WorldWideScience

Sample records for seedling production

  1. 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.

  2. 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...

  3. Production of desert rose seedlings in different potting media

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    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.

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

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    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.

  5. 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...

  6. Biodegradable bags for the production of plant seedlings

    Directory of Open Access Journals (Sweden)

    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.

  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. 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...

  9. Experiences in the containerized tree seedlings forest nurseries production

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    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.

  10. Effect of petroleum products on mangrove seedlings

    Digital Repository Service at National Institute of Oceanography (India)

    Jagtap, T.G.; Untawale, A.G.

    The effect of petrol, diesel and motor oil was studied on the fruits of Rhizophora mucronata and Avicennia officinalis. The former species was found to be more resistant to these petroleum products than the latter, in which more toxic effect were...

  11. 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.

  12. 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...

  13. 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).

  14. 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,...

  15. 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...

  16. 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 ...

  17. EVALUATION OF CO-PRODUCT OF VERMICULITE AS SUBSTRATE IN SEEDLINGS PRODUCTION OF NIM

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    G. H. Silva

    2014-09-01

    Full Text Available This study evaluated the effect of different doses of organic matter and fertilizer PK neem seedlings grown in co-product of vermiculite. At the end of the experiment, the seedlings were separated into root, stem and leaves, then the material was placed in an oven and subsequent weighing. The parameters evaluated were: height, diameter, number of leaves, root length, IQD (Dickson quality index and TDM (total dry mass. The design used in the experiment was the DIC with seven levels of organic matter (OM (0, 5, 10, 15, 20, 25, 30% and three fertilization PK (Phosphorus and Potassium (PK0, PK100, PK300 with four replications. For doses of OM and fertilization was applied polynomial regression grade 2 at 5% of probability. The results of the analysis of variance showed that there were significant positive quadratic effect among all levels of treatment with OM on all variables. However, all variables were not statistically different for PK and PK + OM in all parameters evaluated. Thus the species under study shows no demand of chemical fertilizer in their early growth stages. The IQD values at a dose of 20% of OM indicate higher rates of development. The dose of 5% of OM in co-product of vermiculite is enough to produce seedlings of nem of good quality.

  18. Controlled release fertilizer and container volumes in the production of Parapiptadenia rigida (Benth. Brenan seedlings

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    Ezequiel Gasparin

    2015-10-01

    Full Text Available Growing demand for native tree seedlings will require improvements in quality standards of production processes through the use of more efficient cultivation techniques. This study evaluated the effects of different doses of controlled release fertilizer (CRF and different container volumes in the production of Parapiptadenia rigida seedlings. We examined the effects of five different concentrations (0, 3, 6, 9 and 12 g L-1 substrate of CRF (18-5-9 NPK and three different container volumes (50, 110 and 180 cm3 on seedling height (H and collar diameter (CD measured monthly for seven months and then calculated H/CD ratios. After 210 days of growth, the dry masses of the aerial portions, root systems, and total masses were determined, as well as the concentrations of macro- and micronutrients in the aerial portions of the seedlings. In general, the dose 9 g L-1 substrate combined with the 180 cm3 cultivation tubes demonstrated the best results in terms of the morphological variables analyzed, resulting in consistent quality seedlings for field planting.

  19. RESEARCH ON THE DEVELOPMENT OF ALTERNATIVE TECHNOLOGIES FOR THE PRODUCTION OF TOMATO SEEDLINGS IN DRĂGANU ARGEŞ

    OpenAIRE

    Florina Uleanu; Adriana Bădulescu

    2017-01-01

    This paper aims to find the most efficient techniques for the production of seedlings because it represents one of the greatest concerns of the vegetable growers, being a subject of great interest. A special attention shows determining influence of different pots, plastic or biodegradable, on the growth and development of tomato seedlings. The replanting of the seedlings was carried out in various pots (of polyethylene film, from peat, Jiffy pots, small and big alveolar pallets ) filled wi...

  20. Calculating Optimum sowing factor: A tool to evaluate sowing strategies and minimize seedling production cost

    Science.gov (United States)

    Eric van Steenis

    2013-01-01

    This paper illustrates how to use an excel spreadsheet as a decision-making tool to determine optimum sowing factor to minimize seedling production cost. Factors incorporated into the spreadsheet calculations include germination percentage, seeder accuracy, cost per seed, cavities per block, costs of handling, thinning, and transplanting labor, and more. In addition to...

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

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    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.

  2. Nutrient solution and substrates for ‘cedro doce’ (Pochota fendleri seedling production

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    Oscar J. Smiderle

    Full Text Available ABSTRACT This study assessed the effect of different substrates and addition of nutrient solution on the production of Pochota fendleri seedlings, leaf contents of macro and micronutrients and chlorophyll a and b. The experimental design was completely randomized, in a 3 x 2 factorial scheme, with four replicates. The factors were three substrates, with or without addition of nutrient solution, composing six treatments: (T1 = sand; (T2 = soil; (T3 = sand + soil (1:1; (T4 = sand + nutrient solution; (T5 = soil + nutrient solution; (T6 = sand + soil + nutrient solution. Growth characteristics (height, collar diameter, shoot dry matter, root dry matter, root/shoot ratio and total dry matter and contents of macro- and micronutrients and chlorophyll a and b were evaluated. The use of nutrient solution reduces the time to obtain seedlings of Pochota fendleri, and it is important for proper growth and quality of seedlings. The sequence of nutritional requirement presented by Pochota fendleri seedlings in three substrates with addition of nutrient solution follows the descending order: macronutrients (N > Ca > K > Mg > P > S and micronutrients (Fe > Mn > B > Zn > Cu.

  3. The production of Physalis spp. seedlings grown under different-colored shade nets

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    Daniel Fernandes da Silva

    2016-04-01

    Full Text Available The objective of this study was to evaluate the production of seedlings of Physalis L. species under different-colored shade nets. Four shade nets individually stained white, blue, red and black, all with 50% shading, were used in this study, and an additional  treatment (control was used in which seedlings were grown in full sun. The study examined four species of Physalis, namely, P. peruviana, P. pubescens, P. minima and P. ixocarpa. The experiment followed a randomized block design with three blocks and 25 seeds per plot. The species were sown in styrofoam trays. Germination was monitored daily to calculate the Emergency Velocity Index (EVI and stabilize the overall percentage of emergence. Height, stem diameter, number of leaves, leaf area index and dry mass of seedlings were assessed at 50 days after sowing. The study found that these species react differently to changes in the light spectrum. Seedlings of P. peruviana should be grown under a white or red shade net; of P. pubescens under a white or black shade net; of P. minima under a white, red or black shade net; and of P. ixocarpa under a white shade net. For all species, 50% shade should be used.

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

    African Journals Online (AJOL)

    Yomi

    2011-12-21

    Dec 21, 2011 ... Walnut production does not constitute considerable share in this region. .... average farm's historical selling prices for the 2003-2008 period. The prices ... material costs, depreciation costs and insurance premium. Then, the ...

  5. Production of gherkin seedlings in coconut fiber fertirrigated with different nutrient solutions

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    Francisco de Assis de Oliveira

    Full Text Available ABSTRACT Seedling quality is a key factor to achieve success in vegetable production. The present work aimed to evaluate the production of gherkin seedlings in substrate of coconut fiber fertirrigated with different concentrations of nutrients. The experimental design was completely randomized in a 3 × 5 factorial with four replications. The treatments consisted of combinations of three cultivars of gherkin (Do Norte, Liso de Calcutá, e Liso Gibão with five concentrations of nutrients in the solution (0, 25, 50, 75, and 100%. The nutrient solution, considered standard, matches the recommended solution for melon in hydroponic systems. We evaluated the variables: chlorophyll index, shoot length, number of leaves, stem diameter, main root length, dry weight of leaves, roots, and stem, mass of total dry matter, leaf area, specific leaf area, and leaf area ratio. All variables were affected by the ionic concentration in nutrient solutions. The use of coconut fiber in the production of gherkin seedlings is more efficient with nutrient solutions in concentrations ranging from 75 to 100% of the recommended solution for melon cultivation.

  6. RESEARCH ON THE DEVELOPMENT OF ALTERNATIVE TECHNOLOGIES FOR THE PRODUCTION OF TOMATO SEEDLINGS IN DRĂGANU ARGEŞ

    Directory of Open Access Journals (Sweden)

    Florina Uleanu

    2017-12-01

    Full Text Available This paper aims to find the most efficient techniques for the production of seedlings because it represents one of the greatest concerns of the vegetable growers, being a subject of great interest. A special attention shows determining influence of different pots, plastic or biodegradable, on the growth and development of tomato seedlings. The replanting of the seedlings was carried out in various pots (of polyethylene film, from peat, Jiffy pots, small and big alveolar pallets filled with nutritional mixture. The best growth in height was achieved in seedlings transplanted in polyethylene pots (B1, except for Parris hybrid, the favorable effects on seedlings growth being explained by their better nutritional capacity as a result of the development of a stronger root system. As a type of pot, it is noted that seedlings transplanted into large alveolar pallets formed floral buds before planting in all hybrids studied. The type of pots used to transplant seedlings, and especially their size, positively influences the number of leaves. This work brings to the forefront the influence of different pots of plastic or biodegradable material on the growth and development of tomato seedlings that have been transplanted and maintained in these pots until planting.

  7. The impact of seeds provenance and nursery production method on Austrian pine (Pinus nigra Arn. seedlings quality

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    Vladan Ivetić

    2013-11-01

    Full Text Available The influence of seed provenances and seedling production methodson quality of one and two years old seedlings of Austrian pine wereinvestigated. Seeds from three provenances of Austrian pine (Goč, Studenica and Šargan were used for seedlings production, combined with three production methods: (i the modified seedbeds (bare-root, (ii the container type Plantagrah II and (iii the container type Gočko. Provenance, as well as the combined influence of provenance and production method had minimal influence on the variability of one and two years old Austrian pine seedlings. Nevertheless, the production method had the highest influence. The production system, besides its importance in nursery, will have a high influence on seedlings growth during the first year after planting. Considering the results of this study (e.g. the highest values of the diameter, number of lateral roots, shoot and root dry weight, and quality index and the lowest value of SQ and satisfactory value of S:R, we can conclude that the seedlings produced in container type Gočko led to the highestseedlings quality, recommended especially for afforestation on hard sites.

  8. SEEDLING PRODUCTION OF Hymenaea courbaril L. IN DIFFERENT ENVIRONMENTS, RECIPIENTS AND SUBSTRATE COMPOSITIONS

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    José Luiz Sandes de Carvalho Filho

    2003-01-01

    Full Text Available ABSTRACT: The aim of this work was to evaluate the effect of two environments, differentsubstrate mixtures and two recipient sizes on emergence and seedling development of Hymenaeacourbaril L. Two environments (full sun and environment protected with 50% black screen, foursubstrate mixtures [soil; soil + bovine manure (2:1; soil + sand (1:1 and soil + sand + bovinemanure (1:2:1] and two recipient sizes (11x18cm and 15x20cm plastic bags were tested.Emergency started 20 days after sowing and prolonged till 180 days. Seed emergency reached41% at full sun and 26% in environment protected with 50% black screen. The substrate mixturesoil + sand + bovine manure (1:2:1 can be used for Hymenaea courbaril seedling production in15x20cm plastic bags and full sun environment.

  9. 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...

  10. 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.

  11. Productivity responses of Acer rubrum and Taxodium distichum seedlings to elevated CO2 and flooding

    Science.gov (United States)

    Vann, C.D.; Megonigal, J.P.

    2002-01-01

    Elevated levels of atmospheric CO2 are expected to increase photosynthetic rates of C3 tree species, but it is uncertain whether this will result in an increase in wetland seedling productivity. Separate short-term experiments (12 and 17 weeks) were performed on two wetland tree species, Taxodium distichum and Acer rubrum, to determine if elevated CO2 would influence the biomass responses of seedlings to flooding. T. distichum were grown in replicate glasshouses (n = 2) at CO2 concentrations of 350 or 700 ppm, and A. rubrum were grown in growth chambers at CO2 concentrations of 422 or 722 ppm. Both species were grown from seed. The elevated CO2 treatment was crossed with two water table treatments, flooded and non-flooded. Elevated CO2 increased leaf-level photosynthesis, whole-plant photosynthesis, and trunk diameter of T. distichum in both flooding treatments, but did not increase biomass of T. distichum or A. rubrum. Flooding severely reduced biomass, height, and leaf area of both T. distichum and A. rubrum. Our results suggest that the absence of a CO2-induced increase in growth may have been due to an O2 limitation on root production even though there was a relatively deep (??? 10 cm) aerobic soil surface in the non-flooded treatment. ?? 2001 Elsevier Science Ltd. All rights reserved.

  12. Transcriptional regulation of genes involved in terpenoid índole alkaloid production in Catharanthus roseus seedlings

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    Pedro J. Rocha

    2002-07-01

    Full Text Available Catharanthus roseus (L. G Don is a medicinal plant that produces a variety of terpenoid indole alkaloids (TIAs, some of which display pharmacological activity. C. roseus plants and cell cultures have been used to elucidate the TIAs biosynthetic pathway. A considerable number or enzymes have also been characterised, and their respective genes cloned. TIAs production in C. roseus plant and cell cultures is highly regulated at transcriptional-, develop-mental-, and environmental-level. Studies into TIAs biosynthetic gene regulation have been carried out using cell cultures. However, regulation in plants is almost unknown. Here, biosynthetic genes idc, strl, d4h and dat expres-sion levels are qualitatively examined in a developmental series of C. roseus seedlings. The effect of water- and light-stress and methyl jasmonate (MeJa and acetyl salicylic acid (ASA elicitation is also examined. Comparison between seedlings and cell cultures strongly suggests that TIAs biosynthetic gene transcriptional regulation is different in C.roseus plants and cell cultures.

  13. Sustrates and nutrient solutions for obtaining pipper seedlings and its influences on the production in crops protected

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    Mairely Sarduy Díaz

    2016-10-01

    Full Text Available To achieve the productive success in the production of the pepper (Capsicum annum L. in protected crop is necessary to guarantee the quality of the seedlings. For that the objective of this investigation was to evaluate mixtures with crowd + coconut fiber and worm humus as substrates and three nutritious solutions for the production of seedlings of pepper and its later influence on the production. In the nursery phase an assay in a design totally randomized was used in factorial arrangement 32, being the factors, substrate and nutritious solution where variables of growth and development were evaluated, in 25 seedlings for treatment. In the experiment in field phase was given pursuit to the plants coming from the nine treatments of the nursery phase in a design at random blocks with four replicas, where components of the yield were evaluated in 10 plants by parcel and the yield in the total parcel. The data were processed by means of a variance analysis using the statistical package SPSS version 15. The employment of worm humus with the nutritious solution B and the humus with the crowd and coconut plus the application of the nutritious solutions A and B allows obtaining pepper seedlings with the established quality. These combinations stand out in the production phase for the percentage of flourishing plants, mass of the fruits and the yield, for that the employment of these substrates, constitute new alternatives for this technology.

  14. 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.

  15. 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)

  16. From seed production to seedling establishment: Important steps in an invasive process

    Science.gov (United States)

    Ferreras, Ana Elisa; Galetto, Leonardo

    2010-03-01

    It is widely accepted that exotic invasive species are one of the most important ecological and economic problems. Reproductive and establishment traits are considered key features of a population expansion process, but few works have studied many of these simultaneously. This work examines how large the differences are in reproductive and establishment traits between two Fabaceae, the exotic invasive, Gleditsia triacanthos and the native, Acacia aroma. Gleditsia is a serious leguminous woody invader in various parts of the world and Acacia is a common native tree of Argentina. Both species have similar dispersal mechanisms and their reproductive phenology overlaps. We chose 17 plants of each species in a continuous forest of the Chaco Serrano Forest of Córdoba, Argentina. In each plant we measured fruit production, fruit removal (exclusion experiments), seed predation (pre- and post-dispersal), seed germination, seed bank (on each focal tree, three sampling periods during the year), and density of seedlings (around focal individuals and randomly in the study site). Gleditsia presented some traits that could favour the invasion process, such as a higher number of seeds per plant, percentage of scarified seed germination and density of seedlings around the focal individuals, than Acacia. On the other hand, Gleditsia presented a higher percentage of seed predation. The seed bank was persistent in both species and no differences were observed in fruit removal. This work highlights the importance of simultaneously studying reproductive and establishment variables involved in the spreading of an exotic invasive species. It also gives important insight into the variables to be considered when planning management strategies. The results are discussed from the perspective of some remarkable hypotheses on invasive species and may contribute to rethinking some aspects of the theory on invasive species.

  17. Phenotypic plasticity of fine root growth increases plant productivity in pine seedlings

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    Grissom James E

    2004-09-01

    Full Text Available Abstract Background The plastic response of fine roots to a changing environment is suggested to affect the growth and form of a plant. Here we show that the plasticity of fine root growth may increase plant productivity based on an experiment using young seedlings (14-week old of loblolly pine. We use two contrasting pine ecotypes, "mesic" and "xeric", to investigate the adaptive significance of such a plastic response. Results The partitioning of biomass to fine roots is observed to reduce with increased nutrient availability. For the "mesic" ecotype, increased stem biomass as a consequence of more nutrients may be primarily due to reduced fine-root biomass partitioning. For the "xeric" ecotype, the favorable influence of the plasticity of fine root growth on stem growth results from increased allocation of biomass to foliage and decreased allocation to fine roots. An evolutionary genetic analysis indicates that the plasticity of fine root growth is inducible, whereas the plasticity of foliage is constitutive. Conclusions Results promise to enhance a fundamental understanding of evolutionary changes of tree architecture under domestication and to design sound silvicultural and breeding measures for improving plant productivity.

  18. The effect of light quality on ethylene production in leaves of oat seedlings (Avena sativa L.)

    International Nuclear Information System (INIS)

    Corbineau, F.; Rudnicki, R.M.; Goszczynska, D.M.; Come, D.

    1995-01-01

    The effect of UV, blue, green, red, far-red and white fluorescent lights at a fluence of 1.5–20 μmol m −2 s −1 photon flux density (PFD) on endogenous and ACC-dependent ethylene production by etiolated and green apical oat-leaf segments was investigated. It was found that endogenous ethylene production in light-irradiated green and etiolated oat leaves depends upon light quality and its fluence. All light of the visible spectrum (400–700 nm) at PFD 5–20 μmol m −2 s −1 reduced conversion of ACC to ethylene in green oat leaves incubated in 10 −3 M ACC. Blue light was most effective in the inhibition of ACC-dependent ethylene production at 5–10 μmol m −2 s −1 PFD, and endogenous ethylene formation at 10 μmol m −2 s −1 PFD. At 20 μmol m −2 s −1 PFD, all visible light wavebands substantially reduced endogenous ethylene production but blue and red light were most effective. In etiolated leaves UV at 1.5 μmol m −2 s −1 PFD, enhanced endogenous ethylene production and other lights at 20 μmol m −2 s −1 PFD decreased evolution of ethylene, whereas ACC-dependent ethylene formation was stimulated by UV, red and far-red wavebands. Growth of 10-day old seedlings was reduced by 40% under continuous blue light irradiation relative to that obtained with white light. Irradiation of etiolated and green leaf segments for 18 hr with blue light reduced ACC oxidase activity when compared to dark-treated ones. The influence of light quality and its fluence rate on the control of ethylene biosynthesis in oat leaves is discussed. (author). (author)

  19. Elevated temperature altered photosynthetic products in wheat seedlings and organic compounds and biological activity in rhizopshere soil under cadmium stress

    Science.gov (United States)

    Jia, Xia; Zhao, Yonghua; Wang, Wenke; He, Yunhua

    2015-09-01

    The objective of this study was to investigate the effects of slightly elevated atmospheric temperature in the spring on photosynthetic products in wheat seedlings and on organic compounds and biological activity in rhizosphere soil under cadmium (Cd) stress. Elevated temperature was associated with increased soluble sugars, reducing sugars, starch, and total sugars, and with decreased amino acids in wheat seedlings under Cd stress. Elevated temperature improved total soluble sugars, free amino acids, soluble phenolic acids, and organic acids in rhizosphere soil under Cd stress. The activity of amylase, phenol oxidase, invertase, β-glucosidase, and L-asparaginase in rhizosphere soil was significantly improved by elevated temperature under Cd stress; while cellulase, neutral phosphatase, and urease activity significantly decreased. Elevated temperature significantly improved bacteria, fungi, actinomycetes, and total microorganisms abundance and fluorescein diacetate activity under Cd stress. In conclusion, slightly elevated atmospheric temperature in the spring improved the carbohydrate levels in wheat seedlings and organic compounds and biological activity in rhizosphere soil under Cd stress in the short term. In addition, elevated atmospheric temperature in the spring stimulated available Cd by affecting pH, DOC, phenolic acids, and organic acids in rhizosphere soil, which resulted in the improvement of the Cd uptake by wheat seedlings.

