour, does not establish clock rhythms in response to a single photoperiod. The data presented show that dawn and dusk cues are important signals for setting the state of the circadian oscillator during early development of barley and that the circadian oscillator of barley exhibits photoperiod-dependent oscillation states.

  16. School-based diagnosis and treatment of malaria by teachers using rapid diagnostic tests and artemisinin-based combination therapy: experiences and perceptions of users and implementers of the Learner Treatment Kit, southern Malawi.

    Science.gov (United States)

    Mphwatiwa, Treza; Witek-McManus, Stefan; Mtali, Austin; Okello, George; Nguluwe, Paul; Chatsika, Hard; Roschnik, Natalie; Halliday, Katherine E; Brooker, Simon J; Mathanga, Don P

    2017-08-07

    Training teachers to diagnose uncomplicated malaria using malaria rapid diagnostic tests and treat with artemisinin-based combination therapy has the potential to improve the access of primary school children (6-14 years) to prompt and efficient treatment for malaria, but little is known about the acceptability of such an intervention. This qualitative study explored experiences and perceptions of users and implementers of a programme of school-based malaria case management via a first-aid kit-the Learner Treatment Kit (LTK)-implemented as part of a cluster-randomized controlled trial in Zomba district, Malawi. From 29 primary schools where teachers were trained to test and treat school children for malaria using the LTK, six schools were purposively selected on the basis of relative intervention usage (low, medium or high); school size and geographical location. In total eight focus group discussions were held with school children, parents and guardians, and teachers; and 20 in-depth interviews were conducted with key stakeholders at the school, district and national levels. Interviews were recorded, transcribed, and analysed using a thematic analysis approach. The LTK was widely perceived by respondents to be a worthwhile intervention, with the opinion that trained teachers were trusted providers of malaria testing and treatment to school children. Benefits of the programme included a perception of improved access to malaria treatment for school children; decreased school absenteeism; and that the programme supported broader national health and education policies. Potential barriers to successful implementation expressed included increased teacher workloads, a feeling of inadequate supervision from health workers, lack of incentives and concerns for the sustainability of the programme regarding the supply of drugs and commodities. Training teachers to test for and treat uncomplicated malaria in schools was well received by both users and implementers alike, and

  17. Fungicidal control of Lophodermium seditiosum on Pinus sylvestris seedlings in Swedish forest nurseries

    Energy Technology Data Exchange (ETDEWEB)

    Stenstroem, Elna [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Forest Mycology and Pathology; Arvidsson, Bernt [Svenska Skogsplantor AB, Joenkoeping (Sweden)

    2001-07-01

    During the 1990s, there were serious outbreaks of the pathogen Lophodermium seditiosum on pine seedlings in Swedish forest nurseries, even though the seedlings had been treated with the fungicide propiconazole. The present experiment was carried out to evaluate two other fungicides, fluazinam and azoxystrobin, as possible alternatives to propiconazole. In the tests, which were all carried out in the same forest nursery, seedlings were treated with either propiconazole, fluazinam. or azoxystrobin, and the proportion of needles with ascocarps of L. seditiosum and the number of ascocarps per needle were recorded over the following 2 yrs. Seedlings treated with azoxystrobin already appeared healthier than control seedlings in September of the first year, and by November all azoxystrobin-treated seedlings had fewer ascocarps per needle compared with control seedlings. In autumn of the second year, there were no ascocarps on seedlings treated with fluazinam or azoxystrobin, whereas seedlings treated with propiconazole had similar numbers of ascocarps to non-treated control seedlings.

  18. A rapid inoculation technique for assessing pathogenicity of Fusarium oxysporum f. sp. niveum and F. o. melonis on Cucurbits

    Science.gov (United States)

    Freeman, S.; Rodriguez, R.J.

    1993-01-01

    A continuous-dip inoculation technique for rapid assessment of pathogenicity of Fusarium oxysporum f. sp. niveum and F. o. melonis was developed. The method, adapted from a similar procedure for determining pathogenicity of Colletotrichum magna (causal agent of anthracnose of cucurbits), involves constant exposure of seedlings and cuttings (seedlings with root systems excised) of watermelon and muskmelon to conidial suspensions contained in small scintillation vials. Disease development in intact seedlings corresponded well to disease responses observed with the standard root-dip inoculation/pot assay. The continuous-dip inoculation technique resulted in rapid disease development, with 50% of watermelon cuttings dying after 4–6 days of exposure to F. o. niveum. A mortality of 30% also was observed in watermelon cuttings exposed to conidia of F. o. melonis, as opposed to only a 0–2.5% mortality in seedlings with intact roots. Disease response was similar with muskmelon seedlings and cuttings continuously dip-inoculated with F. o. melonis isolates. However, no disease symptoms were observed in muskmelon seedlings or cuttings inoculated with F. o. niveum. Four nonpathogenic isolates of F. oxysporum did not cause disease symptoms in either watermelon or muskmelon cuttings and seedlings when assayed by this technique. The proposed method enables a rapid screening of pathogenicity and requires less time, labor, and greenhouse space than the standard root-dip inoculation/pot assay. The reliability of the continuous-dip inoculation technique is limited, however, to exposure of intact seedlings at a concentration of 1 × 106conidia per milliliter; the method is not accurate at this range for excised seedlings.

  19. Detection of endogenous gibberellins and their relationship to hypocotyl elongation in soybean seedlings

    International Nuclear Information System (INIS)

    Bensen, R.J.; Beall, F.D.; Mullet, J.E.; Morgan, P.W.

    1990-01-01

    Four gibberellins, GA 53 , GA 19 , GA 20 , and GA 1 , were detected by bioassay, chromatography in two HPLC systems, and combined gas chromatography-mass spectroscopy-selected ion monitoring (GC-MS-SIM) in etiolated soybean (Glycine max [L.] Merr.) hypocotyls. GC-MS-SIM employed [ 2 H 2 ]-labeled standards for each endogenous gibberellin detected, and quantities estimated from bioassays and GC-MS-SIM were similar. This result plus the tentative detection of GA 44 and GA 8 (standards not available) indicates that the early-C-13-hydroxylation pathway for gibberellin biosynthesis predominates in soybean hypocotyls. Other gibberellins were not detected. Growth rates decreased after transfer to low water potential (ψ w ) vermiculite and were completely arrested 24 hours after transfer. The GA 1 content in the elongating region of hypocotyls had declined to 38% of the 0 time value at 24 hours after transfer to low ψ w vermiculite, a level which was only 13% of the GA 1 content in control seedlings at the same time (24 hours posttransfer). Seedlings were growth responsive to exogenous GA 3 , and this GA 3 -promoted growth was inhibited by exogenous ABA. The data are consistent with the hypothesis that changes in GA 1 and ABA levels play a role in adjusting hypocotyl elongation rates. However, the changes observed are not of sufficient magnitude nor do they occur rapidly enough to suggest they are the primary regulators of elongation rate responses to rapidly changing plant water status

  20. Rapid manufacturing for microfluidics

    CSIR Research Space (South Africa)

    Land, K

    2012-10-01

    Full Text Available for microfluidics K. LAND, S. HUGO, M MBANJWA, L FOURIE CSIR Materials Science and Manufacturing P O Box 395, Pretoria 0001, SOUTH AFRICA Email: kland@csir.co.za INTRODUCTION Microfluidics refers to the manipulation of very small volumes of fluid.... Microfluidics is at the forefront of developing solutions for drug discovery, diagnostics (from glucose tests to malaria and TB testing) and environmental diagnostics (E-coli monitoring of drinking water). In order to quickly implement new designs, a rapid...

  1. De Novo Sequencing and Comparative Analysis of Schima superba Seedlings to Explore the Response to Drought Stress.

    Directory of Open Access Journals (Sweden)

    Bao-Cai Han

    Full Text Available Schima superba is an important dominant species in subtropical evergreen broadleaved forests of China, and plays a vital role in community structure and dynamics. However, the survival rate of its seedlings in the field is low, and water shortage could be a factor that limits its regeneration. In order to better understand the response of its seedlings to drought stress on a functional genomics scale, RNA-seq technology was utilized in this study to perform a large-scale transcriptome sequencing of the S. superba seedlings under drought stress. More than 320 million clean reads were generated and 72218 unique transcripts were obtained through de novo assembly. These unigenes were further annotated by blasting with different public databases and a total of 53300 unique transcripts were annotated. A total of 31586 simple sequence repeat (SSR loci were presented. Through gene expression profiling analysis between drought treatment and control, 11038 genes were found to be significantly enriched in drought-stressed seedlings. Based on these differentially expressed genes (DEGs, Gene Ontology (GO terms enrichment and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG enrichment analysis indicated that drought stress caused a number of changes in the types of sugars, enzymes, secondary mechanisms, and light responses, and induced some potential physical protection mechanisms. In addition, the expression patterns of 18 transcripts induced by drought, as determined by quantitative real-time PCR, were consistent with their transcript abundance changes, as identified by RNA-seq. This transcriptome study provides a rapid method for understanding the response of S. superba seedlings to drought stress and provides a number of gene sequences available for further functional genomics studies.

  2. Proteomics and Transcriptomics analysis of Arabidopsis Seedlings in Microgravity

    Data.gov (United States)

    National Aeronautics and Space Administration — On Earth plants are constantly exposed to a gravitational field of 1g. Gravity affects a plant in every step of its development. Germinating seedlings orient their...

  3. Seedlings and Saplings - Spears and Didion Ranches [ds318

    Data.gov (United States)

    California Natural Resource Agency — These data are the total number and average number of saplings and seedlings of trees detected from 0.05-ha circular plot habitat samples taken in 2005 at sample...

  4. Germination, seedling growth and relative water content of shoot in ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-08-18

    Aug 18, 2008 ... (mg), root : shoot length (R:S) ratio, and relative water content of shoot (RWC, %) were investigated in this study. The results ... seedlings may provide an advantage by allowing access ... Residual chlorine was eliminated by.

  5. Effect of ponderosa pine needle litter on grass seedling survival.

    Science.gov (United States)

    Burt R. McConnell; Justin G. Smith

    1971-01-01

    Hard fescue survival rates were followed for 6 years on four different pine needle treatment plots. Needle litter had a significant effect on initial survival of fescue seedlings, but subsequent losses undoubtedly resulted from the interaction of many factors.

  6. Identification of zygotic and nucellar seedlings in polyembryonic mango cultivars

    Directory of Open Access Journals (Sweden)

    Elisa del Carmen Martínez Ochoa

    2012-11-01

    Full Text Available The objective of this work was to evaluate the occurrence of polyembryony in the mango cultivars Manila and Ataulfo, and to determine whether seedlings cultured in vitro are zygotic or nucelar. Percentage of polyembryony was calculated and the number of embryos in 100 seeds of each cultivar was recorded. 'Manila' exhibited 97% polyembryony with 3.4 embryos per seed, while 'Ataulfo' had 95% polyembryony with 3.2 embryos per seed. Later, 20 seeds of each cultivar were established in vitro, and it was analyzed those in which all embryos germinated (12 seeds from 'Manila' and 7 from 'Ataulfo'. DNA was extracted from seedling leaf tissue, and its origin was identified with 14 RAPD primers. The polymorphic markers recognized the seedlings of sexual origin in seven of nine 'Manila' polyembryonic seeds, and in four of seven 'Ataulfo' ones. Also, in polyembryonic seeds not all zygotic seedlings were produced by small embryos located at the micropyle.

  7. The effect of osmopriming on germination, seedling growth and ...

    African Journals Online (AJOL)

    Jane

    2011-10-24

    Oct 24, 2011 ... affecting the oxidative metabolism such as increasing superoxide dismutase ... the adverse effect of salinity by improving germination and seedling growth .... osmoregulation by the accumulation of proline. A positive effect of ...

  8. Cold stratification, but not stratification in salinity, enhances seedling ...

    African Journals Online (AJOL)

    use

    2011-10-26

    Oct 26, 2011 ... Cold stratification was reported to release seed dormancy and enhance plant tolerance to salt stress. ... Key words: Cold stratification, salt stress, seedling emergence, ... methods used to cope with salinity, seed pre-sowing.

  9. Strong microsite control of seedling recruitment in tundra

    DEFF Research Database (Denmark)

    Graae, Bente J; Ejrnæs, Rasmus; Lang, Simone I

    2011-01-01

    The inclusion of environmental variation in studies of recruitment is a prerequisite for realistic predictions of the responses of vegetation to a changing environment. We investigated how seedling recruitment is affected by seed availability and microsite quality along a steep environmental......, the experimental seed addition showed that the microsite environment was even more important. For all species, seedling emergence peaked at the productive end of the gradient, irrespective of the adult niches realized. Disturbance promoted recruitment at all positions along the environmental gradient, not just...... at high productivity. Early seedling emergence constituted the main temporal bottleneck in recruitment for all species. Surprisingly, winter mortality was highest at what appeared to be the most benign end of the gradient. The results highlight that seedling recruitment patterns are largely determined...

  10. Emergence and seedling growth of five forage legume species at ...

    African Journals Online (AJOL)

    Jane

    2011-08-17

    Aug 17, 2011 ... A field study compared the seedling emergence and structure of five forage legumes .... mean seed mass (without seed coat) per species was used for W1 ...... Of light and length: regulation of hypocotyl growth in Arabidopsis.

  11. ARC EMCS Experiments (Seedling Growth-2) Experiment Status

    Science.gov (United States)

    Heathcote, David; Steele, Marianne

    2015-01-01

    Presentation of the status of the ARC ISS (International Space Station) Experiment, Seedling Growth-2 to the Payload Operations Investigator Working Group meeting at MSFC, Huntsville AL. The experiment employs the European Modular Cultivation System (ECMS).

  12. Re-use of seedling containers and Fusarium circinatum association ...

    African Journals Online (AJOL)

    Re-use of seedling containers and Fusarium circinatum association with asymptomatic Pinus patula planting stock. Andrew R Morris, Gerda Fourie, Izette Greyling, Emma T Steenkamp, Nicoletta B Jones ...

  13. Inhibiting effect of ponderosa pine seed trees on seedling growth

    Science.gov (United States)

    Philip M. McDonald

    1976-01-01

    Ponderosa pine seed trees, numbering 4, 8, and 12 per acre, were left standing for 9 years after harvest cutting on the Challenge Experimental Forest, Calif. Seedling heights were measured at ages 5, 9, and 14, and for all ages were poorest if within 20 feet of a seed tree. Seedlings 20 feet or less from a seed tree at the ages given lost the equivalent in years of...

  14. Translocation of 14-C in ponderosa pine seedlings

    Science.gov (United States)

    Robert R. Ziemer

    1971-01-01

    The movement of 14-C from the old needles to the roots, and later to the new needles, was measured in 2-year-old ponderosa pine seedlings. The seedlings were in one of three growth stages at the time of the feeding of 14-CO-2: 9 days before spring bud break with no root activity; 7 days before spring bud break with high root activity; and 7 days after spring bud break...

  15. Morphological and biological features of seedlings of some Trifolium species

    Directory of Open Access Journals (Sweden)

    Valentina A. Kalinkina

    2013-04-01

    Full Text Available The author conducted morphological and biological characteristics of seedlings of six species belonging to three sections: Lupinaster(T. lupinasterL, T. pacificumBobr, T. eximium Steph. Ex. DC., Chronosemium(T. campestre Schreb. and Trifolium (T. arvenseL., T. pratense L. of the genus Trifolium. Dimensional and qualitative morphological characteristics of the main structural elements of the seedlings of these species are represented in the article.

  16. Onion seedlings versus onion sets in organic onion production

    OpenAIRE

    Kivijärvi, Pirjo; Hannukkala, Asko; Haapalainen, Minna; Iivonen, Sari

    2017-01-01

    The objective of this study is to find onion varieties that are suitable for seedling cultivation and high-yielding in our relatively cool and short growing season. In addition, the yield quantity, quality and long-term storage durability of onions produced from either seedlings or sets are compared. Rot incidence and composition of pathogen populations in diseased onions is monitored during the growing season and long-term storage. The field experiments and on-farm trials will be carried out...

  17. Stimulatory effects of aluminum on growth of sugar maple seedlings

    Science.gov (United States)

    George A. Schier; Carolyn J. McQuattie

    2002-01-01

    To determine the effect of aluminum (Al) on sugar maple (Acer saccharum Marsh.), seedlings were grown in sand irrigated with nutrient solution (pH 3.8) containing 0, 2.5, 5, 10, 20, or 40 mg L-1 Al. Seedling growth was enhanced at 2.5 and 5mgL-1 Al. Although higher levels of Al reduced calcium (Ca) and...

  18. Effect of salinity and priming on seedling growth in rapeseed (Brassica napus var oleifera Del. - doi: 10.4025/actasciagron.v35i4.17655

    Directory of Open Access Journals (Sweden)

    Paolo Benincasa

    2013-05-01

    Full Text Available Experiments were performed to examine the effect of salt stress and GA3-priming on initial growth of two rapeseed cultivars, one tolerant and one sensitive to salt stress during germination. Seedlings from seeds germinated in salty (as NaCl and non salty substrate were grown in salty and non salty hydroponics. Salt stress reduced seedling growth of the two genotypes consistently with their degree of stress tolerance during germination. Seedlings from stress sensitive seeds germinated under high salinity showed a rapid recover of growth in non stressing conditions. The effect of salt stress on shoot/root ratio was controversial, increased for lab and decreased for greenhouse experiments, probably due to different timing of stress application and additional experimental conditions. Salt stress decreased leaf photosynthesis and increased thermal dissipation in sensitive seedlings (decrease of ΦPSII and qP, increase of NPQ. The GA3-priming did not affect seedling growth of the stress sensitive cultivar subjected to stress, while it greatly improved the performance of the stress tolerant cultivar.

  19. Silvicultural Attempts to Induce Browse Resistance in Conifer Seedlings

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    Bruce A. Kimball

    2011-01-01

    Full Text Available A multiyear study was conducted to determine if soil amendment combined with topical application of elemental sulfur could be employed to reduce deer browse damage to four conifer species. Fertilizer and sulfur were applied to conifer seedlings at seven sites near Corvallis, OR. Growth and browse damage data were collected for all seedlings over a period of 17 months. Additionally, foliar concentrations of monoterpenes and simple carbohydrates were assessed in western redcedar (Thuja plicata seedlings over a period of three years. Fertilization and sulfur treatments had a moderate impact on growth and no influence on browse damage or the chemical responses. Over the course of the study, browse damage diminished while foliar monoterpene concentrations increased in redcedar. It appears that silvicultural manipulation via sulfur application and/or soil amendment cannot accelerate or alter the ontogenetical changes that may naturally defend seedlings against mammalian herbivores. In a brief trial with captive deer, redcedar browse resistance was influenced by seedling maturation, but not monoterpene content. Other maturation effects may yield significant browse protection to young seedlings.

  20. Image seedling analysis to evaluate tomato seed physiological potential

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    Vanessa Neumann Silva

    Full Text Available Computerized seedling image analysis are one of the most recently techniques to detect differences of vigor between seed lots. The aim of this study was verify the hability of computerized seedling image analysis by SVIS® to detect differences of vigor between tomato seed lots as information provided by traditionally vigor tests. Ten lots of tomato seeds, cultivar Santa Clara, were stored for 12 months in controlled environment at 20 ± 1 ºC and 45-50% of relative humidity of the air. The moisture content of the seeds was monitored and the physiological potential tested at 0, 6 and 12 months after storage, with germination test, first count of germination, traditional accelerated ageing and with saturated salt solution, electrical conductivity, seedling emergence and with seed vigor imaging system (SVIS®. A completely randomized experimental design was used with four replications. The parameters obtained by the computerized seedling analysis (seedling length and indexes of vigor and seedling growth with software SVIS® are efficient to detect differences between tomato seed lots of high and low vigor.

  1. Acclimatization and growth of ornamental pineapple seedlings under organic substrates

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    Ronan Carlos Colombo

    2017-09-01

    Full Text Available The in vitro propagation techniques are commonly used to produce ornamental pineapple seedlings in commercial scale, aiming to attend the growers with genetic and sanitary quality seedlings. However, the choice of the ideal substrate is essential for the acclimatization and growth stage of the seedlings propagated by this technique, since some substrates can increase the seedling mortality and/or limit the seedling growth due to its physical and chemical characteristics. Thus, the aim of this study was to evaluate the acclimatization of ornamental pineapple [Ananas comosus (L. Merr. var. ananassoides (Baker Coppens & Leal] on different substrates. Seedlings with approximately seven centimeters, obtained from in vitro culture, were transplanted into styrofoam trays filled with the following substrates: sphagnum; semi-composed pine bark; carbonized rice husk; sphagnum + semicomposed pine bark; sphagnum + carbonized rice husk; and semi-composed pine bark + carbonized rice husk. Each treatment was replicated five times using 10 plants. At 180 days, there were evaluated the following variables: survival percentage, plant height, number of leaves, leaf area, largest root length, and shoot and root dry matter. The substrate semi-composed pine bark + carbonized rice husk presented the lowest mean (62% for survival percentage. The semi-composed pine bark and semi-composed pine bark + carbonized rice husk treatments presented significant increments in some evaluated biometric characteristics. The semi-composed pine bark is the most favorable substrate for the A. comosus var. ananassoids acclimatization.

  2. Contribution of nitrogen derived from mineral supplementation for soybean seedlings

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    Gerusa Massuquini Conceição

    Full Text Available ABSTRACT Seeds can absorb N from mineral supplementation, thus stimulating seedling development in soybeans (Glycine max (L. Merrill. This study aimed to evaluate the contribution to soybean seedlings of N derived from mineral supplementation in seeds with different nutritional contents. Seeds of the cultivar BMX Potência RR received mineral supplementation enriched with 2.5% excess 15N. The treatments were performed in seeds in two lots, one with high and one with low nutritional content. At 2, 6 and 10 days after sowing on paper towels, the seedlings were collected and separated into cotyledons, roots and shoots. Dry matter production, root length and root volume were assessed. Total N and 15N values were analyzed in the seedling organ tissues. The seeds from the lot with lower nutritional content absorbed more N from the mineral supplement, which was accumulated in the cotyledons and redistributed to the root systems and cotyledons. At 10 days after sowing, most of the N in the organs of soybean seedlings was derived from the seed reserves, regardless of nutritional content. Thus, application of N through mineral supplementation is of low importance for the development and nutrition of seedlings.

  3. Study Some Ecological Characteristics on Germination and Seedling Growth of Milky Thistle (Silybum marianum (L. Gaertn

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    E. Zeidali

    2017-12-01

    Full Text Available Introduction: Milky thistle (Silybum marianum is an annual or biennial plant of the Asteraceae family. Possibly native near the coast of southeast England, it has been widely introduced outside its natural range, for example into North America, Iran, Australia and New Zealand where it is considered an invasive weed. Seed is an important stage of plant life history. Most invasive plants primarily rely on seedling recruitment for population establishment and persistence. The rapid spread of many invasive plants is frequently correlated with special seed traits. Seed trait variations exist not only among species but also within species. Seed traits variations within a species are essential for the seedling establishment at different habitats. Environmental factors, such as temperature, soil solution osmotic potential, solution pH, light quality, management practices and seed location in the soil seedbank, affect weed seed germination and emergence. Fluctuations in temperature can influence seed germination differently than those under constant temperatures; however, such information is not available on Milky thistle. A light requirement for germination is the principal means by which germination can be restricted to an area close to the soil surface, and species requiring light for germination are potentially more likely to be prevalent in no-till and pasture systems. Soil pH affects the development and competitiveness of crops and weeds by affecting the availability of essential minerals, nutrients, the solubility of toxic elements, and soil microflora. Seed burial depth (buried by tillage or other means also affects germination and seedling emergence of several weed species. Better knowledge of the factors that influence seed germination and seedling emergence of Milky thistle could contribute to the development of control measures and help determine its potential for invasion into new areas. The objectives of this study, therefore, were to

  4. Effects of sand burial and seed size on seed germination, seedling emergence and seedling biomass of anabasis aphylla

    International Nuclear Information System (INIS)

    Wang, T.T.; Chu, G.M.; Jiang, P.; Wang, M.

    2017-01-01

    Two greenhouse experiments were conducted to test the effects of sand burial (0-2 cm) and seed size (small, medium and large) on seed germination and seedling growth of Anabasis aphylla, which is typically used as a windbreak and for the fixation of sand in the Gurbantunggut desert of Xinjiang, region of northwest China. The results showed that sand burial significantly affected seed germination, seedling emergence, survival and biomass of A. aphylla. The seed germination rate, seedling emergence rate, seedling survival rate and biomass were highest at the 0.2 and 0.5 cm sand burial depths. At different burial depths, different sizes of A. aphylla seed showed a significant difference in the germination and emergence rate. At the same sand burial depth, the seedling emergence rate of the large seeds was significantly higher than that of medium and small seeds. At sand burial depth of 0.2-2 cm, germination of large seeds and seedling survival rates were significantly higher than those at the same sand burial depth for medium seed germination, and the latter was significantly higher than for small seed. We speculate that tolerance to sand burial and diversity of seed size increased the adaption of A. aphylla to this environment, contributing to its dominance in the windy and sandy area of Gurbantunggut desert. (author)

  5. Bioaccumulation of hexachlorobutadiene in pumpkin seedlings after waterborne exposure.

    Science.gov (United States)

    Hou, Xingwang; Zhang, Haiyan; Li, Yanlin; Yu, Miao; Liu, Jiyan; Jiang, Guibin

    2017-10-18

    Hexachlorobutadiene (HCBD) has been listed as a persistent organic pollutant (POP) in the Stockholm Convention, and is now drawing more and more research interest. However, the understanding of its bioaccumulation, especially in plants, is still very limited. In this work, the behavior of HCBD in aqueous solution and pumpkin seedlings was studied through in-lab hydroponic exposure experiments. It was found that 69% of HCBD volatilized from water to the atmosphere after one day of exposure, and only 1% remained in the solution after four days. This high volatility might be the main cause of the low HCBD levels in aqueous environments. Although a great amount of HCBD volatilized into the atmosphere, only a small proportion of airborne HCBD was captured by the leaves and stems of the blank pumpkin seedling controls. The translocation of HCBD from the leaves to the bottom roots, as well as its release from the roots into the water, was detected. For the exposure groups, the pumpkin seedlings absorbed HCBD from both the hydroponic solution and the air via the roots and leaves, respectively. The concentration of HCBD in the exposed pumpkin roots linearly increased with the continuous addition of HCBD into the exposure system. Upward translocation from the roots to the leaves and downward translocation from the leaves to the roots existed simultaneously in the exposed pumpkin seedlings. However, the concentrations of HCBD in the leaves, stems and roots in the exposure group were much higher than those of the blank plant controls, suggesting little contribution from the airborne HCBD in the hydroponically exposed pumpkin seedlings. The lipid content did not show obvious effects on the bioaccumulation and biodistribution of HCBD in the pumpkin seedlings, indicating that the translocation of HCBD within the pumpkin seedlings might be an active process. This study provided new findings on the environmental behavior of HCBD, which will be helpful for understanding the exposure

  6. Design, implementation and evaluation of a training programme for school teachers in the use of malaria rapid diagnostic tests as part of a basic first aid kit in southern Malawi.

    Science.gov (United States)

    Witek-McManus, Stefan; Mathanga, Don P; Verney, Allison; Mtali, Austin; Ali, Doreen; Sande, John; Mwenda, Reuben; Ndau, Saidi; Mazinga, Charles; Phondiwa, Emmanuel; Chimuna, Tiyese; Melody, David; Roschnik, Natalie; Brooker, Simon J; Halliday, Katherine E

    2015-09-17

    With increasing levels of enrolment, primary schools present a pragmatic opportunity to improve the access of school children to timely diagnosis and treatment of malaria, increasingly recognised as a major health problem within this age group. The expanded use of malaria rapid diagnostic tests (RDTs) and artemisinin combination therapy (ACT) by community health workers (CHWs) has raised the prospect of whether teachers can provide similar services for school children. We describe and evaluate the training of primary school teachers to use a first aid kit containing malaria RDTs and ACT for the diagnosis and treament of uncomplicated malaria in school children in southern Malawi. We outline the development of the intervention as: (1) conception and design, (2) pilot training, (3) final training, and (4) 7-month follow up. The training materials were piloted at a four-day workshop in July 2013 following their design at national stakeholders meetings. The evaluation of the pilot training and materials were assessed in relation to increased knowledge and skill sets using checklist evaluations and questionnaires, the results of which informed the design of a final seven-day training programme held in December 2013. A follow up of trained teachers was carried out in July 2014 following 7 months of routine implementation. A total of 15 teachers were evaluated at four stages: pilot training, two weeks following pilot, final training and seven months following final training. A total of 15 and 92 teachers were trained at the pilot and final training respectively. An average of 93 % of the total steps required to use RDTs were completed correctly at the final training, declining to 87 % after 7 months. All teachers were observed correctly undertaking safe blood collection and handling, accurate RDT interpretation, and correct dispensing of ACT. The most commonly observed errors were a failure to wait 20 minutes before reading the test result, and adding an incorrect volume

  7. Gene expression in plant lipid metabolism in Arabidopsis seedlings.

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    An-Shan Hsiao

    Full Text Available Events in plant lipid metabolism are important during seedling establishment. As it has not been experimentally verified whether lipid metabolism in 2- and 5-day-old Arabidopsis thaliana seedlings is diurnally-controlled, quantitative real-time PCR analysis was used to investigate the expression of target genes in acyl-lipid transfer, β-oxidation and triacylglycerol (TAG synthesis and hydrolysis in wild-type Arabidopsis WS and Col-0. In both WS and Col-0, ACYL-COA-BINDING PROTEIN3 (ACBP3, DIACYLGLYCEROL ACYLTRANSFERASE1 (DGAT1 and DGAT3 showed diurnal control in 2- and 5-day-old seedlings. Also, COMATOSE (CTS was diurnally regulated in 2-day-old seedlings and LONG-CHAIN ACYL-COA SYNTHETASE6 (LACS6 in 5-day-old seedlings in both WS and Col-0. Subsequently, the effect of CIRCADIAN CLOCK ASSOCIATED1 (CCA1 and LATE ELONGATED HYPOCOTYL (LHY from the core clock system was examined using the cca1lhy mutant and CCA1-overexpressing (CCA1-OX lines versus wild-type WS and Col-0, respectively. Results revealed differential gene expression in lipid metabolism between 2- and 5-day-old mutant and wild-type WS seedlings, as well as between CCA1-OX and wild-type Col-0. Of the ACBPs, ACBP3 displayed the most significant changes between cca1lhy and WS and between CCA1-OX and Col-0, consistent with previous reports that ACBP3 is greatly affected by light/dark cycling. Evidence of oil body retention in 4- and 5-day-old seedlings of the cca1lhy mutant in comparison to WS indicated the effect of cca1lhy on storage lipid reserve mobilization. Lipid profiling revealed differences in primary lipid metabolism, namely in TAG, fatty acid methyl ester and acyl-CoA contents amongst cca1lhy, CCA1-OX, and wild-type seedlings. Taken together, this study demonstrates that lipid metabolism is subject to diurnal regulation in the early stages of seedling development in Arabidopsis.

  8. Mangrove microclimates alter seedling dynamics at the range edge.

    Science.gov (United States)

    Devaney, John L; Lehmann, Michael; Feller, Ilka C; Parker, John D

    2017-10-01

    Recent climate warming has led to asynchronous species migrations, with major consequences for ecosystems worldwide. In woody communities, localized microclimates have the potential to create feedback mechanisms that can alter the rate of species range shifts attributed to macroclimate drivers alone. Mangrove encroachment into saltmarsh in many areas is driven by a reduction in freeze events, and this encroachment can further modify local climate, but the subsequent impacts on mangrove seedling dynamics are unknown. We monitored microclimate conditions beneath mangrove canopies and adjacent open saltmarsh at a freeze-sensitive mangrove-saltmarsh ecotone and assessed survival of experimentally transplanted mangrove seedlings. Mangrove canopies buffered night time cooling during the winter, leading to interspecific differences in freeze damage on mangrove seedlings. However, mangrove canopies also altered biotic interactions. Herbivore damage was higher under canopies, leading to greater mangrove seedling mortality beneath canopies relative to saltmarsh. While warming-induced expansion of mangroves can lead to positive microclimate feedbacks, simultaneous fluctuations in biotic drivers can also alter seedling dynamics. Thus, climate change can drive divergent feedback mechanisms through both abiotic and biotic channels, highlighting the importance of vegetation-microclimate interactions as important moderators of climate driven range shifts. © 2017 by the Ecological Society of America.

  9. Growth and ABA responses of maple seedlings to aluminum

    Energy Technology Data Exchange (ETDEWEB)

    Bertrand, A.; Robitaille, G.; Boutin, R. [Canadian Forestry Service, Sainte Foy, PQ (Canada); Nadeau, P. [Agriculture and Agri-Food Canada Research Station, Sainte-Foy, PQ (Canada)

    1995-12-01

    The impacts of low pH and 2.0 mM aluminum (Al) on the growth of sugar maple seedlings was assessed over a 13-week period. The hypothesis was that low pH and high aluminum concentration would lower the vigor of sugar maple seedlings and were contributing factors to sugar maple stand decline. The effects of the stresses were measured in roots and shoots. The concentration of abscisis acid (ABA) in xylem sap in response to Al over time was measured to determine whether it could be used as an indicator of Al stress in sugar maple seedlings. At week 9, total leaf area of Al-treated seedlings was reduced by 27%, but by week 13 leaf area was similar for seedlings in all treatments. None of the other growth parameters examined were negatively affected by the treatments at either week 9 or week 13. ABA concentration in the xylem sap was not affected by any of the treatments. The duration of exposure to Al was found critical when assessing a threshold concentration for Al toxicity because plants can acclimate to an Al concentration previously considered toxic. 36 refs., 1 tab., 6 figs.

  10. Influence of selected Rhizoctonia solani isolates on sugar beet seedlings

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    Skonieczek Paweł

    2016-04-01

    Full Text Available From 2008 to 2010 the levels of sugar beet seedlings infection caused by Rhizoctonia solani were compared in laboratory tests. Seven sugar beet lines were tested: H56, H66, S2, S3, S4, S5 and S6 as well as three control cultivars: Carlos, Esperanza and Janosik. Sugar beet lines with tolerance to rhizoctoniosis and cultivars without tolerance were infected artificially by R. solani isolates: R1, R28a and R28b. These isolates belong to the second anastomosis group (AG, which is usually highly pathogenic to beet roots. The aim of the experiment was to test whether the tolerance of sugar beet genotypes to R. solani AG 2 prevents both root rot, and damping-off of seedlings, induced by the pathogen. Sugar beet lines tolerant to brown root rot in laboratory tests were significantly less sensitive to infection of the seedlings by R. solani AG 2 isolates in comparison to control cultivars. Rhizoctonia solani AG 2 isolates demonstrated considerable differences in pathogenicity against seedlings of sugar beet lines and cultivars. The strongest infection of sugar beet seedlings occurred with the isolate R28b. The greatest tolerance to infection by AG 2 isolates was found for the S5 and S3 breeding lines.

  11. BIOACTIVE COMPOUNDS AND ANTIOXIDANT CAPACITY FROM FIVE TYPES OF SEEDLINGS

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    Florina Maria Copaciu

    2016-10-01

    Full Text Available After germination process, the green seedlings accumulate important quantities of bioactive compounds such as: enzymes, vitamins, minerals, chlorophylls and nutrients. The current study presents a comparison between different bioactive compounds and their antioxidant capacity, after the seedling germination and growth of five seeds (arugula, lentil, wheat, beans and mustard both on soil, in a pot (natural system, and directly on cotton wool soaked, in water (artificial system. In this study the carotenoids content and the antioxidant capacity were analysed. The data of the present study showed that the highest amount of zeaxanthin and β - carotene was found in cultivars of wheat grown in natural system, while the highest antioxidant activity was found in cultivars of wheat, lentils and beans, though in this case with no statistical differences between the systems. The results show statistical differences between the values of bioactive compounds in the five types of seedlings but also in the values obtained for the same seedlings in different systems. The best cultivars for improving the nutritional quality for human consumption are wheat seedlings followed by lentil ones.

  12. Biodegradable bags for the production of plant seedlings

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    Ana Paula Bilck

    2014-10-01

    Full Text Available The production of plant seedlings has traditionally used polyethylene bags, which are thrown out in the soil or burned after transplant because the large amount of organic material attached to the bags makes recycling difficult. Additionally, when a seedling is taken from the bag for transplant, there is the risk of root damage, which compromises the plant’s development. In this study, we developed biodegradable bags to be used in seedling production, and we verify their influence on the development of Brazilian ginseng (Pfaffia glomerata (Spreng Pedersen, when the plant is planted without being removed from the bag. Both black and white biodegradable bags remained intact throughout the seedling production period (60 days. After being transplanted into containers (240 days, they were completely biodegraded, and there was no significant difference between the dry mass of these plants and that of plants that were transplanted without the bags. The plants that were cultivated without being removed from the polyethylene bags had root development difficulties, and the wrapping showed no signs of degradation. The use of biodegradable films is an alternative for the production of bags for seedlings, as these can then be transplanted directly into the soil without removing the bag, reducing the risk of damage to the roots during the moment of transplant.

  13. Allelopathic Responses of Rice Seedlings under Some Different Stresses

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    Tran Dang Khanh

    2018-05-01

    Full Text Available The objective of this study was to evaluate the allelopathic responses of rice seedlings under submergence stress at different temperatures (10, 25, 32, and 37 °C. The results showed that a wide range of allelopathic responses of rice seedlings depended on varieties and stress conditions, with temperature was being a key factor. It showed that the extracts of rice seedlings induced significant suppression on lettuce and radish seedling germination, but had negligible allelopathic effects on growth of barnyardgrass, whilst the emergence and growth of natural weeds was stimulated. In contrast, the root exudates of Koshihikari rice seedlings (K32 at 32 °C reduced the number of total weeds by ≈60.0% and the total dry weight of weeds by 93.0%; i.e., to a greater extent than other root exudates. Among the 13 identified phenolic acids, p-hydroxybenzoic, vanillic, syringic, sinapic and benzoic acids—at concentrations of 0.360, 0.045, 3.052, 1.309 and 5.543 μg/mL might be involved in allelopathic responses of K32, inhibiting the growth of barnyardgrass and natural weeds. Findings of the present study may provide useful information on allelopathic responses of rice under environmental stresses and thus further understand of the competitive relationships between rice and weeds under natural conditions.

  14. Response of Pinus ponderosa Seedlings to Stylet-Bearing Nematodes

    Science.gov (United States)

    Viglierchio, D. R.

    1979-01-01

    Of 12 stylet-bearing nematodes used for inoculations, Pratylenchus penetrans, P. brachyurus, P. vulnus, Ditylenchus destructor, Meloidogyne incognita, M. javanica, and M. hapla reproduced on Pinus ponderosa, while Xiphinema index, Aphelenchus avenae, Paratylenehus neoamblycephalus, Tylenchulus semipenetrans, and Macroposthonia xenoplax did not. P. vulnus, P. brachyurus, P. penetrans, A. avenae, D. destructor, T. semipenetrans, and P. neoamblycephalus significantly suppressed both the shoot and root wet weights of ponderosa pine seedlings obtained from stands in five different locations. X. index significantly suppressed root wet weights, M. xenoplax siguificantly suppressed shoot wet weight, and M. incognita, M. javanica, and M. hapla suppressed neither at the inoculation levels used. Injurious nematodes tended to suppress root growth more than shoot growth. Seedlings from two locations produced greater shoot growth wet weight than did seedlings from the other three locations. The more injurious nematodes tended to cause an increase in the water content of shoots. Frequency analyses of seedling population shoot-root ratios indicated that ponderosa pine seedlings could be selected for better shoot-root ratios as well as for resistance to several pathogenic nematodes. PMID:19300659

  15. Symbiotic propagation of seedlings of Cyrtopodium glutiniferum Raddi (Orchidaceae

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    Fernanda Aparecida Rodrigues Guimarães

    2013-09-01

    Full Text Available In nature, orchid seeds obtain the nutrients necessary for germination by degrading intracellular fungal structures formed after colonization of the embryo by mycorrhizal fungi. Protocols for asymbiotic germination of orchid seeds typically use media with high concentrations of soluble carbohydrate and minerals. However, when reintroduced into the field, seedlings obtained via asymbiotic germination have lower survival rates than do seedlings obtained via symbiotic germination. Tree fern fiber, the ideal substrate for orchid seedling acclimatization, is increasingly scarce. Here, we evaluated seed germination and protocorm development of Cyrtopodium glutiniferum Raddi cultivated in asymbiotic media (Knudson C and Murashige & Skoog and in oatmeal agar (OA medium inoculated with the mycorrhizal fungus Epulorhiza sp., using non-inoculated OA medium as a control. We also evaluated the performance of tree fern fiber, pine bark, eucalyptus bark, corncob and sawdust as substrates for the acclimatization of symbiotically propagated plants. We determined germination percentages, protocorm development and growth indices at 35 and 70 days of cultivation. Relative growth rates and the effects of substrates on mycorrhizal formation were calculated after 165 days of cultivation. Germination efficiency and growth indices were best when inoculated OA medium was used. Corncob and pine bark showed the highest percentages of colonized system roots. The OA medium inoculated with Epulorhiza sp. shows potential for C. glutiniferum seedling production. Corncob and pine bark are promising substitutes for tree fern fiber as substrates for the acclimatization of orchid seedlings.