  20. Production and development of eucalyptus seedlings in function of doses of phosphorus

    Directory of Open Access Journals (Sweden)

    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.

  1. Development and evaluation of TDR probe for water rational management on substrates used in forest seedlings production

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    Lucas Masayuki Sato

    2009-04-01

    Full Text Available Time Domain Reflectometry (TDR is a reliable technique to estimate in situ moisture content in different types of materials using probes. The forest seedlings production implies in a comprehensive and empirical process of water management applied to the substrate used for cultivation in dibble-tube. This type of cultivation requires analysis of the physical characteristics of water and nutrients retention of the substrate. The main goal of this research was to develop and evaluate a TDR coaxial probe for rational management of water in the forest seedlings production. Initially, a physical validation of the probe was performed considering the following parameters: reflection coefficient, characteristic impedance and spatial sensitivity. Also, the performance of the probe was evaluated to estimate water content in laboratory conditions and we obtained a calibration curve for each type of porous material used. The results demonstrated the viability of TDR probes to estimate water content in soil and substrates.

  2. Elevated atmospheric CO2 affected photosynthetic products in wheat seedlings and biological activity in rhizosphere soil under cadmium stress.

    Science.gov (United States)

    Jia, Xia; Liu, Tuo; Zhao, Yonghua; He, Yunhua; Yang, Mingyan

    2016-01-01

    The objective of this study was to investigate the effects of elevated CO2 (700 ± 23 μmol mol(-1)) on photosynthetic products in wheat seedlings and on organic compounds and biological activity in rhizosphere soil under cadmium (Cd) stress. Elevated CO2 was associated with decreased quantities of reducing sugars, starch, and soluble amino acids, and with increased quantities of soluble sugars, total sugars, and soluble proteins in wheat seedlings under Cd stress. The contents of total soluble sugars, total free amino acids, total soluble phenolic acids, and total organic acids in the rhizosphere soil under Cd stress were improved by elevated CO2. Compared to Cd stress alone, the activity of amylase, phenol oxidase, urease, L-asparaginase, β-glucosidase, neutral phosphatase, and fluorescein diacetate increased under elevated CO2 in combination with Cd stress; only cellulase activity decreased. Bacterial abundance in rhizosphere soil was stimulated by elevated CO2 at low Cd concentrations (1.31-5.31 mg Cd kg(-1) dry soil). Actinomycetes, total microbial abundance, and fungi decreased under the combined conditions at 5.31-10.31 mg Cd kg(-1) dry soil. In conclusion, increased production of soluble sugars, total sugars, and proteins in wheat seedlings under elevated CO2 + Cd stress led to greater quantities of organic compounds in the rhizosphere soil relative to seedlings grown under Cd stress only. Elevated CO2 concentrations could moderate the effects of heavy metal pollution on enzyme activity and microorganism abundance in rhizosphere soils, thus improving soil fertility and the microecological rhizosphere environment of wheat under Cd stress.

  3. Biochar can be a suitable replacement for Sphagnum peat in nursery production of Pinus ponderosa seedlings

    Science.gov (United States)

    R. Kasten Dumroese; Jeremiah R. Pinto; Juha Heiskanen; Arja Tervahauta; Katherine G. McBurney; Deborah S. Page-Dumroese; Karl Englund

    2018-01-01

    We replaced a control peat medium with up to 75% biochar on a volumetric basis in three different forms (powder, BC; pyrolyzed softwood pellets, PP; composite wood-biochar pellets, WP), and under two supplies of nitrogen fertilizer (20 or 80 mg N) subsequently grew seedlings with a comparable morphology to the control. Using gravimetric methods to determine irrigation...

  4. Substitution of peat with municipal solid waste compost in watermelon seedling production combined with fertigation

    Directory of Open Access Journals (Sweden)

    Maria Papamichalaki

    2014-12-01

    Full Text Available Interest in reusing organic residues as substrate medium in nurseries has increased worldwide as peat availability has been reduced over time. In this study, the effect of fertigation and/or a partial substitution of peat with municipal solid waste compost (MSWC on the emergence, growth, and nutrition of watermelon (Citrullus lanatus L. seedlings were tested. The MSWC extracts (MSWC:water at 10-1 and 10-2 dilutions maintained seedling germination. Under nursery conditions, six media prepared from commercial peat and MSWC were further assessed in conjunction with nutrient application as basic fertilizer (BF or hydro fertilizer (HF. Adding MSWC to the substrate inhibited seed emergence and mean germination time, whereas fertigation maintained seed emergence in 15% MSWC but decreased in 45% MSWC. Adding 45% MSWC reduced seedling height, leaf number, and fresh weight. The HF increased fresh weight (up to 44% and growth in seedlings cultivated in 15% MSWC. Leaf photosynthetic rate and stomatal conductance increased (up to 2.6-fold in MSWC-based (< 45% MSWC substrates, but no differences were observed in chlorophyll a, chlorophyll b, total carotenoid content, and leaf fluorescence. The HF reduced chlorophyll a and total carotenoids, but increased chlorophyll b content. The K, N, and Na content increased (ranging from 2- to 5-fold when adding MSWC, whereas P content did not differ. Fertigation benefits seedling nutritive status. Low content (15% to 30% of MSWC may act as an alternative substitute for peat with more positive effects if minerals are provided through HF.

  5. Productivity of a plantation of asparagus (Asparagus officinalis var. Altilis initiated green seedlings over four growing seasons

    Directory of Open Access Journals (Sweden)

    Castagnino, A.M.

    2014-01-01

    Full Text Available Although there are two initiation systems for an asparagus crop, i.e. by means of crowns and by means of seedlings, only the former allows the initiation of the definitive plantation in the first year. In order to determine the incidence of the seedling size throughout the first six years since planting, a trial was started on august 21, 2002, with three cell sizes: PG: big, PM: medium and PCH: small (70, 50 and 20 cm3 respectively and two densities: D1:35,714 and D2: 17,857 pl.ha-1, using the hybrid UC-157 and evaluating its productivity in the period 2005- 2008. Fresh weight per harvest (PFC and total annual fresh weight per ha (PFT, number of turions per harvest (NTC and per ha (NT and average weight per turion (PPT were determined. The PTF 2005-2008 was 26.300 Kg ha-1 and NT, with an annual average of 6,575 Kg ha-1 and 480,180 turions, respectively. NT showed a growing tendency throughout the whole period. Whereas, while the PFT grew in 2005-2007, it decreased in 2008 due to lower PPT, caused possibly by intra-specific competition. PM allowed a greater yield PFC: 343 Kg ha-1. The PPT turned out to be similar to that in 2005-2007, however it decreased in 2008. D1 obtained the maximum yield throughout the whole period. It can be concluded that when the aim is to obtain high initial productivity, it would be advisable to use seedlings of good size. Besides, the choice of density is an important factor due to the fact that there seems to be a direct relationship between the planting frame used and the obtained productivity.

  6. Effect of the rearing tank residue of fish farms on the production of passion fruit tree seedlings

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    F. O. R. Silva

    2017-03-01

    Full Text Available The objective of this study was to evaluate the initial growth of seedlings and biomass production of blue and yellow passion fruit trees (round cultivar produced from residue of the rearing tanks of fish farms. The experiment was conducted in a greenhouse using residue obtained from fish farming tanks. Ravine soil (RS, fish tank residue (FR and Tropstrato (TR were used as substrate. The treatments were: T1 = control consisting of Tropstrato substrate; T2 = 25% FR + 75% RS; T3 = 50% FR + 50% RS; T4 = 25% RS + 75% FR; T5 = 100% FR. A completely randomized block design consisting of 5 treatments, 4 replicates and 11 plants per plot was used. Treatment T5 (100% fish farming residue resulted in the largest average number of leaves, highest dry matter production of the aerial part, and highest dry matter accumulation in the root (P<0.05. The worst results were obtained for the treatment using 25% FR (T2, which resulted in less uniformity of the variables studied. Stem height of the passion fruit tree was greater for the treatments that included FR, with the greatest mean height being observed for T5. In conclusion, the treatment using the residue of fish farming tanks was found to be beneficial to produce yellow passion fruit seedlings (round cultivar, representing a good alternative for the reutilization of this residue.

  7. Hypersensitivity of Allium cepa seedling roots to X-rays for production of micronuclei

    International Nuclear Information System (INIS)

    Hori, Takayoshi; Hanmoto, Hidehiro; Fujishige, Ikuko; Inoue, Toshihiro; Taniguchi, Kenji; Itoh, Tetsuo; Fujikawa, Kazuo; Yonezawa, Yoshihiko.

    1995-01-01

    Seedling roots of onion (Allium cepa) were irradiated with various doses of X-rays. Following irradiation, the roots were incubated at 23-25degC for 24 hr, i.e., approximate time for one mitotic cycle, and then fixed, stained and macerated in a 7:3 mixture of acetic dahlia (prepared by dissolving a 0.5 g sample of dahlia violet into 100 ml of 30% acetate) and 1 N HCl for 10-15 min. Terminal 1-2 mm of the root tips were squashed on slides, one root each, and microscopically inspected for the presence of more than one nucleus in the cells. The additional nuclei, which were smaller than the normal, were scored as micronuclei. The frequency of micronuclei increased with dose over the control level (∼0.2x10 -3 ) to a high level of 140x10 -3 at 1 Gy. The frequency recorded at 1 Gy was about two fold higher as compared with the frequency reported by Evans et al. (1959) for micronuclei induced by γ-rays at a comparable dose in the root tip cells of Vica faba seedlings, probably reflecting relatively higher DNA content per cell in Allium somatic cells. We thus may conclude that root-tip meristematic cells of Allium seedlings are hypersensitive to the induction of micronuclei by X-rays. The Allium micronucleus assay may be useful as a system not only for quantitating chromosome damage by low-level radiation but also for detecting environmental mutagens. (author)

  8. SHADING AND SUBSTRATE ON THE PRODUCTION OF SEEDLINGS OF Erythrina velutina Willd.

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    Laércio Wanderley dos Santos

    2013-12-01

    Full Text Available http://dx.doi.org/10.5902/1980509812341Erythrina velutina Willd. (Fabaceae is used in traditional medicine in northeastern Brazil for its sudorificproperties, soothing, emollient, pectoral and local anesthetic. The aim of this study was to evaluate theeffect of substrate and shading on seedlings of Erythrina velutina. The experimental design was completelyrandomized in factorial scheme 5 x 2 (five substrates and two shades, with four replications and 10 plantsin each plot. The substrates were arisco, arisco + cattle manure 2:1 v/v, arisco + cattle manure 3:1 v/v, sand+ cattle manure 2:1 v/v, sand + cattle manure 3:1 v/v. The shadings were 0% shading (full sunlight and50% shading. The characteristics evaluated were stem diameter, height, leaf area, green and dry biomass ofroots and shoots, height/diameter and Dickson quality index.There was no significant difference in diameterbetween the different substrates. The environment in full sun favored the diameter and the root biomasswhereas the height was favored by shade. The substrates with cattle manure in its composition favorsthe development of plants of Erythrina velutina and higher seedling quality are produced in full sun andsubstrate arisco + cattle manure in the ratio 2:1

  9. Biochar Can Be a Suitable Replacement for Sphagnum Peat in Nursery Production of Pinus ponderosa Seedlings

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    R. Kasten Dumroese

    2018-04-01

    Full Text Available We replaced a control peat medium with up to 75% biochar on a volumetric basis in three different forms (powder, BC; pyrolyzed softwood pellets, PP; composite wood-biochar pellets, WP, and under two supplies of nitrogen fertilizer (20 or 80 mg N subsequently grew seedlings with a comparable morphology to the control. Using gravimetric methods to determine irrigation frequency and exponential fertilization to ensure all treatments received the same amount of N at a given point in the growing cycle, we successfully replaced peat with 25% BC and up to 50% PP. Increasing the proportion of biochar in the media significantly increased pH and bulk density and reduced effective cation exchange capacity and air-filled porosity, although none of these variables was consistent with resultant seedling growth. Adherence to gravimetric values for irrigation at an 80% water mass threshold in the container revealed that the addition of BC and WP, but not PP, required adjustments to the irrigation schedule. For future studies, we encourage researchers to provide more details about bulk density, porosity, and irrigation regime to improve the potential inference provided by this line of biochar and growing media work.

  10. Effects of untreated and treated oilfield-produced water on seed germination, seedling development, and biomass production of sunflower (Helianthus annuus L.).

    Science.gov (United States)

    da Costa Marques, Mônica Regina; de Souza, Paulo Sérgio Alves; Rigo, Michelle Machado; Cerqueira, Alexandre Andrade; de Paiva, Julieta L; Merçon, Fábio; Perez, Daniel Vidal

    2015-10-01

    This study aims to evaluate possible toxic effects of oil and other contaminants from oilfield-produced water from oil exploration and production, on seed germination, and seedling development of sunflower (Helianthus annuus L.). In comparison, as treated by electroflocculation, oilfield-produced water, with lower oil and organic matter content, was also used. Electroflocculation treatment of oilfield-produced water achieved significant removals of chemical oxygen demand (COD) (94 %), oil and grease (O&G) (96 %), color (97 %), and turbidity (99 %). Different O&G, COD, and salt levels of untreated and treated oilfield-produced water did not influence germination process and seedling biomass production. Normal seedlings percentage and vigor tended to decrease more intensely in O&G and COD levels, higher than 337.5 mg L(-1) and 1321 mg O2 L(-1), respectively, using untreated oilfield-produced water. These results indicate that this industrial effluent must be treated, in order to not affect adversely seedling development. This way, electroflocculation treatment appears as an interesting alternative to removing oil and soluble organic matter in excess from oilfield-produced water improving sunflower's seedling development and providing a friendly environmental destination for this wastewater, reducing its potential to harm water resources, soil, and biota.

  11. 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.

  12. Effects of organic matter removal, soil compaction, and vegetation control on 5-year seedling performance: a regional comparison of long-term soil productivity sites

    Science.gov (United States)

    Robert L. Fleming; Robert F. Powers; Neil W. Foster; J. Marty Kranabetter; D. Andrew Scott; Felix Jr. Ponder; Shannon Berch; William K. Chapman; Richard D. Kabzems; Kim H. Ludovici; David M. Morris; Deborah S. Page-Dumroese; Paul T. Sanborn; Felipe G. Sanchez; Douglas M. Stone; Allan E. Tiarks

    2006-01-01

    We examined fifth-year seedling response to soil disturbance and vegetation control at 42 experimental locations representing 25 replicated studies within the North American Long-Term Soil Productivity (LTSP) program. These studies share a common experimental design while encompassing a wide range of climate, site conditions, and forest types. Whole-tree harvest had...

  13. Seed production, seed dispersal and seedling establishment of two afromontane tree species in and around a church forest: implications for forest restoration

    Directory of Open Access Journals (Sweden)

    Abrham Abiyu

    2016-07-01

    Full Text Available Background Seed production, seed dispersal and seedling establishment are relevant life phases of plants. Understanding these processes and their patterns is essential to recognize vegetation dynamics and to apply it to forest restoration. Methods For Olea europaea and Schefflera abyssinica, fecundity was estimated using randomized branch sampling. Seed dispersal and seedling establishment were monitored using spatially explicit seed traps and plots. Dispersal functions were calibrated applying inverse modeling. Results O. europaea produced more seeds and had longer dispersal distances compared to S. abyssinica. Correlations between observed and predicted number of recruits were statistically significant. Seedlings of the two species showed different niche requirements. Conclusions The studied species were recruitment-limited due to low dispersal activity or lack of suitable microsites. Restoration relying on natural regeneration should overcome these limitations by increasing disperser visitation and reducing biotic and abiotic stresses.

  14. Cavity size and copper root pruning affect production and establishment of container-grown longleaf pine seedlings

    Science.gov (United States)

    Marry Anne Sword Sayer; James D. Haywood; Shi-Jean Susana Sung

    2009-01-01

    With six container types, we tested the effects of cavity size (i.e., 60, 93, and 170 ml) and copper root pruning on the root system development of longleaf pine (Pinus palustris Mill.) seedlings grown in a greenhouse. We then evaluated root egress during a root growth potential test and assessed seedling morphology and root system development 1 year after planting in...

  15. Mating System and Effective Population Size of the Overexploited Neotropical Tree (Myroxylon peruiferum L.f.) and Their Impact on Seedling Production.

    Science.gov (United States)

    Silvestre, Ellida de Aguiar; Schwarcz, Kaiser Dias; Grando, Carolina; de Campos, Jaqueline Bueno; Sujii, Patricia Sanae; Tambarussi, Evandro Vagner; Macrini, Camila Menezes Trindade; Pinheiro, José Baldin; Brancalion, Pedro Henrique Santin; Zucchi, Maria Imaculada

    2018-03-16

    The reproductive system of a tree species has substantial impact on genetic diversity and structure within and among natural populations. Such information, should be considered when planning tree planting for forest restoration. Here, we describe the mating system and genetic diversity of an overexploited Neotropical tree, Myroxylon peruiferum L.f. (Fabaceae) sampled from a forest remnant (10 seed trees and 200 seeds) and assess whether the effective population size of nursery-grown seedlings (148 seedlings) is sufficient to prevent inbreeding depression in reintroduced populations. Genetic analyses were performed based on 8 microsatellite loci. M. peruiferum presented a mixed mating system with evidence of biparental inbreeding (t^m-t^s = 0.118). We found low levels of genetic diversity for M. peruiferum species (allelic richness: 1.40 to 4.82; expected heterozygosity: 0.29 to 0.52). Based on Ne(v) within progeny, we suggest a sample size of 47 seed trees to achieve an effective population size of 100. The effective population sizes for the nursery-grown seedlings were much smaller Ne = 27.54-34.86) than that recommended for short term Ne ≥ 100) population conservation. Therefore, to obtain a reasonable genetic representation of native tree species and prevent problems associated with inbreeding depression, seedling production for restoration purposes may require a much larger sampling effort than is currently used, a problem that is further complicated by species with a mixed mating system. This study emphasizes the need to integrate species reproductive biology into seedling production programs and connect conservation genetics with ecological restoration.

  16. 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)

  17. Sugarcane biochar as an amendment for greenhouse growing media for the production of cucurbit seedlings

    Science.gov (United States)

    Louisiana sugarcane farmers in 2016 harvested 11.7 million mt millable sugarcane from 163,000 ha, producing 1.47 million mg of raw sugar and an estimated 3.5 million mt of bagasse. Even though Louisiana sugar mills use 80 to 90% of the bagasse for fuel production, another 350,000 to 700,000 mt of ba...

  18. Causes and consequences of unequal seedling production in forest trees: a case study in red oaks

    Science.gov (United States)

    Emily V. Moran; James S. Clark

    2012-01-01

    Inequality in reproductive success has important implications for ecological and evolutionary dynamics, but lifetime reproductive success is challenging to measure in long-lived species such as forest trees. While seed production is often used as a proxy for overall reproductive success, high mortality of seeds and the potential for trade-offs between seed number and...

  19. Trichoderma spp. Improve growth of Arabidopsis seedlings under salt stress through enhanced root development, osmolite production, and Na⁺ elimination through root exudates.

    Science.gov (United States)

    Contreras-Cornejo, Hexon Angel; Macías-Rodríguez, Lourdes; Alfaro-Cuevas, Ruth; López-Bucio, José

    2014-06-01

    Salt stress is an important constraint to world agriculture. Here, we report on the potential of Trichoderma virens and T. atroviride to induce tolerance to salt in Arabidopsis seedlings. We first characterized the effect of several salt concentrations on shoot biomass production and root architecture of Arabidopsis seedlings. We found that salt repressed plant growth and root development in a dose-dependent manner by blocking auxin signaling. Analysis of the wild type and eir1, aux1-7, arf7arf19, and tir1abf2abf19 auxin-related mutants revealed a key role for indole-3-acetic acid (IAA) signaling in mediating salt tolerance. We also found that T. virens (Tv29.8) and T. atroviride (IMI 206040) promoted plant growth in both normal and saline conditions, which was related to the induction of lateral roots and root hairs through auxin signaling. Arabidopsis seedlings grown under saline conditions inoculated with Trichoderma spp. showed increased levels of abscissic acid, L-proline, and ascorbic acid, and enhanced elimination of Na⁺ through root exudates. Our data show the critical role of auxin signaling and root architecture to salt tolerance in Arabidopsis and suggest that these fungi may enhance the plant IAA level as well as the antioxidant and osmoprotective status of plants under salt stress.

  20. IP3 production in the hypersensitive response of lemon seedlings against Alternaria alternata involves active protein tyrosine kinases but not a G-protein

    Directory of Open Access Journals (Sweden)

    XIMENA ORTEGA

    2005-01-01

    Full Text Available IP3 increase and de novo synthesis of scoparone are produced in the hypersensitive response (HR of lemon seedlings against the fungus Alternaria alternata. To elucidate whether a G-protein and/or a protein tyrosine kinase (PTK are involved in signal transduction leading to the production of such a defensive response, we studied the HR in this plant system after treatment with G-protein activators alone and PTK inhibitors in the presence of fungal conidia. No changes in the level of IP3 were detected in response to the treatment with the G-protein activators cholera toxin or mastoparan, although the HR was observed in response to these compounds as determined by the scoparone synthesis. On the contrary, the PTK inhibitors lavendustin A and 2,5-dihidroxy methyl cinnamate (DHMC not only prevented the IP3 changes observed in response to the fungal inoculation of lemon seedlings but also blocked the development of the HR. These results suggest that the IP3 changes observed in response to A. alternata require a PTK activity and are the result of a G-protein independent Phospholipase C activity, even though the activation of a G-protein can also lead to the development of a HR. Therefore, it appears that more than one signaling pathway may be activated for the development of HR in lemon seedlings: one involving a G-protein and the other involving a PTK-dependent PLC.

  1. A bioplastic-based seed coating improves seedling growth and reduces production of coated seed dust. Journal of Crop Improvement

    Science.gov (United States)

    Although recently introduced, film-coating of agronomic seeds is now widely accepted in modern agriculture as an effective technology for protecting germinating seeds and seedlings. These experiments explored the possibility of using a bioplastic-based formulation to film-coat corn (maize) and cano...

  2. Métodos de formação de mudas de maracujazeiro amarelo Methods of yellow passion fruit seedling production

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    Marcelo Fontanetti Verdial

    2000-12-01

    Full Text Available Grande parte do sucesso de uma cultura está em implantá-la com mudas de alta qualidade. O objetivo do estudo foi avaliar métodos de formação de mudas de maracujazeiro amarelo quanto à qualidade das muda formada. Os tratamentos utilizados foram: 1- Mudas formadas em sacolas plásticas, preenchidas com terra adubada e misturada com esterco de curral curtido, com fertirrigação uma vez por semana; 2- Mudas formadas em tubetes de plástico rígido, com substrato à base de casca de pinus e vermiculita, mantidos em bancada e recebendo fertirrigação uma vez por semana; 3- Idêntico ao tratamento 2, utilizando-se bandejas de poliestireno expandido; 4- Idêntico ao tratamento 3, sem fertirrigação, mas com uso de "floating" a cada dois dias; 5- Idêntico ao tratamento 4, com o uso de "floating" todo o período. O delineamento experimental foi completamente aleatorizado, com cinco tratamentos e quatro repetições. Na casa de vegetação, cada parcela foi composta por 64 plantas, sendo avaliadas semanalmente em oito plantas por parcela as seguintes variáveis: altura da planta; comprimento da raiz; matéria seca da parte aérea; matéria seca da parte radicular. O restante das mudas foi levado a campo para determinação da percentagem de pegamento e análise do desenvolvimento vegetativo inicial. Neste segundo estágio, cada parcela foi composta por cinco plantas. Sob casa de vegetação, o tratamento 5 apresentou os maiores valores para todas as variáveis, exceto para comprimento de raiz, onde houve superioridade do tratamento 1. Em campo, observou-se 100% de pegamento para todos os tratamentos, sendo que o tratamento 5 apresentou as maiores médias para altura de plantas.The main part of a successful production of passion fruit is dependent on seedling quality. The present research had the objective of comparing methods of passion fruit seedling production. The treatments were: 1- seedlings formed in plastic bags, filled with fertilized

  3. FOREST SEEDLINGS PRODUCTION USING STABILIZED SEWAGE SLUDGE / PRODUÇÃO DE MUDAS FLORESTAIS UTILIZANDO LODO DE ESGOTO ESTABILIZADO

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    DURVAL R. DE PAULA JR

    2009-11-01

    Full Text Available Aiming tThis study aims at evaluating the physical, chemical and biological characteristics of sewage sludge and its feasibility for use as a component of substrata to produce seedlings of native and exotic trees. The sewage sludge was previously stabilized through the process of composting with grassremnants. Before and after the composting, chemical analyses were carried out in order to quantify levels of heavy metals, macro nutrients and micro nutrients in addition to microbiological analyses of sewage sludge. The mixtures (Treatments in the proportions vary from 0 to 100% of organic compostof sewage sludge (OCSS in composition with carbonized rice husks (CRH and were compared to control treatments, which consisted of commercial substrates (PLANTMAX-EUCATEX and cattle manure. Porosity, density, capacity of water retention and particles size of treatments were evaluated. Results of the physical characterization of substrates revealed that proportions ranging from 100 to 40% of the compost showed better results for tree seedlings cultivation. The use of organic compost of sewage sludge (OCSS to produce seedlings of forest essences is a viable alternative for waste reuse, aggregating not only economy and quality of inputs in the yields, but also environmental benefits.

  4. The Challenge of Peat Substitution in Organic Seedling Production: Optimization of Growing Media Formulation through Mixture Design and Response Surface Analysis.

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    Francesco Giovanni Ceglie

    Full Text Available Peat replacement is an increasing demand in containerized and transplant production, due to the environmental constraints associated to peat use. However, despite the wide information concerning the use of alternative materials as substrates, it is very complex to establish the best materials and mixtures. This work evaluates the use of mixture design and surface response methodology in a peat substitution experiment using two alternative materials (green compost and palm fibre trunk waste for transplant production of tomato (Lycopersicon esculentum Mill.; melon, (Cucumis melo L.; and lettuce (Lactuca sativa L. in organic farming conditions. In general, the substrates showed suitable properties for their use in seedling production, showing the best plant response the mixture of 20% green compost, 39% palm fibre and 31% peat. The mixture design and applied response surface methodology has shown to be an useful approach to optimize substrate formulations in peat substitution experiments to standardize plant responses.

  5. Production of baruzeiro seedling in different protected environments and substrates Produção de mudas de baruzeiro em diferentes ambientes protegidos e substratos

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    Edilson Costa

    2012-08-01

    Full Text Available The high seedlings quality is essential for deployment of homogeneous orchards. This study evaluated the baruzeiro (Dipteryx alata Vog seedlings formation on different substrates within protected environments. It was used substrates with100% of cattle manure; 100% of cassava stems; 100% of vermiculite; 50% of cattle manure + 50% of cassava stems; 50% of cattle manure + 50% of vermiculite; 50% of cassava stems + 50% of vermiculite; and + ⅓ of cattle manure + ⅓ of cassava stems + ⅓ of vermiculite. These substrates were tested in protected areas: greenhouse; black shade net of 50% shading; and aluminized thermo-reflective screen of 50% shading. A completely randomized experimental design with five replicates of four plants was adopted. Initially, data were submitted to analysis of individual variance of the substrates, in each environment of cultivation, then performing the evaluation of the residual mean square and the analysis of these environments together for comparison. The best substrate for baruzeiro seedlings was pure vermiculite. The substrates with 100% of manure and the substrate with 33.33% of the mixed studied materials can be used for seedlings formation. The environment with screen can be indicated for the production of baruzeiro seedlings, since it gave vigor to the seedlings.A qualidade da muda é fundamental para implantação de pomares homogêneos. Desta forma, avaliou-se a formação de mudas de baruzeiro (Dipteryx alata Vog, em diferentes substratos, no interior de ambientes protegidos. Foram utilizados substratos com 100% de esterco bovino; 100% de ramas de mandioca; 100% de vermiculita; 50% de esterco bovino + 50% de ramas de mandioca; 50% de esterco bovino + 50% de vermiculita; 50% de ramas de mandioca + 50% de vermiculita e ⅓ de esterco bovino + ⅓ de ramas de mandioca + ⅓ de vermiculita. Estes substratos foram testados em ambientes protegidos: estufa agrícola; telado de tela preta com 50% de sombreamento e o

  6. Containers of Attalea funifera fibers to produce eucalyptus seedlings

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    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.

  7. Produção de mudas de eucalipto com substratos para sistema de blocos Production of eucalyptus seedlings with substrata in block systems

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    Teresa Aparecida Soares de Freitas

    2010-10-01

    a steel form (11.5 x 2.3 cm, and afterwards moistening and evaluating for the volume and height increment. There was not a difference in the volume increment among the mixtures, and mixture 3 presented a larger increment in height than in mixture 8, however, they didn't differ from those remaining, with those chosen for use in the production of eucalyptus seedlings: FCM (40% + T (60%; CE (60%+ FCM (40%; CE (40% + T (60% and CE (40% + T (30% + FCM (30%. The choice was made in consideration of the component's readiness, because it did not differ in the tests. The Eucalyptus urophylla seedlings were produced in 40x60x7cm trays, with 96 seedlings, sown directly in the blocks made with the selected mixtures pressed or not pressed. At 90 days the seedlings were evaluated for the diameter, height, shoot and root dry matter. In the expedition time, the substrata were evaluated as for the stability of the turf and the aggregation degree of the substrata to the seedlings roots. The nutritional analysis of the shoot seedlings was accomplished (N, P, K, Ca, Mg, Mn, Zn, Fe. All the substrata presented aggregation and good stability. Nutritional problems were not observed in the seedlings. For the production of Eucalyptus urophylla seedlings in blocks with pressed substrata the substratum CE (60% + FCM (40% is recommended, and without being pressed the mixtures: CE (60% + FCM (40%; CE (40% + T (60% and CE (40% + T (30% + FCM (30% were recommended.

  8. Produção de mudas de meloeiro amarelo, sob cultivo protegido, em diferentes substratos Production of yellow melon seedlings in different substrates under protected cultivation

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    Tânia Regina Pelizza

    2013-04-01

    Full Text Available Mudas mal formadas e debilitadas comprometem o desenvolvimento das culturas. O objetivo deste trabalho foi avaliar a produção de mudas de meloeiro amarelo, sob cultivo protegido, em diferentes substratos. Este trabalho foi conduzido em telado, na Universidade Federal de Pelotas (RS, nos meses de novembro e dezembro. Testaram-se os seguintes substratos: T1 (vermicomposto bovino puro; T2 (substrato comercial Plantmax®; T3 (substrato comercial Húmus Fértil®; T4 (vermicomposto bovino 75% + casca de arroz carbonizada 25% e T5 (solo 75% + vermicomposto bovino 25%. Foram avaliados o índice de velocidade e a percentagem de emergência do 6º ao 9º dia; a altura, o comprimento da raiz principal, a massa seca das raízes e da parte aérea das mudas de meloeiro, aos 27 dias. Os substratos que proporcionaram maior índice de velocidade de emergência das mudas de meloeiro amarelo foram Húmus Fértil®, vermicomposto bovino puro e vermicomposto bovino 75% mais casca de arroz carbonizada 25%. Maior altura da muda é obtida com o substrato Húmus Fértil®. O comprimento da raiz principal foi maior com o uso de vermicomposto bovino puro, Húmus Fértil®, vermicomposto bovino puro mais casca de arroz carbonizada (VB75+CAC25, em comparação com solo 75% mais vermicomposto bovino 25%. A massa seca de raiz foi maior quando utilizado Húmus Fértil®, em comparação com solo 75% mais vermicomposto bovino 25%. É possível utilizar substratos isolados ou em combinação para a produção de mudas de meloeiro amarelo sob cultivo protegido. Porém, deve-se evitar o uso de solo 75% em combinação com vermicomposto bovino 25%.Weak and malformed seedlings compromise the development of the crop. The objective of this study was to evaluate the production of yellow melon seedlings in different substrates under protected cultivation. The experiment was conducted in a greenhouse during November and December, at the Federal University of Pelotas (RS. The following

  9. TANNING OF SLUDGE AND ITS INFLUENCE ON THE PRODUCTION OF SEEDLINGS PARICÁ (Schizolobium amazonicum AND THE CHEMICAL PROPERTIES OF SOIL

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    Lorena de Souza Tavares

    2013-08-01

    Full Text Available http://dx.doi.org/10.5902/1980509810547The objective of this study was to assess the influence of the tanning sludge in soil chemical properties and the morphological and nutritional ‘paricá’ seedlings. The experiment was conducted in a greenhouse in a completely randomized design with five replicates, having as a substrate Humic Cambisol, which was characterized chemically and granulometrically, in possession of these results, the soil was previously corrected with lime and NPK. After 100 days of observation, it was analyzed the soil chemical variables (pH, H + Al, Al3+, Ca, Mg, P, K, Na, S, Cr3+, CO, SB, CEC, V, RAS and PST, the morphology plant [height (H, stem diameter (DC, the number of full sheets, the main root length (CR and dry biomass], and the concentrations of N, P, K, Ca, Mg , S, Cr3+ and Na in the plant. The tanning sludge was used as a nutritional supplement in doses of 0.0, 1.5, 3.0, 4.5 and 6.0 g kg-1. The tanning sludge has potential as a corrective of soil acidity, with little significant increase in indicators of salinity, sodicity and Cr3+ content available. However, the use of sludge did not affect the morphological characteristics of seedlings ‘paricá’, but induced an increase in levels K and S in the shoot and Na and S in the root. The greatest concentration of nutrients in ‘paricá’ were obtained with 6.0 g

  10. Substratos alternativos na produção de mudas de Chamaecrista desvauxii Alternative substrates in the production of seedlings of Chamaecrista desvauxii

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    Marcos Vinicius Winckler Caldeira

    2013-02-01

    Full Text Available O objetivo deste estudo foi avaliar o potencial da utilização de resíduos orgânicos como componentes do substrato para produção de mudas de Chamaecrista desvauxii, vulgarmente conhecida como rabo-de-pitu, empregada na recuperação de áreas degradadas. Estabeleceram-se os tratamentos utilizando quatro tipos de substrato: lodo de esgoto (LE, casca de arroz carbonizada (CAC, palha de café in natura (PC in natura e substrato comercial (SC, em diferentes proporções de volume. Quando as mudas atingiram 150 dias de idade, elas foram mensuradas quanto às seguintes características: altura, diâmetro do coleto, relação entre altura e diâmetro do coleto, massa seca da parte aérea, massa seca do sistema radicular, massa seca total, relação entre massa seca da parte aérea e massa seca do sistema radicular e índice de qualidade de Dickson (IQD. Os substratos formulados com lodo de esgoto, casca de arroz carbonizada e palha de café in natura propiciaram os melhores resultados das características avaliadas, sendo o tratamento com 60% LE + 20% CAC + 20% PC in natura o que proporcionou as mais adequadas características morfológicas avaliadas na produção de Chamaecrista desvauxii.The objective of this study was to evaluate the potential of sewage sludge and organic waste as component of substrate for Chamaecrista desvauxii seedlings production. It was established ten treatments using four types of substrate: sewage sludge, carbonized rice hull, coffee straw and commercial substrate in different proportions. When the seedlings were at three months of age, the following parameters were measured: stem diameter, plant height, ratio between plant height and stem diameter, shoot dry mass, dry mass of root system, total dry mass, dry mass ratio of shoot/root dry mass and Dickson quality index (IQD. The substrates made with sewage sludge, carbonized rice hull and coffee straw provided better results of growth of seedlings. Moreover, the

  11. Determinação dos custos da qualidade em produção de mudas de eucalipto Determination of quality costs in eucalyptus seedling production

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    Helio Garcia Leite

    2005-12-01

    Full Text Available Este estudo objetivou determinar os custos da qualidade na produção de mudas de eucalipto em uma empresa que destina sua produção de madeira à fabricação de celulose e papel, situada na Região Centro-Oeste do Brasil. Os custos da qualidade por atividade e as categorias de custos da qualidade por operação foram obtidos por meio de consultas aos arquivos da empresa, entrevista ao pessoal técnico e operacional e observações "in loco". Pelos levantamentos realizados, pode-se concluir que, apesar de os investimentos em prevenção para a qualidade se encontrarem num bom patamar, os custos de falhas estão altos. Isso pode ser atribuído à falta de avaliação, que impede a determinação do grau de conformidade das várias operações que compõem o processo de produção de mudas, aliado à falta de investimentos em alguns pontos estratégicos de prevenção como treinamento para a qualidade. Os custos de falhas em relação ao custo das mudas representam 7,8%. Era até esperado que esse valor fosse maior, considerando-se a ausência de investimentos em avaliação e em treinamento de pessoal operacional. Tal fato pode ser atribuído à alta qualificação do corpo técnico e aos investimentos em pesquisa. Apesar de esse valor parecer pequeno, quando-se extrapola para o programa anual de 10 milhões de mudas e dependendo do custo real da produção, ele pode representar um valor absoluto considerável.This study aimed at the determination of quality costs in production of eucalyptus seedlings, in a company that directs its wood production to cellulose and paper manufacturing, located in the Midwestern Brazil. The quality costs per activity and the categories of quality costs per operation were obtained through consultations to the company files , interviews with the technical and operational staff and in loco observations. Through these procedures, it was concluded that in spite of the fact that the investments in prevention for

  12. Protected environments and substrates for production of genipap seedlings Ambientes protegidos e substratos para formação de mudas de jenipapeiro

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    Adriano Ribeiro Sassaqui

    2013-06-01

    Full Text Available Genipap (Genipa americana L., Rubiaceae is a native Brazilian species and can be used in the recovery of degraded forest areas or for food supply. In order for the species to reach its potential, production of high quality seedlings is essential. The objective of this study was to evaluate genipap seedlings in protected environments and different substrates. The environments tested were: (1 a greenhouse with polyethylene film in the top, with aluminized screen (Aliminet® of 50%-shading under this film, and lateral sides covered with 50%-shading nylon net (Sombrite®, (2 a shaded hut, all sides covered with 50%-shading nylon net (Sombrite®, and (3 a nursery shelter, with all lateral sides uncovered and the roof covered with leaves of buriti (Mauritia flexuosa. In these environments the following substrates were tested: 50% cattle manure + 50% cassava foliage, 50% cattle manure + 50% Vida Verde®, 50% cattle manure + 50% vermiculite, and 25% cattle manure + 25% vermiculite + 25% of cassava foliage + 25% Vida Verde®. Because there was no repetition of the growth environment, the effect of environment was examined using statistical procedures for analysis of combined experiments. Within environments a completely randomized design was used with five replications. All substrates are suitable for the formation of genipap seedlings, where the recommended substrates are: 50% cattle manure + 50% cassava foliage and 50% cattle manure + 50% Vida Verde® for the greenhouse and the substrates composed of 50% cattle manure + 50% vermiculite and 25% cattle manure + 25% cassava foliage + 25% Vida Verde®+ 25% vermiculite for the shaded hut. The buriti shelter is not recommended for production of genipap seedlings.O jenipapo (Genipa americana L., Rubiaceae é uma espécie brasileira nativa e pode ser utilizada na recomposição de áreas de florestas degradadas ou fornecimento de alimentos. Para que a espécie atinja elevado potencial, a produção de mudas de

  13. Effect of Fitomas-E on seedling production of papaya var. Maradol Roja in Cienfuegos,Cuba

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    Fernando G. Serbelló Guzmán

    2016-02-01

    Full Text Available An experiment in nursery in bag conditions was carried out at the Cienfuegos Horticultural Company, in order to evaluate the effect of different alternatives to stimulate the growth and the development of papaya seedlings (Carica papaya L. variety Maradol Red, in the period from June to September 2010. The treatments were: applying Fitomas-E, Trichoderma, EcoMic, the combination of Trichoderma + EcoMic and a control without application. We evaluated the height and diameter at four different positions, the number of leaves, green and dry mass of roots as well as for the external part of the plant at the transplantation time. The obtained data were subjected to the given statistical analyzes. Results indicate that the height and diameter of the papaya plants are increased with the application of Fitomas E and EcoMic, while a higher number of leaves is reached with the application of Fitomas E, and the combination of EcoMic with Trichoderma.