  16. The metabolism and distribution of 14C-8N6-benzyladenine in lettuce seeds and seedlings

    International Nuclear Information System (INIS)

    Seeber, R.G. Jr.

    1989-01-01

    This investigation sought to follow the uptake of the cytokinin, 14 C-8N 6 -benzyladenine (BAP), by lettuce seeds through time, trace the movement of the metabolites through several areas of the seedling, and identify the BAP metabolites. Lettuce seeds (Lactuca sativa L. cv. Grand Rapids) were exposed to a two hour pulse of the radioactive BAP. These seeds were harvested at 4 hour intervals from 2-48 hours. Seedlings incubated from 36-48 hours were cut in two; root, stem, shoot tip and seed coats. Each of these groups were extracted in 70% methanol and their radioactive isolated by high performance liquid chromatography. Radioactive fractions were pooled and reduced for further analysis by thin layer chromatography. The major compound identified throughout the time periods was BAP, exclusively found from 2-20 hours. BAP riboside was found in addition to BAP from 24-32 hours. The 40 and 44 hour extracts contained BAP and its riboside in the shoot and BAP in the seed coat. The 48 hours extract contained BAP and its riboside in both the shoot tip and the seed coat. This study produced information on the following points. A cytokinin exposure of 2 hours or less is needed to break dormancy in these seeds

  17. Fatal outbreak from consuming Xanthium strumarium seedlings during time of food scarcity in northeastern Bangladesh.

    Science.gov (United States)

    Gurley, Emily S; Rahman, Mahmudur; Hossain, M Jahangir; Nahar, Nazmun; Faiz, M Abul; Islam, Nazrul; Sultana, Rebeca; Khatun, Selina; Uddin, Mohammad Zashim; Haider, M Sabbir; Islam, M Saiful; Ahmed, Be-Nazir; Rahman, Muhammad Waliur; Mondal, Utpal Kumar; Luby, Stephen P

    2010-03-18

    An outbreak characterized by vomiting and rapid progression to unconsciousness and death was reported in Sylhet Distrct in northeastern Bangladesh following destructive monsoon floods in November 2007. We identified cases presenting to local hospitals and described their clinical signs and symptoms. We interviewed patients and their families to collect illness histories and generate hypotheses about exposures associated with disease. An epidemiological study was conducted in two outbreak villages to investigate risk factors for developing illness. 76 patients were identified from 9 villages; 25% (19/76) died. Common presenting symptoms included vomiting, elevated liver enzymes, and altered mental status. In-depth interviews with 33 cases revealed that 31 (94%) had consumed ghagra shak, an uncultivated plant, in the hours before illness onset. Ghagra shak was consumed as a main meal by villagers due to inaccessibility of other foods following destructive monsoon flooding and rises in global food prices. Persons who ate this plant were 34.2 times more likely (95% CI 10.2 to 115.8, p-valuestrumarium, or common cocklebur. The consumption of Xanthium strumarium seedlings in large quantities, due to inaccessibility of other foods, caused this outbreak. The toxic chemical in the plant, carboxyatratyloside, has been previously described and eating X. strumarium seeds and seedlings has been associated with fatalities in humans and livestock. Unless people are able to meet their nutritional requirements with safe foods, they will continue to be at risk for poor health outcomes beyond undernutrition.

  18. Evolution under domestication: contrasting functional morphology of seedlings in domesticated cassava and its closest wild relatives.

    Science.gov (United States)

    Pujol, Benoît; Mühlen, Gilda; Garwood, Nancy; Horoszowski, Yael; Douzery, Emmanuel J P; McKey, Doyle

    2005-04-01

    Although cassava (Manihot esculenta ssp. esculenta) is asexually propagated, farmers incorporate plants from seedlings into planting stocks. These products of sex are exposed to selection, which in agricultural environments should favour rapid growth. To examine whether seedling morphology has evolved under domestication, we compared domesticated cassava, its wild progenitor (M. esculenta ssp. flabellifolia) and their sister species (M. pruinosa) under controlled conditions. Field observations complemented laboratory study. In both wild taxa, the hypocotyl did not elongate (hypogeal germination) and cotyledons remained enclosed in the testa. In domesticated cassava, the hypocotyl elongated (epigeal germination), and cotyledons emerged and became foliaceous. The difference in hypocotyl elongation was fixed, whereas cotyledon morphology varied with environmental conditions in M. pruinosa. Comparative analysis suggests that epigeal germination is primitive in Manihot, that the lineage including wild ancestors of cassava evolved hypogeal germination--which confers greater tolerance to risks in their savanna environment--and that with domestication, there was a reversion to epigeal germination and photosynthetic cotyledons, traits conferring high initial growth rates in agricultural habitats. Copyright New Phytologist (2005).

  19. The effects of H2SO4 and (NH42SO4 treatments on the chemistry of soil drainage water and pine seedlings in forest soil microcosms

    Directory of Open Access Journals (Sweden)

    M. I. Stutter

    2004-01-01

    Full Text Available An experiment comparing effects of sulphuric acid and reduced N deposition on soil water quality and on chemical and physical growth indicators for forest ecosystems is described. Six H2SO4 and (NH42SO4 treatment loads, from 0 – 44 and 0 – 25 kmolc ha-1 yr-1, respectively, were applied to outdoor microcosms of Pinus sylvestris seedlings in 3 acid to intermediate upland soils (calc-silicate, quartzite and granite for 2 years. Different soil types responded similarly to H2SO4 loads, resulting in decreased leachate pH, but differently to reduced N inputs. In microcosms of calc-silicate soil, nitrification of NH4 resulted in lower pH and higher cation leaching than in acid treatments. By contrast, in quartzite and granite soils, (NH42SO4 promoted direct cation leaching, although leachate pH increased. The results highlighted the importance of soil composition on the nature of the cations leached, the SO4 adsorption capacities and microbial N transformations. Greater seedling growth on calc-silicate soils under both treatment types was related to sustained nutrient availability. Reductions in foliar P and Mg with higher N treatments were observed for seedlings in the calc-silicate soil. There were few treatment effects on quartzite and granite microcosm tree seedlings since P limitation precluded seedling growth responses to treatments. Hence, any benefits of N deposition to seedlings on quartzite and granite soils appeared limited by availability of co-nutrients, exacerbated by rapid depletion of soil exchangeable base cations. Keywords: acidification, manipulation, nitrogen, ammonium, deposition, soil, drainage, pine, microcosms, forest

  20. THE EFFECT OF MAGNETIC LIQUIDS IN SOME TREE SEEDLINGS

    Directory of Open Access Journals (Sweden)

    Ioan Creanga

    2005-08-01

    Full Text Available The seedlings of two tree species, the black poplar hybrid (Populus canadiensis Moench. and the pedunculate oak (Quercus robur L., among the most important for the temperate region, were treated with various concentrations of oil-ferrofluid based on natural hydrocarbons. The experiment has revealed the ferrofluid influence on the assimilatory pigments as well as on the nucleic acids (spectral measurements in young plantlets aged of 3 months. It was found that the levels of assimilatory pigments are generally diminished though the ratio chlorophyll a/chlorophyll b is generally enhanced for ferrofluid samples suggesting the seedlings sensitivity to the chemical and magnetic stimuli consistent with the ferrofuid addition. The LHC II system (Light Harvesting Complex II sensitivity to external factors might be associated with the ferrofluid influence on the young seedlings photosynthesis.

  1. Endophytic fungi reduce leaf-cutting ant damage to seedlings

    Science.gov (United States)

    Bittleston, L. S.; Brockmann, F.; Wcislo, W.; Van Bael, S. A.

    2011-01-01

    Our study examines how the mutualism between Atta colombica leaf-cutting ants and their cultivated fungus is influenced by the presence of diverse foliar endophytic fungi (endophytes) at high densities in tropical leaf tissues. We conducted laboratory choice trials in which ant colonies chose between Cordia alliodora seedlings with high (Ehigh) or low (Elow) densities of endophytes. The Ehigh seedlings contained 5.5 times higher endophyte content and a greater diversity of fungal morphospecies than the Elow treatment, and endophyte content was not correlated with leaf toughness or thickness. Leaf-cutting ants cut over 2.5 times the leaf area from Elow relative to Ehigh seedlings and had a tendency to recruit more ants to Elow plants. Our findings suggest that leaf-cutting ants may incur costs from cutting and processing leaves with high endophyte loads, which could impact Neotropical forests by causing variable damage rates within plant communities. PMID:20610420

  2. Propagation of Aquilaria malaccensis seedlings through tissue culture techniques

    International Nuclear Information System (INIS)

    Salahbiah Abdul Majid; Zaiton Ahmad; Mohd Rafaie Abdul Salam; Nurhayati Irwan; Affrida Abu Hassan; Rusli Ibrahim

    2010-01-01

    Aquilaria malaccensis or karas is the principal source of gaharu resin, which is used in many cultures for incense, perfumes and traditional medicines. The species is mainly propagated conventionally through seeds, cuttings and graftings. Propagation by seeds is usually a reliable method for other forest species, but for karas, this technique is inadequate to meet the current demand of seedling supplies. This is principally due to its low seed viability, low germination rate, delayed rooting of seedlings, long life-cycle and rare seed production. Tissue culture has several advantages over conventional propagation, especially for obtaining large number of uniform and high-yielding plantlets or clones. This paper presents the current progress on mass-propagation of Aquilaria malaccensis seedlings through tissue culture technique at Nuclear Malaysia. (author)

  3. Survival and Growth of Northern Red Oak Seedlings Following a Prescribed Burn

    Science.gov (United States)

    Paul S. Johnson

    1974-01-01

    Mortality of northern red oak seedlings in a spring prescribed burn was related to temperature near the root collar. Most of the 42 percent of seedlings that survived the burn developed new shoots from the root collar.

  4. A Simple Method for the Assessment of Fusarium Head Blight Resistance in Korean Wheat Seedlings Inoculated with Fusarium graminearum

    Directory of Open Access Journals (Sweden)

    Sanghyun Shin

    2014-03-01

    Full Text Available Fusarium head blight (FHB; scab caused mainly by Fusarium graminearum is a devastating disease of wheat and barley around the world. FHB causes yield reductions and contamination of grain with trichothecene mycotoxins such as deoxynivalenol (DON which are a major health concern for humans and animals. The objective of this research was to develop an easy seed or seedling inoculation assay, and to compare these assays with whole plant resistance of twenty-nine Korean winter wheat cultivars to FHB. The clip-dipping assay consists of cutting off the coleoptiles apex, dipping the coleoptiles apex in conidial suspension, covering in plastic bag for 3 days, and measuring the lengths of lesions 7 days after inoculation. There were significant cultivar differences after inoculation with F. graminearum in seedling relative to the controls. Correlation coefficients between the lesion lengths of clip-dipping inoculation and FHB Type II resistance from adult plants were significant (r=0.45; P<0.05. Results from two other seedling inoculation methods, spraying and pin-point inoculation, were not correlated with adult FHB resistance. Single linear correlation was not significant between seed germination assays (soaking and soak-dry and FHB resistance (Type I and Type II, respectively. These results showed that clip-dipping inoculation method using F. graminearum may offer a real possibility of simple, rapid, and reliable for the early screening of FHB resistance in wheat.

  5. 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

  6. Influence of nutrition and various substrates on spruce seedling growth

    Directory of Open Access Journals (Sweden)

    Đukić Matilda

    2004-01-01

    Full Text Available The results of the influence of main macronutrients (N, P, and K on growth and development of spruce (Picea abies L. Karst one-year old seedlings are presented. They were grown in containers, in nursery conditions, on four different substrates. There is a good influence on biogenous element contents, height, root collar diameter, needle length and mass, root mass as well as physiological vitality of spruce seedlings. It was observed that the effect of nutrition depends also on the type of substrate.

  7. Growth of short-day treated spruce seedlings planted throughout British Columbia. FRDA report No. 209

    Energy Technology Data Exchange (ETDEWEB)

    Krasowski, M.J.; Letchford, T.; Eastham, A.M.

    1993-01-01

    Short photoperiod (SD) treatments of conifer seedlings induce bud dormancy and enhance cold acclimation. Such treatments are also useful in regulating seedling height to meet a specific target and in preparing seedlings for lifting at a desirable time. These trials were designed to compare different SD-treated and untreated stock in terms of their annual height and ground-line stem diameter increments, 1st year post-planting terminal bud phenology, and seedling survival and condition.

  8. Impact of climate change, seedling type and provenance on the risk of damage to Norway spruce (Picea abies (L.) Karst.) seedlings in Sweden due to early summer frosts

    Energy Technology Data Exchange (ETDEWEB)

    Langvall, Ola (Swedish Univ. of Agricultural Sciences, Unit for Field-based Forest Research, Asa Forest Research Station, Lammhult (Sweden))

    2011-04-15

    A model including site-specific microclimate-affecting properties of a forest regeneration area together with seedling characteristics was used to evaluate the accumulated risk of frost damage to Norway spruce (Picea abies (L.) Karst.) seedlings. Climate change in Sweden was simulated on the basis of the regional climate model RCA3. The daily average temperature, the driving factor for bud burst in the model, was adjusted using the difference between the mean of the climate model data for the years 1961-1990 and 2036-2065. The model was run for a highly frost prone, clear-cut site in which bare-rooted Norway spruce seedlings of mid-Swedish provenance were planted. Alternate runs were conducted with data for containerized seedlings and seedlings of Belarusian origin. The study showed that bud burst will occur at earlier dates throughout Sweden in the period 2036-2065 if the climate changes according to either of the climate scenarios examined, compared to the reference period 1961-1990. Furthermore, the risk of damage to Norway spruce seedlings as a result of frost events during summer will increase in southern Sweden and be unaffected or decrease in northern Sweden. The risk of frost damage was exacerbated in containerized seedlings, while the risk was lower for the seedlings of Belarusian provenance when compared with bare-rooted seedlings or seedlings of mid-Swedish origin

  9. Naturally seeded versus planted ponderosa pine seedlings in group-selection openings

    Science.gov (United States)

    Philip M. McDonald; Gary Fiddler; Martin Ritchie; Paula Anderson

    2009-01-01

    The purpose of this article was to determine whether natural regeneration or planted seedlings should be used in group-selection openings. The answer dependson the survival and growth rate of both types of seedlings, and that could depend on the size of the openings and the effect of trees on their edge. In thisside-by-side study, the natural pine seedlings originated...

  10. Air lateral root pruning affects longleaf pine seedling root system morphology

    Science.gov (United States)

    Shi-Jean Susana Sung; Dave Haywood

    2016-01-01

    Longleaf pine (Pinus palustris) seedlings were cultured with air lateral root pruning (side-vented containers, VT) or without (solid-walled containers, SW). Seedling root system morphology and growth were assessed before planting and 8 and 14 months after planting. Although VT seedlings had greater root collar diameter than the SW before planting,...

  11. Characterizing Betula litwinowii seedling microsites at the alpine-treeline ecotone, central Greater Caucasus Mountains, Georgia

    Science.gov (United States)

    Nicole M Hughes; Daniel M. Johnson; Maia Akhalkatsi; Otar Abdaladze

    2009-01-01

    Seedling establishment is an important factor dictating the altitudinal limits of treeline species. Factors that affect seedling mortality and survival, however, have yet to be fully characterized, especially for deciduous treeline species. Here we describe microsite characteristics of successfully established Betula litwinowii seedlings at the...

  12. Four different Phytophthora species that are able to infect Scots pine seedlings in laboratory conditions

    Directory of Open Access Journals (Sweden)

    Tkaczyk Miłosz

    2016-09-01

    Full Text Available To investigate susceptibility of young Scots pine seedlings to four Phytophthora species: Phytophthora cactorum, Phytophthora cambivora, Phytophthora plurivora and Phytophthora pini; seven-day-old seedlings of Scots pine (15 seedlings per experiment were infected using agar plugs of the respective species. Control group also consisted of 15 seedlings and was inoculated with sterile agar plugs. Results unambiguously show that after 4.5 days, all seedlings show clear signs of infection and display severe symptoms of tissue damage and necrosis. Moreover, three and two seedlings in the P. cactorum and P. cambivora infected seedlings groups, respectively, collapsed. The length of largest necrosis measured 13.4±3.90 mm and was caused by P. cactorum. To rule out any putative contamination or infection by secondary pathogens, re-isolations of pathogens from infection sites were performed and were positive in 100% of plated pieces of infected seedlings. All re-isolations were, however, negative in the case of the control group. Detailed microscopic analyses of infected tissues of young seedlings confirmed the presence of numerous Phytophthora species inside and on the surface of infected seedlings. Therefore, our results suggest Phytophthora spp. and mainly P. cactorum and P. cambivora as aggressive pathogens of Scots pine seedlings and highlight a putative involvement of these species in the damping off of young Scots pine seedlings frequently observed in forest nurseries.

  13. Effects of Fusarium circinatum on Disease Development and Gas Exchange in the Seedlings of Pinus spp.

    Directory of Open Access Journals (Sweden)

    Kwan-Soo Woo

    2011-08-01

    Full Text Available Four-year-old seedlings of Pinus thunbergii, Pinus densiflora and Pinus rigida were inoculated with Fusarium circinatum isolate (FT-7, the pitch canker fungus, from P. thunbergii, to evaluate the effects of the pathogen on disease development and gas exchange rate. Needle dehydration was evident on 2 of 10 seedlings of P. thunbergii and P. rigida at 18 and 21 days after inoculation, respectively, while no symptoms were observed in P. densiflora seedlings throughout the experiment. Gas exchange stopped completely in 4 of 5 measured seedlings of P. thunbergii and 2 of 5 measured seedlings of P. rigida at 25 days after inoculation, and in the remaining 3 seedlings of P. rigida at 39 days after inoculation. Disease development in P. thunbergii seedlings was faster than that in P. rigida seedlings. By the time, the experiment was ended at 78 days after inoculation, 9 of 10 seedlings of P. rigida and 8 of 10 seedlings of P. thunbergii seedlings treated with FT-7 was almost dead, but all seedlings of P. densiflora were still healthy. We suggest that P. densiflora is resistant to F. circinatum in the current study, and gas exchange rate of the species after inoculation does not differ significantly compared to that of untreated control.

  14. Economic rationale for planting less trees in the face of seedling mortality

    Science.gov (United States)

    Thomas J. Dean; S. Joseph Chang

    2002-01-01

    Simple economic analyses are used to demonstrate that planting extra trees to compensate for initial seedling mortality can actually reduce the profit expected from a pine plantation. At a 6-percent interest rate, the cost of planting 15 or 25 percent additional seedlings compounded to the end of a 30-year rotation exceeds the revenue lost to these rates of seedling...

  15. Nursery response of container Pinus palustris seedlings to nitrogen supply and subsequent effects on outplanting performance

    Science.gov (United States)

    D. Paul Jackson; R. Kasten Dumroese; James P. Barnett

    2012-01-01

    Container longleaf pine (Pinus palustris) seedlings often survive and grow better after outplanting than bareroot seedlings. Because of this, most longleaf pine are now produced in containers. Little is known about nursery fertilization effects on the quality of container longleaf pine seedlings and how that influences outplanting performance. We compared various...

  16. Cryopreservation of coconut (Cocos nucifera L.) zygotic embryos does not induce morphological, cytological or molecular changes in recovered seedlings.

    Science.gov (United States)

    Sisunandar; Rival, Alain; Turquay, Patricia; Samosir, Yohannes; Adkins, Steve W

    2010-07-01

    The present study aimed at exploring the fidelity of coconut (Cocos nucifera L.) plants recovered from cryopreservation. Zygotic embryos from various different cultivars were cryopreserved following four successive steps, namely: rapid dehydration, rapid freezing, rapid thawing and in vitro recovery followed by acclimatization. At the end of the acclimatization period, the seedlings were compared to counterparts of the same age, which were produced from non-cryopreserved embryos. Both series were submitted to morphological, cytological and molecular comparisons. No significant differences in terms of growth rates could be measured. In addition, no morphological variation could be detected through the measurement of shoot elongation rates, production of opened leaves, and the number and total length of primary roots. Karyotype analysis revealed the same chromosome number (2n = 32) in all studied cultivars independently of cryopreservation. No significant differences could be observed between control and cryopreserved material concerning the type of chromosomes, the length of the long and short arms, the arm length ratio and the centromeric index. However, idiogram analysis did show a greater number of black banding on chromosomes isolated from cryopreserved material. Genetic and epigenetic fidelity was assessed through microsatellite (SSR) analysis and global DNA methylation rates; no significant differences would be observed between genomic DNAs isolated from seedlings originating from cryopreserved embryos and respective controls. In conclusion, our results suggest that the method of cryopreservation under study did not induce gross morphological, genetic or epigenetic changes, thus suggesting that it is an appropriate method to efficiently preserve coconut germplasm.

  17. Purification of acidic phosphatase from mustard seedlings

    OpenAIRE

    sprotocols

    2014-01-01

    ### INTRODUCTION Phosphate esters are widely distributed in any organism. Nucleic acids, metabolic intermediates like glucose-6-phosphate, energy-rich substrates (AMP, creatine phosphate) are some obvious examples. While many metabolic intermediates are activated through the transfer of phosphate groups (e.g., by kinases) it is equally important that phosphate esters can also be rapidly broken down. The hydrolytic removal of phosphate groups from phosphoesters is catalyzed by phosphatases...

  18. Boron toxicity is alleviated by hydrogen sulfide in cucumber (Cucumis sativus L.) seedlings.

    Science.gov (United States)

    Wang, Bao-Lan; Shi, Lei; Li, Yin-Xing; Zhang, Wen-Hao

    2010-05-01

    Boron (B) is an essential micronutrient for plants, which when occurs in excess in the growth medium, becomes toxic to plants. Rapid inhibition of root elongation is one of the most distinct symptoms of B toxicity. Hydrogen sulfide (H(2)S) is emerging as a potential messenger molecule involved in modulation of physiological processes in plants. In the present study, we investigated the role of H(2)S in B toxicity in cucumber (Cucumis sativus) seedlings. Root elongation was significantly inhibited by exposure of cucumber seedlings to solutions containing 5 mM B. The inhibitory effect of B on root elongation was substantially alleviated by treatment with H(2)S donor sodium hydrosulfide (NaHS). There was an increase in the activity of pectin methylesterase (PME) and up-regulated expression of genes encoding PME (CsPME) and expansin (CsExp) on exposure to high B concentration. The increase in PME activity and up-regulation of expression of CsPME and CsExp induced by high B concentration were markedly reduced in the presence of H(2)S donor. There was a rapid increase in soluble B concentrations in roots on exposure to high concentration B solutions. Treatment with H(2)S donor led to a transient reduction in soluble B concentration in roots such that no differences in soluble B concentrations in roots in the absence and presence of NaHS were found after 8 h exposure to the high concentration B solutions. These findings suggest that increases in activities of PME and expansin may underlie the inhibition of root elongation by toxic B, and that H(2)S plays an ameliorative role in protection of plants from B toxicity by counteracting B-induced up-regulation of cell wall-associated proteins of PME and expansins.

  19. Effects of soil quality and depth on seed germination and seedling survival at the Nevada test site

    International Nuclear Information System (INIS)

    Blomquist, K.W.; Lyon, G.E.

    1993-01-01

    The Nuclear Waste Policy Act, as amended in 1987, directs the US Department of Energy (DOE) to study Yucca Mountain, in southern Nevada, as a potential site for long-term storage of high-level nuclear waste. DOE policy mandates the restoration of all lands disturbed by site characterization activities and DOE has developed an environmental program that is to be implemented during site characterization activities at Yucca.Mountain. DOE is currently conducting reclamation feasibility trials as part of this environmental program. No topsoil was saved on disturbances during early site investigation and minimal soil remains at existing disturbances on Yucca Mountain. A study was developed to test the effects of soil quality and depth on seedling emergence and survival. A series of plots was established and two treatments were tested. The first treatment compared native topsoil to subsoil imported from a borrow pit. The second treatment compared four different depth ranges of both soil types. All plots received identical seeding treatments. Seedling density was measured after emergence. Overall seedling densities were low, averaging 10.3 ± 8.8 (SD) plants/m 2 . Statistical analysis revealed a significant interaction between the two treatment factors. The subsoil had increasing densities from the deep soil depths to the shallow depths while the topsoil had increasing densities from the shallow soil depths to the deep depths. The cause of this interaction may have resulted from the bedrock being close to the soil surface of the shallow plots

  20. Seed germination and seedling emergence of Scotch broom (Cytisus scoparius)

    Science.gov (United States)

    Timothy B. Harrington

    2009-01-01

    Scotch broom is a large, leguminous shrub that has invaded 27 U.S. states. The species produces seeds with a hard coat that remain viable in the soil for years. Growth-chamber studies were conducted to determine effects of temperature regime and cold-stratification period on seed germination. Seedling emergence, mortality, and biomass also were studied in response to...

  1. 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 ...

  2. Variability, correlation and path coefficient analysis of seedling traits ...

    African Journals Online (AJOL)

    use

    2011-12-12

    Dec 12, 2011 ... Indirect selection is a useful means for improving yield in cotton crop. The objective of the present study was to determine the genetic variability, broad sense heritability, genetic advance and correlation among the six seedling traits and their direct and indirect effects on cotton yield by using path coefficient ...

  3. Soil seed bank evaluation and seedling establishment along a ...

    African Journals Online (AJOL)

    The effects of rangeland degradation on the size and species composition of the seed bank and seedling establishment in the field were quantified over a two year period (2000–2001 and 2001–2002 growing seasons). Soil seed bank sampling was carried out at three-monthly intervals from 0.25m2 blocks 50mm deep.

  4. Rooting of needle fascicles from western white pine seedlings

    Science.gov (United States)

    Ramond J. Hoff; Geral I. McDonald

    1968-01-01

    In one test, 45 out of 318 (14 percent) needle fascicles from 2-year-old seedlings of Pinus monticola Dougl. were rooted. Eight of the needle fascicles produced shoot growth. In another test, 392 out of 742 (53 percent) needle fascicles were rooted, but none of these produced shoot growth.

  5. Identification of zygotic and nucellar seedlings in citrus interspecific ...

    African Journals Online (AJOL)

    ajl yemi

    2011-12-19

    Dec 19, 2011 ... Department of Plant Breeding and Improvement, Iran Citrus Research Institute, Mottahari Street, Ramsar, .... (C. aurantium) rootstock plants for further agronomic evaluation .... literatures may be attributed to pollination efficiency and ... zygotic seedlings in Swingle citromelo Citrus paradisi × Poncirus tifoliata.

  6. Variability, correlation and path coefficient analysis of seedling traits ...

    African Journals Online (AJOL)

    Indirect selection is a useful means for improving yield in cotton crop. The objective of the present study was to determine the genetic variability, broad sense heritability, genetic advance and correlation among the six seedling traits and their direct and indirect effects on cotton yield by using path coefficient analysis.

  7. Decision making analysis of walnut seedling production on a small ...

    African Journals Online (AJOL)

    The decision has to be made between those three alternatives aiming at achievement of optimal/best economic result for the family farm. Summarizing results obtained from the decision tree, simulation and sensitivity analysis, the optimal solution for the family farm should be to continue production of walnut seedlings with ...

  8. Flood tolerance of oak seedlings from bottomland and upland sites

    Science.gov (United States)

    Michael P. Walsh; Jerry Van Sambeek; Mark Coggeshall; David. Gwaze

    2009-01-01

    Artificial regeneration of oak species in floodplains presents numerous challenges because of the seasonal flooding associated with these areas. Utilizing not only flood-tolerant oak species, but also flood tolerant seed sources of the oak species, may serve to enhance seedling survival and growth rates. Despite the importance of these factors to hardwood forest...

  9. [Comparison of development condition of different Liriope spicata seedlings].

    Science.gov (United States)

    Wang, Yue; Su, He; Zhan, Yan-Ting; Yang, Yang; Dong, Xue-Hui

    2017-04-01

    The study identified the main morphological index of the seedlings classification including seedling age,the root width and number of newborn buds and coarse roots, according to the local agricultural production techniques and assessment of Liriope spicata's growth and development condition. After carrying on K cluster analysis of the morphological, we separated the seedlings into two levels. The first level (Ⅰ): the new talent with the root width exceeding two point five millimeters, the new born buds exceeding three, and with the coarse root exceeding one. The second level (Ⅱ): the old talent with the root width below one millimeters, the newborn buds below two and without coarse root. The study surveyed the plants' growth index dynamics, as well as the yield and quality of the tuberous root. The experimental results suggested that the growth condition of seedling Ⅰwas better, the yield of earthnut higher, the quality of earthnut more excellent. The study lied the foundation of L. spicata's grading standards and standardized production. Copyright© by the Chinese Pharmaceutical Association.

  10. Light-emitting diode lighting for forest nursery seedling production

    Science.gov (United States)

    R. Kasten Dumroese; Jeremiah R. Pinto; Anthony S. Davis

    2015-01-01

    Crop lighting is an energy-intensive necessity for nursery production of high-quality native plants and forest tree seedlings. During the winter months (especially in northern USA latitudes) or overcast or cloudy days, the amount of solar radiation reaching greenhouse crops is insufficient resulting in growth cessation, early terminal bud formation, and failure of...

  11. Differential effects of aluminium on the seedling parameters of wheat ...

    African Journals Online (AJOL)

    Differential effects of aluminium on the seedling parameters of wheat. ... African Journal of Biotechnology ... and Maroon (Al tolerant) were grown on hydroponic solution (non modified Hoagland) containing AlCl3 (0-100-200-300 μM). Factorial ...

  12. Experiences in the containerized tree seedlings forest nurseries production

    Directory of Open Access Journals (Sweden)

    Eduardo González-Izquierdo

    2014-12-01

    Full Text Available The work summarizes the results of the research carried out by the team of forest nurseries at Sustainable Forest Management Group in Pinar del Río University Forest Research Centre in the last 25 years. The characteristics of seedlings quality are presented, the best growing media, the water management to harden the forest species under the ecological conditions of more and more lingering periods of drought. The studied forest species were: Talipariti elatum (Sw. Fryxell, Pinus tropicalis Morelet , Swietenia mahagon(L.Jacq. Swietenia macrophylla King, Caesalpinia violacea (Mill. Stand, Genipa americana L, Gerascanthus gerascanthoides (Kunth Borhidi y Cedrela odorata L. y Eucalyptus grandis Hill ex Maiden. The main results can be summarized in the following way: the size of the containers oscillates between 90 and 300 cubic centimeters; the growing media combines organic and composted components fundamentally of Pinus caribaea and Eucalyptus ssp bark., with proportions that they vary according to the species and the disposability of these components in the nurseries where the plants take place; for the water management hardening procedures were used by watering in last month of the cultivation. In general the economic analyses demonstrated the decrease of the production costs for seedlings with the employment of this novel technology, the same as their advantages on the traditional technology of seedlings production in polybags: humanization of manpower work in forest nursery, reduction of costs production, improvement of produced seedling quality and productivity increase of their workers.

  13. Effect of organic media on growth of vegetable seedlings

    International Nuclear Information System (INIS)

    Unal, M.

    2013-01-01

    Organic media physical and chemical properties are suitable for growing seedling. It is not is low cost for additional chemical substances. In NP/sub 2/O/sub 5/K/sub 2/ O additional media M5 compared to organic media. The purpose of this study was to determine; the use of different growing media for organic production of tomatoes and peppers seedling quality characterictics. The trial was conducted the year 2010 in the greenhouse of Organic Agriculture Program of Arslanbey Vocational School of Kocaeli University. In this research M4 containing peat-stable manure-perlite, M5 containing peat-sand-NPK, M6 containing peat-stable manure and M8 containing peat gave positive results in tomato and pepper seedling cultivation. The quality of tomato and pepper seedling measured values and there were a difference between different growing media statistically at p<0.05 level. However, the width of cotyledons of pepper with different growing medium did not differ statistically. (author)

  14. Photosynthetic Responses of Seedlings of two Indigenous Plants ...

    African Journals Online (AJOL)

    Bheema

    ABSTRACT. The potential role of exotic tree plantations in facilitating successional processes on degraded areas was evaluated in southern Ethiopia, Munessa-Shashemene forest, by examining photosynthetic responses of Bersamaabyssinica Fres. and Croton macrostachyusDel. seedlings naturally grown inside ...

  15. Water application rate and frequency affect seedling survival and ...

    African Journals Online (AJOL)

    Adequate amount of water is critical to successful tree nursery operation among resource-constrained smallholder farmers in Africa. Two experiments were undertaken with the objectives of evaluating effects of water application rate and frequency on seedling growth and survival of Persea americana and Vangueria ...

  16. Glyoxalase I expression pattern in Hevea brasiliensis seedlings ...

    African Journals Online (AJOL)

    Glyoxalase I expression pattern in Hevea brasiliensis seedlings under varied stress conditions. MVP Siraj, A Thulaseedharan, Anu Augustine. Abstract. Drought is one of the most important stress factors which adversely affect plants' growth and productivity. Global climate change may make this situation more serious in the ...

  17. Simulated drought influences oxidative stress in Zea mays seedlings ...

    African Journals Online (AJOL)

    Drought is an abiotic factor that limits the productivity of crop plants survival and productivity. This study was conducted to evaluate the effects of simulated drought on the malondialdehyde (MDA) and antioxidant enzymes activity in Zea mays. Seedlings were grown for 8 weeks in nursery bags filled with sandy-loam soil in ...

  18. Morphological adaptation of Cercis griffithii seedlings in response to ...

    African Journals Online (AJOL)

    The experiment for evaluate the effect of drought and salinity stresses on the morphological behaviours of Afghan redbud seedlings was done in Torogh nursery in Iran country. This study was conducted in a completely randomized design; without stress (tap common water in the nursery- EC 0.8 dS m-1), drought stress ...

  19. Photosynthetic efficiency of Pedunculate oak seedlings under simulated water stress

    Directory of Open Access Journals (Sweden)

    Popović Zorica

    2010-01-01

    Full Text Available Photosynthetic performance of seedlings of Quercus robur exposed to short-term water stress in the laboratory conditions was assessed through the method of induced fluorometry. The substrate for seedlings was clayey loam, with the dominant texture fraction made of silt, followed by clay and fine sand, with total porosity 68.2%. Seedlings were separated in two groups: control (C (soil water regime in pots was maintained at the level of field water capacity and treated (water-stressed, WS (soil water regime was maintained in the range of wilting point and lentocapillary capacity. The photosynthetic efficiency was 0.642±0.25 and 0.522±0.024 (WS and C, respectively, which was mostly due to transplantation disturbances and sporadic leaf chlorosis. During the experiment Fv/Fm decreased in both groups (0.551±0.0100 and 0.427±0.018 in C and WS, respectively. Our results showed significant differences between stressed and control group, in regard to both observed parameters (Fv/Fm and T½. Photosynthetic efficiency of pedunculate oak seedlings was significantly affected by short-term water stress, but to a lesser extent than by sufficient watering.

  20. Germination and early seedling growth of Pinus densata Mast. provenances

    Science.gov (United States)

    Yulan Xu; Nianhui Cai; Bin He; Ruili Zhang; Wei Zhao; Jianfeng Mao; Anan Duan; Yue Li; Keith Woeste

    2016-01-01

    We studied seed germination and early seedling growth of Pinus densata to explore the range of variability within the species and to inform afforestation practices. Phenotypes were evaluated at a forest tree nursery under conditions that support Pinus yunnanensis, one of the presumed parental species of P. densata...

  1. Height suppression of tomato plug seedlings by an environment ...

    African Journals Online (AJOL)

    Experiments were conducted to investigate appropriate concentrations of plant growth retardants (PGRs) and duration of seed soaking in order to suppress hypocotyl length and plug seedling height of 2 tomato cultivars ( Lycopersicum esculentum Mill. cv. Seogeon and Seokwang). Daminozide (B-9), uniconazole ...

  2. Mycorrhizal inoculation of pecan seedlings with some marketable truffles

    Directory of Open Access Journals (Sweden)

    Gian M. Benucci

    2013-12-01

    Full Text Available Pecan is the common name of Carya illinoinensis (Wangenh. K. Koch, an ectomycorrhizal tree native to North America, also frequently known as hickory. Mycorrhizal inoculations of pecan seedlings with: Tuber aestivum Vittad., T. borchii Vittad., T. indicum Cooke & Massee, and T. lyonii Butters are described and discussed.

  3. Sucrose metabolic pathways in sweetgum and pecan seedlings

    Science.gov (United States)

    S.S. Sung; P.P. Kormanik; D.P. Xu; C.C. Black

    1989-01-01

    Sucrose metabolism and glycolysis were studied in one- to two-year-old seedlings of sweetgum (Liquidambar styraciflua L.) and pecan (Carya illinoinensis (Wangenh.) C. Koch). The sucrose synthase pathway was identified as the dominant sucrose metabolic activity in sucrose sink tissues such as terminal buds and the root cambial...

  4. Oak sprouts grow better than seedlings under drought stress

    Czech Academy of Sciences Publication Activity Database

    Pietras, Justyna; Stojanović, Marko; Knott, R.; Pokorný, Radek

    2016-01-01

    Roč. 9, č. 4 (2016), s. 529-535 ISSN 1971-7458 R&D Projects: GA MŠk(CZ) EE2.3.20.0267 Institutional support: RVO:67179843 Keywords : drought stress * sap flow * transpiration * biomass Production * sessile Oak * sprout * seedling Subject RIV: EF - Botanics Impact factor: 1.623, year: 2016

  5. Cross reaction between P-61 sunflower seedlings oleosomal protein ...

    African Journals Online (AJOL)

    A true triacylglycerol lipase was detected in germinating sunflower (Helianthus annuus L.) seedlings associated to oleosomes. This enzyme that has not yet been identified was partially purified as shown by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE) (10%); two protein bands, P-61 and P-66 ...

  6. Proteomic analysis of cold stress responses in tobacco seedlings ...

    African Journals Online (AJOL)

    Cold stress is one of the major abiotic stresses limiting the productivity and the geographical distribution of many important crops. To gain a better understanding of cold stress responses in tobacco (Nicotiana tabacum), we carried out a comparative proteomic analysis. Five-week-old tobacco seedlings were treated at 4°C ...

  7. Neem ( Azadirachta indica a. juss) seedling growth as influenced by ...

    African Journals Online (AJOL)

    The effect of Arbuscular mycorrhizal fungus (AMF), specifically, Glomus moseae and cow dung on the growth of Neem (Azadiracchta indica, A. Juss) seedlings was investigated at the forestry quarters, Lagos Street, Maiduguri, Borno State, Nigeria. The study included three treatments: the cow dung, mycorrhizal treatments ...

  8. Effect on nursery and field performance of Pinus patula seedlings ...

    African Journals Online (AJOL)

    Fusarium circinatum is an important fungal pathogen of Pinus species. In South Africa, it is the most significant pathogen of Pinus patula seedlings in forestry nurseries where it presents a substantial constraint to productivity and can continue to cause mortality in-field for up to two years after establishment. This study ...

  9. Cold stratification, but not stratification in salinity, enhances seedling ...

    African Journals Online (AJOL)

    Cold stratification, but not stratification in salinity, enhances seedling growth of wheat under salt treatment. L Wang, HL Wang, CH Yin, CY Tian. Abstract. Cold stratification was reported to release seed dormancy and enhance plant tolerance to salt stress. Experiments were conducted to test the hypothesis that cold ...

  10. Measuring Maize Seedling Drought Response in Search of Tolerant Germplasm

    Directory of Open Access Journals (Sweden)

    Dirk Hays

    2013-02-01

    Full Text Available To identify and develop drought tolerant maize (Zea mays L., high-throughput and cost-effective screening methods are needed. In dicot crops, measuring survival and recovery of seedlings has been successful in predicting drought tolerance but has not been reported in C4 grasses such as maize. Seedlings of sixty-two diverse maize inbred lines and their hybrid testcross progeny were evaluated for germination, survival and recovery after a series of drought cycles. Genotypic differences among inbred lines and hybrid testcrosses were best explained approximately 13 and 18 days after planting, respectively. Genotypic effects were significant and explained over 6% of experimental variance. Specifically three inbred lines had significant survival, and 14 hybrids had significant recovery. However, no significant correlation was observed between hybrids and inbreds (R2 = 0.03, indicating seedling stress response is more useful as a secondary screening parameter in hybrids than in inbred lines per se. Field yield data under full and limited irrigation indicated that seedling drought mechanisms were independent of drought responses at flowering in this study.

  11. Sugar signalling during germination and early seedling establishment in Arabidopsis

    NARCIS (Netherlands)

    Dekkers, S.J.W.

    2006-01-01

    Sugars have pronounced effects on many plant processes like gene expression, germination and early seedling development. Several screens for sugar insensitive mutants were performed to identify genes involved in sugar response pathways using the model plant Arabidopsis. These include sun, gin and

  12. Measuring Tree Seedlings and Associated Understory Vegetation in Pennsylvania's Forests

    Science.gov (United States)

    William H. McWilliams; Todd W. Bowersox; Patrick H. Brose; Daniel A. Devlin; James C. Finley; Kurt W. Gottschalk; Steve Horsley; Susan L. King; Brian M. LaPoint; Tonya W. Lister; Larry H. McCormick; Gary W. Miller; Charles T. Scott; Harry Steele; Kim C. Steiner; Susan L. Stout; James A. Westfall; Robert L. White

    2005-01-01

    The Northeastern Research Station's Forest Inventory and Analysis (NE-FIA) unit is conducting the Pennsylvania Regeneration Study (PRS) to evaluate composition and abundance of tree seedlings and associated vegetation. Sampling methods for the PRS were tested and developed in a pilot study to determine the appropriate number of 2-m microplots needed to capture...

  13. No de novo sulforaphane biosynthesis in broccoli seedlings

    NARCIS (Netherlands)

    Gorissen, Antonie; Kraut, Nicolai U.; de Visser, Ries; de Vries, Marcel; Roelofsen, Han; Vonk, Roel J.

    2011-01-01

    The isothiocyanate sulforaphane, present in significant amounts in broccoli (Brassica oleracea L.) seedlings in the form of its precursor glucoraphanin, has been identified as an inducer of quinine reductase, a phase-II detoxification enzyme known for its anticarcinogenic properties. Its

  14. Production of nursery-reared seedlings of the gray mangrove ...

    African Journals Online (AJOL)

    The aim of this study is to investigate germination of A. marina seeds and subsequent growth parameters of their seedlings in response to three different salinity levels composed of tap water, 50 % and 100 % seawater (0, 21, 42 ‰ salinity). Experimental results indicate that 21 ‰ salinity (50% seawater) has the highest ...

  15. The effect of ectomycorrhizal fungi and bacteria on pine seedlings

    Directory of Open Access Journals (Sweden)

    Hanna Dahm

    2014-08-01

    Full Text Available The effect of ecomycorrhizal fungi (Hebelon crustuliniforme(Bull.: Fr. Quél. 5392 and Pisolithus tinctorius (Pers. Coker et Couch 5335 and bacteria (Bacillus polymyxa and Azospirillum brasilense. associated with mycorrhizas on the growth of pine seedligs was investigated. In addition the influence of bacteria on fungal biomass production and the relationship between ectomycorrhizal fungi and fungi pathogenic to root of pine seedlings were determined. In general, the shoot/root ratio was higher in plants inoculated with Hebeloma crustuliniforme and bacteria than in the control seedlings (grown only under sterile conditions. In non-sterile substrate the root/shoot ratio of the mycorrhizal seedlings was lower as compared to the control. Similar phenomenon was noted in plants inoculated with the mycorrhizal fungus Pisolithus tinetorius. The bacteria used as well as the time of introduction of these organisms into the cultures of mycorrhiza fungi affected the production of fungal biomass. Hebeloma crustuliniforme and Pisolithus tinctorius inhibited the growth of Rizoctonia solani and Fusarium oxysporum fungi pathogenic to pine seedlings.

  16. Evaluation of polycross sweetpotato seedlings for root yield potential ...

    African Journals Online (AJOL)

    The study aimed at determining the root yield potential of the sweetpotato seedlings, the variation in storage root flesh colour and response of the storage roots to major pests and diseases attacking sweetpotato in the field .The experiment was carried out in the screen house and at the Eastern experimental field of National ...

  17. Morphology targets: What do seedling morphological attributes tell us?

    Science.gov (United States)

    Jeremiah R. Pinto

    2011-01-01

    Morphology is classically defined as the form and structure of individual organisms, as distinct from their anatomy or physiology. We use morphological targets in the nursery because they are easy to measure, and because we can often quantitatively link seedling morphological traits with survival and growth performance in the field. In the 20 years since the Target...

  18. Emergence of forage legume seedlings influenced by water ...

    African Journals Online (AJOL)

    Emergence of forage legume seedlings influenced by water potential and soil strength. DMG Njarui, LM Bahnisch, B O'Hagan, B So. Abstract. No Abstract Available E. Afr. Agric. For. J. 2003 69(1), 29-38. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT.

  19. Regulation of Flavonoid Biosynthetic Genes in Germinating Arabidopsis Seedlings.

    Science.gov (United States)

    Kubasek, WL; Shirley, BW; McKillop, A; Goodman, HM; Briggs, W; Ausubel, FM

    1992-01-01

    Many higher plants, including Arabidopsis, transiently display purple anthocyanin pigments just after seed germination. We observed that steady state levels of mRNAs encoded by four flavonoid biosynthetic genes, PAL1 (encoding phenylalanine ammonia-lyase 1), CHS (encoding chalcone synthase), CHI (encoding chalcone isomerase), and DFR (encoding dihydroflavonol reductase), were temporally regulated, peaking in 3-day-old seedlings grown in continuous white light. Except for the case of PAL1 mRNA, mRNA levels for these flavonoid genes were very low in seedlings grown in darkness. Light induction studies using seedlings grown in darkness showed that PAL1 mRNA began to accumulate before CHS and CHI mRNAs, which, in turn, began to accumulate before DFR mRNA. This order of induction is the same as the order of the biosynthetic steps in flavonoid biosynthesis. Our results suggest that the flavonoid biosynthetic pathway is coordinately regulated by a developmental timing mechanism during germination. Blue light and UVB light induction experiments using red light- and dark-grown seedlings showed that the flavonoid biosynthetic genes are induced most effectively by UVB light and that blue light induction is mediated by a specific blue light receptor. PMID:12297632

  20. Effect of Trichoderma isolates on tomato seedling growth response ...

    African Journals Online (AJOL)

    Jane

    2011-06-29

    Jun 29, 2011 ... Seed germination rate was not affected by Trichoderma application, but .... system architecture under sterile condition (Bjorkman et al. ... MATERIALS AND METHODS .... of application to tomato seed in seedling shoot and root elements content. .... with production of some organic acids in the rhizosphere.

  1. 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)

  2. Influence of near-ultraviolet light enhancement and photosynthetic photon flux density during photoperiod extension on the morphology and lignin content of black spruce seedlings

    International Nuclear Information System (INIS)

    Margolis, H.; Vezina, L.P.; Bellefleur, P.

    1991-01-01

    When containerized black spruce seedlings (Picea mariana (Mill.) B.S.P.) are grown rapidly in greenhouse culture, they sometimes bend over, grow horizontally and become deformed. This phenomenon has been known to affect between 5% and 10% of a winter greenhouse crop. In this study, near-ultraviolet lamps were used to supplement the artificial light received from high-pressure sodium lamps and the effects on seedling morphology and lignin contents were examined. Neither height to diameter ratios nor lignin concentrations were significantly affected by UV radiation flux density. However, seedling biomass, height, root collar diameter, lignin content, and lignin to cellulose ratios of stems were significantly correlated with total photosynthetic photon flux density (PPFD) received during photoperiod extension. Height to diameter ratios were negatively correlated with PPFD during photoperiod enhancement because of a greater relative increase in diameter growth compared with height growth. Neither UV nor PAR flux density affected the percentage of black spruce seedlings having stem deformations greater than 30 ° from the vertical [fr

  3. Elevated [CO2] does not ameliorate the negative effects of elevated temperature on drought-induced mortality in Eucalyptus radiata seedlings.

    Science.gov (United States)

    Duan, Honglang; Duursma, Remko A; Huang, Guomin; Smith, Renee A; Choat, Brendan; O'Grady, Anthony P; Tissue, David T

    2014-07-01

    It has been reported that elevated temperature accelerates the time-to-mortality in plants exposed to prolonged drought, while elevated [CO(2)] acts as a mitigating factor because it can reduce stomatal conductance and thereby reduce water loss. We examined the interactive effects of elevated [CO(2)] and temperature on the inter-dependent carbon and hydraulic characteristics associated with drought-induced mortality in Eucalyptus radiata seedlings grown in two [CO(2)] (400 and 640 μL L(-1)) and two temperature (ambient and ambient +4 °C) treatments. Seedlings were exposed to two controlled drying and rewatering cycles, and then water was withheld until plants died. The extent of xylem cavitation was assessed as loss of stem hydraulic conductivity. Elevated temperature triggered more rapid mortality than ambient temperature through hydraulic failure, and was associated with larger water use, increased drought sensitivities of gas exchange traits and earlier occurrence of xylem cavitation. Elevated [CO(2)] had a negligible effect on seedling response to drought, and did not ameliorate the negative effects of elevated temperature on drought. Our findings suggest that elevated temperature and consequent higher vapour pressure deficit, but not elevated [CO(2)], may be the primary contributors to drought-induced seedling mortality under future climates. © 2013 John Wiley & Sons Ltd.

  4. Common arbuscular mycorrhizal networks amplify competition for phosphorus between seedlings and established plants

    DEFF Research Database (Denmark)

    Merrild, Marie Porret; Ambus, Per; Rosendahl, Søren

    2013-01-01

    ) seedlings grew into established networks of Rhizophagus irregularis and cucumber (Cucumis sativus) in two experiments. One experiment studied seedling uptake of 32P in the network in response to cutting of cucumber shoots; the other analysed seedling uptake of P and nitrogen (N) in the presence of intact...... or severed arbuscular mycorrhizal fungus networks and at two soil P concentrations. Pre‐established and intact networks suppressed growth of tomato seedlings. Cutting of cucumber shoots mitigated P deficiency symptoms of seedlings, which obtained access to P in the extraradical mycelium and thereby showed...

  5. 90SR uptake by Pinus ponderosa and Pinus radiata seedlings inoculated with ectomycorrhizal fungi

    International Nuclear Information System (INIS)

    Entry, J.A.; Emmingham, W.H.; Rygiewicz, P.T.

    1994-01-01

    Strontium-90 ( 90 Sr) is a radionuclide characteristic of fallout from nuclear reactor accidents and nuclear weapons testing. Prior studies have shown that Pinus ponderosa and P. radiata seedlings can remove appreciable quantities of 90 Sr from soil and store it in plant tissue. In this study, we inoculated P. ponderosa and P. radiata seedlings with one of five isolates of ectomycorrhizal fungi. Inoculated and noninoculated (control) seedlings were compared for their ability to remove 90 Sr from an organic growth medium. Ectomycorrhizal P. ponderosa and P. radiata seedlings are able to remove 3-5 times more 90 Sr from contaminated soil than seedlings without ectomycorrhizae. (Author)

  6. Differential radiosensitivity of seeds, seedlings and callus cultures of Petunia inflata

    International Nuclear Information System (INIS)

    Bapat, V.A.; Rao, P.S.

    1976-01-01

    A comparative study of the effects of γ-irradiation on seeds, seedlings and callus cultures of Petunia inflata showed striking differences in radiosensitivity as reflected in differences in mean fresh and dry weights, seedling height and morphology. Seeds subjected to low doses (4-6 kR) of irradiation showed stimulation of seedling height. Direct exposure of seedlings to high doses (10 kR) of irradiation caused inhibition in their development. Callus cultures, however, were more radioresistant compared to seeds and seedlings. Tissues grown on either an irradiated nutrient medium or on a medium in which sucrose alone had been irradiated, showed a marked inhibition in their growth potential

  7. How Rapid is Rapid Prototyping? Analysis of ESPADON Programme Results

    Directory of Open Access Journals (Sweden)

    Ian D. Alston

    2003-05-01

    Full Text Available New methodologies, engineering processes, and support environments are beginning to emerge for embedded signal processing systems. The main objectives are to enable defence industry to field state-of-the-art products in less time and with lower costs, including retrofits and upgrades, based predominately on commercial off the shelf (COTS components and the model-year concept. One of the cornerstones of the new methodologies is the concept of rapid prototyping. This is the ability to rapidly and seamlessly move from functional design to the architectural design to the implementation, through automatic code generation tools, onto real-time COTS test beds. In this paper, we try to quantify the term “rapid” and provide results, the metrics, from two independent benchmarks, a radar and sonar beamforming application subset. The metrics show that the rapid prototyping process may be sixteen times faster than a conventional process.

  8. SALINITY TOLERANCE OF SEVERAL RICE GENOTYPES AT SEEDLING STAGE

    Directory of Open Access Journals (Sweden)

    Heni Safitri

    2018-01-01

    Full Text Available Salinity is one of the most serious problems in rice cultivation. Salinity drastically reduced plant growth and yield, especially at seedling stage. Several rice genotypes have been produced, but their tolerance to salinity has not yet been evaluated. The study aimed to evaluate salinity tolerance of rice genotypes at seedling stage. The glasshouse experiment was conducted at Cimanggu Experimental Station, Bogor, from April to May 2013. Thirteen rice genotypes and two check varieties, namely Pokkali (salt tolerant and IR29 (salt sensitive were tested at seedling stage. The experiment was arranged in a randomized complete block design with three replications and two factors, namely the levels of NaCl (0 and 120 mM and 13 genotypes of rice. Rice seedlings were grown in the nutrient culture (hydroponic supplemented with NaCl at different levels. The growth and salinity injury levels of the genotypes were recorded periodically. The results showed that salinity level of 120 mM NaCl reduced seedling growth of all rice genotypes, but the tolerant ones were survived after 14 days or until the sensitive check variety died. Based on the visual injury symptoms on the leaves, five genotypes, i.e. Dendang, Inpara 5, Inpari 29, IR77674-3B-8-2-2-14-4-AJY2, and IR81493-BBB-6-B- 2-1-2 were tolerant to 120 mM salinity level, while Inpara 4 was comparable to salt sensitive IR29. Hence, Inpara 4 could be used as a salinity sensitive genotype for future research of testing tolerant variety. Further evaluation is needed to confirm their salinity tolerance under field conditions. 

  9. Seed treatments with essential oils protect radish seedlings against drought

    Directory of Open Access Journals (Sweden)

    Joshua D. Klein

    2017-10-01

    Full Text Available Establishment of seedlings of economic crops is often reduced if there is not a steady supply of water. Essential oils (EO from plants are increasingly used instead of synthetic chemicals to protect plant and animal products against biotic and abiotic stresses. We investigated priming radish seeds by soaking or by matriconditioning with synthetic or natural compounds as a means of inducing resistance to drought stress, thus maintaining crop yield. Priming radish seeds for two hours in solutions of essential oils (EO thymol and carvacrol derived from Origanum syriacum, with “oregano natural product” (ONP; a solution of the residue remaining after EO extraction, or with the gibberellin synthesis inhibitor trinexapac ethyl (TE, was much more effective in inducing drought resistance than was matriconditioning with the same compounds in sawdust for two days. The latter treatment induced considerable fungal and bacterial infection in treated seeds if the substrate-matrix was not heat-treated beforehand. The increase in specific leaf area in plants from treated seeds was mostly consistent with an increase in leaf water content. Seed treatments with EO, ONP, and especially TE led to a three-fold increase in radish seedling survival compared with water-treated controls, when 21 day-old seedlings were irrigated after 6 days of drought. Under drought conditions, seedlings from treated seeds had a 2–3-fold increase in relative water content increased 2–3-fold, while membrane permeability decreased 20–50-fold as a result of the treatments. However, the physical benefits of the treatments often did not correlate with treatment-induced increases in physiological parameters such as pigments (chlorophyll, carotenoid, anthocyanin, pigment ratios (chlorophyll a/b, carotenoid/chlorophyll, or antioxidant activity. Seed treatments with biostimulants can be as effective as treatments with synthetic compounds in inducing drought resistance in seedlings.

  10. Utilization of Aseptic Seedling Explants for In vitro Propagation of Indian Red Wood

    Directory of Open Access Journals (Sweden)

    Kishore Kumar CHIRUVELLA

    2013-12-01

    Full Text Available Micropropagation has been advocated as one of the most viable biotechnological tool for ex situ conservation of rare, endangered endemic medicinal plants germplasm. Rapid clonal micropropagation protocol for large-scale multiplication of an endemic medicinal plant Soymida febrifuga (Meliaceae was established from 15-day aseptic seedling cotyledonary node and shoot tip explants. High frequency of sprouting and shoot differentiation was observed from cotyledonary node explants compared to shoot tip, on Murashige and Skoog (MS medium fortified with BA, KN, 2-iP and CM. Of the cytokinins used, BA (3.0 mgl-1 supported highest average number and maximum multiple shoot differentiation (16.6. In vitro proliferated shoots were multiplied rapidly by culturing nodal segments as microcuttings, further subcultured on the same media for elongation. Elongated shoots upon transfer to MS medium fortified with IBA showed rooting within two weeks of culture. Rooted plantlets were successfully hardened and 75% of rooted shoots successfully survived on establishment to the soil. Plants looked healthy with no visually detectable phenotypic variations. This protocol provides a successful and rapid technique that can be used for ex situ conservation minimizing the pressure on wild populations and contributes to the conservation of this endemic medicinally potent flora.

  11. Seedling recruitment of forb species under experimental microhabitats in alpine grassland

    International Nuclear Information System (INIS)

    Li, S. S.; Yu, L.; Lin, W. G.; Pingi, T. F.

    2015-01-01

    Which factors limit plant seedling recruitment in alpine meadow of the Qinghai-Tibetan Plateau (QTP), China? This study examined the relative influence of seed mass and microsites (resulted from grazing disturbance) on field seedling emergence and survival of nineteen alpine herbaceous species with a range of traits in QTP. Seed mass had significant effects on seedling emergence and survival eliminating influence of light and nutrient variances among these species. The larger-seed species had more advantageous than the smaller-seed species in seedling survival, but it was disadvatage for seedling emergence, especially under high nutrient availability and low light intensity conditions. Light had obvious effects on seedling survival, but less effects on seedling emergence for these species. Moreover, nutrient and light treatments altered the regression relationships of seed mass and seedling emergence and survival and the order of significances was L25>L50>L100>L10>L4. These results suggested that seed mass may restrict seedling recruitment processes, however, light and nutrient availability all have significant effects on seedling emergence and survival for these alpine species. Moderate light intensity was propitious to seedling emergence and survival in alpine grassland. This suggests that ecological factors in alpine grassland provide a stochastic influence on different seed-mass species. These trends may help to explain why many small-seeded species of Asteraceae and Gramineae tend to be more abundant in disturbed habitats. (author)

  12. Effects of seed traits variation on seedling performance of the invasive weed, Ambrosia artemisiifolia L.

    Science.gov (United States)

    Ortmans, William; Mahy, Grégory; Monty, Arnaud

    2016-02-01

    Seedling performance can determine the survival of a juvenile plant and impact adult plant performance. Understanding the factors that may impact seedling performance is thus critical, especially for annuals, opportunists or invasive plant species. Seedling performance can vary among mothers or populations in response to environmental conditions or under the influence of seed traits. However, very few studies have investigated seed traits variations and their consequences on seedling performance. Specifically, the following questions have been addressed by this work: 1) How the seed traits of the invasive Ambrosia artemisiifolia L. vary among mothers and populations, as well as along the latitude; 2) How do seed traits influence seedling performance; 3) Is the influence on seedlings temperature dependent. With seeds from nine Western Europe ruderal populations, seed traits that can influence seedling development were measured. The seeds were sown into growth chambers with warmer or colder temperature treatments. During seedling growth, performance-related traits were measured. A high variability in seed traits was highlighted. Variation was determined by the mother identity and population, but not latitude. Together, the temperature, population and the identity of the mother had an effect on seedling performance. Seed traits had a relative impact on seedling performance, but this did not appear to be temperature dependent. Seedling performance exhibited a strong plastic response to the temperature, was shaped by the identity of the mother and the population, and was influenced by a number of seed traits.

  13. The effects of Vexar® seedling protectors on the growth and development of lodgepole pine roots

    Science.gov (United States)

    Engeman, Richard M.; Anthony, R. Michael; Krupa, Heather W.; Evans, James

    1997-01-01

    The effects on the growth and development of lodgepole pine roots from the Vexar® tubes used to protect seedlings from pocket gopher damage were studied in the Targhee National Forest, Idaho and the Deschutes National Forest, Oregon. At each site, Vexar-protected and unprotected seedlings, with and without above-ground gopher damage were examined after six growing seasons for root deformities and growth. Undamaged seedlings exhibited greater growth, reflecting the importance of non-lethal gopher damage as a deterrent to tree growth. Protected seedlings with similar damage history as unprotected seedlings had greater root depth than unprotected seedlings, although unprotected seedlings with no above-ground damage generally had the greatest root weight. In general, the percent of seedlings with root deformities was greater for the unprotected seedlings than for the Vexar-protectd seedlings, although this could be largely due to the greater care required to plant protected seedlings. Acute deformities were more common for unprotected seedlings, whereas root deformities with less severe bending were more common for protected seedlings. The incidence of crossed roots was similar for protected and unprotected seedlings on the Deschutes site, where enough occurrences of this deformity permitted analyses. Protected seedlings were similar in root abundance, root distribution, root size and vigor to the unprotected seedlings, with some indication from the Deshutes study site that root distribution was improved with Vexar protection.

  14. Effects of vesicular-arbuscular mycorrhizal (VAM) fungi on the seedling growth of three Pistacia species.

    Science.gov (United States)

    Caglar, S; Akgun, A

    2006-07-01

    The experiment was undertaken to test the efficiency of inoculation of vesicular-arbuscular mycorrhizal (VAM) fungi on the seedling growth of three Pistacia species used as rootstocks. The stratified Pistacia seeds were inoculated with VAM fungi. The highest rate of inoculated roots was 96.7% in P. khinjuck seedlings with G. clarum and G. etunicatum, 83.3% in P. vera seedlings with G. caledonium and 73.3% in P. terebinthus seedlings with G. caledonium. Mycorrhizal inoculations improved seedling height only in P. terebinthus. Certain mycorrhizal inoculations increased the leaf N, but not P and K contents. Seedlings inoculated with G. caledonium had higher reducing sugar contents. It was concluded that pre-inoculated Pistacia seedlings could have a better growth in the harsh field conditions.

  15. Rapid deployment intrusion detection system

    International Nuclear Information System (INIS)

    Graham, R.H.

    1997-01-01

    A rapidly deployable security system is one that provides intrusion detection, assessment, communications, and annunciation capabilities; is easy to install and configure; can be rapidly deployed, and is reusable. A rapidly deployable intrusion detection system (RADIDS) has many potential applications within the DOE Complex: back-up protection for failed zones in a perimeter intrusion detection and assessment system, intrusion detection and assessment capabilities in temporary locations, protection of assets during Complex reconfiguration, and protection in hazardous locations, protection of assets during Complex reconfiguration, and protection in hazardous locations. Many DOE user-need documents have indicated an interest in a rapidly deployable intrusion detection system. The purpose of the RADIDS project is to design, develop, and implement such a system. 2 figs

  16. [Effects of gap size on seedling natural regeneration in artificial Pinus tabulaeformis plantation].

    Science.gov (United States)

    Han, Wen-Juan; Yuan, Xiao-Qing; Zhang, Wen-Hui

    2012-11-01

    To clarify the effects of gap size created by thinning on the seedling natural regeneration in artificial Pinus tabulaeformis plantation, a plot investigation was conducted to study the ecological factors and the age structure, height, diameter, length of needles, and dry biomass of roots, stems, and needles of 1-10 year-old seedlings in different habitats, and a path analysis was made on the environmental factors affecting the seedling regeneration. Obvious differences were observed in the ecological factors in different size gaps and slope aspects. There lacked of above 3 year-old seedlings in understory and of above 7 year-old seedlings in small gap, and the seedlings of 5 and 6 year-old were lesser in big gap. The 1-10 year-old seedlings could be divided into 3 development phases, i. e. , 1-3 year-old, 4-7 year-old, and 8-10 year-old seedlings, among which, 1-3 year-old seedlings were critical for the establishment and growth of the population. The growth situation of the seedlings in different habitats was in order of big gap in shady slope > big gap in sunny slope > small gap in sunny slope > small gap in shady slope > understory in sunny slope > understory in shady slope. Path analysis showed light intensity had decisive positive effects on the seedling number of different development phases, shrub coverage had decisive negative effects on the seedling number of 4-7 year-old and 8-10 year-old phases, whereas humus dry mass had negative effects on the seedling number of 4-7 year-old but positive effects on the seedling number of 8-10 year-old. It was suggested that in the management of artificial P. tabulaeformis plantation, relatively high intensity thinning combined with shrub clearing should be adopted to provide favorable conditions for the sustainable development of P. tabulaeformis population.

  17. The Importance of Seedlings Quality in Timber and Bio-energy Production on marginal lands

    Science.gov (United States)

    Fragkiskakis, Nikitas; Kiourtsis, Fotios; Keramitzis, Dimitrios; Papatheodorou, Ioannis; Georgiadou, Margarita; Repmann, Frank; Gerwin, Werner

    2017-04-01

    One of the main issues that the forest sector is facing is to achieve a balance between the demand for biomass &wood production and the need to preserve the sustainability and biodiversity of forest ecosystems. The purposes of the new approaches are to ensure more efficient management of ecosystems and implement intensive forestry that will increase biomass production & timber yields. To achieve this, we need to determine the macroeconomic potential of the various options available, including the use of biotechnology and genetics. The success of the forests plantations capacity may be solved through forest certification, based on: a) Stabilization of the forests and soils structure. b) Hierarchy of biomass production in the forest's management process. c) Οrganization and implementation of effective plantation on marginal lands. d) Maintenance or increase of forest productivity by introducing new items as and when they are required. It is important to evaluate of the influence of factors such as the quality of soils of plantation areas, the utilization of the genetic resources and the management of forest operations with the environmental economic criteria such as net present value of benefits (NPV) and the corresponding flow annuities (EACF).The existing evaluations studies showed that the quality of the plantation areas has the most influence and through validated quality seed production can generate an increase in the NPV up to 73%. The importance of seedlings quality in timber and bio-energy production on marginal lands based on the literature it is estimated according to the heredity of the characteristics of the wood structure (except shrinkage). This clearly indicate that seedlings with the appropriate morphological characteristics can significantly improve the growth performance and help to support the development of biomass plantations oriented in tailor-made timber and bio-energy production.

  18. Barriers to seed and seedling survival of once-common Hawaiian palms: the role of invasive rats and ungulates.

    Science.gov (United States)

    Shiels, Aaron B; Drake, Donald R

    2015-05-27

    Mammalian herbivores can limit plant recruitment and affect forest composition. Loulu palms (Pritchardia spp.) once dominated many lowland ecosystems in Hawai'i, and non-native rats (Rattus spp.), ungulates (e.g. pigs Sus scrofa, goats Capra hircus) and humans have been proposed as major causes of their decline. In lowland wet forest, we experimentally determined the vulnerability of seeds and seedlings of two species of Pritchardia, P. maideniana and P. hillebrandii, by measuring their removal by introduced vertebrates; we also used motion-sensing cameras to identify the animals responsible for Pritchardia removal. We assessed potential seed dispersal of P. maideniana by spool-and-line tracking, and conducted captive-feeding trials with R. rattus and seeds and seedlings of both Pritchardia species. Seed removal from the forest floor occurred rapidly for both species: >50 % of Pritchardia seeds were removed from the vertebrate-accessible stations within 6 days and >80 % were removed within 22 days. Although rats and pigs were both common to the study area, motion-sensing cameras detected only rats (probably R. rattus) removing Pritchardia seeds from the forest floor. Captive-feeding trials and spool-and-line tracking revealed that vertebrate seed dispersal is rare; rats moved seeds up to 8 m upon collection and subsequently destroyed them (100 % mortality in 24-48 h in captivity). Surprisingly, seedlings did not suffer vertebrate damage in field trials, and although rats damaged seedlings in captivity, they rarely consumed them. Our findings are consistent with the hypothesis generated from palaeoecological studies, indicating that introduced rats may have assisted in the demise of native insular palm forests. These findings also imply that the seed stage of species in this Pacific genus is particularly vulnerable to rats; therefore, future conservation efforts involving Pritchardia should prioritize the reduction of rat predation on the plant recruitment stages

  19. Effect of Simulated Tillage in Combination with Post-Shattering Temperature Conditions on Senna obtusifolia and Xanthium strumarium Seed Survival, Seedling Emergence and Seedbank Potential

    OpenAIRE

    Taghi Bararpour; Nicholas E. Korres

    2018-01-01

    Two of the most troublesome weeds in soybean, cotton, and corn in cropping systems of mid-south United States (US) are Senna obtusifolia and Xanthium strumarium. Understanding their population dynamics, particularly weed seedling emergence patterns, is important for the timely implementation and the success of weed management strategies. Identifying the sources of variation of emergence patterns could greatly improve our ability to predict emergence timing. A three-years field study was condu...

  20. The effects of ultraviolet-B radiation on loblolly pine. 1: Growth, photosynthesis and pigment production in greenhouse-grown seedlings

    International Nuclear Information System (INIS)

    Sullivan, J.H.; Teramura, A.H.

    1989-01-01

    One-year old loblolly pine (Pinus taeda L.) seedlings were grown in an unshaded greenhouse for 7 months under 4 levels of ultraviolet-B (UV-B) radiation simulating stratospheric ozone reductions of 16, 25 and 40% and included a control with no UV-B radiation. Periodic measurements were made of growth and gas exchange characteristics and needle chlorophyll and UV-B-absorbing-compound concentrations. The effectiveness of UV-B radiation on seedling growth and physiology varied with the UV-B irradiance level. Seedlings receiving the lowest supplemental UV-B irradiance showed reductions in growth and photosynthetic capacity after only 1 month of irradiation. These reductions persisted and resulted in lower biomass production, while no increases in UV-B-absorbing compounds in needles were observed. Seedlings receiving UV-B radiation which simulated a 25% stratospheric ozone reduction showed an increase in UV-B-absorbing-compound concentrations after 6 months, which paralleled a recovery in photosynthesis and growth after an initial decrease in these characteristics. The seedlings grown at the highest UV-B irradiance (40% stratospheric ozone reduction) showed a more rapid increase in the concentration of UV-B-absorbing compounds and no effects of UV-B radiation on growth or photosynthetic capacity until after 4 months at this irradiance. Changes in photosynthetic capacity were probably the result of direct effects on light-dependent processes, since no effects were observed on either needle chlorophyll concentrations or stomatal conductance. Further studies are necessary to determine whether these responses persist and accumulate over subsequent years. (author)

  1. A novel fluorescence imaging approach to monitor salt stress-induced modulation of ouabain-sensitive ATPase activity in sunflower seedling roots.

    Science.gov (United States)

    Mukherjee, Soumya; Bhatla, Satish Chander

    2014-04-01

    Seedlings exposed to salt stress are expected to show modulation of intracellular accumulation of sodium ions through a variety of mechanisms. Using a new methodology, this work demonstrates ouabain (OU)-sensitive ATPase activity in the roots of sunflower seedlings subjected to salt stress (120 mM NaCl). 9-Anthroylouabain (a derivative of ouabain known to inhibit Na(+), K(+) -ATPase activity in animal systems, EC 3.6.3.9) has been used as a probe to analyze OU-sensitive ATPase activity in sunflower (Helianthus annuus) seedling roots by spectrofluorometric estimation and localization of its spatial distribution using confocal laser scanning microscopy. Salt stress for 48 h leads to a significant induction of OU-sensitive ATPase activity in the meristematic region of the seedling roots. Calcium ions (10 mM) significantly inhibit enzyme activity and a parallel accumulation of sodium ions in the cytosol of the columella cells, epidermis and in the cells of the meristematic region of the roots is evident. As a rapid response to NaCl stress, the activity of OU-sensitive ATPase gets localized in the nuclear membrane of root protoplasts and it gets inhibited after treatment with calcium ions. Nuclear membrane localization of the OU-sensitive ATPase activity highlights a possible mechanism to efflux sodium ions from the nucleus. Thus, a correlation between OU-sensitive ATPase activity, its modulation by calcium ions and accumulation of sodium ions in various regions of the seedling roots, has been demonstrated using a novel approach in a plant system. © 2013 Scandinavian Plant Physiology Society.

  2. Diversity for seedling vigor in wild barley (hordeum vulgare L. subs. simpatina) germplasm

    International Nuclear Information System (INIS)

    Tyagi, K.; Park, M.R.; Lee, H.J.; Lee, C.A.; Rehman, S.; Steffenson, B.; Lee, K.J.; Yun, S.J.

    2011-01-01

    Seedling vigor is important for improving stand establishment of barley crops, particularly in arid regions and areas where the soil temperature is low at sowing time. Three hundred and fifteen wild barley accessions from the Wild Barley Diversity Collection (WBDC) were evaluated for nine seedling vigor traits in a poly house and growth chamber under hydroponic conditions. The accessions exhibited significant differences for all traits investigated. Traits showing greatest phenotypic variation were seedling visual score, plant height, shoot fresh weight, shoot dry weight and shoot length. Seed weight exhibited the least variation. Seed weight was significantly correlated with visual seedling score and shoot and seedling fresh and dry weight. Correlation analysis showed that the visual seedling score was a reliable method for estimating seedling vigor in wild barley. The first three principal components (PC) explained 82.3% of the variation present in the WBDC with PC1(54.0%) associated with shoot fresh weight, shoot dry weight, seedling dry weight, seedling fresh weight, shoot length and seedling length. Accessions from the southwest portion of the Fertile Crescent, like WBDC020 (Turkey), WBDC238 (Jordan) and WBDC244 (Jordan) exhibited the highest positive values for most of the plant vigor traits investigated. These wild barley accessions likely carry alleles that will be useful for the improvement of plant vigor traits in cultivated barley. (author)

  3. Colonization with Arbuscular Mycorrhizal Fungi Promotes the Growth of Morus alba L. Seedlings under Greenhouse Conditions

    Directory of Open Access Journals (Sweden)

    Nan Lu

    2015-03-01

    Full Text Available Morus alba L. is an important tree species planted widely in China because of its economic value. In this report, we investigated the influence of two arbuscular mycorrhizal fungal (AMF species, Glomus mosseae and Glomus intraradices, alone and together, on the growth of M. alba L. seedlings under greenhouse conditions. The growth parameters and physiological performance of M. alba L. seedlings were evaluated 90 days after colonization with the fungi. The growth and physiological performance of M. alba L. seedlings were significantly affected by the AMF species. The mycorrhizal seedlings were taller, had longer roots, more leaves and a greater biomass than the non-mycorrhizae-treated seedlings. In addition, the AMF species-inoculated seedlings had increased root activity and a higher chlorophyll content compared to non-inoculated seedlings. Furthermore, AMF species colonization increased the phosphorus and nitrogen contents of the seedlings. In addition, simultaneous root colonization by the two AMF species did not improve the growth of M. alba L. seedlings compared with inoculation with either species alone. Based on these results, these AMF species may be applicable to mulberry seedling cultivation.

  4. Effects of Seedbed Density on Seedling Morphological Characteristics of four Broadleaved Species

    Energy Technology Data Exchange (ETDEWEB)

    Yucedag, C.; Gailing, O.

    2012-11-01

    The aim of this study was to investigate the effects of seedling spacing on morphological characteristics of one year-old Amygdalus communis L., Prunus avium L., Pyrus elaeagnifolia Pall. and Eriolobus trilobatus (Poiret) Roemer seedlings under nursery conditions. Seedlings were grown in completely randomized blocks with four replications. Seedbeds were 1.2 m wide with 5 rows each 20 cm apart. Within-row spacings were chosen as 4, 8 and 12 cm to analyze the effect of seedlings density on growth performance. Seedling spacing significantly affected root collar diameter, shoot height, tap root length and number of fine roots in A. communis and P. avium, but not in P. elaeagnifolia and E. tribolatus. Additionally wider seedling spacings resulted in larger seedlings in A. communis and P. avium. In conclusion, it would be beneficial to use wider seedling spacing in order to obtain better seedling growth in A. communis and P. avium. Larger seedlings could also provide significant advantages because of reduced cultural activities and an expected higher growth and survival rate. (Author) 27 refs.

  5. Implications of seed size for seedling survival in Carnegiea gigantea and Ferocactus wislizeni (Cactaceae)

    Science.gov (United States)

    Bowers, Janice E.; Pierson, E.A.

    2001-01-01

    Larger seeds have been shown to convey benefits for seedling survival but the mechanisms of this process are not well understood. In this study, seed size and seedling survival were compared for 2 sympatric cactus species, Carnegiea gigantea (Engelm.) Britt. & Rose and Ferocactus wislizeni (Engelm.) Britt. & Rose, in laboratory and field experiments in the northern Sonoran Desert. Both species have small seeds, but Ferocactus seeds are nearly twice as long and 3 times as heavy as those of Carnegiea. The difference in size is perpetuated after germination: new Ferocactus seedlings have 4 times the estimated volume of new Carnegiea seedlings. In an outdoor experiment, annual survivorship of both species was low but was 6 times higher for Ferocactus (6 seedlings, 8.1%) than Carnegiea (1 seedling, 1.4%). The pattern of seedling mortality in relation to temperature and rain suggests that, after the initial flush of seed and seedling predation, drought and heat took a greater toll on Carnegiea than Ferocactus seedlings, probably because the larger seedling volume of Ferocactus conferred greater drought tolerance. In addition, F. wislizeni could become established without benefit of nurse plants whereas C. gigantea could not; this might reflect differential tolerance to high soil temperatures.

  6. 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...

  7. Leaf elemental analysis in mycorrhizal post oak seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Boling, B.C. [Department of Biology, University of North Texas, P.O. Box 305220, Denton, TX 76203-5220 (United States); Naab, F.U. [Ion Beam Modification and Analysis Laboratory, Department of Physics, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States)]. E-mail: fun001@unt.edu; Smith, D. [Department of Biology, University of North Texas, P.O. Box 305220, Denton, TX 76203-5220 (United States); Duggan, J.L. [Ion Beam Modification and Analysis Laboratory, Department of Physics, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States); McDaniel, F.D. [Ion Beam Modification and Analysis Laboratory, Department of Physics, University of North Texas, P.O. Box 311427, Denton, TX 76203-1427 (United States)

    2006-09-15

    Growth and element assimilation was investigated in the leaves of post oak seedlings exposed to four different treatment combinations of fertilization and ectomycorrhizal inoculation. Element concentration was analyzed via particle-induced X-ray emission spectrometry (PIXE). PIXE detected 10 of the 13 essential macro and micronutrients: P, S, Mg, Ca, K, Cu, Zn, Mn, Fe and Cl. Mean growth and dry weight was significantly different across the treatment groups as well as the mean concentration of Mg, Al, S, K, Ca, Fe, Cu and Zn. The data suggest that fertilization rather than mycorrhizal inoculation had a stronger influence on nutrient uptake. This study is the first to analyze element concentration in post oak and to investigate the potential benefits of mycorrhizal symbiosis in post oak seedlings in terms of nutrient uptake.

  8. Transcriptional Responses and Gentiopicroside Biosynthesis in Methyl Jasmonate-Treated Gentiana macrophylla Seedlings.

    Directory of Open Access Journals (Sweden)

    Xiaoyan Cao

    Full Text Available Gentiana macrophylla, a medicinal plant with significant pharmacological properties, contains the bioactive compound gentiopicroside. Methyl jasmonate (MeJA is an effective elicitor for enhancing the production of such compounds. However, little is known about MeJA-mediated biosynthesis of gentiopicroside. We investigated this phenomenon as well as gene expression profiles to determine the molecular mechanisms for MeJA-mediated gentiopicroside biosynthesis and regulation in G. macrophylla. Our HPLC results showed that Gentiana macrophylla seedlings exposed to MeJA had significantly higher concentrations of gentiopicroside when compared with control plants. We used RNA sequencing to compare transcriptional profiles in seedlings treated for 5 d with either 0 μmol L-1 MeJA (C or 250 μmol L-1 MeJA (M5 and detected differentially expressed genes (DEGs. In total, 77,482 unique sequences were obtained from approximately 34 million reads. Of these, 48,466 (57.46% sequences were annotated based on BLASTs performed against public databases. We identified 5,206 DEGs between the C and M5 samples, including genes related to the α-lenolenic acid degradation pathway, JA signaling pathway, and gentiopicroside biosynthesis. Expression of numerous enzyme genes in the glycolysis pathway was significantly up-regulated. Many genes encoding transcription factors (e.g. ERF, bHLH, MYB, and WRKY also responded to MeJA elicitation. Rapid acceleration of the glycolysis pathway that supplies precursors for IPP biosynthesis and up-regulates the expression of enzyme genes in that IPP pathway are probably most responsible for MeJA stimulation of gentiopicroside synthesis. Our qRT-PCR results showed that the expression profiles of 12 gentiopicroside biosynthesis genes were consistent with the RNA-Seq data. These results increase our understanding about how the gentiopicroside biosynthesis pathway in G. macrophylla responds to MeJA.

  9. Fatal outbreak from consuming Xanthium strumarium seedlings during time of food scarcity in northeastern Bangladesh.

    Directory of Open Access Journals (Sweden)

    Emily S Gurley

    2010-03-01

    Full Text Available An outbreak characterized by vomiting and rapid progression to unconsciousness and death was reported in Sylhet Distrct in northeastern Bangladesh following destructive monsoon floods in November 2007.We identified cases presenting to local hospitals and described their clinical signs and symptoms. We interviewed patients and their families to collect illness histories and generate hypotheses about exposures associated with disease. An epidemiological study was conducted in two outbreak villages to investigate risk factors for developing illness. 76 patients were identified from 9 villages; 25% (19/76 died. Common presenting symptoms included vomiting, elevated liver enzymes, and altered mental status. In-depth interviews with 33 cases revealed that 31 (94% had consumed ghagra shak, an uncultivated plant, in the hours before illness onset. Ghagra shak was consumed as a main meal by villagers due to inaccessibility of other foods following destructive monsoon flooding and rises in global food prices. Persons who ate this plant were 34.2 times more likely (95% CI 10.2 to 115.8, p-value<0.000 than others to develop vomiting and unconsciousness during the outbreak in our multivariate model. Ghagra shak is the local name for Xanthium strumarium, or common cocklebur.The consumption of Xanthium strumarium seedlings in large quantities, due to inaccessibility of other foods, caused this outbreak. The toxic chemical in the plant, carboxyatratyloside, has been previously described and eating X. strumarium seeds and seedlings has been associated with fatalities in humans and livestock. Unless people are able to meet their nutritional requirements with safe foods, they will continue to be at risk for poor health outcomes beyond undernutrition.