  14. Drought induced changes in growth, leaf gas exchange and biomass production in Albizia lebbeck and Cassia siamea seedlings.

    Science.gov (United States)

    Saraswathi, S Gnaana; Paliwal, Kailash

    2011-03-01

    Diurnal trends in net photosynthesis rate (P(N)), stomatal conductance (g(s)), water use efficiency (WUE) and biomass were compared in six-month-old seedlings of Albizia lebbeck and Cassia siamea, under different levels of drought stress. The potted plants were subjected to four varying drought treatment by withholding watering for 7 (D1), 14(D2) and 25 (D3) days. The fourth group (C) was watered daily and treated as unstressed (control). Species differed significantly (p lebbeck. A significant (p lebbeck, r2 = 0.84; C. siamea, r2 = 0.82). Higher WUE was observed in C. siamea (D2, 7.1 +/- 0.18 micromol m(-2) s(-1); D3, 8.39 +/- 0.11 micromol m(-2) s(-1)) than A. lebbeck, (control, 7.58 +/- 0.3 micromol m(-2) s(-1) and D3, 8.12 +/- 0.15 micromol m(-2) s(-1)). The chlorophyll and relative water content (RWC) was more in A. lebbeck than C. siamea. Maximum biomass was produced by A. lebbeckthan C. siamea. From the study, one could conclude that A. lebbeckis better than C. siamea in adopting suitable resource management strategy and be best suited for the plantation programs in the semi-arid dry lands.

  15. Production of canafístula seedlings cultivated in red-yellow alic latosol in response to macronutrients

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    Cezar Augusto Fonseca e Cruz

    2012-03-01

    Full Text Available Peltophorum dubium (canafístula is a fast-growing, rustic species excellent for use in combined reforestation of degraded areas. The objective of this study was to evaluate the effect of doses of N, P, K, Ca, Mg and S on seedling growth and quality indices; and to determine the recommended dose of these elements for establishment of a suitable fertilization program. The study was conducted in a greenhouse using red-yellow alic latosol as substrate. The experiment was designed following a Baconian matrix, evaluating three doses of the six macronutrients and two additional treatments, one with reference doses and another with no addition of nutrients. A completely randomized design was adopted with four replicates. Analysis using orthogonal contrasts revealed a significant response from all variables being studied to application of macronutrients, except the H/D ratio. The nutrients P and N had the most significant effects, 540 mg/dm3 being the recommended dose of P, and 50 mg/dm3 being the recommended dose of N. No response was observed to application of K, Ca, Mg and S, for most traits being assessed, indicating that the species has a low requirement for these nutrients.

  16. 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...

  17. Relevance of Vṛkṣāyurveda and other traditional methods for organic production of nursery seedlings of useful plants

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    Geetha Suresh

    2013-01-01

    Full Text Available Plant propagation is critical to augment the resource and has been the main concern for farmers and planters through history. India has evolved the science of Vṛkṣāyurveda to address the above issue. An effort is made here to review Vṛkṣāyurveda literature related to nursery techniques. Different libraries were visited and relevant review material obtained by hand search and from databases. Interaction with Sanskrit scholars and eminent scientists working in the field of Vṛkṣāyurveda, as well as the efforts of the authors of this paper, helped in the selection of pertinent literature. In the absence of original texts, authentic translations of the publications were referred. A conscious decision was made to limit the search to the fields of seed storage, pretreatment and nutrition of seedlings. To have a comparative account recent trends and literature on nursery technology were also examined. This was supplemented by interviews with traditional organic farmers. Our survey revealed that the time period of the literature pertaining to Vṛkṣāyurveda ranges from BCE 1200 to the present times. The subject has evolved from morphological descriptions and uses of plants, in texts such as R.gveda and Atharvaveda, to treatises dedicated solely to the art of growing plants like Kṛṣi-Parāśara and Vṛkṣāyurveda. It is also evident that there were important periods when more works appeared across subjects such as water divining, soil types, seed collection and storage, propagation, germination and sprouting, watering regimen, pest, and disease control. The review revealed that valuable information pertaining to nursery techniques is available in Vṛkṣāyurveda, which can be used in the development of nursery protocol. This will not only help in effective organic nursery management, but also ensure the health and livelihood security of the communities involved and effective waste management.

  18. Relevance of Vṛkṣāyurveda and other traditional methods for organic production of nursery seedlings of useful plants.

    Science.gov (United States)

    Suresh, Geetha; Haridasan, K; Krishnamurthy, Kulithala Viswanathan

    2013-07-01

    Plant propagation is critical to augment the resource and has been the main concern for farmers and planters through history. India has evolved the science of Vṛkṣāyurveda to address the above issue. An effort is made here to review Vṛkṣāyurveda literature related to nursery techniques. Different libraries were visited and relevant review material obtained by hand search and from databases. Interaction with Sanskrit scholars and eminent scientists working in the field of Vṛkṣāyurveda, as well as the efforts of the authors of this paper, helped in the selection of pertinent literature. In the absence of original texts, authentic translations of the publications were referred. A conscious decision was made to limit the search to the fields of seed storage, pretreatment and nutrition of seedlings. To have a comparative account recent trends and literature on nursery technology were also examined. This was supplemented by interviews with traditional organic farmers. Our survey revealed that the time period of the literature pertaining to Vṛkṣāyurveda ranges from BCE 1200 to the present times. The subject has evolved from morphological descriptions and uses of plants, in texts such as Ṛgveda and Atharvaveda, to treatises dedicated solely to the art of growing plants like Kṛṣi-Parāśara and Vṛkṣāyurveda. It is also evident that there were important periods when more works appeared across subjects such as water divining, soil types, seed collection and storage, propagation, germination and sprouting, watering regimen, pest, and disease control. The review revealed that valuable information pertaining to nursery techniques is available in Vṛkṣāyurveda, which can be used in the development of nursery protocol. This will not only help in effective organic nursery management, but also ensure the health and livelihood security of the communities involved and effective waste management.

  19. Produção de mudas de Duranta repens L. pelo processo de estaquia Seedlings production ofduranta Duranta repens L. using cuttings process

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    Genilda Canuto Amaral

    2012-06-01

    Full Text Available Devido a fácil adaptação ao clima, solo e por ter um potencial ornamental, a Duranta repens L. é muito utilizada no Brasil. Contudo, objetivou-se avaliar a produção de mudas de D. repens L. pelo processo de estaquia com fornecimento exógeno de AIB em diferentes estações do ano. O delineamento experimental foi inteiramente casualizado, com quatro concentrações de AIB (0, 1000, 3000 e 5000 mg kg-1, três tipos de estacas (herbáceas, semilenhosas e lenhosas e duas épocas do ano (chuvosa e seca. Realizaram-se as avaliações do número de estacas com raízes, sobrevivência das estacas, número de brotações por estaca, comprimento médio da maior raiz e massa seca da parte aérea e da raiz. A dose indicada para propagação de D. repens é de 3000 mg kg-1AIB. As estacas herbáceas e semilenhosas são as mais indicadas e a época chuvosa é mais propícia para produção de mudas de D. repens.Due to easy adaptation to climate, soil and ornamental potential, Duranta repens L. is widely used in Brazil. The study evaluated the production of seedlings of D. repens L. using cutting process with the supply of exogenous IBA in different seasons. The experimental design was completely randomized, with four concentrations of IBA (0, 1000, 3000 e 5000 mg kg-1, three types of cuttings (softwood, semi-hardwood and hardwood and two seasons (wet and dry. We assessed the number of rooted cuttings, survival cuttings, number of shoots per cutting, average length of the longest root and dry mass of shoots and roots. The best dose for propagation of D. repens was 3000 mg kg-1 IBA. The softwood and semi-hardwood cuttings were the most suitable and the rainy season the more favorable for D. repens seedling production.

  20. Presença do arilo na produção de mudas de Maytenus ilicifolia Presence of arils over Maytenus ilicifolia seedlings production

    Directory of Open Access Journals (Sweden)

    Márcio Paim Mariot

    2005-04-01

    Full Text Available A propagação da espinheira-santa (Maytenus ilicifolia é feita por sementes, sendo indicada a retirada do arilo para a semeadura, prática que demanda muito tempo e mão-de-obra. O experimento foi instalado com o objetivo de avaliar a influência do arilo na produção de mudas de espinheira-santa. Foram utilizados dois acessos do Banco Ativo de Germoplasma de M. ilicifolia da Embrapa Clima Temperado, 30 e 91. Os tratamentos utilizados foram: T1 - sementes com arilo retirado logo após a abertura das cápsulas (armazenadas em câmara fria sem arilo; T2 - sementes com arilo retirado no dia da semeadura (armazenadas em câmara fria com arilo e T3 - sementes sem a retirada do arilo. Foram avaliados: dias da semeadura à emergência (DSE; porcentagem de emergência em canteiros (%EC; comprimento da parte aérea (CPA; diâmetro da base do caule (DBC e número de folhas/planta (NF. A presença do arilo nas sementes de M. ilicifolia não influenciou os caracteres DSE, %G, DBC e NF, podendo influenciar apenas no caráter comprimento da parte aérea, dependendo da constituição genética da população, não sendo necessária a retirada do arilo para a semeadura.Maytenus ilicifolia is propagated by seeds and it is indicated to remove arils before sowing, what requires much time and work. An experiment to evaluate the influence of arils over seedlings production was installed in Embrapa Clima Temperado, in Pelotas, RS. Two accesses (30 and 91 of M. ilicifolia Gene Bank were used. The treatments were: T1 - seeds with arils removed immediately after the capsules (fruits being opened (stored in cold room without arils; T2 - seeds with arils removed in the sowing’s day (stored in cold room with arils; T3 - seeds with arils. The characters evaluated were: days of sowing to emergence (DSE; emergence percentage (%G; aerial part length (CPA; stem base diameter (DBC and number of leaves/seedling (NF. The arils in the seeds of M. ilicifolia did not influence

  1. Viabilidade do sistema de produção de mudas em bandejas em três cultivares de cebola Viability of onion seedling production on polyestyrene trays in three cultivars

    Directory of Open Access Journals (Sweden)

    Marie Yamamoto Reghin

    2007-08-01

    cultivo da cebola em um mercado cada vez mais competitivo.The present trial was realized in Ponta Grossa (PR and aimed to evaluate the viability of onion seedling production in polyestyrene trays, compared to conventional system on seedbed, using three cultivars The experimental design used was a randomized block with three replications. The treatments were arranged in a factorial scheme 3x3, being three seedlings type (from trays with 200 and 288 cells and from seedbed, and three cultivars (Mercedes, Bola Precoce and Crioula. Seedlings production on trays were realized under protected cultivation and seedlings from seedbeds produced in the field. Seeds were sowed in May,15th. At 57 days the seedlings were evaluated and then transplanted in plots with four rows and plants arranged in 0,40x0,08m, with 312.500 plants.ha-1. The harvest was realized according to the plant maturation stage. Bulbs were dried and then yield were evaluated. The production cost and seedlings viability were calculated. It was observed the seedlings from trays were superior when compared to seedlings from seedbed, mainly those from 200 cells.This higher seedling quality reflected on later performance obtaining the highest yield from trays of 200 cells. It was intermediary with 288 trays and lower from seedbed seedling. It was observed low seedling useful from seedbed during the selection process (50%. In the case of hybrid the cost of seedling production in seedbed was high, almost comparable to seedling production of open pollinated cultivars on trays of 288 cells. The best cultivars were Crioula and Mercedes. Seedlings production on trays mainly on 200 cells showed viability and represents an important alternative to increase onion yield in a competitive market.

  2. Sugarcane and pine biochar as amendments for greenhouse growing media for the production of bean (Phaseolus vulgaris L.) seedlings

    Science.gov (United States)

    Louisiana sugarcane farmers in 2016 harvested 11.7 million Mg of millable sugarcane from 163,000 ha, producing 1.47 million Mg of raw sugar and an estimated 3.5 million Mg of bagasse. Even though Louisiana sugar mills use 80% to 90% of the bagasse for fuel production, another 350,000 to 700,000 Mg o...

  3. 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 ...

  4. Evaluation of diverse wheat genotypes for potential biomass production through physiological parameters at seedling stage under controlled environment

    International Nuclear Information System (INIS)

    Khattak, G.S.S.

    2014-01-01

    Thirty wheat genotypes from UK, CIMMYT and Pakistan were evaluated under controlled environment conditions for their potential biomass production by measuring stomatal conductance (gs; porometry), leaf photosynthesis (IRGA), carbon isotope discrimination and carbon content (isotope ratio and mass analysis) at Rothamsted Research, Harpenden, UK during 2011. Amongst the dwarf genotypes, Rht2 and Rht3 showed lower stomatal conductance than Seri 32B, Seri 87B and Bathoor-07. For these 5 genotypes and another genotype Inqalab photosynthetic performance was determined by means of IRGA measurements. Of these genotypes Inqalab had the highest photosynthetic activity (A), stomatal conductance (gs), transpiration (E) and leaf intercellular CO/sub 2/ but it also had the lowest water use efficiency (A/gs) and intrinsic water use efficiency (A/E). Seri-87B had the greatest water use efficiency (A/gs) and intrinsic water use efficiency (A/E). All the Pakistani genotypes had large stomatal conductances and high 13C delta and thus may be expected to produce high biomass under irrigations and optimum inputs. (author)

  5. Produção de mudas de mamoeiro utilizando Bokashi e Lithothamnium Production of seedlings of papaya tree using Bokashi and Lithothamnium

    Directory of Open Access Journals (Sweden)

    Oscar Mariano Hafle

    2009-03-01

    plants per experimental plot. Evaluations were done at 15, 30, 60 and 100 days after seeding, which were: emergence (%, number of leaves, the shoot and the root length of the plant (cm, aerial, root and total dry matter weight (mg. There was significant interaction of the factors tested for the shoot length, at sixty and at hundred days after seeding; an isolated effect of the bokashi for all the analyzed variables, except for emergence, shoot length and number of leaves at thirty days after seeding. The conjugated use of the fertilizers showed a positive effect on precocity and plant height, and could be recommended in the formulation of substrate for the production of papaya seedlings.

  6. Pó de coco como substrato para produção de mudas de tomateiro Coconut coir fiber as a potting media for tomato seedling production

    Directory of Open Access Journals (Sweden)

    Elineide B. Silveira

    2002-06-01

    , quatro isolados de Pseudomonas fluorescentes, cinco isolados de Bacillus spp. e a mistura dos isolados Trichoderma + Pseudomonas fluorescentes + Bacillus. As suspensões foram adicionadas dois dias antes do plantio, na concentração de 0,52 A e 5 x 10(6 conídios/mL para bactérias e fungos, respectivamente. O incremento da população microbiana dos substratos não promoveu o crescimento das plântulas de tomateiro. Conclui-se que a utilização de pó de coco em mistura com outros substratos, principalmente com o PlantmaxÒ, é viável barateando o custo de produção de mudas de tomateiro.The production of seedlings is very important in the horticultural transplant industry and depends on the substrate utilization. The use of coconut coir fiber alone was evaluated or in combination with other potting media to produce transplants of tomato cv. 'Santa Adélia'. Cococnut coir fiber potting media PlantmaxÒ and earthworm castings were tested separated and in volumetric combinations: PlantmaxÒ + cocunut coir fiber, worm cast + cocunut coir fiber, PlantmaxÒ + earthworm casting and PlantmaxÒ + coconut coir fiber + earthworm casting, evaluating the variables germination 10 days after planting, leaf number, plant height, shoot fresh matter and shoot dry matter at 25 days after planting. The mixed substrates were superior to those from single components mainly PlantmaxÒ + coconut coir fiber + earthworm casting. The indigenous microbial population in each one of the three substrates was quantified in relation to the variables total bacteria, total fungi, fluorescent Pseudomonas spp., Bacillus and Trichoderma. In coconut coir fiber and earthworm casting the bacterial population surpassed the fungal. Earthworm casting and coconut coir fiber showed respectively higher population of total bacteria (240.56 x 10(4 UFC/g of dry substrate and total fungi (86.98 x 10(4 UFC/g of dry substrate. Fluorescent Pseudomonas spp. were detected in earthworm casting (1.65 x 10(4 UFC/g of dry

  7. AVOCADO SEEDLINGS MULTIPLE STEMS PRODUCTION

    Directory of Open Access Journals (Sweden)

    MARCUS VINICIUS SANDOVAL PAIXÃO

    2016-01-01

    Full Text Available ABSTRACT This study aimed to evaluate the potential of multi-stems in avocado seeds according to their mass as well as the adventitious rooting of multi-stem budding with or without the use of auxin. The research was carried out at the Vegetation House of Federal Institute of Espírito Santo, Campus Santa Teresa -ES, with seeds of different masses: 100 g, in which each experimental unit was made of five seeds, distributed within five repetitions, under a completely randomized design. The seeds were put to germinate and the percentage number of emergence and multiple stems were evaluated. After 150 days, the following evaluations were carried out: survival of rooted cuttings; number of leaves; stem diameter; root length; root volume; root and shoot fresh mass; root and shoot dry mass; shoot height; absolute growth and shoot growth rate; shoot dry weight/root dry mass ratio; shoot height/stem diameter ratio; shoot height/root length and Dickson's quality index ratio. Avocado seeds with mass over 100 g and between 81-100 g presented higher percentage of multiple stems. Rods over 20 cm that were not treated with IBA (indole-3-butyric acid resulted on avocado plants of better quality. The use of IBA (2000 mg L-1 does not affect the rooting and growth of avocado's multi-stem plants.