  10. Quality of Heliconia psittacorum seedlings grown on different substrates

    Directory of Open Access Journals (Sweden)

    Raimundo Luiz Laurinho dos Santos

    2016-01-01

    Full Text Available The production of good seedlings depends on the quality of the matrix and propagation techniques used. In choosing a substrate should be particularly observed physical and chemical characteristics. The objective of this study was to assess the development and vigor of heliconia seedlings from Heliconia psittacorum species, grown on different substrates and mixtures. The materials that form the treatments were: burnt rice husk (RHB, vermiculite (VC, sugarcane waste burnt (SWB, subsoil (S, chicken bedding (CB, cattle manure (CM, earthworm humus (EH, coconut husk powder (CSP and Horticultural Plantmax (HP. The treatments chosen were: 1( ⅔ CM + ⅓ CSP, 2( ⅔CM + ⅓RHB, 3( ⅔CB + ⅓ SWB, 4(CSP, 5(½VC+ ½SWB, 6(⅔ S + ⅓ CB, 7(⅓CM + ⅔SWB, 8(⅔ CM + ⅓SWB, 9(⅔CB + ⅓RHB, 10(⅓CM + ⅔RHB, 11(⅓CB + ⅔SWB, 12(⅔CB + ⅓CSP, 13(⅔EH + ⅓CSP, 14(⅔EH + ⅓SWB, 15(⅓CB + ⅔RHB, 16(⅓EH + ⅔SWB, 17(⅔EH + ⅓RHB, 18( ½VC + ½RHB, 19(S, 20(⅔ S + ⅓ CM, 21(⅔ S + ⅓ EH, 22(EH, 23(HP, 24(⅓EH + ⅔RHB. Samples of all treatment compositions were taken and carried out chemical and physical analysis. A set of ten treatments (1, 2, 5, 7, 8, 10, 14, 16, 20 and 22 basically consisting of CM EH, RHB, CSP and SWB produced the best seedlings and treatment with CB as a main component or not produced the worst seedlings due to high electrical conductivity

  11. Pyridine 2,4-dicarboxylic acid suppresses tomato seedling growth

    Science.gov (United States)

    Fragkostefanakis, Sotirios; Kaloudas, Dimitrios; Kalaitzis, Panagiotis

    2018-01-01

    Pyridine 2,4-dicarboxylic acid is a structural analogue of 2-oxoglutarate and is known to inhibit 2-oxoglutare-dependent dioxygenases. The effect of this inhibitor in tomato seedlings grown in MS media supplied with various concentrations of PDCA was investigated, resulting in shorter roots and hypocotyls in a dose-dependent manner. The partial inhibition of growth in roots was more drastic compared to hypocotyls and was attributed to a decrease in the elongation of root and hypocotyl cells. Concentrations of 100 and 250 μΜ of PDCA decreased hydroxyproline content in roots while only the 250 μΜ treatment reduced the hydroxyproline content in shoots. Seedlings treated with 100 μΜ PDCA exhibited enhanced growth of hypocotyl and cotyledon cells and higher hydroxyproline content resulting in cotyledons with greater surface area. However, no alterations in hypocotyl length were observed. Prolyl 4 hydroxylases (P4Hs) are involved in the O-glycosylation of AGPs and were also highly expressed during seedling growth. Moreover PDCA induced a decrease in the accumulation of HRGPs and particularly in AGPs-bound epitopes in a dose dependent-manner while more drastic reduction were observed in roots compared to shoots. In addition, bulged root epidermal cells were observed at the high concentration of 250 μΜ which is characteristic of root tissues with glycosylation defects. These results indicate that PDCA induced pleiotropic effects during seedling growth while further studies are required to better investigate the physiological significance of this 2-oxoglutarate analogue. This pharmacological approach might be used as a tool to better understand the physiological significance of HRGPs and probably P4Hs in various growth and developmental programs in plants.

  12. Pyridine 2,4-Dicarboxylic Acid Suppresses Tomato Seedling Growth

    Directory of Open Access Journals (Sweden)

    Sotirios Fragkostefanakis

    2018-01-01

    Full Text Available Pyridine 2,4-dicarboxylic acid is a structural analog of 2-oxoglutarate and is known to inhibit 2-oxoglutare-dependent dioxygenases. The effect of this inhibitor in tomato seedlings grown in MS media supplied with various concentrations of PDCA was investigated, resulting in shorter roots and hypocotyls in a dose-dependent manner. The partial inhibition of growth in roots was more drastic compared to hypocotyls and was attributed to a decrease in the elongation of root and hypocotyl cells. Concentrations of 100 and 250 μM of PDCA decreased hydroxyproline content in roots while only the 250 μM treatment reduced the hydroxyproline content in shoots. Seedlings treated with 100 μM PDCA exhibited enhanced growth of hypocotyl and cotyledon cells and higher hydroxyproline content resulting in cotyledons with greater surface area. However, no alterations in hypocotyl length were observed. Prolyl 4 hydroxylases (P4Hs are involved in the O-glycosylation of AGPs and were also highly expressed during seedling growth. Moreover PDCA induced a decrease in the accumulation of HRGPs and particularly in AGPs-bound epitopes in a dose dependent-manner while more drastic reduction were observed in roots compared to shoots. In addition, bulged root epidermal cells were observed at the high concentration of 250 μM which is characteristic of root tissues with glycosylation defects. These results indicate that PDCA induced pleiotropic effects during seedling growth while further studies are required to better investigate the physiological significance of this 2-oxoglutarate analog. This pharmacological approach might be used as a tool to better understand the physiological significance of HRGPs and probably P4Hs in various growth and developmental programs in plants.

  13. Studies on the seedling growth of Adansonia digitata AL. | Chia ...

    African Journals Online (AJOL)

    The germination and growth of seedlings of Adansonia digitata were investigated at the Biological garden of ABU Zaria, Nigeria (07o38′ and 11o11′N) at different planting depths and soil types. The seeds were planted at different planting depths of 1.0 cm, 2.0 cm, 4.0 cm and 6.0 cm in nursery bags and kept in a screen ...

  14. In vitro germination and acclimatization of cambui tree type seedlings

    Directory of Open Access Journals (Sweden)

    Ana da Silva Lédo

    2014-01-01

    Full Text Available There are few reports in literature on the in vitro behavior of cambui tree (Myrciaria tenella O. Berg and acclimatization conditions. The aim of this study was to evaluate the effect of culture media on in vitro germination and the effect of different substrates on the acclimatization of two Myrciaria tenella types. The study was carried out at the Embrapa Tabuleiros Costeiros Laboratory of Plant Tissue Culture, Aracaju, SE. Seeds were extracted from fruits of two Myrciaria tenella types: Orange and Purple Types. The seeds were inoculated in the following culture media: T1 - MS medium + 30g L -1 sucrose, T2 - 1/2 MS medium + 15g L -1 sucrose and T3 - control without MS salts. To study the effect of substrates on acclimatization, seedlings were transferred to plastic containers with capacity of 300cm 3 containing the following sterilized substrates: S1 - soil and powdered coconut husk - SPC (1:1 by volume; S2 - soil, washed sand and powdered coconut husk - SAPC (1:1:1 by volume and S3 - Biomix (r commercial substrate - SC. The medium without MS salts promoted 100% in vitro germination and 1/2 MS medium greater development of seedlings. All substrates studied are suitable for acclimatization of seedlings germinated in vitro. Myrciaria tenella of yellow type showed greater vigor during acclimatization.

  15. Organic matter loading affects lodgepole pine seedling growth.

    Science.gov (United States)

    Wei, Xiaohua; Li, Qinglin; Waterhouse, M J; Armleder, H M

    2012-06-01

    Organic matter plays important roles in returning nutrients to the soil, maintaining forest productivity and creating habitats in forest ecosystems. Forest biomass is in increasing demand for energy production, and organic matter has been considered as a potential supply. Thus, an important management question is how much organic matter should be retained after forest harvesting to maintain forest productivity. To address this question, an experimental trial was established in 1996 to evaluate the responses of lodgepole pine seedling growth to organic matter loading treatments. Four organic matter loading treatments were randomly assigned to each of four homogeneous pine sites: removal of all organic matter on the forest floor, organic matter loading quantity similar to whole-tree-harvesting residuals left on site, organic matter loading quantity similar to stem-only-harvesting residuals, and organic matter loading quantity more similar to what would be found in disease- or insect-killed stands. Our 10-year data showed that height and diameter had 29 and 35 % increase, respectively, comparing the treatment with the most organic matter loading to the treatment with the least organic matter loading. The positive response of seedling growth to organic matter loading may be associated with nutrients and/or microclimate change caused by organic matter, and requires further study. The dynamic response of seedling growth to organic matter loading treatments highlights the importance of long-term studies. Implications of those results on organic matter management are discussed in the context of forest productivity sustainability.

  16. Gluconeogenesis from storage wax in the cotyledons of jojoba seedlings.

    Science.gov (United States)

    Moreau, R A; Huang, A H

    1977-08-01

    The cotyledons of jojoba (Simmondsia chinensis) seeds contained 50 to 60% of their weight as intracellular wax esters. During germination there was a gradual decrease in the wax content with a concomitant rise in soluble carbohydrates, suggesting that the wax played the role of a food reserve. Thin layer chromatography revealed that both the fatty alcohol and fatty acid were metabolized. The disappearance of wax was matched with an increase of catalase, a marker enzyme of the gluconeogenic process in other fatty seedlings. Subcellular organelles were isolated by sucrose gradient centrifugation from the cotyledons at the peak stage of germination. The enzymes of the beta oxidation of fatty acid and of the glyoxylate cycle were localized in the glyoxysomes but not in the mitochondria. The glyoxysomes had specific activities of individual enzymes similar to those of the castor bean glyoxysomes. An active alkaline lipase was detected in the wax bodies at the peak stage of germination but not in the ungerminated seeds. No lipase was detected in glyoxysomes or mitochondria. After the wax in the wax bodies had been extracted with diethyl ether, the organelle membrane was isolated and it still retained the alkaline lipase. The gluconeogenesis from wax in the jojoba seedling appears to be similar, but with modification, to that from triglyceride in other fatty seedlings.

  17. Biostimulant on faveiro (Dimorphandra mollis Benth. seeds and seedling vigor

    Directory of Open Access Journals (Sweden)

    Tathiana Elisa Masetto

    2012-06-01

    Full Text Available This work aimed to verify the effects of biostimulant doses, applied through seeds, on faveiro (Dimorphandra mollis Benth. seeds and seedlings vigor. Seeds were previously sulfuric acid scarified in two consecutive years experiments. On 2006 August (first experiment seeds were submitted on Stimulate®: 0; 3.5; 7.0; 10.5 and 14 mL.0.5 Kg-1 doses (first experiment; and seeds picked in August, 2007, were Stimulate:0; 15; 20 and 25 mL.0.5Kg-1 of seeds treated (second experiment. After the biostimulant treatment seeds were sowed in cells trays containing 1:1 (v:v distroferric red latosol + plantmax®. The effect of different Stimulate® doses on Dimorphandra mollis seeds collected in different years were evaluated on the emergency percentage, speed emergency index, root length, aerial part height and dry seedling weight. It was conducted on entirely casualized with four repetitions of 25 seeds each treatment. The 14 mL (2006 lot and 15 mL (2007 lot 0.5Kg-1 of seeds doses provided larger percentage (50% and 66%, respectively and speed emergency indexes (0.67 and 0.9 respectively. The 20 mL.0.5Kg-1 of seeds dose treatment favored the aerial part length, but it didn't influenced the other Dimorphandra mollis seedlings vigor indexes.

  18. Seedling Performance Associated with Live or Herbicide Treated Tall Fescue

    Directory of Open Access Journals (Sweden)

    Jonathan J. Halvorson

    2015-01-01

    Full Text Available Tall fescue is an important forage grass which can host systemic fungal endophytes. The association of host grass and endophyte is known to influence herbivore behavior and host plant competition for resources. Establishing legumes into existing tall fescue sods is a desirable means to acquire nitrogen and enhance the nutritive value of forage for livestock production. Competition from existing tall fescue typically must be controlled to ensure interseeding success. We used a soil-on-agar method to determine if soil from intact, living (L, or an herbicide killed (K tall fescue sward influenced germination and seedling growth of three cultivars of tall fescue (E+, MaxQ, and E− or legumes (alfalfa, red clover, and white clover. After 30 days, seedlings were larger and present in greater numbers when grown in L soil rather than K soil. Root growth of legumes (especially white clover and tall fescue (especially MaxQ were not as vigorous in K soil as L soil. While shoot biomass was similar for all cultivars of tall fescue in L soil, MaxQ produced less herbage when grown in K soil. Our data suggest establishing legumes or fescue cultivars may not be improved by first killing the existing fescue sod and seedling performance can exhibit significant interseasonal variation, related only to soil conditions.

  19. 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.

  20. Fungi of the genus Fusarium as pathogens of soybean seedlings

    Directory of Open Access Journals (Sweden)

    Joanna Marcinkowska

    2013-12-01

    Full Text Available Twenty isolates of fungi of the genus Fusarium collected in the period 1980-1982 from various organs of diseased soybean plants were investigated. Eight of them proved pathogenic to soybean seedlings. The species F. culmorum was most numerously represented among the isolated (4 of 8 pathogens. Isolates of F. sambucinum were also pathogenic (2 of 4 and those of F. soloni (1 of 3, too. The only isolate of F. avenaceum also caused seedling blight. Two isolates of F. oxysporum and two of F. arthrosporioides were not pathogenic. Numerous isolates affected seed gernination and one greatly inhibited growth of the infected seedlings. Pathogenicity was tested in the laboratory in Petri plates on isolate cultures and on filter paper imbibed with fungal inoculum and, in the greenhouse on a peat and perlite substrate. The degree of infection and the character of the disease symptoms depended on the experimental conditions. The results of experiments in plates and in the greenhouse supplemented one another.

  1. Rapid shallow breathing

    Science.gov (United States)

    Tachypnea; Breathing - rapid and shallow; Fast shallow breathing; Respiratory rate - rapid and shallow ... Shallow, rapid breathing has many possible medical causes, including: Asthma Blood clot in an artery in the ...

  2. Effect of Simulated Tillage in Combination with Post-Shattering Temperature Conditions on Senna obtusifolia and Xanthium strumarium Seed Survival, Seedling Emergence and Seedbank Potential

    Directory of Open Access Journals (Sweden)

    Taghi Bararpour

    2018-04-01

    Full Text Available Two of the most troublesome weeds in soybean, cotton, and corn in cropping systems of mid-south United States (US are Senna obtusifolia and Xanthium strumarium. Understanding their population dynamics, particularly weed seedling emergence patterns, is important for the timely implementation and the success of weed management strategies. Identifying the sources of variation of emergence patterns could greatly improve our ability to predict emergence timing. A three-years field study was conducted to determine the effect of environmental conditions on S. obtusifolia and X. strumarium seedling emergence and seedbank potential. The experiment was conducted with two seed sources; X. strumarium burs and S. obtusifolia seeds from a single maternal plant source, and X. strumarium burs and S. obtusifolia seeds from multiple maternal plant sources, both being exposed either to 5 cm burial depth (buried or left on the soil surface (soil surface in the fallow or planted in spring after their storage under chilled (chill or room temperature (no chill conditions. X. strumarium and S. obtusifolia seedling emergence was lower from burs and seeds that were planted in the soil in September as compared with the chill and/or no chill seeds/burs stored for six months. X. strumarium seedling emergence was reduced from 37 to 1% when burs were left on the soil surface when compared to buried burs. S. obtusifolia seedling emergence was reduced from 47 to 13% when seeds were left on the soil surface as compared to buried. At the end of the experimental period, the soil seedbank of X. strumarium had been significantly depleted, whereas the remaining seeds of S. obtusifolia were viable.

  3. Why Seedlings Die: Linking Carbon and Water Limitations to Mechanisms of Mortality During Establishment in Conifer Seedlings

    Science.gov (United States)

    Reinhardt, K.; Germino, M. J.; Kueppers, L. M.; Mitton, J.; Castanha, C.

    2012-12-01

    BACKGROUND Recent ecophysiological studies aimed at explaining adult tree mortality during drought have examined the carbon (C)-exhaustion compared to the hydraulic-failure hypotheses for death. Prolonged drought leads to durations of stomatal closure (and thus limited C gain), which could result in long periods of negative C balance and fatal reductions in whole-plant C reserves (i.e., available non-structural carbohydrates ["NSC"]). Alternatively, C reserves may not decrease much but could become increasingly inaccessible to sink tissues in long dry-periods due to impediments to translocation of photosynthate (e.g., through disruption of hydrostatic pressure flow in phloem). As C reserves decline or become inaccessible, continued maintenance respiration has been hypothesized to lead to exhaustion of NSC after extended durations of drought, especially in isohydric plant species. On the other hand, hydraulic failure (e.g., catastrophic xylem embolisms) during drought may be the proximate cause of death, occurring before true C starvation occurs. Few studies have investigated specifically the mechanism(s) of tree death, and no published studies that we know of have quantified changes in NSC during mortality. EXPERIMENTAL DESIGN AND HYPOTHESES We conducted two studies that investigated whole-tree and tissue-specific C relations (photosynthetic C gain, respiration, dry-mass gain, and NSC pools) in Pinus flexilis seedlings during the initial establishment phase, which is characterized by progressive drought during summer. We measured survival, growth and biomass allocation, and C-balance physiology (photosynthetic C-gain and chlorophyll fluorescence, respiration C-use, and NSC concentrations) from germination to mortality. We hypothesized that 1) stomatal and biochemical limitations to C gain would constrain seedling survival (through inadequate seasonal C-balance), as has been shown for conifer seedlings near alpine treeline; 2) hydraulic constraints (embolisms and

  4. Increased stability of thylakoid components in Vigna sinensis seedlings grown under ultraviolet-B enhanced radiation

    International Nuclear Information System (INIS)

    Nedunchezhian, N.; Kulandaivelu, G.

    1994-01-01

    Chloroplasts isolated from Vigna sinensis L. seedlings grown under cool fluorescent (control chloroplasts) and ultraviolet-B (UV-B)-enhanced fluorescent (UV chloroplasts) radiation, when incubated at 10, 20, 30 and 40-degrees-C, showed large variations in the photosynthetic electron transport reactions. The overall electron transport activity in both control and UV chloroplasts incubated at 40-degrees-C decreased rapidly. In contrast to this, at 30-degrees-C the control chloroplasts got inactivated very rapidly during the 30 min of incubation while the UV chloroplasts showed high stability. A similar trend was also noticed at 20-degrees-C. At 10-degrees-C, although the rate of inactivation was slow, UV chloroplasts were more stable than control chloroplasts. A similar trend was noticed in photosystem (PS) 2 activity. In contrast to overall electron transport and PS2 reactions, PS1 activity showedonly marginal changes at all temperatures. The polypeptide profiles of chloroplasts exposed to UV-B irradiation for 60 min at different temperatures revealed marked decreases in the level of the 23 and 33 kDa polypeptides in control chloroplasts while in UV chloroplasts these polypeptides were highly stable. In addition, UV chloroplasts contained several new polypeptides of both high and low molecular masses. The polypeptide pattern indicated that higher photochemical activity of UV chloroplasts over the control chloroplasts could be due to stabilization of PS2 core complexes by the new polypeptides induced under UV-B enhanced radiation

  5. Root graviresponsiveness and columella cell structure in carotenoid-deficient seedlings of Zea mays

    Science.gov (United States)

    Moore, R.; McClelen, C. E.

    1985-01-01

    Root graviresponsiveness in normal and carotenoid-deficient mutant seedlings of Zea mays was not significantly different. Columella cells in roots of mutant seedlings were characterized by fewer, smaller, and a reduced relative volume of plastids as compared to columella cells of normal seedlings. Plastids in columella cells of mutant seedlings possessed reduced amounts of starch. Although approximately 10 per cent of the columella cells in mutant seedlings lacked starch, their plastids were located at the bottom of the cell. These results suggest that (i) carotenoids are not necessary for root gravitropism, (ii) graviresponsiveness is not necessarily proportional to the size, number, or relative volume of plastids in columella cells, and (iii) sedimentation of plastids in columella cells may not result directly from their increased density due to starch content. Plastids in columella cells of normal and mutant seedlings were associated with bands of microtubule-like structures, suggesting that these structures may be involved in 'positioning' plastids in the cell.

  6. Survival of planted tupelo seedlings in F- and H-Area tree-kill zones

    International Nuclear Information System (INIS)

    Nelson, E.A.; Rogers, V.A.

    1995-01-01

    Swamp tupelo seedlings were planted in four areas which experienced previous tree mortality at the seeplines of the F- and H-Area Seepage Basins. The sites represented a range in severity of impact and stage of recovery. Seedlings were planted in February of 1994 and followed through the first growing season in the field. Survival on all sites through the first growing season was excellent, with greater than 92% of the seedlings still alive. Most seedlings appeared healthy with few external signs of stress. The performance of the seedlings will be followed in subsequent years to determine the physical state of the soil environment on seedling growth. Hopefully, the results will indicate that artificial reforestation can begin on similarly impacted sites prior to the beginning of natural revegetation of the site

  7. DETERMINATION OF THE SEEDLINGS QUALITY CLASSES OF BLACK LOCUST (Robinia pseudoacacia L. ORIGINS

    Directory of Open Access Journals (Sweden)

    İbrahim Turna

    2000-04-01

    Full Text Available classification criteria is the assesment of height and root-colar diameter together. newly seedling quality classification (YS have highly first grade seedlings. The most important According to the results of this study, all the origins determined with respect to either TSE or determined by using factor analysis. Furthermore the morphological characteristics that affect the seedling quality classification were diameter. The resulting seedling quality classification were controlled by using discriminant analysis. determined according to height, root-colar diameter and combination of both height and root-colar provenances were soved in KTÜ Nursery. One year later, these seedlings were lifted. Quality norms in KTÜ Nursery were used. Eighteen different origin seeds of Black locust of which eleven are egzotic In this present study, 1+0 Black Locust ( Robinia pseudoacacia L. seedlings grown

  8. Growth of transplanted seedlings of timber species in the southern Colombian Amazon: a preliminary study

    International Nuclear Information System (INIS)

    Gruezmacher Monica; Duivenvoorden Joost F

    2008-01-01

    Two commonly used timber species in the area of Amacayacu National Park (Quararibea sp. and Minquartia guianensis) were selected to develop an experiment that compared the early performance of seedlings in mature and old secondary forest. We transplanted seedlings of these species into mature and secondary forest plots and observed height and diameter increments as well as mortality for a period of approximately 70 days. In situ seedling performance under parent trees in mature forests was measured as a control. The structure of both experimental forests was not apparently different.We found similar seedling performance for both species in the two forests. However, the seedlings hardly showed any relative height or relative diameter increment in the short period of measurements. The results show that enriching secondary forests by means of transplanting seedlings from timber species might be a promising way of ecological restoration.

  9. Tree fern trunks facilitate seedling regeneration in a productive lowland temperate rain forest.

    Science.gov (United States)

    Gaxiola, Aurora; Burrows, Larry E; Coomes, David A

    2008-03-01

    Seedling regeneration on forest floors is often impaired by competition with established plants. In some lowland temperate rain forests, tree fern trunks provide safe sites on which tree species establish, and grow large enough to take root in the ground and persist. Here we explore the competitive and facilitative effects of two tree fern species, Cyathea smithii and Dicksonia squarrosa, on the epiphytic regeneration of tree species in nutrient-rich alluvial forests in New Zealand. The difficulties that seedlings have in establishing on vertical tree fern trunks were indicated by the following observations. First, seedling abundance was greatest on the oldest sections of tree fern trunks, near the base, suggesting that trunks gradually recruited more and more seedlings over time, but many sections of trunk were devoid of seedlings, indicating the difficulty of establishment on a vertical surface. Second, most seedlings were from small-seeded species, presumably because smaller seeds can easily lodge on tree fern trunks. Deer browsing damage was observed on 73% of epiphytic seedlings growing within 2 m of the ground, whereas few seedlings above that height were browsed. This suggests that tree ferns provide refugia from introduced deer, and may slow the decline in population size of deer-preferred species. We reasoned that tree ferns would compete with epiphytic seedlings for light, because below the tree fern canopy photosynthetically active radiation (PAR) was about 1% of above-canopy PAR. Frond removal almost tripled %PAR on the forest floor, leading to a significant increase in the height growth rate (HGR) of seedlings planted on the forest floor, but having no effects on the HGRs of epiphytic seedlings. Our study shows evidence of direct facilitative interactions by tree ferns during seedling establishment in plant communities associated with nutrient-rich soils.

  10. Drought resistance of Pinus sylvestris seedlings conferred by plastic root architecture rather than ectomycorrhizal colonisation

    OpenAIRE

    Moser , Barbara; Kipfer , Tabea; Richter , Sarah; Egli , Simon; Wohlgemuth , Thomas

    2015-01-01

    International audience; Abstract ContextIncreased summer drought is considered as a threat to the regeneration of Pinus sylvestris in the Central Alps. To a certain degree, seedlings are able to mitigate negative effects of drought by altering root/shoot ratios. But, seedlings may also enhance access to water and nutrients by cooperation with ectomycorrhizal fungi. AimsWe tested the importance of both mechanisms for drought resistance of P. sylvestris seedlings during early establishment and ...

  11. Research and Development of Statistical Analysis Software System of Maize Seedling Experiment

    OpenAIRE

    Hui Cao

    2014-01-01

    In this study, software engineer measures were used to develop a set of software system for maize seedling experiments statistics and analysis works. During development works, B/S structure software design method was used and a set of statistics indicators for maize seedling evaluation were established. The experiments results indicated that this set of software system could finish quality statistics and analysis for maize seedling very well. The development of this software system explored a...

  12. Quality assessment of truffle-inoculated seedlings in Italy: proposing revised parameters for certification

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    Domizia Donnini

    2014-08-01

    Full Text Available Aim of study: the main aims of this study were to evaluate the quality of truffle-inoculated seedlings produced by commercial nurseries in Italy and to identify their minimum requisites in terms of plant age, health, homogeneity, and cut-off percentage of inoculated Tuber and non-Tuber ectomycorrhizae, based on the analysis of an extensive sample of seedlings subjected to quality control and certification.Area of study: truffle-inoculated seedlings produced by Italian commercial nurseries.Material and Methods: analysis of truffle-inoculated seedlings for health and quality standards; recording of presence of inoculated Tuber spp. and other concurrent fungi according to the official Italian method for certification; selective amplification of ectomycorrhizal DNA by PCR species-specific primers.Main results: We showed that mycorrhization levels in truffle-inoculated seedlings increased with time after truffle-spore inoculation. The highest mean percentage of the inoculated Tuber spp., but also the highest presence of contaminants, were recorded after three years. The mycorrhization level of Tuber melanosporum and T. aestivum was higher in Corylus and Ostrya seedlings than in Q. ilex and Q. pubescens, but the latter two host species showed the lowest presence of other ectomycorrhizal fungi. Mycorrhization level distribution in truffle-inoculated seedlings of suitable batches differed very little from the distribution in only all suitable seedlings. Truffle seedlings with other Tuber spp. were very few and even absent after three years. The general quality of Italian truffle-inoculated seedlings is high but can be improved even further by revising the parameters used for their certification.Research highlights: Mycorrhization assessment in truffle-inoculated seedlings produced by commercial nurseries and a revision of the parameters of quality standards following several years of certification in Italy.Keywords: Truffle cultivation; truffle

  13. Growth Responses of Acacia mangium and Paraserianthes falcataria Seedlings on Different Soil Origin under Nursery Condition

    Directory of Open Access Journals (Sweden)

    Tirtha Ayu Paramitha

    2015-12-01

    Full Text Available The objective of the present study was to examine the growth responses of Acacia mangium (mangium and Paraserianthes falcataria (sengon seedlings growing on different soil origin under nursery condition. This study was started in September 2012 and terminated in March 2013.  The seedlings were grown from seeds sown in a plastic box filled with sterilized sands. One week after sowing, the seedlings were transplanted into polybags contained sterilized soils originated from secondary forest, Imperata cylindrica grassland and ex-coal mining. The number of all seedlings were 180 seedlings consisted of 3 different soils, 2 species of seedlings with 10 seedlings replicated 3 times. Assessment was conducted one week after transplanting, then subsequently monitored every 2 weeks, except dry weighing and counting nodules were performed at the end of the study. A completely randomized design was used in this study. The data was analyzed using Costat software. The study resulted that the different of soil origin influenced on all growth variables of mangium and sengon of 4.5 months old. The survival rate of seedlings, height and diameter increments, dry weight and root nodules were better in both species of seedlings growing on soil originated from secondary forest and Imperata grassland compared with the soil from ex-coal mining. But the survival rates of sengon seedlings were higher than that of mangium on these three soils. The highest dry weight of sengon seedlings was achieved on soil originated from secondary forest. In the present study, soil originated from secondary forest increased more in weight of shoot than root, so that the shoot-root ratio was unbalanced more than one. Based on the results of this study, it is recommended that soil from secondary forest and Imperata grassland can be used as growing media for mangium and sengon seedlings in the nursery.

  14. Seedling Composition and Facilitative Effects of the Herbaceous Layer in a Monsoon-Affected Forest in Nanjenshan, Southern Taiwan

    Directory of Open Access Journals (Sweden)

    Su-Wei Fan

    2010-11-01

    Full Text Available Tree seedlings play an important role in forest regeneration. To understand the factors that control seedling establishment, we (1 compared the composition patterns of tree seedlings and their corresponding overstories, (2 examined the relationships between seedling composition and environmental factors and (3 evaluated the interaction (competition or facilitation between seedlings and herbaceous layer in a wind-stressed forest in Nanjenshan, southern Taiwan. In the study plot, seedling abundance of canopy, subcanopy and shrub species (with true leaves and < 1 cm diameter at breast height and coverage of herbaceous species (including herbaceous species, climbers and tree ferns ≤ ca. 1 m in height were investigated on three transects with a total of 180 contiguous 5 × 5 m quadrats. Clustering classification and ordination methods were used to reveal the tree seedling composition patterns and the relationships between seedling composition and environmental factors. Correlation coefficients were computed between herbaceous coverage and seedling abundance among herb-seedling species pairs and between tall (≥ 1 m high/short (< 0.5 m high herbs and seedlings pairs to test the herb-seedling interaction. The spatial distribution of tree seedlings presented a perfect match to the overstory vegetation pattern. There was a strong relationship among seedling composition, herbaceous composition and topographic features, especially exposure to monsoon winds. Because of the absence of strong correlations between herbaceous structure/species and seedling abundances, the strong linkage in spatial patterns between seedling and herbaceous compositions suggests that certain plant species in the study plot have similar responses to the monsoon exposure. Our results also indicated that seedlings < 1 cm in diameter were strongly influenced by wind stress, similar to the response of the overstory composition, and that the facilitative/competitive effects of the

  15. Implementation of 350-2500 nm diffuse reflectance spectroscopy and High-Performance Thin-Layer Chromatography to rapidly assess manufacturing consistency and quality of cotrimoxazole tablets in Tanzania.

    Science.gov (United States)

    Kaale, Eliangiringa; Hope, Samuel M; Jenkins, David; Layloff, Thomas

    2016-01-01

    To assess the quality of cotrimoxazole tablets produced by a Tanzanian manufacturer by a newly instituted quality assurance programme. Tablets underwent a diffuse reflectance spectroscopy procedure with periodic quality assessment confirmation by assay and dissolution testing using validated HPTLC techniques (including weight variation and disintegration evaluations). Based on results from the primary test methods, the first group of product was 99% compliance. This approach provides a model for rapidly assuring product quality of future procurements of other products that is more cost-effective than traditional pharmaceutical testing techniques. © 2015 John Wiley & Sons Ltd.

  16. Preparation, characterization of silver phyto nanoparticles and their impact on growth potential of Lupinus termis L. seedlings

    Directory of Open Access Journals (Sweden)

    Asma A. Al-Huqail

    2018-02-01

    Full Text Available The current study reports rapid and easy method for synthesis of eco-friendly silver nanoparticles (AgNPs using Coriandrum sativum leaves extract as a reducing and covering agent. The bio-reductive synthesis of AgNPs was monitored using a scanning double beam UV-vis spectrophotometer. Transmission electron microscopy (TEM was used to characterize the morphology of AgNPs obtained from plant extracts. X-ray diffraction (XRD patterns of AgNPs indicate that the structure of AgNPs is the face centered cubic structure of metallic silver. The surface morphology and topography of the AgNPs were examined by scanning electron microscopy and the energy dispersive spectrum revealed the presence of elemental silver in the sample. The silver phyto nanoparticles were collected from plant extract and tested growth potential and metabolic pattern in (Lupinus termis L. seedlings upon exposure to different concentrations of AgNPs. The seedlings were exposed to various concentrations of (0, 0.1, 0.3 and 0.5 mg L−1 AgNPs for ten days. Significant reduction in shoot and root elongation, shoot and root fresh weights, total chlorophyll and total protein contents were observed under the higher concentrations of AgNPs. Exposure to 0.5 mg L−1 of AgNPs decreased sugar contents and caused significant foliar proline accumulation which considered as an indicator of the stressful effect of AgNPs on seedlings. AgNPs exposure resulted in a dose dependent decrease in different growth parameters and also caused metabolic disorders as evidenced by decreased carbohydrates and protein contents. Further studies needed to find out the efficacy, longevity and toxicity of AgNPs toward photosynthetic system and antioxidant parameters to improve the current investigation.

  17. Density dependent interactions between VA mycorrhizal fungi and even-aged seedlings of two perennial Fabaceae species.

    Science.gov (United States)

    Allsopp, N; Stock, W D

    1992-08-01

    The interaction of density and mycorrhizal effects on the growth, mineral nutrition and size distribution of seedlings of two perennial members of the Fabaceae was investigated in pot culture. Seedlings of Otholobium hirtum and Aspalathus linearis were grown at densities of 1, 4, 8 and 16 plants per 13-cm pot with or without vesicular-arbuscular (VA) mycorrhizal inoculum for 120 days. Plant mass, relative growth rates, height and leaf number all decreased with increasing plant density. This was ascribed to the decreasing availability of phosphorus per plant as density increased. O. hirtum was highly dependent on mycorrhizas for P uptake but both mycorrhizal and non-mycorrhizal A. linearis seedlings were able to extract soil P with equal ease. Plant size distribution as measured by the coefficient of variation (CV) of shoot mass was greater at higher densities. CVs of mycorrhizal O. hirtum plants were higher than those of non-mycorrhizal plants. CVs of the facultatively mycorrhizal A. linearis were similar for both mycorrhizal and non-mycorrhizal plants. Higher CVs are attributed to resource preemption by larger individuals. Individuals in populations with high CVs will probably survive stress which would result in the extinction of populations with low CVs. Mass of mycorrhizal plants of both species decreased more rapidly with increasing density than did non-mycorrhizal plant mass. It is concluded that the cost of being mycorrhizal increases as plant density increases, while the benefit decreases. The results suggest that mycorrhizas will influence density-dependent population processes of faculative and obligate mycorrhizal species.

  18. Synthesis of ectomycorrhizae on northern red oak seedlings in a Michigan nursery

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, R.K.; Johnson, P.S.

    1993-01-01

    Vegetative inoculum of the ectomycorrhizal fungus Suillus luteus was thoroughly mixed into fumigated nursery soil, and northern red oak seedlings of four families were evaluated one and two years after sowing for ectomycorrhizal development, growth, and nutrition. At the end of year one, treated seedlings were successfully inoculated with S. luteus, but the percentage varied significantly with family. Suillus luteus persisted on lateral roots two years following sowing. Two of four seedling families inoculated with S. luteus were significantly larger in size than control plants. These results suggest that the fungal symbiont S. luteus can be successfully introduced into nurseries and that early ectomycorrhizal development improves the growth of northern red oak seedlings.

  19. Temperature, precipitation and biotic interactions as determinants of tree seedling recruitment across the tree line ecotone.

    Science.gov (United States)

    Tingstad, Lise; Olsen, Siri Lie; Klanderud, Kari; Vandvik, Vigdis; Ohlson, Mikael

    2015-10-01

    Seedling recruitment is a critical life history stage for trees, and successful recruitment is tightly linked to both abiotic factors and biotic interactions. In order to better understand how tree species' distributions may change in response to anticipated climate change, more knowledge of the effects of complex climate and biotic interactions is needed. We conducted a seed-sowing experiment to investigate how temperature, precipitation and biotic interactions impact recruitment of Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) seedlings in southern Norway. Seeds were sown into intact vegetation and experimentally created gaps. To study the combined effects of temperature and precipitation, the experiment was replicated across 12 sites, spanning a natural climate gradient from boreal to alpine and from sub-continental to oceanic. Seedling emergence and survival were assessed 12 and 16 months after sowing, respectively, and above-ground biomass and height were determined at the end of the experiment. Interestingly, very few seedlings were detected in the boreal sites, and the highest number of seedlings emerged and established in the alpine sites, indicating that low temperature did not limit seedling recruitment. Site precipitation had an overall positive effect on seedling recruitment, especially at intermediate precipitation levels. Seedling emergence, establishment and biomass were higher in gap plots compared to intact vegetation at all temperature levels. These results suggest that biotic interactions in the form of competition may be more important than temperature as a limiting factor for tree seedling recruitment in the sub- and low-alpine zone of southern Norway.

  20. Effects of Different Ectomycorrhizal Fungal Inoculates on the Growth of Pinus tabulaeformis Seedlings under Greenhouse Conditions

    Directory of Open Access Journals (Sweden)

    Nan Lu

    2016-12-01

    Full Text Available The tree species Pinus tabulaeformis Carr. (P. tabulaeformis is commonly planted in China due to its economic and ecological value. In order to identify one or more ectomycorrhizal (ECM fungal species for future P. tabulaeformis afforestation, we investigated the effects of five ECM fungal species: Laccaria laccata, Boletus edulis, Gomphidius viscidus, Suillus grevillei, and Suillus luteus on the growth of P. tabulaeformis seedlings under greenhouse conditions. The growth parameters of P. tabulaeformis seedlings were evaluated 90 days following fungal colonisation. The majority of seedlings were significantly affected by ECM inoculation. Mycorrhizal inoculated seedlings were taller, had more lateral roots, and a greater biomass compared with the non-mycorrhizal (CK seedlings. With the exception of G. viscidus, inoculated seedlings exhibited higher phosphorus, potassium, and nitrogen content compared with the CK seedlings. In addition, ECM colonisation increased the enzymatic activity of catalase, acidic phosphatase, protease, and the urease content in the rhizosphere soil. Our study showed that Laccaria laccata, Suillus grevillei, and Suillus luteus may be useful for improving the growth and cultivation of P. tabulaeformis seedlings. Furthermore, we observed that S. luteus inoculation increased the gas exchange parameters of P. tabulaeformis seedlings under field conditions.

  1. SOURCES OF MYCORRHIZAL INFECTION OF SHOREA ACUMINATA SEEDLINGS UNDER LABORATORY CONDITIONS

    Directory of Open Access Journals (Sweden)

    LEE Su SEE

    1995-01-01

    Full Text Available Uninoculated dipterocarp seedlings raised in normal field soil in nurseries were always found to have mycorrhizas after a few months. This study set out to determine whether dipterocarp seedlings could continue to grow and develop in the absence of mycorrhizas and also to determine possible sources of mycorrhizal infection of dipterocarp seedlings raised under laboratory conditions using Shorea acuminata as a typical example. Seedlings were planted in capped or uncapped perspex boxes containing sterile or non-sterile field soil and watered daily with sterile water or tap water. Seedling growth and development of mycorrhizas were monitored at monthly intervals for up to seven months. Seedlings grown in sterile soil remained uninfected after seven months while infection was found in some of the seedlings grown in normal soil regardless of whether they had been watered with tap water or sterile water. This showed that field soil (i.e. under grass far from the forest contained suitable inoculum for forest tree seedlings. Tap water and the air were not important sources of infection. However, mycorrhizal infection was very uneven indicating that the inoculum was probably very unevenly distributed in the soil or that the inoculum density was rather low. Seedlings grown in sterile soil showed better growth than those grown in normal soil and infection of roots by parasitic fungi in the latter was also observed.

  2. Arbuscular Mycorrhizal Symbiosis Modulates Antioxidant Response and Ion Distribution in Salt-Stressed Elaeagnus angustifolia Seedlings

    Directory of Open Access Journals (Sweden)

    Wei Chang

    2018-04-01

    Full Text Available Elaeagnus angustifolia L. is a drought-resistant species. Arbuscular mycorrhizal symbiosis is considered to be a bio-ameliorator of saline soils that can improve salinity tolerance in plants. The present study investigated the effects of inoculation with the arbuscular mycorrhizal fungus Rhizophagus irregularis on the biomass, antioxidant enzyme activities, and root, stem, and leaf ion accumulation of E. angustifolia seedlings grown during salt stress conditions. Salt-stressed mycorrhizal seedlings produced greater root, stem, and leaf biomass than the uninoculated stressed seedlings. In addition, the seedlings colonized by R. irregularis showed notably higher activities of superoxide dismutase (SOD, catalase (CAT, and ascorbate peroxidase (APX in the leaves of the mycorrhizal seedlings in response to salinity compared to those of the non-mycorrhizal seedlings. Mycorrhizal seedlings not only significantly increased their ability to acquire K+, Ca2+, and Mg2+, but also maintained higher K+:Na+ ratios in the leaves and lower Ca2+:Mg2+ ratios than non-mycorrhizal seedlings during salt stress. These results suggest that the salt tolerance of E. angustifolia seedlings could be enhanced by R. irregularis. The arbuscular mycorrhizal symbiosis could be a promising method to restore and utilize salt-alkaline land in northern China.

  3. Arbuscular Mycorrhizal Symbiosis Modulates Antioxidant Response and Ion Distribution in Salt-Stressed Elaeagnus angustifolia Seedlings.

    Science.gov (United States)

    Chang, Wei; Sui, Xin; Fan, Xiao-Xu; Jia, Ting-Ting; Song, Fu-Qiang

    2018-01-01

    Elaeagnus angustifolia L. is a drought-resistant species. Arbuscular mycorrhizal symbiosis is considered to be a bio-ameliorator of saline soils that can improve salinity tolerance in plants. The present study investigated the effects of inoculation with the arbuscular mycorrhizal fungus Rhizophagus irregularis on the biomass, antioxidant enzyme activities, and root, stem, and leaf ion accumulation of E. angustifolia seedlings grown during salt stress conditions. Salt-stressed mycorrhizal seedlings produced greater root, stem, and leaf biomass than the uninoculated stressed seedlings. In addition, the seedlings colonized by R. irregularis showed notably higher activities of superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX) in the leaves of the mycorrhizal seedlings in response to salinity compared to those of the non-mycorrhizal seedlings. Mycorrhizal seedlings not only significantly increased their ability to acquire K + , Ca 2+ , and Mg 2+ , but also maintained higher K + :Na + ratios in the leaves and lower Ca 2+ :Mg 2+ ratios than non-mycorrhizal seedlings during salt stress. These results suggest that the salt tolerance of E. angustifolia seedlings could be enhanced by R. irregularis. The arbuscular mycorrhizal symbiosis could be a promising method to restore and utilize salt-alkaline land in northern China.

  4. Fifth workshop on seedling physiology and growth problems in oak plantings (abstracts).

    Science.gov (United States)

    Janette R. Thompson; Richard C. Schultz; J.W. Van Sambeek

    1993-01-01

    Research results and ongoing research activities in field performance of planted trees, seedling propagation, physiology, genetics, acorn germination, and natural regeneration for oaks are described in 30 abstracts.

  5. Ninth workshop on seedling physiology and growth problems in oak plantings (abstracts)

    Science.gov (United States)

    D.R. Weigel; J.W. Van Sambeek; C.H., eds. Michler

    2005-01-01

    Research results and ongoing research activities in field performance of oak plantings, seedling propagation, genetics, acorn germination, and natural regeneration of oaks are described in 26 abstracts.

  6. Tenth workshop on seedling physiology and growth problems in oak plantings

    Science.gov (United States)

    Brian Roy Lockhart; Emile S. Gardiner; Daniel C. Dey

    2008-01-01

    Research results and ongoing research activities in field performance of oak plantings, seedling propagation, genetics, acorn germination, and natural regeneration of oaks are described in 15 abstracts.

  7. Common arbuscular mycorrhizal networks amplify competition for phosphorus between seedlings and established plants.

    Science.gov (United States)

    Merrild, Marie P; Ambus, Per; Rosendahl, Søren; Jakobsen, Iver

    2013-10-01

    Common mycorrhizal networks (CMNs) influence competition between plants, but reports regarding their precise effect are conflicting. We studied CMN effects on phosphorus (P) uptake and growth of seedlings as influenced by various disruptions of network components. Tomato (Solanum lycopersicon) seedlings grew into established networks of Rhizophagus irregularis and cucumber (Cucumis sativus) in two experiments. One experiment studied seedling uptake of (32)P in the network in response to cutting of cucumber shoots; the other analysed seedling uptake of P and nitrogen (N) in the presence of intact or severed arbuscular mycorrhizal fungus networks and at two soil P concentrations. Pre-established and intact networks suppressed growth of tomato seedlings. Cutting of cucumber shoots mitigated P deficiency symptoms of seedlings, which obtained access to P in the extraradical mycelium and thereby showed improved growth. Solitary seedlings growing in a network patch that had been severed from the CMN also grew much better than seedlings of the corresponding CMN. Interspecific and size-asymmetric competition between plants may be amplified rather than relaxed by CMNs that transfer P to large plants providing most carbon and render small plants P deficient. It is likely that grazing or senescence of the large plants will alleviate the network-induced suppression of seedling growth. © 2013 The Authors. New Phytologist © 2013 New Phytologist Trust.

  8. [Effects of sowing depth on seedling traits and root characteristics of summer maize].

    Science.gov (United States)

    Cao, Hui-ying; Wang, Ding-bo; Shi, Jian-guo; Zhu, Kun-lun; Dong, Shu-ting; Liu, Peng; Zhao, Bin; Zhang, Ji-wang

    2015-08-01

    Two summer maize hybrids, Zhengdan 958 (ZD958) and Xianyu 335 (XY335), were used as experimental materials. 4 sowing depths (3, 5, 7 and 9 cm) and uneven sowing depth (CK) were designed under sand culture and field experiments to investigate the effects of sowing depth on seedling traits and root characteristics of summer maize. The results showed that the seedling emergence rate gradually decreased and seedling emergence time gradually lengthened as the sowing depth increased. Compared with the sowing depth of 3 cm, the seedling emergence rates of ZD958 and XY335 sown at the depth of 9 cm were reduced by 9.4% and 11.8%, respectively, and the seedling emergence duration was prolonged 1.5 d. With the increasing sowing depth, the seedling length and uniformity decreased significantly, the mesocotyl length increased significantly, while the coleoptile length had no significant difference; the primary radicle length gradually decreased, the total length of secondary radicle gradually increased, and the total root length had no significant difference; the total dry mass of seedling and mesocotyl increased significantly, and the total root dry mass had no significant difference. With the increasing sowing depth, the soluble sugar content in each part of seedling increased and the amount of nutritional consumption of germinating seeds increased, the seedling root growth rate increased, but the root activity decreased, and the number of total nodal root and nodal layers increased. With the increasing sowing depth, harvested ears per unit area were reduced by decreased seedling emergence rate and seedling vigor, thus influenced the yield. In addition, uniform sowing depth could improve the canopy uniformity and relative characteristics, then increase the yield.

  9. SALT-RESPONSIVE ERF1 is a negative regulator of grain filling and gibberellin-mediated seedling establishment in rice.

    Science.gov (United States)

    Schmidt, Romy; Schippers, Jos H M; Mieulet, Delphine; Watanabe, Mutsumi; Hoefgen, Rainer; Guiderdoni, Emmanuel; Mueller-Roeber, Bernd

    2014-02-01

    Grain quality is an important agricultural trait that is mainly determined by grain size and composition. Here, we characterize the role of the rice transcription factor (TF) SALT-RESPONSIVE ERF1 (SERF1) during grain development. Through genome-wide expression profiling and chromatin immunoprecipitation, we found that SERF1 directly regulates RICE PROLAMIN-BOX BINDING FACTOR (RPBF), a TF that functions as a positive regulator of grain filling. Loss of SERF1 enhances RPBF expression resulting in larger grains with increased starch content, while SERF1 overexpression represses RPBF resulting in smaller grains. Consistently, during grain filling, starch biosynthesis genes such as GRANULE-BOUND STARCH SYNTHASEI (GBSSI), STARCH SYNTHASEI (SSI), SSIIIa, and ADP-GLUCOSE PYROPHOSPHORYLASE LARGE SUBUNIT2 (AGPL2) are up-regulated in SERF1 knockout grains. Moreover, SERF1 is a direct upstream regulator of GBSSI. In addition, SERF1 negatively regulates germination by controlling RPBF expression, which mediates the gibberellic acid (GA)-induced expression of RICE AMYLASE1A (RAmy1A). Loss of SERF1 results in more rapid seedling establishment, while SERF1 overexpression has the opposite effect. Our study reveals that SERF1 represents a negative regulator of grain filling and seedling establishment by timing the expression of RPBF.

  10. Effect of heavy metal stress on the catalase activity and expression of isozymes in the leaves of rice seedling

    International Nuclear Information System (INIS)

    Ge Cailin; Yang Xiaoyong; Zhu Hongxia; Wang Zegang; Luo Shishi; Ma Fei; Sun Jinhe

    2002-01-01

    The effect of heavy metal stress on the catalase (CAT) activity and expression of isozymes in the leaves of rice (Wuyujing, Yangdao 6, Shanyou 818) seedling was measured and analyzed. The results showed as follows. (1) When the concentration of Cu, Cd and Hg was in the range of 0.05-2.0 mM, the CAT activity decreased continuously with the concentration of Cu and Cd increasing. However, with the concentration of Hg increasing the CAT activity rapidly decreased first, and then increased slightly, and again decreased obviously, indicating that the Cu, Cd and Hg of 0.05-2.0 mM inhibited the CAT activity in the leaves of rice seedling. (2) The results by using polyacrylamide concentration gradient gel electrophoresis technique to analyze the CAT isozymes indicated that, on the normal condition, there were 1 to 2 CAT isozymes being expressed in the rice leaves (2 CAT isozymes being expressed in Wuyujing leaves, 1 CAT isozymes in Yangdao 6 and Shanyou 818 leaves). 0.1 mM Cd stress induced Wuyujing leaves to express 1 new CAT isozymes, 0.1 mM Cd and Hg stress also induced Yangdao 6 leaves to express 1 new CAT isozymes, but the expression of CAT isozymes, which were expressed in normal condition, were inhibited by Cu, Cd and Hg stress

  11. Effects of gravel mulch on emergence of galleta grass seedlings

    International Nuclear Information System (INIS)

    Winkel, V.K.; Medrano, J.C.; Stanley, C.; Walo, M.D.

    1993-03-01

    The Department of Energy Nevada Operations Office, Technology Development and Program Management Division, has identified the need to clean up several sites on the Nevada Test Site and Tonopah Test Range contaminated with surface plutonium. An important objective of the project identified as the Plutonium In Soils Integrated Demonstration is to develop technologies to stabilize and restore the disturbed sites after decontamination. Revegetation of these contaminated sites will be difficult due to their location in the arid Mojave and Great Basin Deserts. The major factors which will affect successful plant establishment and growth at these sites are limited and sporadic precipitation, limited soil water, extreme air and soil temperatures, limited topsoil, and herbivory . Research has shown that providing microsites for seed via mulching can aid in plant emergence and establishment. Since many of the soils at the sites slated for plutonium decontamination have a large percentage of gravel in the upper 10 cm of soil, the use of gravel as mulch could provide microsites for seed and stabilize soils during subsequent revegetation of the sites. In July 1992, EG ampersand G/EM Environmental Sciences Department initiated a greenhouse study to examine the possible benefits of gravel mulch. The specific objectives of this greenhouse study were to: (1) determine the effects seedling emergence and soil water, and (2) determine effects of irrigation rates on seedling emergence for gravel mulches and other conventional seedbed preparation techniques. A secondary objective was to determine the depth of gravel mulch that was optimal for seedling emergence. Results from this greenhouse study will assist in formulating specific reclamation plans for sites chosen for cleanup

  12. Antioxidant properties of soybean seedlings inoculated with Trichoderma asperellum

    Directory of Open Access Journals (Sweden)

    Manojlović Ana S.

    2017-01-01

    Full Text Available This study was conducted in order to assess the effect of inoculation of soybean (Glycine max L. seeds with Trichoderma asperellum, followed by mites (Tetranychus urticae exposure on lipid peroxidation (LP process and the activity of antioxidant enzymes. T. urticae is an occasional pest of soybean that causes biotic stress. Biotic stress leads to overproduction of reactive oxygen species (ROS which may cause damage to vital biomolecules. Enzymatic antioxidant defense systems protect plants against oxidative stress. T. asperellum is commonly used as biocontrol agent against plant pathogens. It has been suggested that previous inoculation of seeds with T. asperellum may cause induced resistance against biotic stress. The aim of this study was to determine LP intensity and antioxidant enzymes activity in inoculated and non-inoculated soybean seedlings with and without exposure to mites. Noticeably higher LP intensity was detected in non-inoculated group treated with mites compared to control group. Inoculated soybean seedlings treated with mites had lower LP intensity compared to noninoculated group. Also, it has been noticed that inoculation with Trichoderma asperellum itself, produced mild stress in plants. In addition, positive correlation between enzymes activity and LP was noticed. The level of oxidative stress in plants was followed by the change of LP intensity. According to results obtained, it was concluded that the greatest oxidative stress occurred in non-inoculated group treated with mites and that inoculation successfully reduced oxidative stress. The results indicate that inoculation of soybean seeds with T. asperellum improves resistance of soybean seedlings against mites attack. [Project of the Serbian Ministry of Education, Science and Technological Development, Grant no. TR-31022

  13. Drought-Induced Leaf Proteome Changes in Switchgrass Seedlings

    Directory of Open Access Journals (Sweden)

    Zhujia Ye

    2016-08-01

    Full Text Available Switchgrass (Panicum virgatum is a perennial crop producing deep roots and thus highly tolerant to soil water deficit conditions. However, seedling establishment in the field is very susceptible to prolonged and periodic drought stress. In this study, a “sandwich” system simulating a gradual water deletion process was developed. Switchgrass seedlings were subjected to a 20-day gradual drought treatment process when soil water tension was increased to 0.05 MPa (moderate drought stress and leaf physiological properties had expressed significant alteration. Drought-induced changes in leaf proteomes were identified using the isobaric tags for relative and absolute quantitation (iTRAQ labeling method followed by nano-scale liquid chromatography mass spectrometry (nano-LC-MS/MS analysis. Additionally, total leaf proteins were processed using a combinatorial library of peptide ligands to enrich for lower abundance proteins. Both total proteins and those enriched samples were analyzed to increase the coverage of the quantitative proteomics analysis. A total of 7006 leaf proteins were identified, and 257 (4% of the leaf proteome expressed a significant difference (p < 0.05, fold change <0.6 or >1.7 from the non-treated control to drought-treated conditions. These proteins are involved in the regulation of transcription and translation, cell division, cell wall modification, phyto-hormone metabolism and signaling transduction pathways, and metabolic pathways of carbohydrates, amino acids, and fatty acids. A scheme of abscisic acid (ABA-biosynthesis and ABA responsive signal transduction pathway was reconstructed using these drought-induced significant proteins, showing systemic regulation at protein level to deploy the respective mechanism. Results from this study, in addition to revealing molecular responses to drought stress, provide a large number of proteins (candidate genes that can be employed to improve switchgrass seedling growth and

  14. Cadmium stress in wheat seedlings: growth, cadmium accumulation and photosynthesis

    DEFF Research Database (Denmark)

    Ci, Dunwei; Jiang, Dong; Wollenweber, Bernd

    2010-01-01

    parameters were generally depressed by Cd stress, especially under the high Cd concentrations. Cd concentration and accumulation in both shoots and roots increased with increasing external Cd concentrations. Relationships between corrected parameters of growth, photosynthesis and fluorescence and corrected......Seedlings of wheat (Triticum aestivum L.) cultivars Jing 411, Jinmai 30 and Yangmai 10 were exposed to 0, 10, 20, 30, 40 or 50 μM of CdCl2 in a solution culture experiment. The effects of cadmium (Cd) stress on wheat growth, leaf photon energy conversion, gas exchange, and Cd accumulation in wheat...

  15. 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.

  16. Root activity distribution pattern of Ganesh pomegranate (Punica granatum) seedlings

    International Nuclear Information System (INIS)

    Kotur, S.C.; Murthy, S.V.K.

    2001-01-01

    In one-year old Ganesh pomegranate seedlings raised on a loamy sand (Typic Haplustalf) under rain fed conditions, during winter (January-March) one-half of the active roots (44-51%) resided at 50 cm radial distance. Depth wise, bulk (44-78%) of the roots were found at 15 cm depth. The results indicate that the zone of high root activity is located around 50 cm distance from trunk and applications of fertilizers in this zone may lead to enhanced use efficiency of fertilizers. (author)

  17. Seedling Emergence and Phenotypic Response of Common Bean Germplasm to Different Temperatures under Controlled Conditions and in Open Field

    Directory of Open Access Journals (Sweden)

    Antonio M. DE RON

    2016-08-01

    Full Text Available Rapid and uniform seed germination and seedling emergence under diverse environmental conditions is a desirable characteristic for crops. Common bean genotypes (Phaseolus vulgaris L. differ in their low temperature tolerance regarding growth and yield. Cultivars tolerant to low temperature during the germination and emergence stages and carriers of the grain quality standards demanded by consumers are needed for the success of the bean crop. The objectives of this study were i to screen the seedling emergence and the phenotypic response of bean germplasm under a range of temperatures in controlled chamber and field conditions to display stress-tolerant genotypes with good agronomic performances and yield potential, and ii to compare the emergence of bean seedlings under controlled environment and in open field conditions to assess the efficiency of genebanks standard germination tests for predicting the performance of the seeds in the field. Three trials were conducted with 28 dry bean genotypes in open field and in growth chamber under low, moderate and warm temperature. Morpho-agronomic data were used to evaluate the phenotypic performance of the different genotypes. Cool temperatures resulted in a reduction of the rate of emergence in the bean genotypes, however, emergence and early growth of bean could be under different genetic control and these processes need further research to be suitably modeled. Nine groups arose from the Principal Component Analysis (PCA representing variation in emergence time and proportion of emergence in the controlled chamber and in the open field indicating a trend to lower emergence in large and extra-large seeded genotypes. Screening of seedling emergence and phenotypic response of the bean germplasm under a range of temperatures in controlled growth chambers and under field conditions showed several genotypes, as landraces 272, 501, 593 and the cultivar Borlotto, with stress-tolerance at emergence and high

  18. Seedling Emergence and Phenotypic Response of Common Bean Germplasm to Different Temperatures under Controlled Conditions and in Open Field.

    Science.gov (United States)

    De Ron, Antonio M; Rodiño, Ana P; Santalla, Marta; González, Ana M; Lema, María J; Martín, Isaura; Kigel, Jaime

    2016-01-01

    Rapid and uniform seed germination and seedling emergence under diverse environmental conditions is a desirable characteristic for crops. Common bean genotypes (Phaseolus vulgaris L.) differ in their low temperature tolerance regarding growth and yield. Cultivars tolerant to low temperature during the germination and emergence stages and carriers of the grain quality standards demanded by consumers are needed for the success of the bean crop. The objectives of this study were (i) to screen the seedling emergence and the phenotypic response of bean germplasm under a range of temperatures in controlled chamber and field conditions to display stress-tolerant genotypes with good agronomic performances and yield potential, and (ii) to compare the emergence of bean seedlings under controlled environment and in open field conditions to assess the efficiency of genebanks standard germination tests for predicting the performance of the seeds in the field. Three trials were conducted with 28 dry bean genotypes in open field and in growth chamber under low, moderate, and warm temperature. Morpho-agronomic data were used to evaluate the phenotypic performance of the different genotypes. Cool temperatures resulted in a reduction of the rate of emergence in the bean genotypes, however, emergence and early growth of bean could be under different genetic control and these processes need further research to be suitably modeled. Nine groups arose from the Principal Component Analysis (PCA) representing variation in emergence time and proportion of emergence in the controlled chamber and in the open field indicating a trend to lower emergence in large and extra-large seeded genotypes. Screening of seedling emergence and phenotypic response of the bean germplasm under a range of temperatures in controlled growth chambers and under field conditions showed several genotypes, as landraces 272, 501, 593, and the cultivar Borlotto, with stress-tolerance at emergence, and high yield

  19. Rapid flow imaging method

    International Nuclear Information System (INIS)

    Pelc, N.J.; Spritzer, C.E.; Lee, J.N.

    1988-01-01

    A rapid, phase-contrast, MR imaging method of imaging flow has been implemented. The method, called VIGRE (velocity imaging with gradient recalled echoes), consists of two interleaved, narrow flip angle, gradient-recalled acquisitions. One is flow compensated while the second has a specified flow encoding (both peak velocity and direction) that causes signals to contain additional phase in proportion to velocity in the specified direction. Complex image data from the first acquisition are used as a phase reference for the second, yielding immunity from phase accumulation due to causes other than motion. Images with pixel values equal to MΔΘ where M is the magnitude of the flow compensated image and ΔΘ is the phase difference at the pixel, are produced. The magnitude weighting provides additional vessel contrast, suppresses background noise, maintains the flow direction information, and still allows quantitative data to be retrieved. The method has been validated with phantoms and is undergoing initial clinical evaluation. Early results are extremely encouraging

  20. Effect of Ionic and Chelate Assisted Hexavalent Chromium on Mung Bean Seedlings (Vigna radiata L. wilczek. var k-851 During Seedling Growth

    Directory of Open Access Journals (Sweden)

    Mohanty, Monalisa

    2013-04-01

    Full Text Available The effect of Cr+6 with and without chelating agents were assessed in mung bean seedlings grown hydroponically. It was noted that the growth parameters showed a declining trend with increasing Cr+6 concentrations without chelate application. Among the seedlings grown with chelated chromium complexes, Cr+6–DTPA (10µM showed highest growth rate of roots as well as shoots. At higher concentration of Chromium i.e. Cr+6 (100µM, there exhibited high chlorophyll content in mung bean leaves where the seedlings showed stunted growth. The seedlings treated without and with chelated chromium complexes showed increased proline content as compared to control. The enzymatic study showed that, the catalase activity was maximum in shoots as compared to roots and the reverse is true in the case of peroxidase activity i.e. the roots showed higher value than that of the shoots.

  1. Mycorrhization of containerised Pinus nigra seedlings with Suillus granulatus under open field conditions

    Energy Technology Data Exchange (ETDEWEB)

    Lazarevic, J.; Keca, N.; Martinovie, A.

    2012-07-01

    Seedling mycorrhization acts as an efficient tool for improving the quality of seedlings. In this study, the effectiveness of Suillus granulatus, originating from Pinus heldreichii forests (Montenegro), to produce containerized ectomycorrhizal seedlings of autochthonous Pinus nigra in open field conditions was investigated. Spore (106, 107, 108) and vegetative (1:16, 1:8, 1:4) inoculation on ectomycorrhizal formation and seedling growth were tested. Spore and vegetative inoculums of autochthonous Pisolithus arhizus were used in the same trial as additional control treatments. The utilization of vegetative and spore inoculums of autochthonous S. granulatus has proven to be an effective method of obtaining containerized ectomycorrhizal P. nigra seedlings under open field conditions after 11 months. S. granulatus spore inoculations resulted in well developed ectomycorrhiza, decreasing the growth of the P. nigra seedlings in the first growing season. Mycelial inoculations resulted in slightly developed S. granulatus ectomycorrhiza, which increased the growth of the seedlings. Therefore, it would be feasible to use spore inocula of S. granulatus, with 10{sup 6} spores per plant, to produce ectomycorrhizal P. nigra plants on a large scale. Controlled mycorrhizal inoculation of seedlings is not a common practice in Montenegrin and Serbian nurseries; as such, the obtained results will contribute to the enhancement of nursery production of Pinus nigra and other conifers. This also could be assumed as a starting point for many further efforts and investigations with autochthonous fungal and plant material in this region. (Author) 47 refs.

  2. Freeze injury to roots of southern pine seedlings in the USA | South ...

    African Journals Online (AJOL)

    ... and therefore root injury was often overlooked. Many freeze-injured seedlings died within two months of the freeze event. Since freeze injury symptoms to roots were overlooked, foresters offered various reasons (other than the freeze) for the poor seedling performance. Keywords: acclimation, frost, nursery, Pinus elliottii, ...

  3. Sharing rotting wood in the shade: ectomycorrhizal communities of co-occurring birch and hemlock seedlings

    Science.gov (United States)

    Sarah K. Poznanovic; Erik A. Lilleskov; Christopher R. Webster

    2015-01-01

    Coarse woody debris (CWD) is an important nursery environment for many tree species. Understanding the communities of ectomycorrhizal fungi (ECMF) and the effect of ECMF species on tree seedling condition in CWD will elucidate the potential for ECMF-mediated effects on seedling dynamics. In hemlock-dominated stands, we characterized ECMF communities associated with...

  4. AMMONIUM TOXICITY AND NITRATE RESPONSE OF AXENICALLY GROWN DACTYLORHIZA-INCARNATA SEEDLINGS

    NARCIS (Netherlands)

    DIJK, E; ECK, N

    1995-01-01

    The response to ammonium- and nitrate-nitrogen of seedlings of the calcicole orchid species Dactylorhiza incarnata (L.) Soo was tested in axenic in vitro culture of c. 3-month-old protocorms. A pronounced toxicity of ammonium ions was observed. Seedlings raised from plants of a coastal population

  5. Effect of apical meristem clipping on carbon allocation and morphological development of white oak seedlings

    Science.gov (United States)

    Paul P. Kormanik; Shi-Jean S. Sung; T.L. Kormanik; Stanley J. Zarnoch

    1994-01-01

    Seedlings from three open-pollinated half-sib white oak seedlots were clipped in mid-July and their development was compared to nonclipped controls after one growing season.In general when data were analyzed by family, clipped seedlings were significantly less desirable in three to six of the eight variables tested.Numerically, in all families seedlots, the clipped...

  6. Effects of sediment disturbance regimes on Spartina seedling establishment : Implications for salt marsh creation and restoration

    NARCIS (Netherlands)

    Cao, Haobing; Zhu, Zhenchang; Balke, Thorsten; Zhang, Liquan; Bouma, Tjeerd J.

    Seedling establishment is an important process relevant for the restoration of salt marsh within the framework of sustainable coastal defense schemes. Recent studies have increasingly highlighted how the short-term (i.e., the day-to-day) sediment dynamics can form major bottlenecks for seedling

  7. Interacting effects of grazing and habitat conditions on seedling recruitment and establishment

    Czech Academy of Sciences Publication Activity Database

    Kladivová, A.; Münzbergová, Zuzana

    2016-01-01

    Roč. 27, č. 4 (2016), s. 834-843 ISSN 1100-9233 R&D Projects: GA ČR(CZ) GA15-11635S Institutional support: RVO:67985939 Keywords : calcareous grassland * soil depth * species composition * Ellenberg indicator values * seedling mortality * browsing * seedling survival * Czech carst Subject RIV: EF - Botanics Impact factor: 2.924, year: 2016

  8. Innovating a system for producing and distributing hybrid oil palm seedlings to smallholder farmers in Benin

    NARCIS (Netherlands)

    Vissoh, Pierre V.; Tossou, Rigobert C.; Akpo, Essegbemon; Kossou, Dansou; Jiggins, Janice

    2017-01-01

    This article analyses the development of a system for producing and distributing hybrid oil palm seedlings to small-scale famers. The existing seed system had become so corrupted that the seedlings actually planted were largely of unimproved kinds. The article describes institutional experiments

  9. Mosaic Stunting in jack pine seedlings in a northern Michigan bareroot nursery

    Science.gov (United States)

    Lynette Potvin; R. Kasten Dumroese; Martin F. Jurgensen; Dana Richter

    2010-01-01

    Mosaic, or patchy, stunting of bareroot conifer seedlings is thought to be caused by deficiencies of mycorrhizal fungi following fumigation, resulting in reduced nutrient uptake, particularly phosphorus. Mosaic stunting of jack pine (Pinus banksiana) seedlings was observed in 2005 at the USDA Forest Service JW Toumey Nursery in Watersmeet, MI. We initiated a study to...

  10. Development of a doorframe-typed swinging seedling pick-up device for automatic field transplantation

    Energy Technology Data Exchange (ETDEWEB)

    Han, H.; Mao, H.; Hu, J.; Tian, K.

    2015-07-01

    A doorframe-typed swing seedling pick-up device for automatic field transplanters was developed and evaluated in a laboratory. The device, consisting of a path manipulator and two grippers, can move the pins slowly to extract seedlings from the tray cells and return quickly to the pick-up point for the next extraction. The path manipulator was constructed with the creative design of type-Ⅱ mechanism combination in series. It consists of an oscillating guide linkage mechanism and a grooved globoidal cam mechanism. The gripper is a pincette-type mechanism using the pick-up pins to penetrate into the root mass for seedling extraction. The dynamic analysis of the designed seedling pick-up device was simulated with ADAMS software. Being the first prototype, various performance tests under local production conditions were conducted to find out the optimal machine operation parameters and transplant production conditions. As the gripper with multiple fine pins was moved by the swing pick-up device, it can effectively complete the transplanting work cycle of extracting, transferring, and discharging a seedling. The laboratory evaluation showed that the pick-up device equipped with two grippers can extract 80 seedlings/min with a 90% success and a 3% failure in discharging seedlings, using 42-day-old tomato plantlets. The quality of extracting seedlings was satisfactory. (Author)

  11. Seedling establishment and physiological responses to temporal and spatial soil moisture changes

    Science.gov (United States)

    Jeremy Pinto; John D. Marshall; Kas Dumroese; Anthony S. Davis; Douglas R. Cobos

    2016-01-01

    In many forests of the world, the summer season (temporal element) brings drought conditions causing low soil moisture in the upper soil profile (spatial element) - a potentially large barrier to seedling establishment. We evaluated the relationship between initial seedling root depth, temporal and spatial changes in soil moisture during drought after...

  12. Project 722: Seedling diseases of sugar beet – diversity and host interactions

    Science.gov (United States)

    In five years of testing, Rhizoctonia solani and Fusarium spp. were commonly isolated from infected field-isolated diseased sugar beet seedlings. Which fungus is more commonly isolated from seedlings has varied over the seasons. For example, R. solani was the most frequently isolated pathogen in 201...

  13. Fusarium spp. and Pinus strobus seedlings: root disease pathogens and taxa associated with seed

    Science.gov (United States)

    C. M. Ocamb; J. Juzwik; F. B. Martin

    2002-01-01

    Eastern white pine (Pinus strobus L .) seeds were sown in soil infested wlth Fusarium proliferatum, root necrosis developed on seedling roots, and F. proliferatum as reisolated from symptomatic roots; thus, demonstrating that F. proliferatum is pathogenic to eastern white pine seedling. Soils...

  14. Morphotypes of Dactylorhiza incarnata (L. Soу (Orchidaceae seedlings in vitro

    Directory of Open Access Journals (Sweden)

    Oleg A. Marakaev

    2012-03-01

    Full Text Available The morphotypes, linear parameters and morphological features for Dactylorhiza incarnata seedlings in vitro have been set. The uneven growth and development of seedlings in depending from the location and degree of contact with the medium have been identified.

  15. Quantifying flooding effects on hardwood seedling survival and growth for bottomland restoration

    Science.gov (United States)

    John M. Kabrick; Daniel C. Dey; J.W. Van Sambeek; Mark V. Coggeshall; Douglass F. Jacobs

    2012-01-01

    Growing interest worldwide in bottomland hardwood restoration necessitates improved ecological understanding of flooding effects on forest tree seedlings using methodology that accurately reflects field conditions. We examined hardwood seedling survival and growth in an outdoor laboratory where the timing, depth, duration, and flow rate of flood water can be carefully...

  16. Root morphology and growth of bare-root seedlings of Oregon white oak

    Science.gov (United States)

    Peter J. Gould; Constance A. Harrington

    2009-01-01

    Root morphology and stem size were evaluated as predictors of height and basal-area growth (measured at groundline) of 1-1 Oregon white oak (Quercus garryana Dougl. ex Hook.) seedlings planted in raised beds with or without an additional irrigation treatment. Seedlings were classified into three root classes based on a visual assessment of the...

  17. An improved method for seed-bank analysis : Seedling emergence after removing the soil by sieving

    NARCIS (Netherlands)

    ter Heerdt, G.N.J.; Bekker, R.M.; Bakker, J.P.; Verweij, G.L.

    1. The seedling emergence method for assessing the size of the seed bank is improved by washing soil samples on a fine sieve and spreading the thus concentrated samples in a 3-5 mm thick layer on sterilized potting compost. 2. The method largely increases the number of seedlings that emerge as

  18. The role of large container seedlings in afforesting oaks in bottomlands

    Science.gov (United States)

    Daniel C. Dey; John M. Kabrick; Michael Gold

    2006-01-01

    We planted large container (RPM®) and 1-0 bareroot seedlings of pin oak (Quercus palustris Muenchh.) and swamp white oak (Q. bicolor Willd.) in crop fields in the Missouri River floodplain. We also evaluated the benefits of soil mounding and a grass (Agrostis gigantea Roth) cover crop. RPM®) oak seedlings had significantly greater...

  19. Production and early field performance of RPM® seedlings in Missouri floodplains

    Science.gov (United States)

    Daniel C. Dey; Wayne Lovelace; John M. Kabrick; Michael A. Gold

    2004-01-01

    A new nursery culture process has been developed to produce large container RPM? seedlings in an effort to improve the success in artificially regenerating hardwoods. Major features of the process include air root pruning of seedlings grown in a well aerated soil medium to encourage a dense, fibrous root system. Production has focused on native bottomland tree, shrub,...

  20. FOLIAR N RESPONSE OF PONDEROSA PINE SEEDLINGS TO ELEVATED CO2 AND O3

    Science.gov (United States)

    Interactions between needle N status and exposure to combined CO2 and O3 stresses were studied in Pinus ponderosa seedlings. The seedlings were grown for three years (April 1998 through March 2001) in outdoor chambers in native soils from eastern Oregon, and exposed to ambient ...

  1. Tree planting in Haiti: How to plant and care for your nursery grown seedlings

    Science.gov (United States)

    Kyrstan Hubbel; Yvonne Barkley; Jeremiah R. Pinto; R. Kasten Dumroese; Sabine Deristin; Raymond Joseph; Randy Brooks; Anthony S. Davis

    2016-01-01

    Seedlings need the right amounts of sunlight, water and nutrients to live and grow into healthy trees. Different types of trees have different requirements, so seedlings will need planting sites that meet all of their requirements. For example, pine trees need full sun, a moderate amount of water and a certain combination of nutrients to grow into healthy trees. If you...

  2. Fungicide seed treatments for evaluating the corn seedling disease complex following a winter rye cover crop

    Science.gov (United States)

    Seed treatments have been used to manage corn seedling diseases since the 1970’s and they contain a combination of active ingredients with specificity towards different pathogens. We hypothesized that using different seed treatment combinations and assessing seedling disease incidence and severity ...

  3. Tree invasion in a semi-arid savanna in Zimbabwe : seedling recruitment of Acacia karroo

    NARCIS (Netherlands)

    Chirara, C. (Chipangura)

    2001-01-01

    In this thesis Chirara reports on his study on the competitive interaction between savanna grasses and young tree seedlings of Acacia karroo, from hereon indicated as ' Acacia seedlings' . Acacia is one of the tree species that dominates savanna grassland in situations of overgrazing (bush

  4. A systems genetics study of seed quality and seedling vigour in Brassica rapa

    NARCIS (Netherlands)

    Basnet, R.K.

    2015-01-01

    Summary

    Seed is the basic and most critical input for seed propagated agricultural crops: seed quality and seedling vigour determine plant establishment, growth and development in both natural and agricultural ecosystems. Seed quality and seedling vigour are mainly

  5. Grass or fern competition reduce growth and survival of planted tree seedlings

    Science.gov (United States)

    Larry H. McCormick; Todd W. Bowersox

    1997-01-01

    Bareroot seedlings of northern red oak, white ash, yellow-poplar and white pine were planted into herbaceous communities at three forested sites in central Pennsylvania that were clearcut 0 to 1 year earlier. Seedlings were grown 4 years in the presence and absence of either an established grass or hay-scented fern community. Survival and height growth were measured...

  6. The impact of the herbicide atrazine on growth and photosynthesis of seagrass, Zostera marina (L.), seedlings

    International Nuclear Information System (INIS)

    Gao Yaping; Fang Jianguang; Zhang Jihong; Ren Lihua; Mao Yuze; Li Bin; Zhang Mingliang; Liu Dinghai; Du Meirong

    2011-01-01

    Highlights: → Impact of the widely used herbicide atrazine on eelgrass seedlings was studied. → Atrazine presents a threat to eelgrass seedlings growth and photosynthesis. → The impact of atrazine on eelgrass seedlings is much higher than for adult plants. - Abstract: The impact of the widely used herbicide atrazine on seedling growth and photosynthesis of eelgrass was determined. The long-term impact of the herbicide atrazine (1, 10 and 100 μg/L) on growth of eelgrass Zostera marina (L.) seedlings, maintained in outdoor aquaria, was monitored over 4 weeks. Exposure to 10 μg/L atrazine resulted in significantly lower plant fresh weight and total chlorophyll concentration and up to 86.67% mortality at the 100 μg/L concentration. Short-term photosynthetic stress on eelgrass seedlings was determined and compared with adult eelgrass using chlorophyll fluorescence. The effective quantum yield in eelgrass seedlings was significantly depressed at all atrazine concentrations (2, 4, 8, 16, 32 and 64 μg/L) even within 2 h and remained at a lower level than for adult plants for each concentration. These results indicate that atrazine presents a potential threat to seagrass seedling functioning and that the impact is much higher than for adult plants.

  7. The role of plant water relations in achieving and maintaining the target seedling

    Science.gov (United States)

    John G. Mexal; Nabil Khadduri

    2011-01-01

    Water management is one of the most important factors in achieving the target seedling. Water is required for cell growth, nutrient transport, cooling through transpiration, and in small amounts for the photosynthetic reaction. Furthermore, judicious use of limiting water availability during the hardening phase can induce budset and increase seedling cold hardiness....

  8. Seedling regeneration on decayed pine logs after the deforestation events caused by pine wilt disease

    Directory of Open Access Journals (Sweden)

    Y. Fukasawa

    2016-12-01

    Full Text Available Coarse woody debris (CWD forms an important habitat suitable for tree seedling establishment, and the CWD decay process influences tree seedling community. In Japan, a severe dieback of Pinus densiflora Sieb. & Zucc. caused by pine wilt disease (PWD damaged huge areas of pine stands but creates huge mass of pine CWD. It is important to know the factors influencing seedling colonization on pine CWD and their variations among geographical gradient in Japan to expect forest regeneration in post-PWD stands. I conducted field surveys on the effects of latitude, climates, light condition, decay type of pine logs, and log diameter on tree seedling colonization at ten geographically distinct sites in Japan. In total, 59 tree taxa were recorded as seedlings on pine logs. Among them, 13 species were recorded from more than five sites as adult trees or seedlings and were used for the analyses. A generalized linear model showed that seedling colonization of Pinus densiflora was negatively associated with brown rot in sapwood, while that of Rhus trichocarpa was positively associated with brown rot in heartwood. Regeneration of Ilex macropoda had no relationships with wood decay type but negatively associated with latitude and MAT, while positively with log diameter. These results suggested that wood decay type is a strong determinant of seedling establishment for certain tree species, even at a wide geographical scale; however, the effect is tree species specific.

  9. Long-distance dispersal helps germinating mahogany seedlings escape defoliation by a specialist caterpillar

    Science.gov (United States)

    Julian M. Norghauer; James Grogan; Jay R. Malcolm; Jeanine M. Felfili

    2010-01-01

    Herbivores and pathogens with acute host specificity may promote high tree diversity in tropical forests by causing distance- and density-dependent mortality of seedlings, but evidence is scarce. Although Lepidoptera larvae are the most abundant and host-specific guild of herbivores in these forests, their impact upon seedling distributions remains largely unknown. A...

  10. Establishment of northern red oak genetic tests with nursery-graded seedlings

    Science.gov (United States)

    S. A. Lay; M. A. Remaley; S. E. Schlarbaum; P. P. Kormanik; T. Tibbs; R. A. Cox; T. LaFarge; A. M. Saxton

    1997-01-01

    Artificial regeneration of northern red oak (Quercus rubra L.) has had variable success over time. Current nursery practices generally involve the growth of seedlings to a standardized height and form with little regard to seed source, seedling quality, or subsequent field performance. Additionally, there is not an accepted culling criteria for...

  11. METHYL JASMONATE AND STEM BENDING HARDENING AND INITIAL GROWTH OF Cordia trichotoma SEEDLINGS

    Directory of Open Access Journals (Sweden)

    Danielle Acco Cadorin

    2015-12-01

    Full Text Available The submission of seedlings to mechanical stimuli and plant growth regulator promote their hardening and can be included in the routine of nurseries, favoring the survival and initial growth in the field. The study aimed to evaluate the effects of applying methyl jasmonate and stem bending in hardening and initial growth of Cordia trichotoma seedlings. Seedlings were subjected to 20 stem bending daily for 4 weeks; 20 stem bending daily for 8 weeks; 50 µmol.L-1 of methyl jasmonate applied weekly for 4 weeks; 50 µmol.L-1 of methyl jasmonate applied weekly for 8 weeks and the control treatment. The design was a completely randomized, with five repetitions of the fourteen seedlings. Seedlings submitted to hardening treatments showed less increment in height, greater increment in stem diameter and less value for strength index. Seedlings of control treatment had greater loss of root tissue electrolytes and less potential for root regeneration. In the field, 180 days after planting, seedlings submitted to eight weeks of stem bending and eight methyl jasmonate applications showed greater increment in height and stem diameter. The results indicate that both stem bending such as methyl jasmonate application for eight weeks are effective in promoting hardening and improve the starting performance in field of Cordia trichotoma seedlings.