  8. Onion seedling production in styrofoam trays under controlled environment, as summer-planted onions Plantas de cebola produzidas em bandejas sob cultivo protegido, no verão

    Directory of Open Access Journals (Sweden)

    Maria Cristina Veiga De Vincenzo

    2003-02-01

    Full Text Available Summer-planted onion (Allium cepa L. can increase grower profits, but the production of seedlings for transplant is difficult. This experiment was carried out in Piracicaba, SP, Brazil, with the objective of studying the behavior of the short-day onion hybrid Mercedes, in its initial stage, under controlled greenhouse environment, as summer-planted onions. Four formulated substrates, two different numbers of plants per cell were tested, and 288-cell styrofoam trays used. Trials were set up in split-plot design (n=3. Substrate and number of plants per cell represented main plots, and N application (2 and 3 times a week the subplots. The number of three plants per cell decrease the earlier onset of bulbing and increase plant height; substrates did not show differences; and the N application 3 times a week increased plant height and leaf dry weight, but did not result in earlier onset of bulbing.Uma das dificuldades do cultivo do verão da cebola (Allium cepa L., que permite maior lucro pois esta é a época de entressafra, é a produção de plantas para o transplante. Com o objetivo de verificar o comportamento na fase de muda do híbrido Mercedes, sob cultivo protegido como cultura de verão, o experimento foi instalado em estufa, em Piracicaba, SP com bandejas de isopor de 288 células. Foram testados quatro substratos. e dois números de plantas por células (3 e 4 plantas/célula, sendo sub-plot a suplementação mineral com nitrogênio 2 e 3 vezes por semana com nitrato de cálcio + nitrato de potássio. O delineamento experimental foi inteiramente casualizado, com fatorial 4 x 2 em parcelas subdivididas, e três repetições. A densidade de três plantas por célula apresentou menor taxa de bulbificação precoce e maior altura da planta; não houve diferença quanto aos substratos e que a aplicação de nitrogênio três vezes por semana apresentou os maiores valores de altura da planta e peso da matéria seca da parte aérea, n

  9. 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.

  10. 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...

  11. Substratos no desenvolvimento inicial de quatro cultivares de pessegueiro e uma nectarineira Substrates in the initial production of four peach varieties and one nectarine variety seedlings

    Directory of Open Access Journals (Sweden)

    Américo Wagner Júnior

    2008-08-01

    Full Text Available Entre os fatores que contribuem para melhor desenvolvimento inicial das plantas, estão a qualidade da semente e o substrato utilizado.Objetivou-se avaliar o efeito do substrato na formação inicial de pessegueiro e nectarineira. O trabalho foi realizado no Departamento de Fitotecnia, da Universidade Federal de Viçosa, de fevereiro a março de 2004. Foram utilizados quatro cultivares de pessegueiro, 'Alô Doçura', 'Campinas 1', 'Relíquia' e 'Ouromel' e uma cultivar de nectarineira 'Josefina'. Sementes retiradas de frutos maturos, foram estratificadas em câmara fria, com temperatura de 5±1ºC e ausência de luz. Após a germinação, no interior da casa-de-vegetação, procedeu-se à semeadura em recipientes plásticos (3 litros, contendo os substratos: Plantmax®; Plantmax® + Areia (1:1 v/v; Plantmax® + Latossolo Vermelho (1:1 v/v; Plantmax® + Latossolo Vermelho + Areia (1:1:1 v/v. Foi utilizado o delineamento experimental inteiramente casualizado, num fatorial 5 x 4 (cultivar x substrato, com cinco repetições, considerando-se como unidade experimental cada recipiente plástico. Após 38 dias da semeadura foram analisadas: porcentagem de emergência, número de folhas, comprimento total, altura e comprimento de raiz, diâmetro do caule, massa da matéria seca total, da parte aérea e da raiz e o número de brotações primárias. O substrato teve efeito no desenvolvimento inicial de pessegueiro, obtendo-se os melhores resultados com o substrato comercial Plantmax®. O maior acúmulo de massa de matéria seca total e da parte aérea foi obtido com os cultivares 'Campinas 1' e 'Relíquia', sendo que esse último, também proporcionou maior número de brotações primárias.Among the factors that contribute for the best initial plants growing are seed quality and substrate utilized. The aim of this work was to evaluate the effect of substrate on the initial production peach and nectarine seedlings. The work was carried out in the

  12. [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.

  13. Produtividade da couve-flor em função da idade de transplantio das mudas e tamanhos de células na bandeja Cauliflower production depending on age of seedling and cell size of the trays

    Directory of Open Access Journals (Sweden)

    Maria Carolina Godoy

    2005-07-01

    Full Text Available O experimento foi realizado de novembro de 2000 a abril de 2001, na UNESP em São Manuel (SP. Estudou-se o efeito do tamanho da célula da bandeja de poliestireno expandido e a idade de transplantio das mudas sobre a produção de couve-flor, híbrido Shiromaru II. Usaram-se bandejas com 128 e 288 células, correspondentes a 34,6 e 9,7 cm³/célula, respectivamente, e mudas transplantadas aos 27, 34, 41 e 48 dias após a semeadura. Os tratamentos foram arranjados como fatorial 2 x 4, dispostos no delineamento de blocos casualizados, com cinco repetições. Foram avaliados, por ocasião do transplantio, o número de folhas, peso fresco, peso seco e área foliar das mudas. A parcela experimental no campo foi constituída por dez plantas. Nas colheitas, avaliaram-se a porcentagem de plantas com cabeça comercial e nestas, o número de folhas, peso fresco e diâmetro da cabeça. A produção total por parcela foi obtida com a soma do peso fresco de todas as cabeças consideradas comerciais. A produção de mudas em bandejas com 128 células proporcionou maior porcentagem de plantas comerciais (64% relativamente às bandejas com 288 células (45%, maior peso médio de cabeça (337 g na bandeja com 128 e 247 g na bandeja com 288 células e maior produção de plantas comerciais (36,9 t/ha em bandeja de 128 células e 19,9 t/ha em bandeja de 288 células. As mudas transplantadas com 32 dias apresentaram maior peso médio de cabeça (319 g. Concluiu-se ser recomendável produzir mudas de couve-flor em bandejas com 128 células.The experiment was carried out from November/2000 to April/2001, in São Manuel, São Paulo State, Brazil. The effect of cell size of two polyestyrene trays and age of seedling at transplanting date was observed, on the production of cauliflower, hybrid Shiromaru II. Trays with 128 and 288 cells, corresponding to 34.6 and 9.7 cm³/cell, respectively, were used with seedlings transplanted at 27; 34; 41 and 48 days after sowing date

  14. Disponibilidade de boro em substrato para produção de porta-enxertos de citros em fase de sementeira Boron availability in the growth media for production of citrus rootstock seedlings

    Directory of Open Access Journals (Sweden)

    Dirceu Mattos Junior

    2008-12-01

    Full Text Available A produção de mudas cítricas em ambiente protegido, associada ao uso de substratos, requer estratégias adequadas de manejo no viveiro. Problemas de falta e/ou excesso de nutrientes freqüentemente causam prejuízos ao setor. Em citros ocorrem diferentes respostas à disponibilidade de boro (B para a planta e são comuns danos causados pela toxidez desse nutriente. Este trabalho teve como objetivo avaliar os efeitos da adição de B no substrato sobre a absorção e o crescimento de duas variedades de porta-enxertos de citros em fase de sementeira. O experimento foi desenvolvido em esquema fatorial, com limão 'Cravo' e citrumelo 'Swingle' e quatro doses de B misturadas ao substrato na forma de H3BO3 (0, 3, 6, e 12 g m-3 de B, em três repetições. Avaliaram-se os teores de B no substrato no início do experimento, aos 55 e 110 dias de sementeira, e o crescimento dos seedlings e a absorção de B pelas plantas nos mesmos intervalos. Os teores de B no substrato variaram entre 0,1 e 4,7 mg L-1. Aos 55 e 110 dias, houve decréscimo nos teores do nutriente nas plantas provavelmente devido às perdas do nutriente do substrato por lixiviação. Observaram-se sintomas visuais de fitotoxicidade de B nos porta-enxertos cultivados no substrato tratado com 3 g m-3 de B, quando o teor na planta foi >100 mg kg-1. O excesso de B causou redução no crescimento dos porta-enxertos. O maior crescimento e acúmulo de B na massa seca de plantas de citrumelo 'Swingle', comparado ao 'Cravo, indicam maior tolerância do primeiro à fitotoxicidade de B.The production of citrus nursery trees under protected environment using growth media requires healthy management practices. Problems associated with deficiency and/or nutrient excess have frequently caused economic losses in the nursery. Citrus grow differently depending on boron (B availability in the growth media, even tough B toxicity commonly cause damage to plants. This research aimed to evaluate the effects

  15. PRODUCTION OF PASSION FRUIT SEEDLINGS WITH THE RESIDUE OF AGROINDUSTRIAL PROCESSING OF POTATOES AS A STRATEGY IN THE SUSTAINABILITY OF AGRICULTURAL FAMILY ACTIVITY

    Directory of Open Access Journals (Sweden)

    Leonardo Humberto Silva e Castro

    2012-12-01

    Full Text Available In order to contribute to family farming sustainable development and to the environmental management of the residue generated from potato processing by the company "Bem Brasil Alimentos LTDA" from Araxa, Minas Gerais, Brazil, an experiment was conducted at the Experimental Farm of Araxa (FEAX - EPAMIG between February to April of 2012, aiming to analyze passion fruit seedlings development from the use of different doses of this residue such as substrate, to reduce costs of raw materials. The experiment was conducted in randomized block design with six treatments, four repetitions and 20 plants per plot, being the treatments, blends of soil (latosol with levels of 10%, 20% and 30% of potato processing residue associated to chemical treatment and a witness. After 70 days of sowing, the height of air part (cm, root length (cm, number of leaves and total dry matter (g were evaluated. The best treatment was the M4 which used latosol + chemical treatment + 20% of residue. It was diagnosed that the use of agroindustrial potato processing residue, as part of the substrate, is a favorable alternative for passion fruit seedlings development. Thus, it gives a destination to this residue instead of discarding it into the environment, as well as decreases the costs of raw material that permit its correct ecological use, besides generating more income for family farmers.

  16. 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...

  17. The influence of ascorbic acid on the oxygen consumption and the heat production by the cells of wheat seedling roots with their mitochondrial electron transport chain inhibited at complexes I and III

    International Nuclear Information System (INIS)

    Gordon, L.K.; Rakhmatullina, D.F.; Ogorodnikova, T.I.; Alyabyev, A.J.; Minibayeva, F.V.; Loseva, N.L.; Mityashina, S.Y.

    2007-01-01

    The influence of exogenous ascorbic acid (AsA) on oxidative phosphorylation was studied using wheat seedling roots. Treatment of them with AsA stimulated the rates of oxygen consumption and the heat production and caused a decrease of the respiratory coefficient. The increase in respiration was prevented by inhibitors of ascorbate oxidase, diethyldithiocarbamate (DEDTC), and of cytochrome oxidase, cyanide (KCN). Exogenous AsA sharply stimulated the rate of oxygen consumption of roots when complexes I and III of the mitochondrial electron transport chain were inhibited by rotenone and antimycin A, respectively, while the rates of heat production did not change significantly. It is concluded that AsA is a potent energy substrate, which can be used in conditions of failing I and III complexes in the mitochondrial electron transport chain

  18. Seedling formation and field production of beetroot and lettuce in Aquidauana, Mato Grosso do Sul, Brazil Formação de mudas e produção a campo de beterraba e alface em Aquidauana-MS

    Directory of Open Access Journals (Sweden)

    Paulo AM Leal

    2011-12-01

    Full Text Available In horticulture, the proper use of containers and substrates for the production of seedlings are important factors that affect crop productivity in the field. This study aimed to evaluate the effect of different containers and substrates in the production of lettuce (Lactuca sativa, cv Veneranda and beetroot (Beta vulgaris, cv Top Tall Early Wonder seedlings in nursery with monofilament screen, 50% of shading, and the productivity of these species when transplanted to field plots. In protected cultivation, a completely randomized experimental design, in a 3 x 3 factorial scheme (three polystyrene trays, R1= 72, R2= 128 and R3= 200 cells and three substrates, S1= 93% of soil + 7% of organic compost, S2= 86% of soil + 14% of organic compost and S3= 79% of soil + 21% of organic compost was used, with 15 replications, where one plantlet was a replication. In the field, the nine treatments were evaluated in a completely randomized experimental design. The 72 cells tray with 7% commercial organic compost substrate promoted the best beetroot and lettuce seedlings. In the field, the plants from the 72 cell tray produced greater plants, independent of substrates type.Na olericultura o uso adequado de recipientes e substratos para a produção de mudas são fatores importantes e que afetam a produtividade das culturas a campo. No presente trabalho objetivou-se avaliar, em viveiro de tela de monofilamento com 50% de sombreamento, o efeito de diferentes recipientes e substratos na produção de mudas de alface (Lactuca sativa, cv Veneranda e beterraba (Beta vulgaris, cv Top Tall Early Wonder, bem como a produtividade dessas espécies quando transplantadas em canteiros a campo. No ambiente protegido utilizou-se o delineamento experimental inteiramente casualizado, em esquema fatorial 3 x 3, sendo os fatores 3 recipientes (R1= 72, R2= 128 e R3= 200 células de poliestireno e 3 substratos (S1= 93% de solo + 7% de composto orgânico, S2= 86% de solo + 14% de

  19. 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...

  20. Natural products use for protection of seedling in planting trees Uso de produtos naturais para proteção de mudas na arborização de pastagens

    Directory of Open Access Journals (Sweden)

    Valéria Cristina Zago

    2008-04-01

    Full Text Available Conventional productive systems have depleted environmental resources and weakened unsustainable agroecosystems. Silvopastoral systems can be a viable alternative for the recovery of degraded areas. The objective of this experiment was to evaluate natural products used to protect seedlings in planting trees in pastures which the cattle is permanently grazing and the seedlings have no mechanical restraint to keep the cattle away. The experiment was conducted at “Embrapa Gado de Corte”, Mato Grosso do Sul State, Brazil, from February 2nd 2005 to March 28th 2005. The statistical design employed was the split-plot random design, with ten replications. The following treatments were given to the plots: 1 cattle manure around the tree seedlings; 2 dried bovine blood; 3 crushed egg shells; and 4 no protection (control. The subplots contained five tree species: Myroxylon peruiferum (Bálsamo, Dipteryx alata (Cumbaru, Schizolobium parahyba (Guapuruvu, Genipa americana (Jenipapo and Mimosa caesalpineaefolia (Sansão do campo. Herbivory was intense for all treatments. The survival rate of S. parahyba was 72.5%, and 100% of M. caesalpineafolia died. Cattle manure produced the best results, with partial protection of tree seedlings. Application of egg or blood did not offer any protection to the young trees. The concentration and frequency of application of manure for seedling protection deserves further attention.Os sistemas de produção convencional têm esgotado os recursos ambientais, o que torna o agroecossistema frágil e insustentável. Sistemas silvipastoris podem ser alternativas viáveis na recuperação de pastagens degradadas. Este estudo foi desenvolvido com o objetivo de avaliar produtos naturais na implantação de espécies arbóreas em pastagens com presença constante de bovinos, sem proteção das mudas. O experimento foi conduzido na Embrapa Gado de Corte, Campo Grande, MS, no período de 02/02/2005 a 28/03/2005. O delineamento

  1. Produção de mudas de espécies das Restingas do município do Rio de Janeiro, RJ, Brasil Seedling production of Restinga species of Rio de Janeiro Municipality, RJ, Brazil

    Directory of Open Access Journals (Sweden)

    Luiz Roberto Zamith

    2004-03-01

    Full Text Available Os impactos antrópicos sobre as Restingas vêm se intensificando de tal forma nas últimas décadas que hoje é prioritária a conservação dos poucos remanescentes existentes e a restauração de áreas degradadas. A produção de mudas é etapa importante neste processo. Dados fenológicos obtidos para 72 espécies mostraram grande variação na época e na duração da frutificação, indicando que a colheita de sementes deve ser realizada ininterruptamente ao longo do ano, para que seja obtida diversidade expressiva de espécies. Cinqüenta por cento destas espécies não apresentaram qualquer restrição para a produção de mudas. O tempo necessário para o início da emergência da parte aérea e/ou a percentagem máxima de germinação foram comparados para 44 espécies e as grandes amplitudes de variação intra- e interespecíficas encontradas sugerem a ocorrência de vários tipos de dormência. Os resultados indicam a grande viabilidade da produção de mudas destinadas a futuros plantios como estratégia a ser utilizada para a recuperação das populações naturais de espécies ameaçadas e para a restauração de Restingas degradadas.The impact of human activities on the Restingas has been so intense in recent decades that there is now an urgent need for conservation of remnant patches and restoration of degraded areas. The production of seedlings is an important phase in the restoration process. Phenological data obtained for 72 species showed a wide variation in the timing and duration of fruiting. Therefore, seed harvest should take place continuously throughout the year in order to cover a high diversity of species. Fifty per cent of the 72 species showed no restrictions for seedling production. The necessary timing for the beginning of shoot emergence and for maximum germination percentage were compared for 44 species. The large amplitude of intra- and interspecific variation suggests the occurrence of distinct types of

  2. 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.

  3. Métodos de produção de mudas, distribuição de matéria seca e produtividade de plantas beterraba Seedlings production and yield of beet plants

    Directory of Open Access Journals (Sweden)

    Vandeir Francisco Guimarães

    2002-09-01

    Full Text Available Comparou-se desenvolvimento de mudas de beterraba (cv. Tall Top Early Wonder, produzidas por diferentes métodos, através da distribuição de matéria seca na planta. Comparou-se os tratamentos T1 - mudas produzidas em bandejas de 288 células (1,2 x 10-5 m³; T2 - 200 células (1,6 x 10-5 m³ ; T3 - 128 células (3,2 x 10-5 m³; T4 - 128 células (7,2 x 10-5 m³; T5 - semeadura direta e T6 - mudas de raiz nua. Aos 28 dias após a semeadura (DAS, as mudas produzidas em bandejas foram transplantadas para campo, juntamente com mudas de raiz nua (T6. O delineamento experimental foi de blocos ao acaso com quatro repetições. Foram coletadas plantas semanalmente dos 28 aos 98 DAS. Determinou-se a matéria seca das folhas, pecíolos, raízes e da parte aérea e a matéria fresca das raízes. Aos 98 DAS, realizou-se a colheita das raízes comerciais, expressando-se a produtividade em kg ha-1. Para o tratamento T5, o espessamento da raiz tuberosa começou 42 DAS. Por sua vez, as plantas provenientes dos tratamentos T1, T2, T3, T4 e T6 iniciaram o acúmulo de matéria seca nas raízes a partir dos 56 DAS. Os métodos de produção de mudas não influenciaram significativamente na produtividade da cultura, porém aumentaram o ciclo, quando comparado à semeadura direta. Caso a disponibilidade de área seja fator limitante, a produção de mudas em bandejas é recomendável, sendo indicadas bandejas de 288 células.Different methods of beet seedling production were evaluated by distributing dry matter on the plants. The experimental design was of randomized blocks with four replications and six treatments: T1 - seedlings produced in trays of 288 cells (1.2 x 10-5 m³; T2 - 200 cells (1.6 x 10-5 m³; T3 - 128 cells (3.2 x 10-5 m³; T4 - 128 cells (7.2 x 10-5 m³; T5 - direct sowing and T6 - bare-root seedlings. The seedlings produced in trays and the bare-root seedlings were transplanted to the field on the 28th day after the sowing (DAS, with spacing of

  4. Volume de recipientes e composição de substratos para produção de mudas de mamoneira Recipients volume and substrate composition for castor seedlings production

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    Rosiane de Lourdes Silva de Lima

    2006-06-01

    have to be set in order to succeed, such as recipient volume, substrate composition and period of seedling at nursery. A trial was run in greenhouse at Embrapa Algodão, Campina Grande, Paraíba State, Brazil, in a randomized block design with four replications and 25 treatments in 5² factorial distribution of five recipient volumes and five substrate compositions. Between 15 and 43 days after emergence, five destructive measurements were weekly performed for obtaining data on plant height, stem diameter, leaf area, number of leaves and dry weight of shoot and roots. Significant effects of treatments were detected on all variables analyzed. Seedlings growth stabilized about 36 days after emergence regardless recipient volume. Substrates composed by soil mixed to peanut hulls or bovine manure propitiated the best seedlings growth, while those ones containing sugarcane bagasse or agave mucilage were the worst. Recipients with 2 L of volume were the most appropriated to castor seedlings production.

  5. Production of tomato seedlings using different substrates and trays in three protected environments Produção de mudas de tomate usando-se diferentes substratos e tipos de bandejas em três ambientes protegidos

    Directory of Open Access Journals (Sweden)

    Edilson Costa

    2012-10-01

    Full Text Available The seedlings production is an essential part for vegetables production. Thus, this study aimed to evaluate the environment, the substrates and the containers in the development of tomato seedlings, cv. Santa crus Kada Gigante, in Aquidauana -MS, Brazil region, from October to November, 2008. Polystyrene trays with 72; 128 and 200 cells, filled with four substrates (soil; Plantmax®; coconut fiber and vermiculite were tested in three protected environments (greenhouse; screened with Sombrite® and screened with Aluminet®. The experimental design was completely randomized, factorial scheme 3x4 (three trays x four substrates, with four replications, being analyzed individual variance analysis and joint analysis for the environments. The environment with screens (Sombrite® and Aluminet®, the trays with 72 cells and the vermiculite produced better results.A produção de mudas é uma etapa essencial na cadeia produtiva de hortaliças. Desta forma, este trabalho teve os objetivos de avaliar a ambiência, os substratos e os recipientes no desenvolvimento de mudas de tomateiro, cv. Santa Cruz Kada Gigante, na região de Aquidauana-MS, de outubro a novembro de 2008. Foram testadas bandejas de poliestireno com 72; 128 e 200 células, preenchidas com quatro substratos: solo; Plantmax®; fibra de coco fina, e vermiculita, em três ambientes protegidos: estufa, telado com Sombrite® e telado com Aluminet®. O experimento foi conduzido em delineamento inteiramente casualizado, em esquema fatorial 3 x 4 (três bandejas x quatro substratos, com quatro repetições, realizando-se de análises de variâncias individuais e análise conjunta dos ambientes. Os ambientes telados (Sombrite® e Aluminet®, a bandeja com 72 células e a vermiculita produziram as melhores mudas.

  6. Lotus tenuis Seedling Establishment and Biomass Production in Flooding Pampa Grasslands (Buenos Aires , Argentina Establecimiento de Plántulas y Producción de Biomasa de Lotus tenuis en Pastizales de la Pampa Deprimida (Buenos Aires, Argentina

    Directory of Open Access Journals (Sweden)

    Osvaldo R Vignolio

    2011-03-01

    Full Text Available Biomass and plant density of Lotus tenuis Waldst. & Kit. ex Willd. have been reported in decreasing in grasslands and pastures. Our objective was to determine if L. tenuis biomass and plant density can be increased in grassland through seed addition. Two separated experiments under cattle grazing exclusion were conducted in three paddocks of a Flooding Pampa grassland. The first experiment was from autumn 2004 to autumn 2006 and the second from autumn 2005 to autumn 2007. Different L. tenuis seed additions (0, 57, 229, 917 and 1833 seeds m-² were broadcast into experimental plots. In the second experiment, besides seed additions there was a reseeding of approximately 900 seed m-² from seed rain produced by plants of grassland. Seed density explained the 81% and 19% of the variation in seedling density and L. tenuis biomass, respectively. Seedling emergence occurred mainly between autumn and early spring, while seedling mortality was mainly between late spring and early summer. Lotus tenuis adult plant density and biomass production increased with seed additions. Total biomass production in the plant community varied between 589.94 ± 26.89 and 1042.44 ± 54.39 g m-² yr-1 and the differences were principally attributed to precipitations. Lotus tenuis biomass contribution was of approximately 10%. The results suggest that L. tenuis seedling and plant establishment and biomass production can be increased through seed addition and/or seed rain through grazing exclusion during reproductive period.En pastizales y pasturas ha sido documentada la reducción de la densidad de plantas y de la biomasa de Lotus tenuis Waldst. & Kit. ex Willd. Nuestro objetivo fue determinar si su densidad de plantas y su producción de biomasa pueden ser incrementadas en un pastizal mediante la adición de semillas. Dos experimentos sin pastoreo fueron realizados en tres potreros de un pastizal de la Pampa Deprimida. El primer experimento fue realizado entre otoño 2004

  7. SUBSTRATES FOR PRODUCTION AND GROWTH OF MANGABA (Hancornia speciosa Gomes SEEDLINGS PRODUÇÃO E CRESCIMENTO DE MUDAS DE MANGABEIRA (Hancornia speciosa Gomez EM DIFERENTES SUBSTRATOS

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    Maria Eloisa Cardoso da Rosa

    2007-09-01

    Full Text Available

    Mangaba (Hancornia speciosa Gomez seedlings were transplanted eleven months after emergence to the following substrates: soil (Oxisol, soil + 33% calcined sugar-cane bagasse, and soil + 66% calcined sugar-cane bagasse, with and without lime and fertilizer. At 70, 100 and 130 days after transplanting, plants were evaluated for height and number of leaf pairs. At the end of the experiment – 130 days – roots and aerial part dry matter were weighed. The addition of 0.5 kg.m-3 of 10-10-10 fertilizer to the soil was the best treatment. Root dry matter was slightly higher than aerial part dry matter on some treatments. Roots have developed more than aerial parts. In general, substrates with pH values between 5.2 and 5.5 promote higher growth of mangaba seedlings, but those with pH between 6.0 and 6.8 cause seedling growth reduction.

    KEY-WORDS: Mangaba; native fruit trees; lime; fertilizer; substrate.

    Mudas de mangabeira (Hancornia speciosa Gomez com onze meses de idade foram submetidas a diferentes combinações de substratos: solo apenas (Latossolo Vermelho-Amarelo, solo + 33% de bagacilho de cana calcinado, e solo + 66% de bagacilho de cana calcinado, os quais receberam ou não calagem e adubação. Após a aplicação dos tratamentos, foram avaliados aos 70, 100 e 130 dias, o diâmetro basal das mudas, a altura de plantas e o número de pares de folhas, bem como o peso seco da parte aérea e da raiz, ao final do experimento. Pôde-se verificar que a adição de 0,5 kg.m-3 do adubo químico 10-10-10 ao solo foi o melhor tratamento, nas condições estudadas. Houve uma tendência de superioridade do peso seco da raiz, em relação à parte aérea, em parte dos tratamentos, evidenciando um maior desenvolvimento da raiz das mudas de mangaba, em rela

  8. Produção de mudas de Aloysia gratissima (Gillies & Hook. Tronc. por meio da propagação sexuada e assexuada Aloysia gratissima (Gillies & Hook. Tronc. seedling production through sexual and asexual propagation

    Directory of Open Access Journals (Sweden)

    F.M. Santos

    2009-01-01

    Full Text Available A alfazema-do-Brasil é planta de importância medicinal, como produtora de terpenos. A principal descrição etnofarmaco-botânica aponta como sendo eficaz para infecções brônquicas, pulmonares e da bexiga. O objetivo do trabalho foi estudar a propagação de A. gratissima visando a obtenção de mudas. Na propagação sexuada estudou-se a influência da temperatura na presença e ausência de luz e três épocas de coleta das sementes (março, junho e setembro. Na propagação via semente foram testados três diferentes substratos (areia, palha de arroz carbonizada, Plantmax®. Na propagação vegetativa foram testados dois tipos de estacas (herbáceas e semi-lenhosas e de dois substratos (areia e Plantmax®. Os resultados indicaram que na propagação sexuada, a germinação das sementes foi maior nas temperaturas constantes de 20 e 25°C, e a melhor época de coleta de sementes foi em março. O substrato comercial mostrou-se superior para o crescimento das plântulas, atingindo 93,25% de emergência das sementes e 100% de sobrevivência. Para a propagação assexuada, as estacas herbáceas em substrato comercial e areia apresentaram 96 e 95% de enraizamento, respectivamente.Brazilian-lavender is a medicinally important plant since it produces terpenes. As regards ethnopharmacology, it is mainly efficient against bronchial, lung and bladder infections. The aim of this work was to study Aloysia gratissima propagation for seedling production. In sexual propagation, temperature influence in the presence and absence of light and three seed harvesting times (March, June, and September were studied. Three different substrates (sand, carbonized rice husk, Plantmax® were also evaluated for seed germination. In vegetative propagation, two cutting types (herbaceous and semihardwood and two substrates (sand, Plantmax® were tested. Seed germination was higher under constant temperatures of 20 and 25ºC, and March was the best seed harvest time for

  9. Uso de esterco associado à adubação mineral na produção de mudas de mamoeiro (Carica papaya L. The use of manure associated with mineral fertilization in papaya (Carica papaya L. seedling production

    Directory of Open Access Journals (Sweden)

    Regina Célia Faria Simão Canesin

    2006-12-01

    Full Text Available Na composição do substrato para produção de mudas de mamoeiro, recomenda-se o uso de adubação orgânica, que traz como vantagens a melhoria das características físicas, químicas e biológicas do solo, criando um ambiente favorável ao desenvolvimento inicial das mudas, bem como boa resposta do mamoeiro. Os materiais orgânicos desempenham ainda um importante papel na nutrição das plantas como fornecedores de nutrientes. Contudo, observa-se que existe uma grande variação nas recomendações e quase sempre a adubação orgânica está associada à adubação mineral. Neste contexto, o objetivo deste trabalho foi o de verificar os efeitos do uso de esterco de curral associado ou não à adubação mineral no substrato sobre a formação de mudas de mamoeiro. O Experimento foi conduzido na FEP/UNESP/Câmpus de Ilha Solteira-SP. O delineamento utilizado foi em blocos, em esquema de parcelas subdivididas, sendo parcelas as cultivares e subparcelas os substratos. Cada parcela com 5 repetições e 10 plantas úteis por subparcela. Para a comparação das médias, utilizou-se o teste de Tukey. Com base nos resultados obtidos, pode-se concluir que: a Na formação das mudas de mamoeiro, o esterco de curral pode ser utilizado sem a necessidade de adubação mineral com o superfosfato simples e o cloreto de potássio; b O esterco de curral foi capaz de fornecer às mudas de mamoeiro os nutrientes N, P, K, Ca, Mg e Cu, necessários para seu desenvolvimento até o transplantio para o campo.The use of organic fertilization is recommended to be added to the substrate for papaya seedling production, as it enhances the physical, chemical and biological characteristics of the soil, creating a favorable environment for the initial development of the plants, which results in better plant growth. The organic matter has also the important role of providing nutrients to the plants. However, there is great variation in the recommendations, and in most cases

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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.

  12. Produção de mudas de maracujazeiro-doce micorrizadas em solo desinfestado e adubado com fósforo Production of mycorrhized sweet passion fruit seedlings in disinfected and phosphorus fertilized soil

    Directory of Open Access Journals (Sweden)

    Érika Cristina Teixeira dos Anjos

    2005-04-01

    other fungi stimulated plant development after 45 days. Quadratic models indicated maximum values of plant height in soil, with P values estimated between 15.40 and 16.07 mg dm-3 in disinfected soil and 14.85 and 15.60 mg dm-3 in non disinfected soil, obtained in treatments with S. heterogama and G. albida, respectively. Higher spores density and mycorrhizal colonization were observed in treatments with these fungi, comparing with the native AMF. Growth of sweet passion fruit seedlings can be improved by mycorrhization with selected AMF, with reduction of time spent on seedling production.

  13. Produção de mudas de almeirão e cultivo no campo, em sistema agroecológico Agroecological seedling production and field cultivation of chicory

    Directory of Open Access Journals (Sweden)

    Dercio C. Pereira

    2012-10-01

    evaluated at 13 and 26 DAE. However, the commercial substrate was superior to other treatments for root length. The organic substrates can be recommended for seedling production of chicory with a satisfactory development in trays and in the field, and also at post-harvest. The use of compost as a substrate for seedlings provided the development of more vigorous seedlings and stronger plants in field than the commercial substrate.

  14. 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 ...

  15. Utilização de compostos orgânicos como substratos na produção de mudas de hortaliças Utilization of organic compost as substrate for vegetable seedling production

    Directory of Open Access Journals (Sweden)

    Marco Antonio de A Leal

    2007-09-01

    Full Text Available Visando determinar a viabilidade da utilização de compostos orgânicos obtidos com palhada de Crotalaria juncea L. e capim Napier (Pennisetum purpureum Schum. como substratos na produção de mudas de hortaliças, realizaram-se experimentos com alface (folhosa, beterraba (raiz e tomate (hortaliça de fruto. Estudou-se a eficiência de compostos produzidos a partir dos materiais: 100% de Crotalária Júncea; 66% de Crotalária Júncea + 33% de Napier; 33% de Crotalária Júncea + 66% de Napier; 100% de Napier; 33% de Crotalária Júncea + 66% de Napier, inoculado com 5% da massa com esterco bovino; 33% de Crotalária Júncea + 66% de Napier, inoculado com 100 L de Agrobio diluído a 5%; 100% de Napier, inoculado com 100 litros de Agrobio diluído a 5%. Como controle utilizou-se o substrato comercial Plantmax HT®. Avaliou-se altura da parte aérea, número de folhas, produção de massa fresca na parte aérea e produção de massa seca na parte aérea. O composto produzido com a mistura de 66% de Crotalária Júncea e 33% de Napier mostrou-se superior aos demais tratamentos para produção de mudas de alface, beterraba e tomate.The viability of the organic compost utilization as a substrate for vegetable seedlings production, obtained from Crotalaria juncea L. and Napier grass (Pennisetum purpureum Schum., was determined. The research was developed with lettuce (leaf vegetable, beetroot (root vegetable and tomato (fruit vegetable. The organic composts were produced from: 100% Crotalaria Juncea; 66% Crotalaria Juncea + 33% Napier; 33% Crotalaria Juncea + 66% Napier; 100% Napier; 33% Crotalaria Juncea + 66% Napier, inoculated with 5% of the mass with cattle manure; 33% Crotalaria Juncea + 66% Napier, inoculated with 100 L of 5% diluted Agrobio; 100% Napier, inoculated with 100 L of 5% diluted Agrobio. We evaluated the height, leaf number, aerial green weight and aerial dry weight. A commercial substrate Plantmax HT® was used as control. The

  16. 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.

  17. 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.

  18. Produção de mudas de tomateiro em substratos contendo fibra de coco e pó de rocha Tomato seedlings production using substrates with coconut fiber and rock waste

    Directory of Open Access Journals (Sweden)

    Regynaldo A Sampaio

    2008-12-01

    Full Text Available Com o objetivo de avaliar proporções dos resíduos fibra de coco (FC e pó de rocha de granito (RG como substratos na produção de mudas de tomateiro, cultivar Kada Gigante, realizou-se um experimento em casa de vegetação na UFMG-ICA. Foi utilizado o delineamento experimental em blocos ao acaso, com quatro repetições. Os tratamentos foram constituídos por uma testemunha e seis proporções de fibra de coco (FC e pó de rocha de granito (RG: T1 - Substrato comercial Hortimix®; T2 - 0% FC + 100% RG; T3 - 20% FC + 80% RG; T4 - 40% FC + 60% RG; T5 - 60% FC + 40% RG; T6 - 80% FC + 20% RG; T7 - 100% FC + 0% RG. O cultivo foi feito em bandeja de poliestireno expandido com células de 3,5 x 3,5 x 5,0 cm. Foram avaliados o diâmetro do coleto, a altura da planta, o índice de velocidade de emergência, a percentagem de emergência e a massa fresca e seca da parte aérea e da raiz. Em praticamente todas as características avaliadas o substrato comercial foi superior aos substratos contendo fibra de coco e pó de rocha. Considerando-se apenas os substratos contendo fibra de coco e pó de rocha, as mudas com melhores características foram obtidas com a mistura de aproximadamente 70% em volume de fibra de coco.A greenhouse experiment was carried out to evaluate the ratio of coconut fiber and rock waste, in the tomato seedling production (cultivar Kada Gigante, in Montes Claros, Brazil. The experimental design was of randomized complete blocks with four replicates. The treatments were composed of a control and six ratios of coconut fiber (FC and rock waste (RG: T1 - Commercial Substrate Hortimix®; T2 - 0% FC + 100% RG; T3 - 20% FC + 80% RG; T4 - 40% FC + 60% RG; T5 - 60% FC + 40% RG; T6 - 80% FC + 20% RG; T7 - 100% FC + 0% RG. The cultivation was done in polystyrene trays with cells of 3.5 x 3.5 x 5,0 cm. Stem diameter, seedling height, emergency speed index, emergency percentage, root and aerial part of fresh and dry matter were evaluated. In

  19. 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.

  20. 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)

  1. Wpływ intensyiuności światła i długości dnia na produkcję biomasy siewek zbóż w uprawie hydroponicznej [Influence of light intensity and daylength on biomass production by cereal seedlings in hydroponic culture

    Directory of Open Access Journals (Sweden)

    J. Telżyńska

    2015-06-01

    Full Text Available The influence of light intensity, daylength and of the duration of the cultivation cycle on biomass production was investigated in the case of wheat, rye, oats and barley seedlings reared in hydroponic culture in the glasshouse. The investigations performed show together with the literature data that there is a possibility of obtaining very high yields from a very small surface area if the cultivation cycles are appropriately schemed, and the technical installations and suitable light combinations are applied.

  2. 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 ...

  3. 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

  4. 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 ...

  5. 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 ...

  6. 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.

  7. 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)

  8. 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)

  9. 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...

  10. 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.

  11. 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.

  12. 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

  13. Efeito do tamanho da semente, subtrato ambiente na produção de mudas de Copernicia Hospita Martius Effect of seed size, substrate, and environment on the production of Copernicia hospita Martius seedlings

    Directory of Open Access Journals (Sweden)

    Alexandre Bosco de Oliveira

    2009-12-01

    Full Text Available A carnaúba hospedeira faz parte de um grupo de plantas da família Arecaceae, de relevante importância social e econômica para as regiões tropicais. Neste trabalho, objetivou-se determinar a influência do tamanho da semente, tipo de substrato e do ambiente na produção de mudas de carnaúba hospedeira (Copernicia hospita Martius. As sementes de diferentes tamanhos (pequena, média, grande e mistura foram semeadas em substratos constituídos de areia vermelha + bagana de carnaúba + húmus (2,5:2,5:1 em volume e solo + arisco + composto orgânico Polefértil (2:2:1 em volume e cultivadas em ambientes distintos (pleno sol e casa de vegetação. As variáveis analisadas foram: comprimento do limbo foliar principal, área foliar, diâmetro do coleto, comprimento da maior raiz e massa da matéria seca da parte aérea e radicular. O tamanho da semente exerceu efeito significativo sobre todas as variáveis. O substrato influenciou, significativamente, o comprimento do limbo e da maior raiz e área foliar. Quanto ao ambiente, as únicas variáveis não afetadas por esse fator foram as produções de matéria seca, tanto da parte aérea como radicular. Para a produção de mudas de C. hospita recomenda-se a utilização de sementes grandes, semeadas no substrato constituído de areia vermelha + bagana de carnaúba + húmus, em cultivo a pleno sol.The 'Hostess' Carnauba belongs to a group of plants from the Arecaceae family, which is of relevant social and economic importance for tropical areas in Brazil. The objective of this research was to study the effect of the size of the seed , substrate, and environment on the production of seedlings of 'Hostess' Carnauba (Copernicia hospita Martius. Seeds of different sizes (small, medium, large, and a mixture of different sizes were planted in different substrates composed of red sand + carnauba straw + humus (2,5:2,5:1 in volume and soil + dark sand + organic compost Polefértil (2:2:1 in volume, and

  14. [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.