  12. RESULTS ON THE EFFECT OF DIFFERENT TYPES OF ROMANIAN NATIVE PEAT BIO COMPOSITES POTS ON SEEDLING GROWTH

    OpenAIRE

    Florina Uleanu

    2013-01-01

    Seedlings production is an important link in vegetable culture because many vegetables species are grown by producing prior of seedlings. The theme work is in line with Western trends to produce seedlings by integrating new vegetables technologies, profitable, with positive effect on limiting pathogens to obtain seedlings, using biodegradable pots. Were conducted various observations and measurements on plants when they have reached the optimum phase for planting. We have determined: height o...

  13. Detection of QTLs for seedling characteristics in barley (Hordeum vulgare L.) grown under hydroponic culture condition.

    Science.gov (United States)

    Wang, Qifei; Sun, Genlou; Ren, Xifeng; Wang, Jibin; Du, Binbin; Li, Chengdao; Sun, Dongfa

    2017-11-07

    Seedling characteristics play significant roles in the growth and development of barley (Hordeum vulgare L.), including stable stand establishment, water and nutrients uptake, biotic resistance and abiotic stresses, and can influence yield and quality. However, the genetic mechanisms underlying seedling characteristics in barley are largely unknown and little research has been done. In the present work, 21 seedling-related characteristics are assessed in a barley double haploid (DH) population, grown under hydroponic conditions. Of them, leaf age (LAG), shoot height (SH), maximum root length (MRL), main root number (MRN) and seedling fresh weight (SFW) were investigated at the 13th, 20th, 27th, and 34th day after germination. The objectives were to identify quantitative trait loci (QTLs) underlying these seedling characteristics using a high-density linkage map and to reveal the QTL expression pattern by comparing the QTLs among four different seedling growth stages. A total of 70 QTLs were distributed over all chromosomes except 4H, and, individually, accounted for 5.01%-77.78% of phenotypic variation. Out of the 70 detected QTLs, 23 showed a major effect on 14 seedling-related characteristics. Ten co-localized chromosomal regions on 2H (five regions), 3H (two regions) and 7H (three regions) involved 39 QTLs (55.71%), each simultaneously influenced more than one trait. Meanwhile, 9 co-localized genomic regions involving 22 QTLs for five seedling characteristics (LAG, SH, MRL, MRN and SFW) at the 13th, 20th, 27th and 34th day-old seedling were common for two or more growth stages of seedling. QTL in the vicinity of Vrs1 locus on chromosome 2H with the favorable alleles from Huadamai 6 was found to have the largest main effects on multiple seedling-related traits. Six QTL cluster regions associated with 16 seedling-related characteristics were observed on chromosome 2H, 3H and 7H. The majority of the 29 regions identified for five seedling characteristics were

  14. Somatic mutations in leafs of tobacco seedlings induced by ionizing radiation and pesticide

    International Nuclear Information System (INIS)

    Shin, H. S.; Kim, J. K.; Song, H. S.; Lee, Y. I.

    2001-01-01

    Somatic mutations induced by the combined treatment of pesticide and ionizing radiation were analyzed in the leaves of tobacco seedlings. The pesticide (1,5 and 10 ppm of parathion) was sprayed directly onto the seedlings. The seedlings, with or without pretreatment of pesticide, were irradiated with 0.1 ∼10 Gy of gamma ray. The difference in the somatic mutation frequencies were not significant among groups treated with different concentration of pesticide. The somatic mutations in tobacco seedlings irradiated with gamma-ray showed a clear dose-response relationship in a range of 0.1 to 10 Gy. However, the combined treatment of pesticide and radiation did not cause any synergistic enhancement in the mutation frequencies. The highest efficiency in the induction of somatic mutations could be obtained by irradiating the seedlings with 5 Gy, 12 hours after 1 ppm of pesticide treatment, or 24 hours after 5 ppm of pesticide treatment

  15. Growth of young Tabebuia aurea seedlings under irrigation with wastewater from fish farming

    Directory of Open Access Journals (Sweden)

    José R. de S. Pinto

    2016-06-01

    Full Text Available ABSTRACT This study aimed to evaluate the growth of young Tabebuia aurea seedlings irrigated with different concentrations of wastewater from fish farming. The experiment was conducted in a seedling nursery, from June to August 2013. The treatments consisted of five concentrations of wastewater from fish farming diluted in freshwater (0, 25, 50, 75 and 100% of wastewater. Plant height, stem diameter and plant height/stem diameter ratio were evaluated every 15 days to verify the effects of treatments on seedlings growth. At the end of the experiment, individual leaf area, leaf area, leaf dry matter, stem dry matter, root dry matter, total dry matter and Dickson quality index were also evaluated. The reuse of wastewater from fish farming diluted at concentrations of 25 and 50% in freshwater is a viable alternative in the production of Tabebuia aurea seedlings. However, higher concentrations hinder the production of seedlings of this species.

  16. Effects of exogenous melatonin on antioxidant capacity in Actinidia seedlings under salt stress

    Science.gov (United States)

    Xia, Hui; Ni, Zhiyou; Pan, Dongming

    2017-11-01

    To investigate the alleviation of exogenous melatonin (MT) in Actinidia seedlings under 100 mM NaCl stress, one-year-old Actinidia deliciosa seedlings were treated with 0.1, 0.5 and 1μM of exogenous melatonin solution, respectively. The results showed that the antioxidant substance (ASA, TPC, TFC and TFAC) contents and antioxidative capacity (DPPH, ABTS and FRAP) of Actinidia seedlings under salt stress were significantly increased compared with the CK. At the same time, the antioxidant substance contents of Actinidia seedlings with MT pretreatment were significantly higher than those of CK and S, then the antioxidative capacity was improved, and the damage of Actinidia seedlings under salt stress was alleviated. And the treatment with 0.1μM MT solution was the most significant.

  17. Development of seedlings of watermelon cv. Crimson Sweet irrigated with biosaline water

    Directory of Open Access Journals (Sweden)

    José E. S. B. da Silva

    2015-09-01

    Full Text Available ABSTRACTThe limited access and the scarcity of good quality water for agriculture are some of the major problems faced in agricultural areas, particularly in arid and semiarid regions. The aim of this study was to evaluate the quality of watermelon seedlings (cv. Crimson Sweet, irrigated with different concentrations of biosaline water of fish culture. The experimental design was completely randomized with five treatments, corresponding to biosaline water at different concentrations (0, 33, 50, 67 and 100%, and four replicates of 108 seedlings. Watermelon seeds were sown in plastic trays filled with commercial substrate and irrigated with different solutions of biosaline water. Seedlings were harvested for biometric analysis at 14, 21 and 28 days after sowing. The use of biosaline water did not affect emergence and establishment of seedlings until 14 days after sowing, the period recommended for transplantation. However, the use of biosaline water affected the development of seedlings with longer exposure time.

  18. How do riparian woody seedlings survive seasonal drought?

    Science.gov (United States)

    Stella, John C; Battles, John J

    2010-11-01

    In semi-arid regions, a major population limitation for riparian trees is seedling desiccation during the dry season that follows annual spring floods. We investigated the stress response of first-year pioneer riparian seedlings to experimental water table declines (0, 1 and 3 cm day(-1)), focusing on the three dominant cottonwood and willows (family Salicaceae) in California's San Joaquin Basin. We analyzed growth and belowground allocation response to water stress, and used logistic regression to determine if these traits had an influence on individual survival. The models indicate that high root growth (>3 mm day(-1)) and low shoot:root ratios (water-use efficiency for surviving water stress. Both S. gooddingii and sandbar willow (S. exigua) reduced leaf size from controls, whereas Fremont cottonwood (Populus fremontii) sustained a 29% reduction in specific leaf area (from 13.4 to 9.6 m(2) kg(-1)). The functional responses exhibited by Goodding's willow, the more drought-tolerant species, may play a role in its greater relative abundance in dry regions such as the San Joaquin Basin. This study highlights the potential for a shift in riparian forest composition. Under a future drier climate regime or under reduced regulated river flows, our results suggest that willow establishment will be favored over cottonwood.

  19. Germination and seedling morphology of four South American Smilax (Smilacaceae

    Directory of Open Access Journals (Sweden)

    Aline Redondo Martins

    2012-03-01

    Full Text Available Species of Smilax, also known as greenbrier, are widely distributed in Brazil and their commercial trades are carried out by the extractivism of native species. We the aim to provide information about the germination and development of seedlings in four Smilax species, different experiments were developed under controlled conditions. We evaluated two germination treatments: temperature (30ºC and 20-30ºC and light (presence/ absence, and for few cases the tetrazolium treatment was applied. A different treatment response was observed among the studied species. Light had a significant influence in S. brasiliensis, with the highest germination rates at 20-30ºC in dark conditions. S. campestris showed significant differences among temperature treatments, but not to light; while S. cissoides showed high germination rates (66-78%, independently of treatment. However, S. polyantha had low germination rates (19-24%. After one year, the expanded leaves showed different characteristics among the studied species. Leaves of S. brasiliensis were ovate, coriaceous, three main veins and prickle-like structures only on the midrib on abaxial face. S. campestris leaves were oblong, coriaceous and prickle-like structures were located at the leaf midrib and margin. S. cissoides had ovate-elliptic, membranaceous leaves, with three main veins with prickle-like structures on the abaxial face. S. polyantha leaves showed ovateelliptic, coriaceous leaves, with three main veins, translucent secondary veins and no prickle-like structures. A seedling identification key was elaborated based on morphological characteristics.

  20. Germination and seedling morphology of four South American Smilax (Smilacaceae).

    Science.gov (United States)

    Martins, Aline Redondo; Soares, Anielca Nascimento; Bombo, Aline Bertolosi; Fidelis, Alessandra; Novembre, Ana Dionisia da Luz Coelho; da Glória, Beatriz Appezzato

    2012-03-01

    Species of Smilax, also known as greenbrier, are widely distributed in Brazil and their commercial trades are carried out by the extractivism of native species. We the aim to provide information about the germination and development of seedlings in four Smilax species, different experiments were developed under controlled conditions. We evaluated two germination treatments: temperature (30 degrees C and 20-30 degrees C) and light (presence/ absence), and for few cases the tetrazolium treatment was applied. A different treatment response was observed among the studied species. Light had a significant influence in S. brasiliensis, with the highest germination rates at 20-30 degrees C in dark conditions. S. campestris showed significant differences among temperature treatments, but not to light; while S. cissoides showed high germination rates (66-78%), independently of treatment. However, S. polyantha had low germination rates (19-24%). After one year, the expanded leaves showed different characteristics among the studied species. Leaves of S. brasiliensis were ovate, coriaceous, three main veins and prickle-like structures only on the midrib on abaxial face. S. campestris leaves were oblong, coriaceous and prickle-like structures were located at the leaf midrib and margin. S. cissoides had ovate-elliptic, membranaceous leaves, with three main veins with prickle-like structures on the abaxial face. S. polyantha leaves showed ovate-elliptic, coriaceous leaves, with three main veins, translucent secondary veins and no prickle-like structures. A seedling identification key was elaborated based on morphological characteristics.

  1. Transport of sterols to the plasma membrane of leek seedlings

    International Nuclear Information System (INIS)

    Moreau, P.; Hartmann, M.A.; Perret, A.M.; Sturbois-Balcerazak, B.; Cassagne, C.

    1998-01-01

    To investigate the intracellular transport of sterols in etiolated leek (Allium porrum L.) seedlings, in vivo pulse-chase experiments with [1-14C]acetate were performed. Then, endoplasmic reticulum-, Golgi-, and plasma membrane (PM)-enriched fractions were prepared and analyzed for the radioactivity incorporated into free sterols. In leek seedlings sterols are present as a mixture in which (24R)-24-ethylcholest-5-en-3beta-ol is by far the major compound (around 60%). The other sterols are represented by cholest-5-en-3beta-ol, 24-methyl-cholest-5-en-3beta-ol, (24S)-24-ethylcholesta-5,22E-dien-3beta-ol, and stigmasta-5,24(24(1))Z-dien-3Beta-ol. These compounds are shown to reside mainly in the PM. Our results clearly indicate that free sterols are actively transported from the endoplasmic reticulum to the PM during the first 60 min of chase, with kinetics very similar to that of phosphatidylserine. Such a transport was found to be decreased at low temperature (12 degrees C) and following treatment with monensin and brefeldin A. These data are consistent with a membrane-mediated process for the intracellular transport of sterols to the PM, which likely involves the Golgi apparatus

  2. Hardening of eucalyptus seedlings via salicylic acid application

    Directory of Open Access Journals (Sweden)

    Eduardo Henrique Lima Mazzuchelli

    2014-09-01

    Full Text Available The agricultural and forest productivity suffer restrictions imposed by water stress, high temperature and high solar radiation. This study aimed to evaluate the capacity of stress attenuation and growth promotion of salicylic acid (SA application in eucalyptus (E. urophylla x E. grandis hybrid seedlings under water stress. A completely randomized design, in a 3x4 factorial scheme (three water treatments: constant irrigation with daily replacement of 40% (CI40% or 100% (CI100% of evapotranspirated water, and temporary irrigation suspension with replacement of only 40% of evapotranspirated water (S40%; and four SA concentrations: 0 mg L-1, 100 mg L-1, 200 mg L-1 and 300 mg L-1, was used. Plant photosynthetic parameters and biometric features were evaluated. The stomatal limitation was higher in plants under S40% irrigation, however, the SA application reverted this result, allowing the maintenance of the photosynthetic potential. There was interaction between irrigation regimes and SA doses for number of leaves, leaf area/number of leaves ratio and shoot and root dry mass. It was concluded that the application of 200 mg L -1 of SA positively affected the growth of eucalyptus seedlings under water stress, being considered an auxiliary management technique to their hardening process.

  3. Umedecimento do substrato na emergência e vigor de plântulas de pupunheira Substrate moisture level effect on seedling emergency and vigor of peach palm

    Directory of Open Access Journals (Sweden)

    Cibele Chalita Martins

    2009-03-01

    Full Text Available A germinação rápida e uniforme das sementes, seguida por pronta emergência das plântulas são características altamente desejáveis na formação de mudas. O objetivo deste trabalho foi verificar o efeito de diferentes níveis de umedecimento do substrato vermiculita sobre a porcentagem de emergência e o vigor de plântulas de pupunheira. O umedecimento da vermiculita com água nas quantidades de 60 a 90 ml/100 g de substrato (de 0,6 a 0,9 x o peso deste em água ou 77,6 a 86,7% da capacidade de retenção do substrato em água, respectivamente resultaram na maior porcentagem de emergência das plântulas. O umedecimento com 90 ml água/100 g de vermiculita resultou em maior velocidade de emergência e vigor de plântulas (comprimento, diâmetro e massa.The rapid and uniform germination of seeds, followed by prompt emergency are highly desirable characteristics for seedlings formation. This research aimed to determine the effect of different level of vermiculite substrate wetting on the emergency percentage and vigor of peach palm seedlings. The wetting of vermiculite with water in quantities from 60 to 90 ml/100 g of substrate (from 0.6 to 0.9 x the weight of water or 77.6 to 86.7% of the retention capacity of the substrate in water, respectively had shown higher emergence percentage of seedlings. The wetting with 90 ml water /100 g of vermiculite resulted in the higher speed of emergency and vigor of seedlings (length, diameter and mass.

  4. Effects of soil type and light on height growth, biomass partitioning, and nitrogen dynamics on 22 species of tropical dry forest tree seedlings: Comparisons between legumes and nonlegumes.

    Science.gov (United States)

    Smith-Martin, Christina M; Gei, Maria G; Bergstrom, Ellie; Becklund, Kristen K; Becknell, Justin M; Waring, Bonnie G; Werden, Leland K; Powers, Jennifer S

    2017-03-01

    The seedling stage is particularly vulnerable to resource limitation, with potential consequences for community composition. We investigated how light and soil variation affected early growth, biomass partitioning, morphology, and physiology of 22 tree species common in tropical dry forest, including eight legumes. Our hypothesis was that legume seedlings are better at taking advantage of increased resource availability, which contributes to their successful regeneration in tropical dry forests. We grew seedlings in a full-factorial design under two light levels in two soil types that differed in nutrient concentrations and soil moisture. We measured height biweekly and, at final harvest, biomass partitioning, internode segments, leaf carbon, nitrogen, δ 13 C, and δ 15 N. Legumes initially grew taller and maintained that height advantage over time under all experimental conditions. Legumes also had the highest final total biomass and water-use efficiency in the high-light and high-resource soil. For nitrogen-fixing legumes, the amount of nitrogen derived from fixation was highest in the richer soil. Although seed mass tended to be larger in legumes, seed size alone did not account for all the differences between legumes and nonlegumes. Both belowground and aboveground resources were limiting to early seedling growth and function. Legumes may have a different regeneration niche, in that they germinate rapidly and grow taller than other species immediately after germination, maximizing their performance when light and belowground resources are readily available, and potentially permitting them to take advantage of high light, nutrient, and water availability at the beginning of the wet season. © 2017 Botanical Society of America.

  5. High-light acclimation in Quercus robur L.seedlings upon over-topped a shaded environment

    Science.gov (United States)

    Anna M. Jensen; Emile S. Gardiner; Kevin C. Vaughn

    2012-01-01

    High developmental plasticity at the seedling-level during acclimation to the light environment may be an important determinant of seedling establishment and growth in temperate broadleaf forests, especially in dense understories where spatial light availability can vary greatly. Pedunculate oak (Quercus robur L.) seedlings were raised beneath a...

  6. Longleaf Pine Root System Development and Seedling Quality in Response to Copper Root Pruning and Cavity Size

    Science.gov (United States)

    Mary Anne Sword Sayer; Shi-Jean Susana Sung; James D. Haywood

    2011-01-01

    Cultural practices that modify root system structure in the plug of container-grown seedlings have the potential to improve root system function after planting. Our objective was to assess how copper root pruning affects the quality and root system development of longleaf pine seedlings grown in three cavity sizes in a greenhouse. Copper root pruning increased seedling...

  7. Influence of irrigation method and container type on Northern red oak seedling growth and media electrical conductivity

    Science.gov (United States)

    Anthony S. Davis; Douglass F. Jacobs; Ronald P. Overton; R. Kasten Dumroese

    2008-01-01

    Container production of hardwood seedlings has not been extensively practiced. Efficient nursery production of hardwood seedlings in containers can be limited by formation of a broad foliar canopy, which limits irrigation uniformity. This study was established to investigate suitability of subirrigation, a method of irrigating seedlings from the container base that...

  8. Linking carbon and water limitations to drought-induced mortality of Pinus flexilis seedlings

    Science.gov (United States)

    Reinhardt, Keith; Germino, Matthew J.; Kueppers, Lara M.; Domec, Jean-Christophe; Mitton, Jeffry

    2015-01-01

    Survival of tree seedlings at high elevations has been shown to be limited by thermal constraints on carbon balance, but it is unknown if carbon relations also limit seedling survival at lower elevations, where water relations may be more important. We measured and modeled carbon fluxes and water relations in first-year Pinus flexilis seedlings in garden plots just beyond the warm edge of their natural range, and compared these with dry-mass gain and survival across two summers. We hypothesized that mortality in these seedlings would be associated with declines in water relations, more so than with carbon-balance limitations. Rather than gradual declines in survivorship across growing seasons, we observed sharp, large-scale mortality episodes that occurred once volumetric soil-moisture content dropped below 10%. By this point, seedling water potentials had decreased below −5 MPa, seedling hydraulic conductivity had decreased by 90% and seedling hydraulic resistance had increased by >900%. Additionally, non-structural carbohydrates accumulated in aboveground tissues at the end of both summers, suggesting impairments in phloem-transport from needles to roots. This resulted in low carbohydrate concentrations in roots, which likely impaired root growth and water uptake at the time of critically low soil moisture. While photosynthesis and respiration on a leaf area basis remained high until critical hydraulic thresholds were exceeded, modeled seedling gross primary productivity declined steadily throughout the summers. At the time of mortality, modeled productivity was insufficient to support seedling biomass-gain rates, metabolism and secondary costs. Thus the large-scale mortality events that we observed near the end of each summer were most directly linked with acute, episodic declines in plant hydraulic function that were linked with important changes in whole-seedling carbon relations.

  9. Linking carbon and water relations to drought-induced mortality in Pinus flexilis seedlings.

    Science.gov (United States)

    Reinhardt, Keith; Germino, Matthew J; Kueppers, Lara M; Domec, Jean-Christophe; Mitton, Jeffry

    2015-07-01

    Survival of tree seedlings at high elevations has been shown to be limited by thermal constraints on carbon balance, but it is unknown if carbon relations also limit seedling survival at lower elevations, where water relations may be more important. We measured and modeled carbon fluxes and water relations in first-year Pinus flexilis seedlings in garden plots just beyond the warm edge of their natural range, and compared these with dry-mass gain and survival across two summers. We hypothesized that mortality in these seedlings would be associated with declines in water relations, more so than with carbon-balance limitations. Rather than gradual declines in survivorship across growing seasons, we observed sharp, large-scale mortality episodes that occurred once volumetric soil-moisture content dropped below 10%. By this point, seedling water potentials had decreased below -5 MPa, seedling hydraulic conductivity had decreased by 90% and seedling hydraulic resistance had increased by >900%. Additionally, non-structural carbohydrates accumulated in aboveground tissues at the end of both summers, suggesting impairments in phloem-transport from needles to roots. This resulted in low carbohydrate concentrations in roots, which likely impaired root growth and water uptake at the time of critically low soil moisture. While photosynthesis and respiration on a leaf area basis remained high until critical hydraulic thresholds were exceeded, modeled seedling gross primary productivity declined steadily throughout the summers. At the time of mortality, modeled productivity was insufficient to support seedling biomass-gain rates, metabolism and secondary costs. Thus the large-scale mortality events that we observed near the end of each summer were most directly linked with acute, episodic declines in plant hydraulic function that were linked with important changes in whole-seedling carbon relations. © The Author 2015. Published by Oxford University Press. All rights reserved

  10. The influence of seedling density in containers on morphological characteristics of European beech

    Directory of Open Access Journals (Sweden)

    Wrzesiński Piotr

    2015-09-01

    Full Text Available This study examines the influence on growth parameters, in particular the morphological features of the root system, of 1-year-old European beech seedlings cultivated in containers with two different densities. The experiment was conducted in the container nursery in Skierdy (Forest District of Jabłonna in spring 2011. After 10 months of cultivation in Hiko polyethylene containers, above- and below-ground parts of the seedlings were measured. The measurements of the root system were conducted with a scanner and the WinRHIZO software. No influence due to the seedling density on either shoot height or thickness was observed, but instead the research showed that different seedling densities affected the development of root systems. The mean root thickness and dry mass of the European beech seedlings were significantly higher at the lower density. The influence of seedling density on the development of root mass deserves special attention as it is the most important factor affecting future growth of the seedlings during cultivation. This tendency also suggests that the amount of nutrients allocated to shoot development may be higher in order to improve the efficiency of photosynthesis. At both densities, differences in biomass accumulation affected the root-toshoot ratio. In seedlings cultivated at the lower density, the increased dry root matter of the seedlings resulted in a significant increase in the root-to-shoot ratio. This may cause a potential growth advantage of these seedlings after they are planted and may thus result in a more productive cultivation.

  11. Seed size effects on the response of seedlings of Acacia asak (Forssk.) Willd to water stress

    International Nuclear Information System (INIS)

    El Atta, H.A.; Areef, I.M.; Ahmed, A.I.

    2016-01-01

    Dry tropical forests are characterized by unpredictable spells of drought and climate change. Saudi Arabia mostly falls within the arid zone and some few scattered areas fall in the semiarid zone mainly in the South Western region. Rainfall is sparse and with sporadic distribution. Drought is the most critical factor for restoration of the tree cover. Within a tree, seeds vary in size from large to small seeds. Although several researchers have studied the effect of within species variation in seed size on seedlings growth parameters, however there is a lack of knowledge regarding the effect of seed size on stress tolerance (Khurana and Singh 2000). We assumed that seedlings grown from different seed sizes from the same tree species may influence their response to water stress. Seeds of Acacia asak (Forssk.) Willd. were categorized into large, medium and small seeds on the basis of the seed weight. Seedlings from the three seed sizes were grown in potted soil and subjected to 5 levels of field water capacity (FC) (100, 75, 50, 25 and 15 percent) in the greenhouse. The Objective was to evaluate the response of seedling grown (from different seed sizes) to water stress and to understand the acclimation of seedlings to water stress. Water stress significantly reduced RWC, leaf area, and shoot length, fresh and dry weight. Significant correlations between growth parameters and water stress level were recorded. Seedlings from large seeds were heavier and comparatively less affected by drought compared to seedlings from smaller seeds. In all seedlings root length increased significantly and more biomass was allocated to roots than to shoots. However, at severe water stress (15 percent FC) no significant differences were reported between the three seedling categories. Therefore, raising of seedlings from large seeds is more appropriate for tree restoration programs under drought conditions. (author)

  12. Rapid geodesic mapping of brain functional connectivity: implementation of a dedicated co-processor in a field-programmable gate array (FPGA) and application to resting state functional MRI.

    Science.gov (United States)

    Minati, Ludovico; Cercignani, Mara; Chan, Dennis

    2013-10-01

    Graph theory-based analyses of brain network topology can be used to model the spatiotemporal correlations in neural activity detected through fMRI, and such approaches have wide-ranging potential, from detection of alterations in preclinical Alzheimer's disease through to command identification in brain-machine interfaces. However, due to prohibitive computational costs, graph-based analyses to date have principally focused on measuring connection density rather than mapping the topological architecture in full by exhaustive shortest-path determination. This paper outlines a solution to this problem through parallel implementation of Dijkstra's algorithm in programmable logic. The processor design is optimized for large, sparse graphs and provided in full as synthesizable VHDL code. An acceleration factor between 15 and 18 is obtained on a representative resting-state fMRI dataset, and maps of Euclidean path length reveal the anticipated heterogeneous cortical involvement in long-range integrative processing. These results enable high-resolution geodesic connectivity mapping for resting-state fMRI in patient populations and real-time geodesic mapping to support identification of imagined actions for fMRI-based brain-machine interfaces. Copyright © 2013 IPEM. Published by Elsevier Ltd. All rights reserved.

  13. Implementing MRI-based target delineation for cervical cancer treatment within a rapid workflow environment for image-guided brachytherapy: A practical approach for centers without in-room MRI.

    Science.gov (United States)

    Trifiletti, Daniel M; Libby, Bruce; Feuerlein, Sebastian; Kim, Taeho; Garda, Allison; Watkins, W Tyler; Erickson, Sarah; Ornan, Afshan; Showalter, Timothy N

    2015-01-01

    Magnetic resonance imaging (MRI)-based intracavitary brachytherapy offers several advantages over computed tomography (CT)-based brachytherapy, but many centers are unable to offer it at the time of brachytherapy because of logistic and/or financial considerations. We have implemented a method of integrating MRI into a CT-guided, high-dose-rate intracavitary brachytherapy workflow in clinics that do not have immediately available MRI capability. At our institution, patients receiving high-dose-rate intracavitary brachytherapy as a component of the definitive treatment of cervical cancer have a Smit sleeve placed during the first brachytherapy fraction in a dedicated suite with in-room CT-on-rails. After the first fraction of brachytherapy, an MRI is obtained with the Smit sleeve, but no applicator, in place. For each subsequent fraction, CT scans are coregistered to the MRI scan by the Smit sleeve. The gross target volume is defined by MRI and overlaid on the CT images for each brachytherapy treatment for dose optimization. This MRI-integrated workflow adds workflow is a feasible compromise to preserve an efficient workflow while integrating MRI target delineation, and it provides many of the advantages of both MRI- and CT-based brachytherapy. The future collection and analysis of clinical data will serve to compare the proposed approach to non-MRI containing techniques. Copyright © 2015 American Brachytherapy Society. Published by Elsevier Inc. All rights reserved.

  14. Photosynthetic and enzymatic metabolism of Schinus terebinthifolius Raddi seedlings under water deficit

    Directory of Open Access Journals (Sweden)

    Danieli Pieretti Nunes

    Full Text Available ABSTRACT Schinus terebinthifolius Raddi is a tree species that can be used in the recovery of degraded areas, as it exhibits rapid growth and has a very expansive root system, facilitating water uptake from the deeper layers of the soil. The objective of this study was to evaluate photosynthesis and enzymatic activity in S. terebinthifolius seedlings under conditions of water deficit and their potential to recover following re-irrigation. The experiment was conducted in a greenhouse under a plastic covering where plants were distributed into two groups: Group 1 - control plants, where irrigation was maintained at 70% of the water retention capacity, and Group 2 - stressed plants, where irrigation was suspended until the photosynthetic rate neared zero, followed by rehydration for 12 days, then a further suspension of irrigation. At the beginning of the experiment and during the suspension of irrigation and rehydration, plants were evaluated for gas and antioxidant enzyme exchanges. Hydric stress significantly reduced photosynthesis, stomatal transpiration conductance, carboxylation efficiency of Rubisco, and the chlorophyll content of the S. terebinthifolius plants. Following rehydration, plants recovered the carboxylation efficiency of Rubisco, but not the photosynthetic rate. Antioxidant enzyme activity increased in both the aerial part and the root in response to water deficit.

  15. An inexpensive setup for assessing the impact of ambient solar ultraviolet radiation on seedlings

    International Nuclear Information System (INIS)

    Adamse, P.; Reed, H.E.; Krizek, D.T.; Britz, S.J.; Mirecki, R.M.

    1997-01-01

    Because of reductions in stratospheric ozone levels due to chlorofluoromethanes and other trace gases, there has been growing concern about the impact of possible increases in ultraviolet-B (UV-B) radiation. Until recently, most studies have focused on the effects of enhanced UV-B levels, however, these have inherent technical difficulties. Ultraviolet-B exclusion studies afford the investigator a rapid means of assessing the effects of present levels of solar UV-B radiation. Unlike UV-B enhancement, UV-B exclusion studies use the sun as the source of UV-B radiation and selective filters to transmit or absorb this portion of sunlight. This article describes a simple, inexpensive system that was used over a 3-yr period to determine seedling response of cucumber (Cucumis sativus L.), soybean (Glycine max (L.) Merr.), and New Zealand spinach ((Tetragonia tetragonoides (Pallas) Kuntze) to UV-B exclusion. Plants of all three species grown outdoors under UV-B absorbing polyester showed an increase in leaf enlargement and biomass accumulation in comparison to those grown under UV-B transmitting cellulose acetate filters. The bask materials used consist of plastic window boxes, plastic filters that transmit or absorb in the UV-B region, wire supports, and binder clips. This setup can be used to demonstrate bask principles of photobiology and stress physiology. It is ideal for students interested in conducting short-term science projects on the effects of solar UV radiation

  16. Pilot Implementations

    DEFF Research Database (Denmark)

    Manikas, Maria Ie

    by conducting a literature review. The concept of pilot implementation, although commonly used in practice, is rather disregarded in research. In the literature, pilot implementations are mainly treated as secondary to the learning outcomes and are presented as merely a means to acquire knowledge about a given...... objective. The prevalent understanding is that pilot implementations are an ISD technique that extends prototyping from the lab and into test during real use. Another perception is that pilot implementations are a project multiple of co-existing enactments of the pilot implementation. From this perspective......This PhD dissertation engages in the study of pilot (system) implementation. In the field of information systems, pilot implementations are commissioned as a way to learn from real use of a pilot system with real data, by real users during an information systems development (ISD) project and before...

  17. Water deficit modulates gene expression in growing zones of soybean seedlings. Analysis of differentially expressed cDNAs, a new beta-tubulin gene, and expression of genes encoding cell wall proteins.

    Science.gov (United States)

    Creelman, R A; Mullet, J E

    1991-10-01

    Transfer of soybean seedlings to low-water-potential vermiculite (psi w = -0.3 MPa) results in a reversible decrease in hypocotyl growth and modulation of several polysomal mRNAs (Plant Physiol 92: 205-214). We report here the isolation of two cDNA clones (pGE16 and pGE95) which correspond to genes whose mRNA levels are increased, and one cDNA clone (pGE23) which corresponds to a gene whose mRNA level is decreased in the hypocotyl zone of cell elongation by water deficit. In well-watered seedlings mRNAs hybridizing to pGE16 and pGE95 are most abundant in mature regions of the seedling, but in water-deficient seedlings mRNA levels are reduced in mature regions and enhanced in elongating regions. RNA corresponding to soybean proline-rich protein 1 (sbPRP1) shows a similar tissue distribution and response to water deficit. In contrast, in well-watered seedlings, the gene corresponding to pGE23 was highly expressed in the hypocotyl and root growing zones. Transfer of seedlings to low-water-potential vermiculite caused a rapid decrease in mRNA hybridizing to pGE23. Sequence analysis revealed that pGE23 has high homology with beta-tubulin. Water deficit also reduced the level of mRNA hybridizing to JCW1, an auxin-modulated gene, although with different kinetics. Furthermore, mRNA encoding actin, glycine-rich proteins (GRPs), and hydroxyproline-rich glycoproteins (HRGPs) were down-regulated in the hypocotyl zone of elongation of seedlings exposed to water deficit. No effect of water deficit was observed on the expression of chalcone synthase. Decreased expression of beta-tubulin, actin, JCW1, HRGP and GRP and increased expression of sbPRP1, pGE95 and pGE16 in the hypocotyl zone of cell elongation could participate in the reversible growth inhibition observed in water-deficient soybean seedlings.

  18. Pilot implementation

    DEFF Research Database (Denmark)

    Hertzum, Morten; Bansler, Jørgen P.; Havn, Erling C.

    2012-01-01

    A recurrent problem in information-systems development (ISD) is that many design shortcomings are not detected during development, but first after the system has been delivered and implemented in its intended environment. Pilot implementations appear to promise a way to extend prototyping from...... the laboratory to the field, thereby allowing users to experience a system design under realistic conditions and developers to get feedback from realistic use while the design is still malleable. We characterize pilot implementation, contrast it with prototyping, propose a iveelement model of pilot...... implementation and provide three empirical illustrations of our model. We conclude that pilot implementation has much merit as an ISD technique when system performance is contingent on context. But we also warn developers that, despite their seductive conceptual simplicity, pilot implementations can be difficult...

  19. RESULTS ON THE EFFECT OF DIFFERENT TYPES OF ROMANIAN NATIVE PEAT BIO COMPOSITES POTS ON SEEDLING GROWTH

    Directory of Open Access Journals (Sweden)

    Florina Uleanu

    2013-07-01

    Full Text Available Seedlings production is an important link in vegetable culture because many vegetables species are grown by producing prior of seedlings. The theme work is in line with Western trends to produce seedlings by integrating new vegetables technologies, profitable, with positive effect on limiting pathogens to obtain seedlings, using biodegradable pots. Were conducted various observations and measurements on plants when they have reached the optimum phase for planting. We have determined: height of seedlings, root length, leaf number, root volume total weight, weight of the aerial and weight of roots. The obtained data was calculated and considered as average / variant.

  20. EFFECTS OF CRUDE OIL POLLUTED SOIL ON THE SEEDLING GROWTH OF PENNISETUM GLAUCUM (L. R. BR.

    Directory of Open Access Journals (Sweden)

    Muhammad SHAFIQ

    2017-12-01

    Full Text Available Pollution by crude oil is an important environmental issue all around the world. Increase in oil pollution level in the environment produce toxic effects on flora and fauna of the region. The effects of different levels (0%, 5%, 10%, 15%, and 20% of crude oil polluted soil on the growth of pearl millet (Pennisetum glaucum were studied. The polluted soil affected the root, shoot length, seedling size, number of leaves and leaf area of P. glaucum. The significant (p<0.05 effects of polluted soil on fresh and dry weight of root, stem, leaves, and seedling of P. glaucum were also recorded. Leaf area, leaf number and total seedling dry weight were noticeably reduced in 10 and 15% polluted soil than control soil treatment. Principally, 20% crude oil polluted soil treatment exhibited highest percentage of decrease in most of the seedling growth parameters of P. glaucum than control. Hence, the effects on seedling growth parameters were increased with increasing levels of polluted soil. For most of the growth parameters, the mean values obtained were found higher for the control soil and progressively decreased from 5-20% crude oil polluted soils. The seedlings of P. glaucum were also tested for tolerance to polluted soil treatment. The results showed that the seedlings of P. glaucum showed high percentage of tolerance to low concentration (5% of polluted soil treatment as compared to control soil treatment (0%.

  1. Spatial distribution of seeds and seedlings of two tropical tree species: Is there correspondence between patterns?

    International Nuclear Information System (INIS)

    Parrado Rosselli, Angela

    2007-01-01

    The spatial patterns of seed and seedling distribution relative to parent trees (seed and seedling shadow, respectively) were studied for Dacryodes chimantensis (Burseraceae) and Brosimum utile (Moraceae), two common tree species of terra firme forests of Colombian Amazonia. The general objective was to assess whether the patterns imposed by seed dispersal change or persist in subsequent life stages occurring during the transition from seeds/saplings to adult stages. Seed and seedling shadows on the ground were characterized for each tree species along four 50-m radial transects from the base of the parent tree. Causes of seed and seedling predation as a function of distance to the parent tree were determined, as well as the spatial consistency between life stages. Results showed that seed density of both Dacryodes and Brosimum declined leptokurtically with distance, and it was skewed towards the parent tree. However, seed density was more skewed and leptokurtic in Dacryodes than in Brosimum. The overall trend was maintained in the seedling stage of both species and was positively correlated with the distribution patterns of seeds. Seed and seedling predation were positively correlated with density and negatively correlated with the distance from the parent tree. Factors that could be generating the high consistency between the spatial patterns of seed and seedling distribution are discussed, as well as its implications in the population structure of both species and the debate on the factors that influence the spatial distribution of plant species in tropical rain forests.

  2. Effect of CO2 Enrichment on the Growth and Nutrient Uptake of Tomato Seedlings

    Institute of Scientific and Technical Information of China (English)

    LI Juan; ZHOU Jian-Min; DUAN Zeng-Qiang; DU Chang-Wen; WANG Huo-Yan

    2007-01-01

    Exposing tomato seedlings to elevated CO2 concentrations may have potentially profound impacts on the tomato yield and quality. A growth chamber experiment was designed to estimate how different nutrient concentrations influenced the effect of elevated CO2 on the growth and nutrient uptake of tomato seedlings. Tomato (Hezuo 906) was grown in pots placed in controlled growth chambers and was subjected to ambient or elevated CO2 (360 or 720 μL L-1), and four nutrient solutions of different strengths (1/2-, 1/4-, 1/8-, and 1/16-strength Japan Yamazaki nutrient solutions) in a completely randomized design. The results indicated that some agricultural characteristics of the tomato seedlings such as the plant height, stem thickness, total dry and fresh weights of the leaves, stems and roots, the G value (G value = total plant dry weight/seedling age),and the seedling vigor index (seedling vigor index = stem thickness/(plant height × total plant dry weight) increased with the elevated CO2, and the increases were strongly dependent on the nutrient solution concentrations, being greater with higher nutrient solution concentrations. The elevated CO2 did not alter the ratio of root to shoot. The total N, P, K, and C absorbed from all the solutions except P in the 1/8- and 1/16-strength nutrient solutions increased in the elevated CO2 treatment. These results demonstrate that the nutrient demands of the tomato seedlings increased at elevated CO2 concentrations.

  3. N2-fixation and seedling growth promotion of lodgepole pine by endophytic Paenibacillus polymyxa.

    Science.gov (United States)

    Anand, Richa; Grayston, Susan; Chanway, Christopher

    2013-08-01

    We inoculated lodgepole pine (Pinus contorta var. latifolia (Dougl.) Engelm.) with Paenibacillus polymyxa P2b-2R, a diazotrophic bacterium previously isolated from internal stem tissue of a naturally regenerating pine seedling to evaluate biological nitrogen fixation and seedling growth promotion by this microorganism. Seedlings generated from pine seed inoculated with strain P2b-2R were grown for up to 13 months in a N-limited soil mix containing 0.7 mM available N labeled as Ca((15)NO3)2 to facilitate detection of N2-fixation. Strain P2b-2R developed a persistent endophytic population comprising 10(2)-10(6) cfu g(-1) plant tissue inside pine roots, stems, and needles during the experiment. At the end of the growth period, P2b-2R had reduced seedling mortality by 14 % and (15)N foliar N abundance 79 % and doubled foliar N concentration and seedling biomass compared to controls. Our results suggest that N2-fixation by P. polymyxa enhanced growth of pine seedlings and support the hypothesis that plant-associated diazotrophs capable of endophytic colonization can satisfy a significant proportion of the N required by tree seedlings growing under N-limited conditions.

  4. Use of aquatic macrophytes in substrate composition to produce moringa seedlings

    Directory of Open Access Journals (Sweden)

    Walda Monteiro Farias

    2016-03-01

    Full Text Available The use of aquatic macrophytes in substrate composition to produce seedlings of moringa is a sustainable alternative. Therefore, the objective of this research was to evaluate the development of moringa seedlings using substrates composed with aquatic macrophytes, and to determine concentrations of N, P and K in the seedlings. We used different combinations of weeds (M, manure (E and topsoil (TV to compose the substrates. The experiment was conducted in a 3 × 4 factorial in randomized arrangement with four replications. We evaluated plant height, crown diameter and stem, relative growth rate in height, canopy diameter and in stem, dry matter of aerial part and of roots, root length and root/shoot ratio, besides the content of N, P and K in seedlings. Moringa seedlings showed reduced growth when produced in substrates composed only with cattail. Water lettuce and substrates composed of 60% M + 30%E + 10 % TV and 70% M + 30% E, promoted greater nutrition and growth of moringa seedlings. The substrate 60M +30E +10TV composed by water hyacinth and cattail resulted in greater amount of P in moringa seedlings.