  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. Recipientes e substratos na produção de mudas de Maytenus ilicifolia e Apuleia leiocarpa Pot and substrate on seedling production of Maytenus ilicifolia and Apuleia leiocarpa

    Directory of Open Access Journals (Sweden)

    Fernando Teixeira Nicoloso

    2000-12-01

    Brazilian forest trees due to the excessive exploration of natural resources and, therefore, information about suitable methods for their propagation is relevant. The aim of this work was to evaluate different pots and the types of substrate in the production of seedlings of ‘cancorosa’ and ‘grápia’. The treatments followed a bifactorial scheme (7x3, represented by seven pot sizes: plastic bag (small, medium, and large size, respectively, 1515, 3064, and 6031cm³, laminated wooden pot (small, medium and large size, respectively, 497, 829, and 1161cm³ and plastic tube (only one size, cylindrical model, 50cm³, and three types of substrates: soil alone (profile A from a red yellow podzolic soil, soil + carbonized rice husk, and medium sand + carbonized rice husk, 1:1 v/v. The sowing of both species was effectuated on 12 December 1997 and the experiment lasted for 135 days under ambient temperature. At this date, the percentage of plant survival, plant height, stem diameter 0,5cm aboveground, length of the root system, dry weight of roots, stem, leaves, and total of the plant, as well as the physical properties of the substrates were analyzed. The small plastic bag, in combination with soil + carbonized rice husk, shows a suitable condition on the seedlings production of ‘cancorosa’. The medium and large plastic bags and the large wooden pot, in combination with soil + carbonized rice husk and soil alone, present an adequate condition on the seedlings production of ‘grápia’.

  17. Crescimento vegetativo e produtividade de cafeeiros Conilon propagados por estacas em tubetes Vegetative growth and productivity of Conilon coffee-trees proceeding from seedlings produced of deep-rooted cuttings in plastic tubes

    Directory of Open Access Journals (Sweden)

    José Augusto Teixeira do Amaral

    2007-12-01

    Full Text Available Objetivou-se neste trabalho avaliar o crescimento vegetativo e a produtividade de cafeeiros conilon (Coffea canephora Pierre ex Froehner, oriundos de mudas produzidas por estacas plantadas inicialmente em tubetes plásticos de 50 cm³ de capacidade. O experimento foi constituído de cinco tratamentos, que corresponderam aos tempos de permanência das estacas nos tubetes: 0; 15; 30; 45 e 60 dias. Transcorridos esses tempos as mudas foram, sucessivamente, transplantadas para sacos de polietileno, contendo mistura de terra, esterco de curral e adubo químico, enviveiradas em um viveiro coberto com sombrite (50%, provido de micro aspersão automática. As mudas permaneceram no viveiro com micro aspersão automática por 150 dias, quando então foram transferidas para o viveiro de aclimatação, onde ficaram por mais 30 dias. Após esse período, em setembro de 1999, as mudas foram plantadas em condições de campo, na área experimental do CCA-UFES, em Alegre, Sul do Estado do Espírito Santo. Foram feitas as seguintes medições: crescimento de ramos ortotrópicos e plagiotrópicos no segundo ano após o plantio e as quatro primeiras colheitas. A produção inicial de mudas de café conilon em tubetes não afetou o crescimento vegetativo, tampouco a produção de frutos.The objective of this work was to evaluate the vegetative growth and productivity of conilon coffee-tree (Coffea canephora Pierre ex Froehner, proceeding from seedlings produced of deep-rooted cuttings initially in plastic tubes with capacity of 50 cm³. The treatments were constituted of permanence period in plastic tube for 0; 15; 30; 45 and 60 days. After these periods the plants were transplanted for polyethylene bags filled with substrate (soil + sand + manure bovine and chemical fertilization maintained on the greenhouse with environment under shading canvas (50% and automatic micro aspersion during 150 days. After this time the plants were maintained during 30 days in

  18. 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.

  19. PRODUÇÃO IN VITRO DE MUDAS DE Cattleya walkeriana E Cyrtopodium palmifrons A PARTIR DE SEMENTES IN VITRO PRODUCTION OF SEEDLINGS OF Cattleya walkeriana AND Cytopodium palmifrons FROM SEEDS

    Directory of Open Access Journals (Sweden)

    Iraídes Fernandes Carneiro

    2007-09-01

    Full Text Available

    Sementes de Cattleya walkeriana e de Cyrtopodium palmifrons (Orchidaceae foram transferidas assepticamente para meios de cultura Knudson, MS (Murashige & Skoog e MS suplementado com IAA (1, 15 e 30 mg L-1 e cinetina (0,25, 5 e 10 mg L-1, para germinação. Elas foram incubadas à temperatu ra de 23 +/- 2°C, sob luz fluorescente por um período de 30 a 45 dias. As plântulas obtidas foram repicadas para meio Knudson, permanecendo em incubação por quatro meses e, em seguida, transferidas para meio fresco, até atingirem tamanho para aclimatação. O cultivo in vitro de ambas as espécies foi considerado viável, havendo comportamento diferente entre as espécies, em relação à produção de protocormóides, níveis de oxidação e crescimento in vitro. Os resultados mostraram que um meio me nos concentrado como Knudson pode ser utilizado sem adição de reguladores de crescimento para produção de mudas tanto para Cattleya walkeriana quanto para Cyrtopodium palmifrons.

    PALAVRAS-CHAVE: Orchidaceae; cultura de tecidos; orquídea.

    Seeds of Cattleya walkeriana and Cyrtopodium palmjfrons (Orchidaceae were aseptically transferred to culture medium Knudson, MS (Murashige& Skoog and MS supplemented with IAA (l, 15 and 30 mg L-1 and kinetine (0.25, 5 and 10 mg L-1 for germination. They were kept at room temperature (23 +/- 2°C under fluorescent light for 30 to 45 days. The seedlings were transferred to pots containing culture medium Knudson and incubated for four months at room temperature and transferred to fresh culture medium until the seedlings attained approximately 1.0 to 2.0 cm size for

  20. Controle de plantas daninhas na produção de mudas de plantas ornamentais Weed control in ornamental plant seedling production

    Directory of Open Access Journals (Sweden)

    F.C.L. Freitas

    2007-09-01

    g ha-1 de oxyfluorfen, para plantas de copo-de-leite, estrelítzia e palmeira-australiana, respectivamente, na aplicação em área total, e nas concentrações superiores a 0,0018%, na aplicação dirigida, aos 30 DAA.This study aimed to evaluate efficacy of oxyfluorfen in controlling Pilea microphylla for the production of ornamental plant shoots. Two experiments were carried out in a randomized block design, arranged in a factorial scheme 2 x 7, with three replicates. One trial was composed by three ornamental plant species (Zantedeschia aethiopica, Strelitzia reginae and Archontophoenix cunninghamiana and seven oxyfluorfen rates (0, 24, 72, 144, 216, 288 and 360 g ha-1, sprayed in a total area; the other trial was composed by the same species and seven oxyfluorfen concentrations (0.00000, 0.00036, 0.00072, 0.00144, 0.00288, 0.00576 and 0.01152% of a.i. applied directly as spray, without reaching the ornamental plant leaves. Each experimental unit was represented by a pot with an ornamental plant shoot, infested with Pilea microphylla. At 15, 30 and 60 days after application (DAA visual evaluations of the control on P. microphylla and toxicity on ornamental plants were carried out. For the total area spray, the A. cunninghamiana plant pots demanded high herbicide doses due to this species' larger foliar area, during application, making the herbicide contact with weeds difficult. Still in this application modality,light intoxication symptoms were observed in the ornamental plants, being more evident in the A. cunninghamiana plants. For the direct spray modality, no interaction among the factors, species and herbicide concentration, nor herbicide behavior differences were observed for the characteristics evaluated. Intoxication was not observed in the ornamental plants in none of the treatments evaluated, for the direct spray modality. Efficient P. microphylla control was verified for rates above 90% at 300, 320 and 340 kg ha-1 of oxyfluorfen, plants of Z

  1. 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)

  2. [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.

  3. Produção de mudas de Etlingera elatior (Jack R.M. Sm. através da cultura de tecidos vegetais in vitro Etlingera elatior seedling production through in vitro tissue culture

    Directory of Open Access Journals (Sweden)

    C.L.S. Rescarolli

    2009-01-01

    inteiros. Apesar do efeito do seccionamento do rizoma e da concentração de BAP, no número de brotos e raízes, as plantas não mostraram diferença no crescimento da planta e das raízes. A micropropagação da espécie Etlingera elatior é possível, possibilitando a produção de mudas em larga escala.The use of natural products to treat diseases has been common for humans since the beginning of times. Etlingera elatior (torch ginger, an herbaceous species very common in gardens and muddy areas, has been cited by the popular culture as treatment for muscular pains and rheumatism, which has stimulated the pharmaceutical industry to start investing in studies on its activity. However, phytomass production by high-quality healthy plants is still incipient. The utilization of plant biotechnology, specially in vitro vegetative propagation, allows the large-scale production of seedlings and/or phytomass of high genetic and phytosanitary quality in a short time and small area. The aim of this work was to evaluate the action of disinfectant agents on the production of aseptic explants, as well as the effect of culture medium composition and rhizome splitting on the development, multiplication and rooting of plants in vitro in order to establish the micropropagation process. Lateral buds were disinfected with ethanol and calcium and sodium hypochlorite. Aseptic rhizomes were longitudinally sectioned and multiplied in MS culture medium containing BAP (0.0, 1.0 and 2.0 mg L-1. The establishment of aseptic cultures by using 70% ethanol, 1% NaClO and 1% and 5% CaClO resulted in 10 to 40% explant survival. The multiplication rate obtained for whole and longitudinally sectioned rhizomes cultivated in MS medium did not present significant difference for sprout number. However, sectioned rhizome cultivated in MS medium added of 1.0 mg L-1 BAP had a significant increase in sprout number, relative to whole rhizomes at the same BAP concentration. In the presence of BAP, there was a

  4. Vegetable seedling production with sugarcane bagasse ash

    Science.gov (United States)

    The eleven sugarcane mills in Louisiana processed 380,000 ac and 12.8 million tons of harvested sugarcane in 2014, producing 1.5 million tons of raw sugar (brown sugar), and an estimated 3 million tons of the fibrous plant residue called bagasse. Bagasse is the fibrous material remaining after remov...

  5. PRODUCTION OF TOMATO SEEDLINGS UNDER SALINE IRRIGATION

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Brasiliano Campos

    2007-01-01

    Full Text Available Processing tomato is the most important vegetable crop of the Brazilian agribusiness and few researches have been conducted to evaluate the tolerance of this crop to saline stress. In this study, the effects of five levels of salinity of the irrigation water (1, 2, 3, 4 and 5 dS m-1 and three equivalent proportions of Na:Ca:Mg (1:1:0.5, 4:1:0.5 and 7:1:0.5 were tested on the emergence and vigor of processing tomato, cultivar IPA 6. Seeds were sowed in expanded polystyrene tray (128 cells and each tray received 1 L of water after sowing. The trays were piled and, four days after sowing, they were placed on suspended supports in a greenhouse. Irrigation was accomplished daily from the fifth day after sowing. Only dry weight of shoot and root was affected by sodium proportions, while linear reductions of the speed of emergence, stem length and the dry weight of shoot and root were observed with increasing salinity. Root was more affected than shoot by salinity and relative growth ratioincreased with salinity levels on the 14-21 days after sowing period, indicating that the crop showed a certain increase of salinity tolerance with the time of exposure to salts.

  6. 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.

  7. 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.

  8. 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.

  9. Produção de mudas de limão cravo em substrato com biofertilizante bovino irrigado com águas salinas Production of rangpur lemon seedlings in substrate with bovine biofertilizer irrigated with saline water

    Directory of Open Access Journals (Sweden)

    Alex Matheus Rebequi

    2009-12-01

    Full Text Available Um experimento foi instalado no período de março a maio de 2008, em ambiente telado, para avaliar os efeitos da salinidade da água de irrigação e do biofertilizante bovino na formação de mudas de limão cravo. O substrato foi material dos primeiros 20 cm de um Argissolo Amarelo Distrófico não salino, com os tratamentos dispostos em esquema fatorial 5 x 2 com seis repetições, referente a cinco valores de condutividades elétrica da água de irrigação (0,5; 1,0; 2,0; 3,0 e 4,0 dS.m-1, obtidos pela diluição de uma água fortemente salina (14,3 dS.m-1 com água não salina (0,5 dS.m-1, em solo sem e com biofertilizante comum, diluído em água na proporção de 1:1 aplicado ao nível de 10% do volume do substrato, um dia antes da semeadura. Pelos resultados, se constatou superioridade dos dados obtidos nos tratamentos com o biofertilizante em relação aos dos tratamentos sem o respectivo insumo.One experiment was developed during the period from March to May of 2008 in a canvassed shelter to evaluate the effects of saline water and bovine biofertilizer on seedling formation of rangpur lemon. The substrate used was composed by soil at 20 cm depth of a non saline yellow distrofic Oxisoil, with treatments distributed in a factorial arrangement 5 x 2 with six repetitions, referring to water electrical conductivity (0.5, 1.0, 2.0, 3.0 e 4.0 dS.m-1 obtained by dilution of saline water (14.3 dS.m-1 with non saline water (0.5 dS.m-1 in soil with and without biofertilizer diluted in water 1:1 proportion applied in 10% of substrate volume, one day before sowing. According to results, it was observed a superiority of data from treatments with biofertilizer in relation to those without this product.

  10. The impact of seeds provenance and nursery provenance method on Austrian pine (Pinus nigra Arn. seedlings quality

    Directory of Open Access Journals (Sweden)

    Vladan Ivetić

    2013-12-01

    Full Text Available The influence of seed provenances and seedling production methods on quality of one and two years old seedlings of Austrian pine were investigated. Seeds from three provenances of Austrian pine (Goc, Studenica and Sargan were used for seedlings production, combined with three production methods: (i the modified seedbeds (bare-root, (ii the container type Plantagrah II and (iii the container type Gocko. Provenance, as well as the combined influence of provenance and production method had minimal influence on the variability of one and two years old Austrian pine seedlings. Nevertheless, the production method had the highest influence. The production system, besides its importance in nursery, will have a high influence on seedlings growth during the first year after planting. Considering the results of this study (e.g. the highest values of the diameter, number of lateral roots, shoot and root dry weight, and quality index and the lowest value of SQ and satisfactory value of S:R, we can conclude that the seedlings produced in container type Gocko led to the highest seedlings quality, recommended especially for afforestation on hard sites.     

  11. 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.

  12. 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

  13. 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.

  14. Composição de substratos e tamanho de recipientes na produção e qualidade das mudas de maracujazeiro 'amarelo' Composition of substrates and volume of recipients in the production and quality of yellow passion fruit seedlings

    Directory of Open Access Journals (Sweden)

    Elisângela Aparecida da Silva

    2010-06-01

    Full Text Available A produção de mudas de maracujazeiro 'amarelo' (Passiflora edulis Sims. f. flavicarpa Degener de boa qualidade genética, fitossanitária e bem nutridas é de suma importância. A multiplicação rápida depende de alguns fatores preponderantes, relacionados com a produção de mudas, ligados especificamente aos substratos e recipientes. Este experimento foi realizado visando à avaliação da produção de mudas em diferentes substratos e dois tamanhos de recipientes, em viveiro de produção de mudas da Universidade Estadual de Mato Grosso do Sul (UEMS, Cassilândia/MS. Foram testados quatro substratos: solo puro, solo + esterco (2:1 v:v, Plantmaxâ e solo + 150 mg.dm-3 de superfosfato simples e dois tamanhos de recipientes de polietileno preto: 14x20 cm (1000 mL e 10x20 cm (700 mL. Utilizou-se o delineamento experimental em blocos casualizados, em esquema fatorial 4 (substratos x 2 (tamanhos de recipientes, com 4 repetições e dez plantas por parcela. Avaliaram-se as características: índice de velocidade de emergência (IVE, altura da muda (cm, comprimento de raiz (cm, diâmetro do colo (mm, número de folhas/planta, índice de clorofila foliar (ICC, massa seca da parte aérea, massa seca da raiz e massa seca total. Os resultados para as variáveis analisadas indicaram que apenas para o número de folhas/planta houve diferença significativa para o tamanho de recipiente utilizado. O solo + esterco e o Plantmax® favoreceram todos os parâmetros de crescimento nos recipientes de 700 mL. O solo puro não é recomendado para a produção de mudas de maracujazeiro 'amarelo' em ambos recipientes; pois favoreceu apenas o comprimento de raiz e massa seca da parte aérea.The production of yellow passion fruit seedlings (Passiflora edulis Sims. f. flavicarpa Degener with genetic and phytosanitary quality, well-nourished and precocious, is of great importance. Fast multiplication depends on some preponderant factors related to seedling production

  15. Growth and nutrient balance of Enterolobium contortsiliquum seedlings with addition of organic substrates and wastewater

    Directory of Open Access Journals (Sweden)

    Emanuel França Araújo

    2016-06-01

    Full Text Available Given the strong generation of solid organic waste and wastewater, the use of these materials as a primary source of nutrients is an important practice in environmental management, especially in the production of seedlings with emphasis on degraded areas. The objective of this study was to evaluate growth and nutrient balance of “tamboril” (Enterolobium contortsiliquum (Vell. Morong seedlings grown on substrates with different formulations proportions of organic matter irrigated with wastewater. It was tested five ratios of organic composts and soil: 0:100; 20:80; 40:60; 60:40 and 80:20 v/v. Two procedences of irrigation water was tested: water supply and wastewater from swine farming, arranged in a completely randomized design in a factorial scheme 5 x 2, with four replications. At 90 days, we evaluate seedlings morphological variables, the integrate diagnosis recommendation index and the nutrient balance index. The organic residue contributes to seedlings growth and nutritional balance. The proportion 80:20 proved to be the most suitable for “tamboril” seedlings production. Seedlings presented lower growth and nutritional balance when irrigate with swine farm wastewater.

  16. 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.