  5. Effect of X-irradiation on the growth and some antioxidase activity in wheat seedlings

    International Nuclear Information System (INIS)

    Li Qun; Gu Ruiqi

    1997-01-01

    Wheat seedlings of 48h after germination were irradiated with various dosage of X-rays. High dosage X-irradiation, 8 Gy and 14 Gy can inhibited the growth, decrease the freshness weight of wheat seedlings. The height and weight of wheat seedlings decreased with the development of X-irradiation of dosage. The concentration of protein and activity of some antioxidases include ascorbic acid peroxidase (ASA-POD), glutathione peroxidase (GSH-Px) and glutathione transferase (GSH-Ts) were observed on 2nd and 4th day after irradiation. The concentration of protein in wheat seedlings decreases with the development of X-irradiation of dosage. The concentration of protein on 4th day was higher than that on 2nd day showed that the damage of wheat seedlings induced by X-irradiation was resumed during the culture process. X-irradiation can increase activity of ASA-POD, GSH-Px and GSH-Ts of wheat seedlings, and the increase rate of 14 Gy X-irradiation was higher than that of 8 Gy. The activity of ASA-POD and GSH-Px increased during the culture process and the activity of GSH-Ts decreased. That's show that wheat seedlings can increase the activity of antioxidases to resist the damage induced by high dosage X-irradiation. The results of low dosage X-irradiation, 2 Gy is similar as the control

  6. Long-term Seedling Dynamics of Tree Species in a Subtropical Rain Forest, Taiwan

    Directory of Open Access Journals (Sweden)

    Chia-Hao Chang-Yang

    2013-03-01

    Full Text Available Knowledge of demographical rates at seedling stage is critical for understanding forest composition and dynamics. We monitored the seedling dynamics of tree species in a subtropical rain forest in Fushan, northern Taiwan (24°45’ N, 121°35’ E during an 8-yr period (2003–2010. There were great temporal fluctuations in the seedling density, which might be largely driven by the pulses of seedling recruitment. Interspecific variation in the seedling abundance, however, was not related to the reproductive adult abundance. Previous studies showed that frequent typhoon disturbances contributed to the high canopy openness and high understory light availability at Fushan, which might benefit tree regeneration. But our results do not support this idea. Most of the newly recruited seedlings died within six months and only grew 1.55 ± 0.20 cm per year, which might be suppressed by the dense understory vegetation. Our results suggested that the majority of tree species in Fushan were recruitment limited, which might have important consequences for species coexistence. High temporal variability in recruitment density and low growth rates of seedlings emphasize the importance of long-term studies to our understandings of forest dynamics.

  7. Effects of Management Practices and Topography on Ectomycorrhizal Fungi of Maritime Pine during Seedling Recruitment

    Directory of Open Access Journals (Sweden)

    Arthur Guignabert

    2018-05-01

    Full Text Available Symbiosis with ectomycorrhizal (ECM fungi can be important for regeneration success. In a context of increasing regeneration failures in the coastal forest of maritime pine in Southwest France, we tried to identity whether differences in ECM communities could partly explain the variation of regeneration success and how they are influenced by forest practices and stand characteristics. In particular, we focused on the effects of harvesting methods (comparing mature forest with seed-tree regeneration and clear-cuts and topography (bottom-, mid-, and top positions. Five field trials (two in regeneration failure areas and three in successful areas were used to sample 450 one-year-old seedlings. Assessments of ECM of seedling nutrient concentrations and of seedling growth based on exploration types were made. ECM root colonisation was similar in all harvesting treatments, suggesting that enough inoculum remained alive after logging. Harvesting-induced effects modifying soil properties and light availability respectively impacted ECM composition and seedling growth. Topography-induced variations in water and nutrient availability led to changes in ECM composition, but had little impact on seedling growth. Contact, short-distance, and long-distance exploration types improved the nutritional status of seedlings (Ca, K, and N, showing that mycorrhization could play an important role in seedling vitality. However, neither ECM root colonisation nor exploration types could be related to regeneration failures.

  8. GROWTH OF Jacaranda puberula Cham. SEEDLINGS IN NURSERY UNDER DIFFERENT SHADING LEVELS

    Directory of Open Access Journals (Sweden)

    Lausanne Soraya de Almeida

    2010-08-01

    Full Text Available Jacaranda puberula, known as caroba, is a species that presents potential use for the recovery of degraded areas, since it possesses fast growth and adapts well to sandy and loamy soils. It presents great aggressiveness in secondary forests and it can be used as urban tree because it produces beautiful lilac flowers. With the intention of obtaining information about potential species for use in recovery of riparian forest, were tested in the nursery of the city hall of the municipal district of Colombo, the development of seedlings of Jacaranda puberula submitted at 30, 50 and 70% of shading. There were used 40 seedlings by treatment and there were evaluated the following parameters: height (60, 90 and 120 days and diameter (90 and 120 days of all seedlings, leaf area and root and shoot dry weight of 6 seedlings per treatment. The largest averages of the analyzed variables were obtained for the 30% shading, except for root dry weight.  The seedlings exposed to full sun presented high mortality rate and was not compared to the others. The smallest averages of the analyzed variables, except for height, were observed for the shading of 70%, indicating that this treatment is not advisable for the production of seedlings of this species in nursery. The best condition for planting the seedlings appears to be in open areas with shading of 30 to 50%, since its natural occurrence is not at full exposure.

  9. Factors Affecting Planting Depth and Standing of Rice Seedling in Parachute Rice Transplanting

    Science.gov (United States)

    Astika, I. W.; Subrata, I. D. M.; Pramuhadi, G.

    2018-05-01

    Parachute rice transplanting is a simple and practical rice transplanting method. It can be done manually or mechanically, with various possible designs of machines or tools. This research aimed at quantitatively formulating related factors to the planting depth and standing of rice seedling. Parachute seedlings of rice were grown at several sizes of parachute soil bulb sizes. The trays were specially designed with a 3D printer having bulb sizes 7, 8, 9, 10 mm in square sides and 15 mm depth. At seedling ages of 8-12 days after sowing the seedling bulbs were drops into puddled soil. Soil hardness was set at 3 levels of hardness, measured in hardness index using golf ball test. Angle of dropping was set at 3 levels: 0°, 30°and 45° from the vertical axis. The height of droppings was set at 100 cm, 75 cm, and 50 cm. The relationship between bulb size, height of dropping, soil hardness, dropping angle and planting depth was formulated with ANN. Most of input variables did not significantly affect the planting depth, except that hard soil significantly differs from mild soil and soft soil. The dropping also resulted in various positions of the planted seedlings: vertical standing, sloped, and falling. However, at any position of the planted seedlings, the seedlings would recover themselves into normally vertical position. With this result, the design of planting machinery, as well as the manual planting operation, can be made easier.

  10. Melatonin Has the Potential to Alleviate Cinnamic Acid Stress in Cucumber Seedlings

    Directory of Open Access Journals (Sweden)

    Juanqi Li

    2017-07-01

    Full Text Available Cinnamic acid (CA, which is a well-known major autotoxin secreted by the roots in cucumber continuous cropping, has been proven to exhibit inhibitory regulation of plant morphogenesis and development. Melatonin (MT has been recently demonstrated to play important roles in alleviating plant abiotic stresses. To investigate whether MT supplementation could improve cucumber seedling growth under CA stress, we treated cucumber seeds and seedlings with/without MT under CA- or non-stress conditions, and then tested their effects on cucumber seedling growth, morphology, nutrient element content, and plant hormone. Overall, 10 μM MT best rescued cucumber seedling growth under 0.4 mM CA stress. MT was found to alleviate CA-stressed seedling growth by increasing the growth rates of cotyledons and leaves and by stimulating lateral root growth. Additionally, MT increased the allocation of newly gained dry weight in roots and improved the tolerance of cucumber seedlings to CA stress by altering the nutrient elements and hormone contents of the whole plant. These results strongly suggest that the application of MT can effectively improve cucumber seedling tolerance to CA stress through the perception and integration of morphology, nutrient element content and plant hormone signaling crosstalk.

  11. Tillers induction in Bactris gasipaes var. gasipaes seedlings

    Directory of Open Access Journals (Sweden)

    Ernani Augusto Ochekoski Mossanek

    2014-04-01

    Full Text Available Bactris gasipaes produces heart-of-palm. Peach palm is a perennial crop that has a tillering capacity, being an alternative to illegal extraction. There is a lack of studies about vegetative propagation technics for this species. The present study aimed to analyze different tillering induction methods in Bactris gasipaes var. gasipaes seedlings in four different seasons. The treatments were: 1 stem bending; 2 stem bending and application of 150 mg kg-1 of benzylaminopurine; 3 stem bending and application of 150 mg kg-1 of gibberellic acid and; 4 stem girdling. The experimental design was random with 4 replicates of 20 plants per treatment. Anatomical analyses were conducted at the stem, and the tillering and mortality of the treated plants were evaluated. It was possible to identify the stem tissues and the meristematic apex site by anatomical analysis. The stem bending treatments were inefficient; but girdling presented potential as tillers inducer.

  12. NUTRIENT RIQUERIMENT OF Schizolobium amazonicum, Herb (PARICÁ SEEDLINGS

    Directory of Open Access Journals (Sweden)

    Teresa Cristina Lara Lanza de Sá e Melo Marques

    2004-07-01

    Full Text Available Macronutrients concentrations in leave, stem, and root tissues of Schizolobium amazonicum Herb. were determined under greenhouse conditions using the missing element technique. The experimental design was a completely randomized block with four replications and 13 treatments. Seedlings 0.05–0.10 -m high were planted into 3 L pots filled with nutritive solution. Based on the concentrations of macronutrients in the leaves of the complete and the deficient treatments, suitable and deficient levels (g kg-1 of macronutrients for S. amazonicum are: a suitable: 4 for P; 15 for K; 40 for Ca; 4 for Mg; and 3 for S; 33of B; 5 of Cu; 540 of Fe, 88 of Mn; and 71 of Zn; b critical: 1 for P; 4 for K; 8 for Ca; 1 for Mg; and 2 for S; 31 of B; 4 of Cu; 140 of Fe; 38 of Mn; and 24 of Zn

  13. Imaging analysis of direct alanine uptake by rice seedlings

    International Nuclear Information System (INIS)

    Nihei, Naoto; Masuda, Sayaka; Rai, Hiroki; Nakanishi, Tomoko M.

    2008-01-01

    We presented alanine, a kind of amino acids, uptake by a rice seedling to study the basic mechanism of the organic fertilizer effectiveness in organic farming. The rice grown in the culture solution containing alanine as a nitrogen source absorbed alanine approximately two times faster than that grown with NH 4 + from analysis of 14 C-alanine images by Imaging Plate method. It was suggested that the active transport ability of the rice seeding was induced in roots by existence of alanine in the rhizosphere. The alanine uptake images of the rice roots were acquired every 5 minutes successively by the real-time autoradiography system we developed. The analysis of the successive images showed that alanine uptake was not uniform throughout the root but especially active at the root tip. (author)

  14. Development of an automatic visual grading system for grafting seedlings

    Directory of Open Access Journals (Sweden)

    Subo Tian

    2017-01-01

    Full Text Available In this study, a visual grading system of vegetable grafting machine was developed. The study described key technology of visual grading system of vegetable grafting machine. First, the contrasting experiment was conducted between acquired images under blue background light and natural light conditions, with the blue background light chosen as lighting source. The Visual C++ platform with open-source computer vision library (Open CV was used for the image processing. Subsequently, maximum frequency of total number of 0-valued pixels was predicted and used to extract the measurements of scion and rootstock stem diameters. Finally, the developed integrated visual grading system was experimented with 100 scions and rootstock seedlings. The results showed that success rate of grading reached up to 98%. This shows that selection and grading of scion and rootstock could be fully automated with this developed visual grading system. Hence, this technology would be greatly helpful for improving the grading accuracy and efficiency.

  15. Utilization of Aseptic Seedling Explants for In vitro Propagation of Indian Red Wood

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    Kishore Kumar CHIRUVELLA

    2013-12-01

    Full Text Available Micropropagation has been advocated as one of the most viable biotechnological tool for ex situ conservation of rare, endangered endemic medicinal plants germplasm. Rapid clonal micropropagation protocol for large-scale multiplication of an endemic medicinal plant Soymida febrifuga (Meliaceae was established from 15-day aseptic seedling cotyledonary node and shoot tip explants. High frequency of sprouting and shoot differentiation was observed from cotyledonary node explants compared to shoot tip, on Murashige and Skoog (MS medium fortified with BA, KN, 2-iP and CM. Of the cytokinins used, BA (3.0 mgl-1 supported highest average number and maximum multiple shoot differentiation (16.6. In vitro proliferated shoots were multiplied rapidly by culturing nodal segments as microcuttings, further subcultured on the same media for elongation. Elongated shoots upon transfer to MS medium fortified with IBA showed rooting within two weeks of culture. Rooted plantlets were successfully hardened and 75% of rooted shoots successfully survived on establishment to the soil. Plants looked healthy with no visually detectable phenotypic variations. This protocol provides a successful and rapid technique that can be used for ex situ conservation minimizing the pressure on wild populations and contributes to the conservation of this endemic medicinally potent flora.

  16. Effects of seed mass on seedling success in Artocarpus heterophyllus L., a tropical tree species of north-east India

    Science.gov (United States)

    Khan, M. L.

    2004-03-01

    I examined the effects of seed mass on performance of seedlings of Artocarpus heterophyllus L. (Moraceae), a large evergreen late successional shade-tolerant tree species in three contrasting light conditions. Seed mass varied many fold from 1.5 to 14 g in A. heterophyllus. Germination and germination time showed a significant correlation with seed mass. Germination differed significantly among three light regimes (50%, 25% and 3%). Seed mass and light level significantly affected seedling survival. The seedlings that emerged from large seeds survived better than those from small seeds under all light regimes. Survival of seedlings was maximum in 25% light regime for all seed mass classes but did not differ significantly from that at 50% light regime. Survival was significantly lower in 3% light as compared to 50% and 25% light regimes. Seedling vigor (expressed in terms of seedling height, leaf area and dry weight) was also significantly affected by seed mass and light regimes. Seedlings that emerged from larger seeds and grew under 50% light regime produced the heaviest seedlings, while those resulting from smaller seeds and grown under 3% light regime produced the lightest seedlings. Resprouting capacity of seedlings after clipping was significantly affected by seed mass and light regime. Seedlings emerging from larger seeds were capable of resprouting several times successively. Resprouting was more pronounced under 50% and 25% light regimes as compared to 3% light. Success of A. heterophyllus regeneration appears to be regulated by an interactive effect of seed mass and light regime.

  17. Effects of Azospirillum lipoferum on seedling characteristics derived from sunflower (Helianthus annus L. seed water deficit conditions

    Directory of Open Access Journals (Sweden)

    H. Hadi

    2016-05-01

    Full Text Available Seedling characteristics of different sunflower (Helianthus annus L. cultivars under drought stress and inoculation with the Azospirillum lipoferum in a spilt-factorial layout based on randomized complete block design with three replications were evaluated. Treatments included dehydration stress (seed produced on maternal plants which irrigated after 60 (desirable irrigation, 120 (medium stress, 180 mm (severe stress evaporation from evaporation pan class A, different sunflower cultivars (Lakomka, Master, Favorite, Soor and Armavirosky and inoculation with bacteria (Azospirillum lipoferum and control. Bacteria allocated in the main plots and seeds which derived from dehydration stress conditions and different cultivars were allocated in sub plots as a factorial layout. Results showed that the time of seedling emergence, seedling vigor index, leaf petiole, stem and seedling dry weight were increased 14, 44, 30, 31, 22 and 27 percent by inoculating with bacteria, respectively. The percent of Seedling emergence of seeds derived from medium stress 48 percent was more than optimal irrigation conditions. Final appearance, speed of emergence, emergence index, dry weight and stamina seedling resulting from severe stress conditions were decreased compared with optimal irrigation. Seedling emergence of seeds derived from medium stress which inoculated with bacteria increased by 9 percent. Emergence speed index, appearance, stamina and seedling dry weights of seeds which inoculated with bacteria increased at medium and sever water stress. With consideration of the effect of dehydration stress on germination and seedling emergence, seed inoculation with bacteria improved seedling emergence and seedling vigor of seeds derived from dehydration stress conditions.

  18. Arabidopsis phosphoinositide-specific phospholipase C 4 negatively regulates seedling salt tolerance.

    Science.gov (United States)

    Xia, Keke; Wang, Bo; Zhang, Jiewei; Li, Yuan; Yang, Hailian; Ren, Dongtao

    2017-08-01

    Previous physiological and pharmacological studies have suggested that the activity of phosphoinositide-specific phospholipase C (PI-PLC) plays an important role in regulating plant salt stress responses by altering the intracellular Ca 2+ concentration. However, the individual members of plant PLCs involved in this process need to be identified. Here, the function of AtPLC4 in the salt stress response of Arabidopsis seedlings was analysed. plc4 mutant seedlings showed hyposensitivity to salt stress compared with Col-0 wild-type seedlings, and the salt hyposensitive phenotype could be complemented by the expression of native promoter-controlled AtPLC4. Transgenic seedlings with AtPLC4 overexpression (AtPLC4 OE) exhibited a salt-hypersensitive phenotype, while transgenic seedlings with its inactive mutant expression (AtPLC4m OE) did not exhibit this phenotype. Using aequorin as a Ca 2+ indicator in plc4 mutant and AtPLC4 OE seedlings, AtPLC4 was shown to positively regulate the salt-induced Ca 2+ increase. The salt-hypersensitive phenotype of AtPLC4 OE seedlings was partially rescued by EGTA. An analysis of salt-responsive genes revealed that the transcription of RD29B, MYB15 and ZAT10 was inversely regulated in plc4 mutant and AtPLC4 OE seedlings. Our findings suggest that AtPLC4 negatively regulates the salt tolerance of Arabidopsis seedlings, and Ca 2+ may be involved in regulating this process. © 2017 John Wiley & Sons Ltd.

  19. Identification of 'Ubá' mango tree zygotic and nucellar seedlings using ISSR markers

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    Aline Rocha

    2014-10-01

    Full Text Available Polyembryonic seeds are characterized by the development of over one embryo in the same seed, which can be zygotic and nucellar. The objective of this work was to identify the genetic origin, whether zygotic or nucellar, of seedlings of polyembryonic seeds of 'Ubá' mango tree using ISSR markers, and relating them with the vigor of the seedlings. Thus, mangos were harvested in Visconde do Rio Branco (accession 102 and Ubá (accessions 112, 138, 152 and 159, whose seeds were germinated in plastic trays filled with washed sand. Fifty days after sowing, seedlings from five seeds of each one of the accessions 102, 112, 138, 159 and from 10 seeds of the accession 152, were analyzed. These sseedlings were characterized and evaluated for plant height, stem circumference and mass of fresh aerial part and the most vigorous seedling was the one displaying at least two of these traits higher than the other seedlings from seed. Leaves were collected for genomic DNA extraction, which was amplified using seven ISSR primers previously selected based on the amplification profile and considering the number and resolution of fragments. Zygotic seedlings were found in 18 seeds, which were the most vigorous in six seeds. The results evidenced the existence of genetic variability in orchards using seedlings grown from seeds, because the farmer usually uses the most vigorous ones, assuming that this is of nucellar origin. These results also indicate that the most vigorous seedling are not always nucellar, inasmuch as of 20% of the total seeds evaluated, the zygotic seedling was the most vigorous.

  20. Seedling Regeneration in the Alpine Treeline Ecotone: Comparison of Wood Microsites and Adjacent Soil Substrates

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    Adelaide Chapman Johnson

    2016-11-01

    Full Text Available Although climate warming is generally expected to facilitate upward advance of forests, conifer seedling regeneration and survival may be hindered by low substrate moisture, high radiation, and both low and high snow accumulation. To better understand substrate-related factors promoting regeneration in the alpine treeline ecotone, this study compared 2 substrates supporting conifer seedlings: rotten downed wood and adjacent soil. Study locations, each with 3 levels of incoming radiation, were randomly selected at forest line–alpine meadow borders in Pacific Northwest wilderness areas extending along an east–west precipitation gradient. Associations among substrate type, seedling density, radiation, site moisture, site temperature, plant water potential, and plant stomatal conductance were assessed. Wood microsites, flush with the ground and supporting Abies spp conifer seedlings, extended up to 20 m into alpine meadows from the forest line. Although wood microsites thawed later in the spring and froze earlier in the fall, they had warmer summer temperatures, greater volumetric water content, and more growing degree hours, and seedlings growing on wood had higher water potentials than seedlings growing on adjacent soil. At drier eastern sites, there was a positive relationship between seedling density and volumetric water content. Further, there was a positive relationship between seedling stomatal conductance and volumetric water content. Our study indicates that in the Pacific Northwest. and likely elsewhere, seedlings benefit from wood microsites, which provide greater water content. Given predictions of increased summer drought in some locations globally, wood microsites at forest line–alpine meadows and forest line–grasslands borders may become increasingly important for successful conifer regeneration.

  1. [Effects of different endophytic fungi on seedling growth of Dendrobium devonianum].

    Science.gov (United States)

    Huang, Hui; Shao, Shi-Cheng; Gao, Jiang-Yun

    2016-06-01

    To obtain seedling growth-promoting fungi is a key step in restoration-friendly cultivation of medicinal Dendrobium species, since there are a large number of functionally-unknown endophytic fungi in the roots of Dendrobium plants.In this study, six functionally-unknown endophytic fungal strains were isolated from roots of D.devonianum using single peleton isolation technology, and used in inoculation experiments to test their effectiveness for seedling growth in D.devonianum.After 90 days of inoculation, comparing with the control treatment, FDdS-1, FDdS-2 and FDdS-4 showed strong pathogenic or fatal effects on seedlings; while, FDdS-12, FDdS-9 and FDdS-5 had different effects on seedling growth.FDdS-5 had significant promoting effects on height, fresh and dry weight, stem diameter and root numbers, while FDdS-9 only had significant promoting effect on seedling height, and FDdS-12 had a negative effect on seedling growth.According to the anatomical features of the inoculated roots, FDdS-5 fungi could infect the velamina of seedlings and the existence of symbiosis pelotons in the cortex cells, suggesting that FDdS-5 is a mycorrhiza fungi of D.devonianum.FDdS-5 and FDdS-9 were identified as Sebacina vermifera and Sebacina sp.by molecular technologies.By using FDdS-5 in the restoration-friendly cultivation of D.devonianum, it could effectively promote seedling growth and shorten the seedling growth periods.The results will aid in reintroduction and cultivation of D.devonianum. Copyright© by the Chinese Pharmaceutical Association.

  2. Responses of seminal wheat seedling roots to soil water deficits.

    Science.gov (United States)

    Trejo, Carlos; Else, Mark A; Atkinson, Christopher J

    2018-04-01

    The aims of this paper are to develop our understanding of the ways by which soil water deficits influence early wheat root growth responses, particularly how seminal roots respond to soil drying and the extent to which information on differences in soil water content are conveyed to the shoot and their impact on shoot behaviour. To achieve this, wheat seedlings have been grown, individually for around 25 days after germination in segmented soil columns within vertical plastic compartments. Roots were exposed to different soil volumetric moisture contents (SVMC) within the two compartments. Experiments where the soil in the lower compartment was allowed to dry to different extents, while the upper was maintained close to field capacity, showed that wheat seedlings allocated proportionally more root dry matter to the lower drier soil compartment. The total production of root, irrespective of the upper or lower SVMC, was similar and there were no detected effects on leaf growth rate or gas exchange. The response of seminal roots to proportionally increase their allocation of dry matter, to the drier soil was unexpected with such plasticity of roots system development traditionally linked to heterogeneous nutrient distribution than accessing soil water. In experiments where the upper soil compartment was allowed to dry, root growth slowed and leaf growth and gas exchange declined. Subsequent experiments used root growth rates to determine when seminal root tips first came into contact with drying soil, with the intentions of determining how the observed root growth rates were maintained as an explanation for the observed changes in root allocation. Measurements of seminal root ABA and ethylene from roots within the drying soil are interpreted with respect to what is known about the physiological control of root growth in drying soil. Copyright © 2018 Elsevier GmbH. All rights reserved.

  3. Evaluation of Freezing Damage in some Pistachio Seedling Rootstocks

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    Maryam Afrousheh

    2018-06-01

    Full Text Available A greenhouse experiment was conducted to evaluate the freezing damage in some pistachio rootstocks by ion leakage and pH changes of leaked solution. A factorial experiment was carried out in randomized block designs (RBD with three factors: Temperature (A including 4 ̊C, 0 ̊C, -2 ̊C, -4 ̊C, -6 ̊C, Time (B including 3, 12, 24h , and Rootstock (C including P. vera cv 'Badami Zarand' (V13 and 'Sarakhs' (S5, P. mutica (M1and P. atlantica (A7. For this, one-year-old seedlings were kept at these five temperatures in incubator for 2 hours. Then in the first 24 hours in three hour intervals and during four days, EC and pH in leaked solution were measured daily. After four days the seedling samples were autoclaved at temperatures 105°C for 4 minutes to destroy all cell membrane. EC and pH of remaining solution were measured again and the percentage of ionic leakage was calculated. The results showed that the best time to evaluate the pH and ionic leakage was 24 hours after incubation of samples. Based on the results, ionic leakage dramatically increased with decreasing temperatures from 0°C to -6°C, while pH of leaked solution had no significant difference in 0°C and 4°C temperature treatments. When temperature reduced from 0°C to -6°C, like ionic leakage, pH greatly reduced. So the pH of the leaked solution could be an appropriate tool to study the freezing damage of pistachio rootstocks. Based on the results of pH and ionic leakage, P. mutica and P. atlantica were the most frost tolerant and sensitive rootstocks of this experiment, respectively.

  4. QTL Analysis of Anoxic Tolerance at Seedling Stage in Rice

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    Yang WANG

    2010-09-01

    Full Text Available Coleoptile lengths of 7-day-old seedlings under anoxic stress and normal conditions were investigated in two permanently segregated populations and their parents in rice (Oryza sativa L.. Using anoxic response index, a ratio of coleoptile length under anoxic stress to coleoptile length under normal conditions, as an indicator of seedling anoxic tolerance (SAT, QTLs for SAT were detected. Two loci controlling SAT, designated as qSAT-2-R and qSAT-7-R, were detected in a recombinant inbred line (RIL population (247 lines derived from a cross between Xiushui 79 (japonica variety and C Bao (japonica restorer line. qSAT-2-R, explaining 8.7% of the phenotype variation, was tightly linked with the SSR marker RM525. qSAT-7-R, explaining 9.8% of the phenotype variation, was tightly linked with the marker RM418. The positive alleles of the two loci came from C Bao. Six loci controlling SAT, designated as qSAT-2-B, qSAT-3-B, qSAT-5-B, qSAT-8-B, qSAT-9-B and qSAT-12-B, were detected in a backcross inbred line (BIL population (98 lines derived from a backcross of Nipponbare (japonica/Kasalath (indica//Nipponbare (japonica. The positive alleles of qSAT-2-B, qSAT-3-B and qSAT-9-B, which explained 16.2%, 11.4% and 9.5% of the phenotype variation, respectively, came from Nipponbare. Besides, the positive alleles of qSAT-5-B, qSAT-8-B and qSAT-12-B, which explained 7.3%, 5.8% and 14.0% of the phenotype variation, respectively, were from Kasalath.

  5. Toxicity Effect of Cr Stress on Seed Germination and Seedling Growth in Lactuca Sativa

    Science.gov (United States)

    Ma, Wan Zheng; Ma, Wan Min; Du, Ying Ying; Dan, Qiong Peng; Yin, Bing; Dai, Shan Shan; Hao, Xiang

    2018-03-01

    The impact of Cr6+ on the growth of lactuca sativa in Greenhouse Cucumber was investigated. The seeds of lacuna sativa Italian bolting resistance lettuce were treated by different Cr6+ concentration to study the effects on its seed germination and seedling growth. The results showed that the seed germination rate, vigor index of seedlings decreased with increment of Cr6+ concentration to varying degrees, and vigor germination, vigor index, raw weight, root length significantly lower. The absorption of lettuce seedlings on different nutrient elements is impacted by the concentration of Cr6+.

  6. Effects of liquid fertilizer application on the morphology and outplanting success of container longleaf pine seedlings

    Science.gov (United States)

    D. Paul Jackson; R. Kasten Dumroese; James P. Barnett; William B. Patterson

    2010-01-01

    Of a range of fertilization rates (0.5, 1.0, 2.0, 3.0, and 4.0 mg nitrogen (N) per seedling per week) applied for 20 weeks, the 2.0-N and 3.0-N seedlings produced good root collar diameter (RCD) growth (6.9 and 7.1 mm, respectively) and needle length ≤ 30 cm. Root collar development did not differ significantly in seedlings receiving the 4.0-mg-N treatment from those...

  7. Rapid Prototyping Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The ARDEC Rapid Prototyping (RP) Laboratory was established in December 1992 to provide low cost RP capabilities to the ARDEC engineering community. The Stratasys,...

  8. 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.

  9. Bacillus amyloliquefaciens L-S60 Reforms the Rhizosphere Bacterial Community and Improves Growth Conditions in Cucumber Plug Seedling

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    Yuxuan Qin

    2017-12-01

    Full Text Available Vegetable plug seedling has become the most important way to produce vegetable seedlings in China. This seedling method can significantly improve the quality and yield of vegetables compared to conventional methods. In the process of plug seedling, chemical fertilizers or pesticides are often used to improve the yield of the seedlings albeit with increasing concerns. Meanwhile, little is known about the impact of beneficial bacteria on the rhizosphere microbiota and the growth conditions of vegetables during plug seedling. In this study, we applied a culture-independent next-generation sequencing-based approach and investigated the impact of a plant beneficial bacterium, Bacillus amyloliquefaciens L-S60, on the composition and dynamics of rhizosphere microbiota and the growth conditions of cucumbers during plug seedling. Our results showed that application of L-S60 significantly altered the structure of the bacterial community associated with the cucumber seedling; presence of beneficial rhizosphere species such as Bacillus, Rhodanobacter, Paenibacillus, Pseudomonas, Nonomuraea, and Agrobacterium was higher upon L-S60 treatment than in the control group. We also measured the impact of L-S60 application on the physiological properties of the cucumber seedlings as well as the availability of main mineral elements in the seedling at different time points during the plug seedling. Results from those measurements indicated that L-S60 application promoted growth conditions of cucumber seedlings and that more available mineral elements were detected in the cucumber seedlings from the L-S60 treated group than from the control group. The findings in this study provided evidence for the beneficial effects of plant growth-promoting rhizosphere bacteria on the bacterial community composition and growth conditions of the vegetables during plug seedling.

  10. Rapid Tooling via Stereolithography

    OpenAIRE

    Montgomery, Eva

    2006-01-01

    Approximately three years ago, composite stereolithography (SL) resins were introduced to the marketplace, offering performance features beyond what traditional SL resins could offer. In particular, the high heat deflection temperatures and high stiffness of these highly filled resins have opened the door to several new rapid prototyping (RP) applications, including wind tunnel test modelling and, more recently, rapid tooling.

  11. Treaty implementation

    International Nuclear Information System (INIS)

    Dunn, L.A.

    1990-01-01

    This paper touches on three aspects of the relationship between intelligence and treaty implementation, a two-way association. First the author discusses the role of intelligence as a basis for compliance monitoring and treaty verification. Second the authors discusses payoffs of intelligence gathering and the intelligence process of treaty implementation, in particular on-site inspection. Third, the author goes in another direction and discusses some of the tensions between the intelligence gathering and treaty-implementation processes, especially with regard to extensive use of on-site inspection, such as we are likely to see in monitoring compliance of future arms control treaties

  12. Rapid surveys for program evaluation: design and implementation of an experiment in Ecuador Encuestas rápidas para la evaluación de programas: diseño y aplicación de un experimento en el Ecuador

    Directory of Open Access Journals (Sweden)

    Kate Macintyre

    1999-09-01

    Full Text Available This paper presents details from the field test of two rapid surveys in Ecuador in 1995. It focuses on how the surveys were designed and implemented, including descriptions of the sampling procedures, the preparation and use of preprogrammed palmtop computers for data entry, the selection criteria for the interviewing team, and how the training was designed. Lessons are drawn that will assist health professionals plan and carry out better rapid data collection in the future. The objective of the study was to evaluate the reliability and validity of data gathered during the rapid surveys as compared with a recent "gold standard" national survey. A two-way factorial design was used to control for differences in sampling (probability versus quasi-probability and methods of data collection (paper versus palmtop computer. Few differences were detected between the surveys done on palmtops as compared to paper ones, but urban and rural differentials in contraceptive use were less pronounced in the rapid surveys than in the earlier, national survey. This suggests that caution should be exercised in interpreting the disaggregated data in these rapid surveys. In-depth interviews revealed two features of the rapid surveys that were especially popular: the palmtops for their speed of data entry, and the short questionnaire for its "low impact" on a respondent's time. The common belief that computers would disturb respondents was not found to be the case. Even with no computer experience, the interviewers rapidly mastered the new technology.Este trabajo detalla algunos aspectos de la prueba en el terreno de dos encuestas rápidas efectuadas en el Ecuador en 1995. Examina el diseño y la aplicación de las encuestas; la preparación y el uso de computadoras de bolsillo preprogramadas para la inclusión de los datos; los criterios de selección del equipo de entrevistadores, y el diseño del adiestramiento. Se extraen lecciones que ayudarán a los

  13. Transcriptomics analysis of etiolated Arabidopsis thaliana seedlings in response to microgravity

    Data.gov (United States)

    National Aeronautics and Space Administration — Gene expression profile of two-week-old etiolated Arabidopsis seedlings under microgravity on board space flight BRIC16 were compared with ground grown control in...

  14. SEED, SEEDLINGS AND GERMINATION MORPHOLOGY OF Copaifera langsdorfii Desf. (Leguminosae-Caesalpinioideae

    Directory of Open Access Journals (Sweden)

    Maria Elane de Carvalho Guerra

    2006-12-01

    Full Text Available The knowledge of seed and seedling morphology are extremely important to the identification and preservation of plant species. In order to studying seed and seedling morphology and seed germination of copaiba (Copaifera langsdorfii Desf seeds, experiments were conducted at the Laboratory of Seed Analysis and Laboratory of Botany of the Federal University of Ceará. In copaíba seeds the characteristics studied were shape, size (length, width, thickness and morphology. The kind of germination, the root systems, hypocotyls, epicotyls and first leaves were the characteristics evaluated in copaiba seedlings. Ruler and pachimeter were used to make the measurements, as well as optical microscope and magnifying glass. The seeds are exalbumin kind, have neuter photoblastism and epigeous germination. Seed coat shows a palisade cell layer with a conspicuous light line. The seedlings have compound first leaves and axial root system.

  15. On DNA synthesis during C14O2 assimilation by peas seedlings

    International Nuclear Information System (INIS)

    Karimov, Kh.Kh.; Nikolaeva, M.I.

    1976-01-01

    In this article authors try to determine how much p articipate t hephotosynthesis in the new formation of DNA seedlings, depends this processfrom the light and realize at this the synthesis DNA in chloroplasts

  16. Localization of cells containing sedimented amyloplasts in the shoots of normal and lazy rice seedlings.

    Science.gov (United States)

    Abe, K; Takahashi, H; Suge, H

    1994-12-01

    We have examined the localization of the cells containing sedimented amyloplasts (putative statocytes) and its relation to the graviresponding sites in the shoots of normal and lazy rice seedlings. All graviresponsive organs of the shoots of normal rice seedlings, the mesocotyl, the coleoptile and the leaf-sheath base, were found to possess the statocytes. This is the first indication that mesocotyl senses gravity by its own cells in inducing gravitropic bending in rice seedlings. In lazy-Kamenoo, although the shoots lost their gravitropic response with the advance of age, sedimentation of amyloplasts itself might not be attributable to the agravitropic growth of the shoots, because, including those of the leaf-sheath bases that had lost their response to gravity, sedimented amyloplasts appeared to be identical to those of normal Kamenoo and of younger seedlings of lazy-Kamenoo whose gravitropism is still apparent.

  17. Effects of 60Co γ-rays irradiation on germination and seedling growth of Hibiscus syriacus

    International Nuclear Information System (INIS)

    Li Xiufen; Wu Fulan; Zhang Deshun; Meng Zhennong; Cao Jiyun

    2009-01-01

    The seeds of Hibiscus syria cus were irradiated by 60 Co γ-rays at dose rate of 50 ∼ 500Gy/h for 0.5 and 1h, the seed germination rate and the seedling growth characters were surveyed. The results indicated that the seed germination was promoted when the absorbed dose was below 200Gy, and the seedling survival rate was increased when the dose was below 100Gy. The germination was inhibited, leaves and secondary roots were difficult to form, and the seedlings blasting occurred when the dose was over 200Gy. The dose rate affects the irradiation results. Absorbed dosed of 50 ∼ 100Gy were suggested for increasing seedling growth rate and 100 ∼ 200Gy were recommend for mutagenesis. (authors)

  18. Effects of water-soluble humic extract and biofertilizer on development of Callophyllum brasiliense seedlings

    Directory of Open Access Journals (Sweden)

    Jader Galba Busato

    2016-06-01

    Full Text Available The objective of this work was to evaluate the effects of water-soluble humic extract (EHSA, Hortbio® biofertilizer (HORT and both compounds combination (EHSA+HORT on vegetative growth, nutrient absorption and chlorophyll levels in guanandi (Callophyllum brasiliense seedlings. Isolated and combined additions of EHSA and HORT did not affect seedlings height, number of leaves, leaf and root dry matter and leaf area during early stages of seedling growth. However, HORT and EHSA+HORT treatments increased chlorophyll levels and total N content. Addition of HORT resulted in S, Zn, Mg, Mn and Cu increases in the seedlings leaves, while ESHA application increased K, Mg, S and B. P and Ca levels were not altered by the treatments, however, addition of EHSA and EHSA+HORT reduced significantly the absorption of Cu, Fe, Mn and Zn.

  19. The role of vanillin and p-coumaric acid in the growth of Scotch pine seedlings

    Directory of Open Access Journals (Sweden)

    M. Michniewicz

    2015-01-01

    Full Text Available It was stated that vanillin and p-coumaric acid used at concentrations 10-8-10-5M stimulated the growth of pine seedlings. Most effective were these substances used at concentration 10-7M. Both phenolic compounds stimulated the elongation, fresh and dry weight in very young seedlings (up to 3-4 weeks and increased the fresh and dry weight only in older ones (7 weeks. The stimulation of growth processes in pine seedlings treated with vanillin and p-coumaric acid coincided with the increase of auxins in roots and with the decrease of free gibberellins in these plant organs. Neither vanillin nor p-coumaric acid influenced the level of ABA-like inhibitor both in the shoots and roots of pine seedlings.

  20. Cross-shore gradients of physical disturbance in mangroves: implications for seedling establishment

    NARCIS (Netherlands)

    Balke, T.; Bouma, T.; Herman, P.M.J.; Horstman, E.M.; Sudtongkong, C.; Webb, E.L.

    2013-01-01

    Mangroves may grow in an active sedimentary environment and are therefore closely linked to physical coastal processes. Seedlings colonize dynamic tidal flats, after which mangroves have the potential to change their physical environment by attenuating hydrodynamic energy and trapping sediments.

  1. Morphology and anatomy of the seedling and the tirodendro of Calophyllum brasiliense Cambess. (Clusiaceae

    Directory of Open Access Journals (Sweden)

    Valquíria Aparecida Mendes de Jesus

    2014-10-01

    Full Text Available Calophyllum brasiliense Cambess. is a tree species that is presented as an alternative to replace endangered species of hardwood. The morphology and anatomy of the seedling of this species is the object of the present study. Seedlings at different stages of development were obtained in greenhouse and analyzed fresh and fixed in FAA (Formalin-Acetic-Alcohol 50. The anatomical analysis was done by the freehand and microtome sections, according to standard techniques in plant anatomy. The seedling and/or tirodendro is cryptocotylar and hypogeal, has cataphylls, and presents eophylls and metaphylls simple with venation pinnate craspedodromous simple. The root is polyarch, the hypocotyl is very short, the cotyledons have an oily and starchy reserve, the epicotyl has stem structure, and eophylls and metaphylls are dorsiventral. The seedling may be classified in the Horsfieldia type/subtype.

  2. Produce of seedlings of cedar in function of types of container and fertilization sources

    Directory of Open Access Journals (Sweden)

    Osmar Henrique de Castro Pias

    2015-06-01

    Full Text Available The aim of this study was to evaluate the production of cedar seedlings according to the size of containers and nutrient sources. It was tested three types of containers (Root trainers, plastic bag and plastic vase, three sources of fertilization (Conventional, Kimcoat® and Osmocote® in seven evaluations. The cedar seedlings in root trainers, fertilized with source Osmocote® presented the greatest increments in height and stem diameter when compared to another sources of fertilization. The plastic bag and plastic vase containers promoted similar seedlings height growth. However the seedlings grown in plastic vase presented greatest growth in stem diameter when compared with the ones in plastic bag.

  3. Toxic metabolities of disulfoton: behavior in bean-seedlings, in soil, and in nutrient solution

    International Nuclear Information System (INIS)

    Andrea, M.M. de

    1986-10-01

    The absorption, translocation and degradation in bean-seedlings of three toxic metabolites of the pesticide 14 C- disulfoton from nutrient solution or three different types of Brazilian soils is studied. (M.A.C.) [pt

  4. The effects of ultraviolet radiation on the growth and gross morphology of Zea mays, Linn. seedlings

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Ann Kristine Joy T.; Mendiola, Carlo Paulo T

    2000-03-01

    The study was conducted with a descriptive experimental design in order to determine the effects of broad spectrum ultraviolet radiation on growth factors, seedling height, root length, chlorophyll content, organic weights, and percentage survival, as well as gross morphological factors, leaf, stem, and root appearance, of native sweet corn seedlings. The study was limited to the seedling stage of the plant and observations were taken after 20 days of treatment. The results gathered show that there was a visible manifestation of the detrimental effects of UV on the irradiated seedlings. There were observed decreases in the growth parameters while the gross morphological parameters exhibited signs of wilting and stress. It was therefore concluded that based on the observed results, UV had a detrimental effect on the studied growth and gross morphological parameters. (Author)

  5. [Status of traditional Chinese medicine materials seed and seedling breeding bases].

    Science.gov (United States)

    Li, Ying; Huang, Lu-Qi; Zhang, Xiao-Bo; Wang, Hui; Cheng, Meng; Zhang, Tian; Yang, Guang

    2017-11-01

    Seeds and seedlings are the material basis of traditional Chinese medicine materials production, and the construction of traditional Chinese medicine materials seed and seedling breeding bases is beneficial to the production of high-quality traditional Chinese medicine materials. The construction of traditional Chinese medicine materials seed and seedling breeding bases is one of the major topics of Chinese medica resources census pilot. Targets, tasks of traditional Chinese medicine materials seed and seedling breeding bases based on Chinese medica resources census pilot were expounded.Construction progress including hardware construction, germplasm conservation and breeding, procedures and standardsestablishment, social servicesare presented. Development counter measures were proposed for the next step: perfect the standard and system, maintain and strengthen the breeding function, strengthen the cultivation of multi-level talents, explore market development model, joint efforts to deepen services and development. Copyright© by the Chinese Pharmaceutical Association.

  6. Hemagglutinating and acid phosphatase (AcPASE activities in developing seedlings of four species of Cucurbitaceae

    Directory of Open Access Journals (Sweden)

    Irena Lorenc-Kubis

    2014-01-01

    Full Text Available The acid phosphatase and hemagglutinating activities of four species of Cucurbitaceae were determined during seeds germination and seedlings development. In all cases traces of enzyme and hemagglutinating activities were found in dry and imbibided seeds. In developing seedlings of Cucumis sativus the activities increased to maximum on the 3rd day while in other species on the 6th day of germination and than fell down. Dot blot and Western blot techniques have shown that in seeds and seedlings of all investigated species present were proteins which cross-reacted with antibodies raised against lectins: CLBa and Con A. It has been shown that proteins from seeds and seedlings of Cucurbita maxima var. bambino, Cucurbita pepo var. giromontia and Cucumis sativus had more pronounced antigenical similarity to lectin CLBa (from Cucurbitaceae than Con A, while proteins from cotyledons of Cucurbita pepo var. patissonina reacted better with antibodies raised against Con A (the lectin from Papilionaceae than with CLBa.

  7. Agroforestry wastes used for germination and development of sweet angelim seedlings

    Directory of Open Access Journals (Sweden)

    João Ricardo Avelino Leão

    2013-03-01

    Full Text Available This paper aimed to define the ideal type of agroforestry substrate and the adequate depth of sweet angelim sowing, providing information on the development of seedlings, as well as on low-cost substrates which are easy to be obtained. An experiment in a greenhouse was carried out, in a completely randomized design with treatments distributed in a factorial scheme (5x3, with the factors agroforestry substrates and depths being replicated seven times with a seed in each container. The following parameters were analyzed: germination percentage, germination speed index, total dry weight, number of leaves, seedlings height and coll diameter, and Dickson’s seedling quality index. The results showed that the most suitable substrate for germination and development of this native species was that containing Brazil nut shell, peanut hull, or açai seed, and the ideal depth for sowing and managing seedlings was on the surface.

  8. Effects of Microbiotic Soil Crust Organisms and Mycorrhizal Fungi on Seedling Growth of Blackbrush (Coleogyne ramosissima)

    National Research Council Canada - National Science Library

    Pendleton, Rosemary

    1999-01-01

    .... A series of experiments conducted from 1993 to 1997 tested the effect of inoculation with arbuscular mycorrhizal fungi on the growth of young blackbrush seedlings under a variety of soil nutrient conditions...

  9. Changes in Endogenous Cytokinins During Germination and Seedling Establishment of Tagetes minuta L.

    Czech Academy of Sciences Publication Activity Database

    Stirk, W.A.; Gold, J.D.; Novák, Ondřej; Strnad, Miroslav; van Staden, J.

    2005-01-01

    Roč. 47, č. 1 (2005), s. 1-7 ISSN 0167-6903 Institutional research plan: CEZ:AV0Z50380511 Keywords : Cytokinins * Germination * Seedling establishment Subject RIV: EF - Botanics Impact factor: 0.841, year: 2005

  10. Juglone effects on seedling growth in intact and coatless seeds of ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-17

    Dec 17, 2008 ... Key words: Juglone, muskmelon, seedling growth, protein content, polyphenol oxidase activity. INTRODUCTION ... Juglone has been isolated from many plants in the .... In pea seeds, a relation between PPO activity and seed.

  11. The Effects of Intermittent Flooding on Seedlings of Three Forest Species

    Science.gov (United States)

    P.H. Anderson; S.R. Pezeshki

    1999-01-01

    Under greenhouse conditions, seedlings of three forest species, baldcypress (Taxodium distichum), nuttall oak (Quercus nuttallii), and swamp chestnut oak (Quercus michauxii) were subjected to an intermittent flooding and subsequent physiological and growth responses to such conditions were evaluated....

  12. Protocols for sagebrush seed processing and seedling production at the Lucky Peak Nursery

    Science.gov (United States)

    Clark D. Fleege

    2010-01-01

    This paper presents the production protocols currently practiced at the USDA Forest Service Lucky Peak Nursery (Boise, ID) for seed processing and bareroot and container seedling production for three subspecies of big sagebrush (Artemisia tridentata).

  13. Evaluation of substrates for seedlings establishment in laboratory of Puya raimondii Harms (Bromeliaceae

    Directory of Open Access Journals (Sweden)

    Giovana Vadillo

    2006-10-01

    Full Text Available Puya raimondii Harms (Bromeliaceae is a monocarpic plant, that can produce about 6 to 12 million seeds, nevertheless is very rare to find seedlings in their natural habitat, indicating difficulties for its establishment. In this work, the conditions for establishment of P. raimondii under laboratory conditions were determined carrying out experiments to determine the better substrate. It was compared the survival and vigour of P. raimondii seedling that were transplanted in peat, moss, peat-soil and moss-soil substrates. The peat substrate showed high survival and was better for establishment of seedlings because it maintains steady and suitable humidity and pH conditions, this allowed that seedlings presents a good vigour. Substrates with very little (case peat-earth or too much (case moss humidity retention had a negative effect over vigour and development.

  14. Effect of long-term drought on carbon allocation and nitrogen uptake of Pinus sylvestris seedlings

    Science.gov (United States)

    Pumpanen, Jukka; Aaltonen, Heidi; Lindén, Aki; Köster, Kajar; Biasi, Christina; Heinonsalo, Jussi

    2015-04-01

    Weather extremes such as drought events are expected to increase in the future as a result of climate change. The drought affects the allocation of carbon assimilated by plants e.g. by modifying the root to shoot ratio, amount of fine roots and the amount of mycorrhizal fungal hyphae. We studied the effect of long term drought on the allocation of carbon in a common garden experiment with 4-year-old Pinus sylvestris seedlings. Half of the seedlings were exposed to long-term drought by setting the soil water content close to wilting point for over two growing seasons whereas the other half was grown in soil close to field capacity. We conducted a pulse labelling with 13CO2 in the end of the study by injecting a known amount of 13C enriched CO2 to the seedlings and measuring the CO2 uptake and distribution of 13C to the biomass of the seedlings and to the root and rhizosphere respiration. In addition, we studied the effect of drought on the decomposition of needle litter and uptake of nitrogen by 15N labelled needles buried in the soil in litter bags. The litterbags were collected and harvested in the end of the experiment and the changes in microbial community in the litterbags were studied from the phospholipid fatty acid (PLFA) composition. We also determined the 15N isotope concentrations from the needles of the seedlings to study the effect of drought on the nitrogen uptake of the seedlings. Our results indicate that the drought had a significant effect both on the biomass allocation of the seedlings and on the microbial species composition. The amount of carbon allocated belowground was much higher in the seedlings exposed to drought compared to the control seedlings. The seedlings seemed to adapt their carbon allocation to long-term drought to sustain adequate needle biomass and water uptake. The seedlings also adapted their osmotic potential and photosynthesis capacity to sustain the long-term drought as was indicated by the measurements of osmotic potential

  15. Physiological responses of seeds and seedlings of lettuce submitted to Philodendron bipinnatifidum extract

    OpenAIRE

    Tiago Zanatta Aumonde; Emanuela Garbin Martinazzo; Tiago Pedó; Junior Borella; Luciano do Amarante; Francisco Amaral Villela; Dario Munt de Moraes

    2013-01-01

    The work was conducted to evaluate the effect of different Philodendron bipinnatifidum Schott. extract concentrations on the physiology and enzymatic metabolism of lettuce seeds and seedlings. The treatments extracts of mature leaves at concentrations of 0, 6, 12, 25 and 50%. Were evaluated the germination, first count germination, speed and germination speed index, length of shoot and primary root, seedling total dry mass, electrical conductivity, chlorophyll content, activity of the enzymes...

  16. 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...

  17. Heat shock protein Hsp90-2 expression in the Arabidopsis thaliana seedlings under clinorotation

    Science.gov (United States)

    Kozeko, Liudmyla

    Heat shock proteins 90 kDa (Hsp90) are abundant under normal conditions and induced by stress. This family is distinguished from other chaperones in that most of its substrates are signal transduction proteins. Previously, we determined some time-dependent increase in the Hsp90 level in pea seedlings in response to simulated microgravity that indicated a stress-reaction. However, expression of the individual members of the Hsp90 family have specific pattern. The purpose of this study was to investigate possible alterations in the gene expression pattern of cytosolic Hsp90-2 in Arabidopsis thaliana seedlings under 2D-clinorotation. To obtain detailed expression pattern of the HSP90-2 genes we used seeds that provides a resource of loss-of-function mutations gene expression patterns via translational fusions with the reporter gene, GUS (a line N 166718, NASC). There were two variants of the experiment: 1) seedlings grew under clinorotation for 10, 12, 14 d; 2) seedlings grew in the stationary conditions for 10 d followed by clinorotation for 3 h -at 22o C and 16h light cycle. The seedlings grown in the stationary conditions were used as a control. GUS staining showed that HSP90-2 expression was regulated during seedling development and affected by clinorotation in the heterozygous mutant plants. In the homozygous for the mutation plants, HSP90-2 expression was stable during seedling development and not affected by clinorotation. GUS staining was observed in cotyledons, leaves and hypocotyls of the seedlings (especially intense in vascular bundles), indicating intensive cellular processes with participation of this chaperone. Possible pathways of influence of clinorotation on HSP90-2 expression are discussed.

  18. Physico-chemical changes in karkade (Hibiscus sabdariffa L.) seedlings responding to salt stress.

    Science.gov (United States)

    Galal, Abdelnasser

    2017-03-01

    Salinity is one of the major abiotic stress factors affecting series of morphological, physiological, metabolic and molecular changes in plant growth. The effect of different concentrations (0, 25, 50, 100 and 150 mM) of NaCl on the vegetative growth and some physiological parameters of karkade (Hibiscus sabdariffa var. sabdariffa) seedling were investigated. NaCl affected the germination rate, delayed emergence and retarded vegetative growth of seedlings. The length of seedling as well as the leaf area was significantly reduced. The fresh weight remained lower in NaCl treated seedlings compared to control. NaCl at 100 and 150 mM concentrations had significant effect on the dry matter contents of the treated seedlings. The chloroplast pigments in the treated seedlings were affected, suggesting that the NaCl had a significant effect on the chlorophyll and carotenoid biosynthesis. The results showed that the salt treatments induced an increase in proline concentration of the seedlings. The osmotic potential (ψs) of NaCl treated seedlings decreased with increasing NaCl concentrations. Salt treatments resulted in dramatic quantitative reduction in the total sterol percent compared with control ones. Salt stress resulted in increase and decrease of Na + and K + ions, respectively. NaCl salinity increased lipid peroxidation. SDS-PAGE was used to evaluate protein pattern after applying salt stress. High molecular weight proteins were intensified, while low molecular weight proteins were faint. NaCl at 100 and 150 mM concentration distinguished with new protein bands. Salt stress induced a new peroxidase bands and increased the band intensity, indicating the protective role of peroxidase enzyme.

  19. Carbon dynamics of Acer pseudoplatanus seedlings under drought and complete darkness.

    Science.gov (United States)

    Piper, Frida I; Fajardo, Alex

    2016-11-01

    Carbon (C) storage is considered a key component to plant survival under drought and shade, although the combined effects of these factors on survival remain poorly understood. We investigated how drought and shade alter the C dynamics and survival of tree seedlings, and whether drought limits the access to or usage of stored C. We experimentally applied two levels of soil humidity (well-watered versus drought, the latter induced by dry-down) and light availability (light versus complete darkness) on 1-year-old seedlings of Acer pseudoplatanus L. for 3 months. We quantified the survival, biomass, growth rate and non-structural carbohydrates (NSC) of seedlings at their time of death or at the end of the experiment for those that survived. We found that the soil dried out faster when drought was combined with light than when it was combined with complete darkness. Seedlings subjected to both drought and light showed reduced growth and reached 100% mortality earlier than any other treatment, with the highest NSC concentrations at the time of death. Seedlings exposed to both drought and complete darkness died significantly earlier than seedlings exposed to complete darkness only, but had similar NSC concentrations at time of their death, suggesting that drought accelerated the use of stored C under complete darkness. Complete darkness significantly reduced seedling growth and whole-plant NSC concentrations regardless of soil humidity, while root NSC concentrations were significantly more reduced when complete darkness was combined with drought conditions. Thus, the C dynamics in A. pseudoplatanus seedlings under complete darkness was not hindered by drought, i.e., the access and use of stored C was not limited by drought. The contrasting growth and C storage responses driven by drought under light versus complete darkness are consistent with a key role of the drought progression in the C dynamics of trees. © The Author 2016. Published by Oxford University Press. All

  20. Use of rice seedlings to estimate uptake of radiocesium from soil to plants in Fukushima Prefecture

    International Nuclear Information System (INIS)

    Fujimura, Shigeto; Suzuki, Yasukazu; Ohno, Takeshi

    2013-01-01

    The uptake of radiocesium to plants from the soil is affected by many environmental factors, and it is difficult to determine the contribution of uptake among these factors. In addition, these environmental factors should be investigated independently for each field. The aim of this study was to develop a practical and simple method for the estimate of uptake of radiocesium from soil to plants. Rice seedlings were used to estimate the root uptake of radiocesium from seven different soils. To confirm that the seedlings were the effective indicator, the concentration of "1"3"7Cs in the seedlings was compared with that in brown rice and sunflower. The seedlings were cultivated for a week from germination in a phytotron and the concentrations of "1"3"7Cs in the seedlings above ground were determined. To obtain brown rice and sunflower, rice and sunflower were cultivated either in a pot (1/5000 a Wagner pot, 4000 cm"3) placed in a glasshouse or in a paddy field in Fukushima prefecture for two to four months. The concentration of "1"3"7Cs in the rice seedlings ranged from 150 to 1900 Bq kg"-"1, and that in brown rice and sunflower ranged from 2 to 880 Bq kg"-"1 and from 580 to 3900 Bq kg"-"1, respectively. The Spearman's rank correlation coefficient between the measured concentration of "1"3"7Cs in rice seedlings and the measured concentration of "1"3"7Cs in brown rice and sunflower was 1.0 (p < 0.001 and p = 0.09, respectively). This suggests that the use of rice seedlings in this experiment over a period of two weeks provides an effective indicator for the uptake of "1"3"7Cs from soil to plants over a longer period of time. (author)

  1. Use of rice seedlings to estimate uptake of radiocesium from soil to plants in Fukushima Prefecture

    International Nuclear Information System (INIS)

    Fujimura, Shigeto; Suzuki, Yasukazu; Ohno, Takeshi

    2012-01-01

    The uptake of radiocesium to plants from the soil is affected by many environmental factors, and it is difficult to determine the contribution of uptake among these factors. In addition, these environmental factors should be investigated independently for each field. The aim of this study was to develop a practical and simple method for the estimate of uptake of radiocesium from soil to plants. Rice seedlings were used to estimate the root uptake of radiocesium from seven different soils. To confirm that the seedlings were the effective indicator, the concentration of 137 Cs in the seedlings was compared with that in brown rice and sunflower. The seedlings were cultivated for a week from germination in a phytotron and the concentrations of 137 Cs in the seedlings above ground were determined. To obtain brown rice and sunflower, rice and sunflower were cultivated either in a pot (1/5000 a Wagner pot, 4000 cm 3 ) placed in a glasshouse or in a paddy field in Fukushima prefecture for two to four months. The concentration of 137 Cs in the rice seedlings ranged from 150 to 1900 Bq kg -1 , and that in brown rice and sunflower ranged from 2 to 880 Bq kg -1 and from 580 to 3900 Bq kg -1 , respectively. The Spearman's rank correlation coefficient between the measured concentration of 137 Cs in rice seedlings and the measured concentration of 137 Cs in brown rice and sunflower was 1.0 (p < 0.001 and p = 0.09, respectively). This suggests that the use of rice seedlings in this experiment over a period of two weeks provides an effective indicator for the uptake of 137 Cs from soil to plants over a longer period of time. (author)

  2. Root system architecture: The invisible trait in container longleaf pine seedlings

    Science.gov (United States)

    Shi-Jean Susana Sung; R. Kasten Dumroese

    2013-01-01

    Longleaf pine (Pinus palustris Mill.) seedlings cultured in four cavity volumes (60 to 336 ml [3.7 to 20.5 cubic inches]), two root pruning treatments (with or without copper coating), and 3 nitrogen levels (low to high) were grown for 29 weeks before they were outplanted into an open area in central Louisiana. Twenty-two months after outplanting, 3 seedlings were...

  3. Some aspects of the Seed Germination and Seedling Growth of two Savanna tree Species

    OpenAIRE

    D.A. Agboola; A.A. Ajiboye; O.O. Fawibe; M.O. Atayese

    2014-01-01

    Studies were made on some aspects of the seed germination and seedling growth of two multipurpose trees. These include the effect of pre sowing treatments, seed sizes and gibberellic acid on the germination of seeds and seedling growth. The tree species include Prosopis africana (Guil & Perr) Taub and Dialium guineense (wild). Two seed sizes designated small- size (Ss) and Big-size (Bs) were identified in the seed. The effect of gibberellic acid (GA3) had a greater significance effect (P < 0....

  4. Effect of phosphate-solubilizing bacteria isolated from semiarid soils on pitahaya seedlings (Hylocereus undatus)

    OpenAIRE

    Bautista-Cruz, Angélica; Ortiz-Hernández, Yolanda Donají; Martínez-Gallegos, Verónica; Martínez Gutiérrez, Gabino

    2015-01-01

    Phosphate-solubilizing bacteria (PSB) are a group of organisms that solubilize fixed forms of phosphorus, making it available for the plant growth. The effect of three PSB strains, called PSBMi, PSBHc and PSBVa, on growth of pitahaya seedlings (Hylocereus undatus) was studied in a growth chamber. The results indicated that plant stem diameter, plant height, plant total dry weight and root length were greatest in pitahaya seedlings inoculated with PSBMi. The increase in these plant growth vari...

  5. A Predictive Coexpression Network Identifies Novel Genes Controlling the Seed-to-Seedling Phase Transition in Arabidopsis thaliana.

    Science.gov (United States)

    Silva, Anderson Tadeu; Ribone, Pamela A; Chan, Raquel L; Ligterink, Wilco; Hilhorst, Henk W M

    2016-04-01

    The transition from a quiescent dry seed to an actively growing photoautotrophic seedling is a complex and crucial trait for plant propagation. This study provides a detailed description of global gene expression in seven successive developmental stages of seedling establishment in Arabidopsis (Arabidopsis thaliana). Using the transcriptome signature from these developmental stages, we obtained a coexpression gene network that highlights interactions between known regulators of the seed-to-seedling transition and predicts the functions of uncharacterized genes in seedling establishment. The coexpressed gene data sets together with the transcriptional module indicate biological functions related to seedling establishment. Characterization of the homeodomain leucine zipper I transcription factor AtHB13, which is expressed during the seed-to-seedling transition, demonstrated that this gene regulates some of the network nodes and affects late seedling establishment. Knockout mutants for athb13 showed increased primary root length as compared with wild-type (Columbia-0) seedlings, suggesting that this transcription factor is a negative regulator of early root growth, possibly repressing cell division and/or cell elongation or the length of time that cells elongate. The signal transduction pathways present during the early phases of the seed-to-seedling transition anticipate the control of important events for a vigorous seedling, such as root growth. This study demonstrates that a gene coexpression network together with transcriptional modules can provide insights that are not derived from comparative transcript profiling alone. © 2016 American Society of Plant Biologists. All Rights Reserved.

  6. Component optimization of dairy manure vermicompost, straw, and peat in seedling compressed substrates using simplex-centroid design.

    Science.gov (United States)

    Yang, Longyuan; Cao, Hongliang; Yuan, Qiaoxia; Luoa, Shuai; Liu, Zhigang

    2018-03-01

    Vermicomposting is a promising method to disposal dairy manures, and the dairy manure vermicompost (DMV) to replace expensive peat is of high value in the application of seedling compressed substrates. In this research, three main components: DMV, straw, and peat, are conducted in the compressed substrates, and the effect of individual components and the corresponding optimal ratio for the seedling production are significant. To address these issues, the simplex-centroid experimental mixture design is employed, and the cucumber seedling experiment is conducted to evaluate the compressed substrates. Results demonstrated that the mechanical strength and physicochemical properties of compressed substrates for cucumber seedling can be well satisfied with suitable mixture ratio of the components. Moreover, DMV, straw, and peat) could be determined at 0.5917:0.1608:0.2475 when the weight coefficients of the three parameters (shoot length, root dry weight, and aboveground dry weight) were 1:1:1. For different purpose, the optimum ratio can be little changed on the basis of different weight coefficients. Compressed substrate is lump and has certain mechanical strength, produced by application of mechanical pressure to the seedling substrates. It will not harm seedlings when bedding out the seedlings, since the compressed substrate and seedling are bedded out together. However, there is no one using the vermicompost and agricultural waste components of compressed substrate for vegetable seedling production before. Thus, it is important to understand the effect of individual components to seedling production, and to determine the optimal ratio of components.

  7. Seedling performance within eight different seed-size alpine forbs under experimentation with irradiance and nutrient gradients

    International Nuclear Information System (INIS)

    Dong, W.; Jun, Z.Y.; Lin, W.G.; Jin, F.

    2014-01-01

    Relative performance of seedlings of species with different seed sizes may vary in response to resource availability, and may affect seedling growth. The objective was to test this hypothesis from alpine forbs species in the Qinghai-Tibetan Plateau. We examined the relative growth rate, allocation and performances of eight native forbs species covering a wide range of seed size in response to four light and three nutrient regimes. Light availability had a significant effect on seedling emergence time, but not on other seedling morphological performances. Seedling emergence time and seed size were negatively correlated with each other for three species within Asteraceae family, i.e. heaviest seeds emerged earlier. Seed size, nutrient availability and their interaction affected most of studied morphological and growth traits of seedlings. Fertilisation modified the relationship between seed size and seedling biomass. Our study showed that seed size and nutrient availability had significant effects on seedling performance in alpine meadows. Seedlings from the larger-seed species presented stronger advantage in initial seedling mass and height under most of resources conditions. (author)

  8. Modeling of genetic gain for single traits from marker-assisted seedling selection in clonally propagated crops

    Science.gov (United States)

    Ru, Sushan; Hardner, Craig; Carter, Patrick A; Evans, Kate; Main, Dorrie; Peace, Cameron

    2016-01-01

    Seedling selection identifies superior seedlings as candidate cultivars based on predicted genetic potential for traits of interest. Traditionally, genetic potential is determined by phenotypic evaluation. With the availability of DNA tests for some agronomically important traits, breeders have the opportunity to include DNA information in their seedling selection operations—known as marker-assisted seedling selection. A major challenge in deploying marker-assisted seedling selection in clonally propagated crops is a lack of knowledge in genetic gain achievable from alternative strategies. Existing models based on additive effects considering seed-propagated crops are not directly relevant for seedling selection of clonally propagated crops, as clonal propagation captures all genetic effects, not just additive. This study modeled genetic gain from traditional and various marker-based seedling selection strategies on a single trait basis through analytical derivation and stochastic simulation, based on a generalized seedling selection scheme of clonally propagated crops. Various trait-test scenarios with a range of broad-sense heritability and proportion of genotypic variance explained by DNA markers were simulated for two populations with different segregation patterns. Both derived and simulated results indicated that marker-based strategies tended to achieve higher genetic gain than phenotypic seedling selection for a trait where the proportion of genotypic variance explained by marker information was greater than the broad-sense heritability. Results from this study provides guidance in optimizing genetic gain from seedling selection for single traits where DNA tests providing marker information are available. PMID:27148453

  9. Optimizing Transcriptome Assemblies for Eleusine indica Leaf and Seedling by Combining Multiple Assemblies from Three De Novo Assemblers

    Directory of Open Access Journals (Sweden)

    Shu Chen

    2015-03-01

    Full Text Available Due to rapid advances in sequencing technology, increasing amounts of genomic and transcriptomic data are available for plant species, presenting enormous challenges for biocomputing analysis. A crucial first step for a successful transcriptomics-based study is the building of a high-quality assembly. Here, we utilized three different de novo assemblers (Trinity, Velvet, and CLC and the EvidentialGene pipeline tr2aacds to assemble two optimized transcript sets for the notorious weed species, . Two RNA sequencing (RNA-seq datasets from leaf and aboveground seedlings were processed using three assemblers, which resulted in 20 assemblies for each dataset. The contig numbers and N50 values of each assembly were compared to study the effect of read number, k-mer size, and in silico normalization on assembly output. The 20 assemblies were then processed through the tr2aacds pipeline to remove redundant transcripts and to select the transcript set with the best coding potential. Each assembly contributed a considerable proportion to the final transcript combination with the exception of the CLC-k14. Thus each assembler and parameter set did assemble better contigs for certain transcripts. The redundancy, total contig number, N50, fully assembled contig number, and transcripts related to target-site herbicide resistance were evaluated for the EvidentialGene and Trinity assemblies. Comparing the EvidentialGene set with the Trinity assembly revealed improved quality and reduced redundancy in both leaf and seedling EvidentialGene sets. The optimized transcriptome references will be useful for studying herbicide resistance in and the evolutionary process in the three allotetraploid offspring.

  10. Performance of Oak Seedlings Grown under Different Oust® XP Regimes

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    Andrew Self

    2014-06-01

    Full Text Available Herbaceous weed control (HWC is prescribed for growing season control of vegetative competition in hardwood afforestation attempts on former agricultural areas. Without HWC, planted seedlings often exhibit poor growth and survival. While currently employed HWC methods are proven, there is a substantial void in research comparing HWC treatments spanning multiple years. A total of 4,320 bare-root seedlings of three oak species were planted on three Mississippi sites. All sites were of comparable soils and received above average precipitation for the majority of the three-year study. Eight combinations of HWC and mechanical site preparation were utilized at each site, with 480 seedlings planted in each of the nine blocks, and a total of 1,440 seedlings per species planted across all sites. Treatments were installed on 3.1 m centers, with mechanical treatments as follows: control, subsoiling, bedding, and combination plowing. HWC treatments included one and two-year applications of Oust® XP. Treatments were applied over seedlings post-planting in 1.5 m bands, at a rate of 140.1 g product/hectare. Excepting one species, HWC dependent height or groundline diameter differences were not detected among mechanical treatments, species, HWC regime, or combinations thereof. No survival differences were observed among site preparation treatments or species. However, analysis detected a growing season/HWC treatment interaction for seedling survival.

  11. Brassinosteroid and gibberellin control of seedling traits in maize (Zea mays L.).

    Science.gov (United States)

    Hu, Songlin; Sanchez, Darlene L; Wang, Cuiling; Lipka, Alexander E; Yin, Yanhai; Gardner, Candice A C; Lübberstedt, Thomas

    2017-10-01

    In this study, we established two doubled haploid (DH) libraries with a total of 207 DH lines. We applied BR and GA inhibitors to all DH lines at seedling stage and measured seedling BR and GA inhibitor responses. Moreover, we evaluated field traits for each DH line (untreated). We conducted genome-wide association studies (GWAS) with 62,049 genome wide SNPs to explore the genetic control of seedling traits by BR and GA. In addition, we correlate seedling stage hormone inhibitor response with field traits. Large variation for BR and GA inhibitor response and field traits was observed across these DH lines. Seedling stage BR and GA inhibitor response was significantly correlate with yield and flowering time. Using three different GWAS approaches to balance false positive/negatives, multiple SNPs were discovered to be significantly associated with BR/GA inhibitor responses with some localized within gene models. SNPs from gene model GRMZM2G013391 were associated with GA inhibitor response across all three GWAS models. This gene is expressed in roots and shoots and was shown to regulate GA signaling. These results show that BRs and GAs have a great impact for controlling seedling growth. Gene models from GWAS results could be targets for seeding traits improvement. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Stress-induced accumulation of wheat germ agglutinin and abscisic acid in roots of wheat seedlings

    International Nuclear Information System (INIS)

    Cammue, B.P.A.; Broekaert, W.F.; Kellens, J.T.C.; Peumans, W.J.; Raikhel, N.V.

    1989-01-01

    Wheat germ agglutinin (WGA) levels in roots of 2-day-old wheat seedlings increased up to three-fold when stressed by air-drying. Similar results were obtained when seedling roots were incubated either in 0.5 molar mannitol or 180 grams per liter polyethylene glycol 6,000, with a peak level of WGA after 5 hours of stress. Longer periods of osmotic treatment resulted in a gradual decline of WGA in the roots. Since excised wheat roots incorporate more [ 35 S]cysteine into WGA under stress conditions, the observed increase of lectin levels is due to de novo synthesis. Measurement of abscisic acid (ABA) levels in roots of control and stressed seedlings indicated a 10-fold increase upon air-drying. Similarly, a five- and seven-fold increase of ABA content of seedling roots was found after 2 hours of osmotic stress by polyethylene glycol 6,000 and mannitol, respectively. Finally, the stress-induced increase of WGA in wheat roots could be inhibited by growing seedlings in the presence of fluridone, an inhibitor of ABA synthesis. These results indicate that roots of water-stressed wheat seedlings (a) contain more WGA as a result of an increased de novo synthesis of this lectin, and (b) exhibit higher ABA levels. The stress-induced increase of lectin accumulation seems to be under control of ABA

  13. Machine site preparation improves seedling performance on a high-elevation site in southwest Oregon

    International Nuclear Information System (INIS)

    McNabb, D.H.; Baker-Katz, K.; Tesch, S.D.

    1993-01-01

    Douglas-fir (Pseudotsuga menziesii) seedlings planted on areas receiving one of four site-preparation treatments (scarify, scarify/till, soil removal, and soil removal/till) and on unprepared control areas were compared for 5 yr at a high-elevation, nutrient-poor site in the western Siskiyou Mountains of southwest Oregon. Fifth-year survival of seedlings was at least 85% among machine-prepared plots, compared to 42% on control plots. Cover of competing vegetation remained less than 25% during the period for all machine treatments. In contrast, vegetation cover on control plots was 30% at the time of planting and increased to nearly 75% after 5 yr. Competing vegetation clearly impeded seedling performance. The effects of unusually droughty conditions at the time of planting in 1982 were examined further by interplanting additional seedlings in the soil-removal treatment in 1985. The interplanting was followed by more normal spring precipitation, and seedlings grew better over 5 yr than those planted in 1982. The slow recovery of competing vegetation and generally poor seedling growth on all treatments during both planting years are attributed to low soil fertility

  14. Do seedling functional groups reflect ecological strategies of woody plant species in Caatinga?

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    Tatiane Gomes Calaça Menezes

    2017-11-01

    Full Text Available ABSTRACT It is assumed that morphological traits of seedlings reflect different strategies in response to environmental conditions. The ecological significance of this has been widely documented in rainforests, where habitat structure and species interactions play an important role in community assembly. However, in seasonally dry ecosystems, where environmental filtering is expected to strongly influence community structure, this relationship is poorly understood. We investigated this relationship between functional groups of seedlings and life history traits and tested whether functional group predicts the ecological strategies employed by woody species to deal with the stressful conditions in seasonally dry ecosystems. Seedling functional groups, life history traits and traits that reflect ecological strategies for occupying seasonally dry environments were described for twenty-six plant species. Seedlings of species from the Caatinga vegetation exhibited a functional profile different from that observed in rainforests ecosystems. Phanerocotylar-epigeal seedlings were the most frequently observed groups, and had the largest range of ecological strategies related to dealing with seasonally dry environments, while phanerocotylar-hypogeal-reserve seedlings exhibited an increase in frequency with seasonality. We discuss these results in relation to those observed in other tropical forests and their ecological significance in seasonally dry environments.

  15. Properties of Plasma Membrane from Pea Root Seedlings under Altered Gravity

    Science.gov (United States)

    Klymchuk, D.; Baranenko, V.; Vorobyova, T. V.; Kurylenko, I.; Chyzhykova, O.; Dubovoy, V.

    In this study, the properties of pea (Pisum sativum L.) plasma membrane were examined to determine how the membrane structure and functions are regulated in response to clinorotation (2 rev/min) conditions. Membrane preparations enriched by plasma membrane vesicles were obtained by aqueous two-phase partitioning from 6-day seedling roots. The specific characteristics of H^+-ATPase, lípid composition and peroxidation intensity as well as fluidity of lipid bilayer were analysed. ATP hydrolytic activity was inhibited by ortovanadate and was insensitive to aside and nitrate in sealed plasma membrane vesicles isolated from both clinorotated and control seedlings. Plasma membrane vesicles from clinorotated seedlings in comparison to controls were characterised by increase in the total lipid/protein ratio, ATP hydrolytic activity and intensifying of lipid peroxidation. Sitosterol and campesterol were the predominant free sterol species. Clinorotated seedlings contained a slightly higher level of unsaturated fatty acid than controls. Plasma membrane vesicles were labelled with pyrene and fluorescence originating from monomeric (I_M) molecules and excimeric (I_E) aggregates were measured. The calculated I_E/I_M values were higher in clinorotated seedlings compared with controls reflecting the reduction in membrane microviscosity. The involvement of the changes in plasma membrane lipid content and composition, fluidity and H^+-ATPase activity in response of pea seedlings to altered gravity is discussed.

  16. Interactive effects of rice residue and water stress on growth and metabolism of wheat seedlings

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    Nimisha Amist

    2014-08-01

    Full Text Available In the present study effects of rice residue with and without water stress were studied on Triticum aestivum L. cv. Shatabadi. The mixture of residue and garden soil in 1:1 ratio was considered as 50% (R1 and only decomposed residue as 100% (R2. Garden soil was taken as control. Twenty five seeds were sown in each experimental trays filled with soil mixture according to the treatments. Trays were arranged in two groups. After 15 days one set was subjected to water stress (WS by withholding water supply for 3 days. Morphological and biochemical parameters of 18 days old seedlings were recorded. Seedling height decreased in all treatments. A gradual decrease in relative water content, pigment and protein contents of wheat seedlings were observed. Sugar and proline contents increased in treatments. An increase in malondialdehyde (MDA content and antioxidative enzyme activities was recorded. Elevation in catalase activity was observed in all treatments except in plants with water deficit. Ascorbate peroxidase (APX and guaiacol peroxidase (GPX activities increased when residue mixed with soil but decreased in seedlings under the combined influence of the residue and water stress. Higher amount of MDA and lower activities of APX and GPX reflected the oxidative damage in seedlings under combined treatments. Rice residue inhibited growth of wheat seedlings. Water stress intensified the effects of residue.

  17. On hybridising lettuce seedlings with nanoparticles and the resultant effects on the organisms' electrical characteristics.

    Science.gov (United States)

    Gizzie, Nina; Mayne, Richard; Patton, David; Kendrick, Paul; Adamatzky, Andrew

    2016-09-01

    Lettuce seedlings are attracting interest in the computing world due to their capacity to become hybrid circuit components, more specifically, in the creation of living 'wires'. Previous studies have shown that seedlings can be hybridised with gold nanoparticles and withstand mild electrical currents. In this study, lettuce seedlings were hybridised with a variety of metallic and non-metallic nanomaterials: carbon nanotubes, graphene oxide, aluminium oxide and calcium phosphate. Toxic effects and the following electrical properties were monitored: mean potential, resistance and capacitance. Macroscopic observations revealed only slight deleterious health effects after administration with one variety of particle, aluminium oxide. Mean potential in calcium phosphate-hybridised seedlings showed a considerable increase when compared with the control, whereas those administered with graphene oxide showed a small decrease; there were no notable variations across the remaining treatments. Electrical resistance decreased substantially in graphene oxide-treated seedlings whereas slight increases were shown following calcium phosphate and carbon nanotubes applications. Capacitance showed no considerable variation across treated seedlings. These results demonstrate that use of some nanomaterials, specifically graphene oxide and calcium phosphate, may be towards biohybridisation purposes including the generation of living 'wires'. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Production and development of eucalyptus seedlings in function of doses of phosphorus

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    José Henrique Tertulino Rocha

    2013-12-01

    Full Text Available This study evaluated the effect of phosphorus (P on the survival in the nursery and early development in the field of clonal Eucalyptus urophylla x Eucalyptus grandis seedlings. The experimental design was completely randomized with four treatments and five replicates of 30 plants per replicate. At the end of the cycle (90 days, 15 seedlings were used for determining the dry matter accumulation and nutrient concentration in the shoot. The rest was planted in the field to determine the percentage of survival and early development. The treatments consisted of four doses of P fertilization (0.0, 1.3, 2.6 and 5.2 mg plant-1. To obtain high quality seedlings in conditions similar to this experiment it is required doses of P in the range from 3.6 to 3.8 mg plant-1. Doses greater than 4 mg plant-1 affect the development and quality of eucalyptus seedlings. An adequate phosphorus fertilization of eucalyptus seedlings increase, by about 30%, the percentage of surviving seedlings in the field.

  19. Interspecific variation in tree seedlings establishment in canopy gaps in relation to tree density

    Energy Technology Data Exchange (ETDEWEB)

    Reader, R.J.; Bonser, S.P.; Duralia, T.E.; Bricker, B.D. [Guelph Univ., ON (Canada). Dept. of Botany

    1995-10-01

    We tested whether interspecific variation in tree seedling establishment in canopy gaps was significantly related to interspecific variation in tree density, for seven deciduous forest tree species (Quercus alba, Hamamelis virginiana, Acer rubrum, Sassafras albidum, Quercus rubra, Prunus serotina, Ostrya virginiana). For each species, seedling establishment was calculated as the difference in seedling density before experimental gap creation versus three years after gap creation. In each of the six experimentally-created gap types (33% or 66% removal of tree basal area from 0.01ha, 0.05ha or 0.20ha patches), differences in seedling establishment among species were significantly related to differences in their density in the tree canopy. A regression model with log{sub e} tree density as the independent variable accounted for between 93% and 98% of interspecific variation in seedling establishment. Our results provide empirical support for models of tree dynamics in gaps that assume seedling establishment depends on canopy tree density. 17 refs, 1 fig, 3 tabs

  20. Elevational Distribution of Adult Trees and Seedlings in a Tropical Montane Transect, Southwest China

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    Xiaoyang Song

    2016-08-01

    Full Text Available Montane habitats are characterized by high variation of environmental factors within small geographic ranges, which offers opportunities to explore how forest assemblages respond to changes in environmental conditions. Understanding the distributional transition of adult trees and seedlings will provide insight into the fate of forest biodiversity in response to future climate change. We investigated the elevational distribution of 156 species of adult trees and 152 species of seedlings in a tropical montane forest in Xishuangbanna, southwest China. Adult trees and seedlings were surveyed within 5 replicate plots established at each of 4 elevational bands (800, 1000, 1200, and 1400 m above sea level. We found that species richness of both adult trees and seedlings changed with elevation, showing a notable decline in diversity values from 1000 to 1200 m. Tree species composition also demonstrated distinct differences between 1000 and 1200 m, marking the division between tropical seasonal rain forest (800 and 1000 m and tropical montane evergreen broad-leaved forest (1200 and 1400 m. The results suggested that soil moisture and temperature regimes were associated with elevational distribution of tree species in this region. We also observed that seedlings from certain species found at high elevations were also distributed in low-elevation zones, but no seedlings of species from low elevations were distributed in high-elevation zones. The increase in temperature and droughts predicted for this region may result in the contraction of tropical seasonal rain forest at lower elevations and a downhill shift of higher tropical montane tree species.