  17. Lettuce (Lactuca sativa L. seedling production with different sources of phosphate and phosphate solubilizing microorganisms / Produção de mudas de alface (Lactuca sativa L. em presença de diferentes fontes fosfatadas e microrganismos

    Directory of Open Access Journals (Sweden)

    Germano Nunes Silva Filho

    2009-10-01

    Full Text Available The objective of this work was to evaluate the behaviour of phosphate solubilizing microorganisms (fungus: 310A, 061, 062 e 251, bacterias 163, 160 e 161 in promoting nutrition and growth of lettuce(Lactuca sativa L. seedlings cultivated in trays with sterilized substrate fertilized and phosphates source. A randomized completely design was used, with a factorial 4x8 scheme (four treatments with phosphate nutrition and inoculated with eight phosphate solubilizing microorganisms and four replications. Each replication was made of 10 cells. The experiment was evaluated 35 days after planting for dry matter, P percentage and total phosphorus of above ground parts. The triple super phosphate (SFT had better results than the others, including the control treatment, in all analyzed parameters. On the dry matter production, it was observed negative effect from inoculation in five treatments fertilized with SFT. There was no effect of isolates on the phosphorus content values. In the values of total phosphorus, the isolates 061, 062 e 163 increased the parameter values on the fertilized treatment with SFT. The natural phosphates presented low efficiency when compared to dissolvable fertilizer on the availability of phosphorus to the plants.O objetivo deste trabalho foi avaliar o comportamento de microrganismos solubilizadores de fosfatos (fungos: 310A, 061, 062 e 251; bactérias: 163, 160 e 161 na promoção da nutrição e crescimento de mudas de alface (Lactuca sativa L., cultivadas em bandejas com substrato esterilizado e adubadas com fontes fosfatadas. Foi utilizado um delineamento inteiramente casualizado, arranjo fatorial 4 x 8 (quatro tratamentos de adubação fosfatada e oito tratamentos de inoculação microrganismos solubilizadores de fosfatos com quatro repetições por isolado. Cada repetição foi constituída de 10 células. Aos 35 dias de cultivo, as plantas foram colhidas avaliando-se a matéria seca, porcentagem de P e P total da parte a

  18. Formação do porta-enxerto Trifoliata: época de semeadura e tegumento na emergência de plântulas Production of Trifoliata rootstock: season and seedcoat in seedling emergency

    Directory of Open Access Journals (Sweden)

    Roberto Pedroso de Oliveira

    2007-02-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da época de semeadura e do tegumento da semente na emergência de plântulas e o tempo necessário para formação do porta-enxerto Trifoliata. O experimento foi realizado em casa de vegetação, em Pelotas-RS. A semeadura foi realizada em tubetes de 50cm3, contendo substrato comercial. Os tratamentos compreenderam duas épocas de semeadura (inverno e primavera e três tratamentos do tegumento das sementes (tegumento íntegro, com furo no endosperma, e sem tegumento. Esses foram dispostos em delineamento de blocos ao acaso, em esquema fatorial, com quatro repetições, sendo as unidades experimentais constituídas por 42 tubetes com uma semente cada. Os porta-enxertos foram considerados aptos para o transplantio quando atingiram 15cm de altura. A velocidade e a porcentagem final de germinação de Trifoliata foi significativamente superior na primavera (95,6% em relação ao inverno (83,6%. Independentemente da época do ano, a remoção do tegumento favoreceu a germinação (96,9% em relação ao uso de semente com tegumento íntegro (84,8%. O período necessário para a formação dos porta-enxertos nos tubetes foi de 70 dias na primavera e de 130 dias no inverno.This study was aimed at evaluating the effect of the time of sowing and the seedcoat in seedling emergency and production of Trifoliata rootstock. The experiment was carried out in a glasshouse, in Pelotas-RS. Sowing was performed in dibble tubes of 50cm3, containing commercial substrate. Two sowing plates (winter and spring and three seedcoat treatments (integral tegument, with a hole in the endosperm and without tegument were studied. The experimental design was a randomized complete block, in a factorial schedule, with four replications and experimental units composed by 42 dibble tubes with one seed each. The rootstocks were considered adequate for the transplant when they reached 15cm height. The speed and final germination

  19. 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...

  20. Comportamento de cinco genótipos de coqueiro (Cocos nucifera L. na fase de germinação e de crescimento de mudas, sob diferentes sistemas de produção Behavior of five genotypes of coconut tree (Cocos nucifera L. in the phase of germination and seedling growth, under different systems of production

    Directory of Open Access Journals (Sweden)

    WALDIR SEBASTIÃO DE FARIA

    2002-08-01

    60 dias de viveiro, e maior número de folhas.With the objective to evaluate the performance of five genotypes of dwarf and hybrids of coconut tree: dwarf green of Jiqui (AVeJ, red dwarf of Gramame (AVG, dwarf yellow of Malaysia (AAM, hybrid of red dwarf Gramame x giant Brazil of Forte beach (AVG x GBrPF and the hybrid of dwarf yellow of Gramame x giant of the African west (AAG x GOA, in the germination and growth stage, in different production systems, an experiment was carried out in August of 1998, in the Experimental Station of the Faculdade de Agronomia e Medicina Veterinária of the Universidade Federal of Mato Grosso, located in Santo Antônio de Leverger. It was evaluated the performance of five genotypes of coconut tree in the germination and growth stage of seedlings originated from seeds placed in the horizontal and vertical positions, and kept at 50% of shade or full sun. Those factors were combined factorially, resulting in 20 treatments, which were arranged in the completely randomized design. The evaluated characteristics were: accumulated germination, percentage of germination, percentage of seedling capable of being transplanted for the field, seedling height, number of leaves, circumference of the girth, weight of the seedling and weight of the aerial part. The hybrid (AAG x GOA and the AVG presented, respectively, larger and smaller values for the characteristics: germination percentage, percentage of seedling capable of being transplanted for the field, number of leaves, circumference of the girth and of the seedling heights to the 30, 60 and 90 days of nursery. The seedlings of larger weights corresponded to the hybrid (AVG x GBrPF, and the one of smaller weights, to the AAM. The hybrid AVG x GBrPF produced seedlings that presented heavier aerial part and AVG the lightest. The seedlings produced from the seeds under shade of 50% presented larger heights and weights. The seeds germinated in the horizontal position produced seedlings higher to the

  1. Performance of Oak Seedlings Grown under Different Oust® XP Regimes

    Directory of Open Access Journals (Sweden)

    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.

  2. Reforestation of bauxite mine spoils with Eucalyptus tereticornis Sm. seedlings inoculated with arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    N. Krishnakumar

    2012-11-01

    Full Text Available Open cast mining for bauxite at Yercaud hills (India resulted indegradation of forest ecosystem and production of large quantities of waste rocks (called mine spoils. To ameliorate mine spoils, topsoil is used to spread over before the planting of tree species, conventional method as the topsoil has a good structure, water holding capacity and beneficial microbes like Arbuscular Mycorrhizal (AM fungi essential for plant growth.However, the use of top soil is expensive and in this study bauxite mine spoils were reforestated with AM fungi instead of it. The beneficial microbes AM fungi (Glomus aggregatum Schenck & Smith, G. fasciculatum(Thatcher Gerd. & Trappe emend. Walker & Koske, G. geosporum(Nicol. & Gerd. Walker were isolated, cultured and inoculated into the seedlings of Eucalyptus tereticornis Sm. and grown in bauxite mine spoils as potting medium under nursery conditions. Then, the biomass improved seedlings of E. tereticornis with inoculation of AM fungi were directly transplanted at bauxite mine spoils. After transplantation of the seedlings at bauxite mine spoils, the growth and survival rate were monitored for two years. The AM fungi inoculated seedlings of E. tereticornis showed 95% survival over the control seedlings and their growth was also significantlyhigher. Tissue nutrients (N, P, K were also found higher inAM fungi inoculated E. tereticornis than un inoculated control seedlings.

  3. Reforestation of Bauxite mine spoils with Eucalyptus tereticornis Sm. seedlings inoculated with Arbuscular mycorrhizal fungi

    Directory of Open Access Journals (Sweden)

    A. Karthikeyan

    2012-12-01

    Full Text Available Open cast mining for bauxite at Yercaud hills (India resulted in degradation of forest ecosystem and production of large quantities of waste rocks (called mine spoils. To ameliorate mine spoils, topsoil is used to spread over before the planting of tree species, conventional method as the topsoil has a good structure, water holding capacity and beneficial microbes like Arbuscular Mycorrhizal (AM fungi essential for plant growth. However, the use of top soil is expensive and in this study bauxite mine spoils were reforestated with AM fungi instead of it. The beneficial microbes AM fungi (Glomus aggregatum Schenck & Smith, G. fasciculatum (Thatcher Gerd. & Trappe emend. Walker & Koske, G. geosporum (Nicol. & Gerd. Walker were isolated, cultured and inoculated into the seedlings ofEucalyptus tereticornis Sm. and grown in bauxite mine spoils as potting medium under nursery conditions. Then, the biomass improved seedlings of E. tereticornis with inoculation of AM fungi were directly transplanted at bauxite mine spoils. After transplantation of the seedlings at bauxite mine spoils, the growth and survival rate were monitored for two years. The AM fungi inoculated seedlings ofE. tereticornis showed 95% survival over the control seedlings and their growth was also significantly higher. Tissue nutrients (N, P, K were also found higher in AM fungi inoculated E. tereticornis than un inoculated control seedlings

  4. 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.

  5. 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

  6. Influência do substrato e do tamanho da célula de bandejas de poliestireno expandido no desenvolvimento de mudas e produção de calêndula (Calendula officinalis L. Influence of substrate and cell size of expanded polystyrene tray on the development and production of marigold (Calendula officinalis L. seedlings

    Directory of Open Access Journals (Sweden)

    C.K.R Barbosa

    2010-03-01

    influence of two cell sizes of expanded polystyrene trays (40 cm³ and 12 cm³ and two substrates (soil + cattle manure and Plantmax® commercial substrate for vegetables on marigold production and seedling quality. Experimental design in both assays was in randomized blocks, in a 2x2 factorial arrangement (two substrates and two cell sizes, with six replicates. Treatments regarding cell sizes were trays presenting 128 cells (40 cm³ and trays containing 288 cells (12 cm³. The used substrates were cerrado soil + cattle manure (1:1 and Plantmax® commercial substrate for vegetables. Part of the seedlings was transplanted to evaluate capitulum production. There were significant differences among substrates for total, root and shoot dry matter. The use of substrate containing cerrado soil and cattle manure led to the best development of marigold seedlings. However, the different types of substrates and polystyrene trays did not significantly influence capitulum production in transplanted seedlings.

  7. Produção de mudas do tipo rebentão, utilizando coroas de três cultivares de abacaxi inoculadas com fungos micorrízicos Production of seedlings type suckers, using crowns of three cultivars of pineapple inoculated with mycorrhizal fungi

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    Paulo Cesar dos Santos

    2011-09-01

    alternativa para a produção de mudas de abacaxizeiro, sendo mais eficiente na cultivar 'Smooth Cayenne', que produziu 26 mudas em coroas cultivadas até 420 dias após o plantio.One of the main obstacles to the development of pineapple cultivation in Brazil has been the absence of seedlings in both quantity and quality, to spread. Among the alternatives, the obtaining of seedlings is verified starting from the sprouting from crowns of fruits, which are normally discarded by the consumer. Furthermore, the use of arbuscular mycorrhizal fungi (AMF can be an alternative for improving the production of seedlings, since these fungi can shorten the time of seedlings of various fruit. In that sense, the objective of this work was to evaluate the production of seedlings type suckers, using the method of destruction of the apical meristem of the crown of the pineapple plants inoculated with FMAs. For such, we used the randomized complete block design, factorial 3x3, with three cultivars of pineapple ('Smooth Cayenne', 'Pérola' and 'Jupí' and three microbiological treatments (no inoculation, Glomus etunicatum and a mixture of Glomus clarum and Gigaspora margarita, with four replications. The first emissions were recorded at 30, 60 and 90 days after planting for cultivar Smooth, 'Pérola' and 'Jupí', respectively. The pineapple tree 'Smooth Cayenne' produced 80 to 69% seedlings more than the cultivars 'Pérola' and 'Jupí', respectively. In microbiological treatments there was a significant difference for the suckers issued, in which the mixed treatment was the most prevalent issue when compared with treatment with G. etunicatum. Nutritional assessments in the crowns, inoculation with the mixed treatment promoted an increase of 85 and 66% for P, 22 and 13% for N and 6 and 19% for K, compared to treatments G. etunicatum and control respectively. It is concluded that the production of suckers from crown whose principal gem was beheaded is an alternative for the production of pineapple

  8. Rice Seedling Substrate Produced by Coal Gangue

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    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.

  9. 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, ...

  10. A Gate-to-gate Case Study of the Life Cycle Assessment of an Oil Palm Seedling

    Science.gov (United States)

    Muhamad, Halimah; Sahid, Ismail Bin; Surif, Salmijah; Ai, Tan Yew; May, Choo Yuen

    2012-01-01

    The palm oil industry has played an important role in the economic development of Malaysia and has enhanced the economic welfare of its people. To determine the environmental impact of the oil palm seedling at the nursery stage, information on inputs and outputs need to be assessed. The oil palm nursery is the first link in the palm oil supply chain. A gate-to-gate study was carried out whereby the system boundary was set to only include the process of the oil palm seedling. The starting point was a germinated seed in a small polyethylene bag (6 in × 9 in) in which it remained until the seedling was approximately 3 to 4 months old. The seedling was then transferred into a larger polyethylene bag (12 in × 15 in), where it remained until it was 10–12 months old, when it was planted in the field (plantation). The functional unit for this life cycle inventory (LCI) is based on the production of one seedling. Generally, within the system boundary, the production of an oil palm seedling has only two major environmental impact points, the polybags used to grow the seedling and the fungicide (dithiocarbamate) used to control pathogenic fungi, as both the polybags and the dithiocarbamate are derived from fossil fuel. PMID:24575222

  11. 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.

  12. Produção de mudas de alface, pepino e pimentão em substratos combinando areia, solo e Plantmax® Production of lettuce, cucumber and sweet pepper seedlings in substrate with different combinations of sand, soil and Plantmax®

    Directory of Open Access Journals (Sweden)

    Oscar José Smiderle

    2001-11-01

    . Higher production of seedling dry matter in lettuce and sweet pepper was obtained with the Plantmax®; substrate. Lower cucumber seedling dry matter production was obtained with the mixture of these three substrates. The performance obtained with the mixture of Plantmax®; with soil or sand, indicates it as a viable alternative to the use of commercial substrate

  13. Responses of Tree Seedlings near the Alpine Treeline to Delayed Snowmelt and Reduced Sky Exposure

    Directory of Open Access Journals (Sweden)

    Maaike Y. Bader

    2017-12-01

    Full Text Available Earlier snowmelt changes spring stress exposure and growing-season length, possibly causing shifts in plant species dominance. If such shifts involve trees, this may lead to changes in treeline position. We hypothesized that earlier snowmelt would negatively affect the performance of tree seedlings near the treeline due to higher spring stress levels, but less so if seedlings were protected from the main stress factors of night frosts and excess solar radiation. We exposed seedlings of five European treeline tree species: Larix decidua, Picea abies, Pinus cembra, Pinus uncinata, and Sorbus aucuparia to two snow-cover treatments (early and late melting, with about two weeks difference combined with reduced sky exposure during the day (shading or night (night warming, repeated in two years, at a site about 200 m below the regional treeline elevation. Physiological stress levels (as indicated by lower Fv/Fm in the first weeks after emergence from snow were higher in early-emerging seedlings. As expected, shade reduced stress, but contrary to expectation, night warming did not. However, early- and late-emerging seedlings did not differ overall in their growth or survival, and the interaction with shading was inconsistent between years. Overall, shading had the strongest effect, decreasing stress levels and mortality (in the early-emerging seedlings only, but also growth. A two-week difference in snow-cover duration did not strongly affect the seedlings, although even smaller differences have been shown to affect productivity in alpine and arctic tundra vegetation. Still, snowmelt timing cannot be discarded as important for regeneration in subalpine conditions, because (1 it is likely more critical in very snow-rich or snow-poor mountains or landscape positions; and (2 it can change (subalpine vegetation phenology and productivity, thereby affecting plant interactions, an aspect that should be considered in future studies.

  14. Morphology, gas exchange, and chlorophyll content of longleaf pine seedlings in response to rooting volume, copper root pruning, and nitrogen supply in a container nursery

    Science.gov (United States)

    R. Kasten Dumroese; Shi-Jean Susana Sung; Jeremiah R. Pinto; Amy Ross-Davis; D. Andrew Scott

    2013-01-01

    Few pine species develop a seedling grass stage; this growth phase, characterized by strong, carrot-like taproots and a stem-less nature, poses unique challenges during nursery production. Fertilization levels beyond optimum could result in excessive diameter growth that reduces seedling quality as measured by the root bound index (RBI). We grew longleaf pine (Pinus...

  15. Adubação na produção de plântulas do marmeleiro 'Japonês' Fertilization in the production of seedlings of 'japanese' quince tree

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    João Paulo Vanin

    2010-06-01

    Full Text Available Conduziu-se este trabalho, com o objetivo de verificar a ação da adubação por cobertura e por liberação lenta, no crescimento de plântulas do marmeleiro 'Japonês'. Sementes do marmeleiro 'Japonês' foram estratificadas à frio-úmido por 30 dias e, em seguida, foram dispersas em bandejas de poliestireno de 72 células (células com capacidade de 120 cm³, uma semente por célula, contendo Vermiculita® de grânulos finos como substrato. No primeiro experimento, a Vermiculita® foi acrescida de diferentes doses do adubo de liberação lenta Basacot® (15-8-12: 0, 3, 6, 9, 12 e 15 kg m-3 de substrato. No segundo experimento, as sementes foram dispersas em bandejas similares, preenchidas com Vermiculita® e passados 30 dias da semeadura, foram realizadas adubações por cobertura com nitrogênio na forma de uréia (45% de N, via água de irrigação: 0, 300, 600, 900, 1200 e 1500 mg dm-3. As aplicações foram parceladas em duas vezes em intervalos de 10 dias, adicionada em cada célula 10 mL de solução por aplicação. As bandejas permaneceram dentro de telado constituído de sombrite 50% de luminosidade e foram irrigadas diariamente. Aos 60 dias após a semeadura, foi mensurada a porcentagem de emergência, o comprimento médio das plântulas, número médio de folhas, massa seca média da parte aérea e total das plântulas. Concluiu-se que a adição de 9 kg de Basacot® em cada m-3 de Vermiculita® favoreceu o melhor desenvolvimento das plântulas.The objective of the present work was to verify the effect of the fertilizations by covering and slow liberation, on the growth of seedlings of the 'Japanese' quince tree. Seeds of the 'Japanese' underwent cold-humid stratification for 30 days and were then dispersed in polystyrene trays of 72 cells (cells with capacity of 120 cm³, one seed for cell, containing thin granule Vermiculite® as substrate. In the first experiment, we added to Vermiculite® different doses of the fertilizer of

  16. Potential impacts of using sewage sludge biochar on the growth of plant forest seedlings

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    Maria Isidoria Silva

    Full Text Available ABSTRACT: Sewage sludge has long been successfully used in the production of nursery plants; however, some restriction may apply due to its high pathogenic characteristics. The process of charring the organic waste significantly reduces that undesired component and may be as effective as the non-charred residue. The aim of this study was to evaluate the effect of sewage sludge biochar on the growth and morphological traits of eucalyptus ( Eucalyptus grandis L. seedlings, and compare results with those observed when using uncharred sewage sludge. Treatments were arranged in a completely randomized design, in a 2 x 2 factorial scheme, with four replications. Charred and non-charred sewage sludge were tested with and without NPK addition. A control treatment was also evaluated. Ten weeks old eucalyptus seedlings were transferred to the pots and grew for eight weeks. Chlorophyll content, plant height and stem diameter were measured at 0, 30 and 60 days after transplant. Shoot and root biomass were measured after plant harvest. Dickson Quality Index was calculated to evaluate the overall quality of seedlings. Biochar was effective in improving the seedlings quality, and had similar effects as the non-charred waste. Therefore, sewage sludge biochar has the potential to improve the process of production of forest species seedlings and further reduce the environmental risks associated with the use of non-charred sewage sludge.

  17. Fate of 14C-labelled diazinon in rice seedling and paddy soil

    International Nuclear Information System (INIS)

    Lee, Seong Kye; Kim, Kyoon; Park, Chang Kyu; Hwang, Eul Chul

    1985-01-01

    The fate of diazinon in the intact rice plants and submerged paddy soil has been investigated with (2- 14 C pyrimidine) diazinon. The labelled diazinon solution was applied to paddy water and distribution of radioactivities in the rice seedlings, paddy soil, volatile fraction and carbon dioxide has been ascertained at end the of incubation times of 0.5,1,4,6 and 9 days respectively. In addition, extract of plants and paddy soils were subjected to TLC separation for examination of possible transformation products of diazinon. The results may be summarized as follow; 1. Total recoveries of radiactivities were between 57.2∼73.6 per cent. 2. Radioactivity in rice seedlings increased with incubation periods reaching one tenth of treated radioactivity at the end of 9 day incubation. 3. Non-extractable radioactivity in paddy soil increased with incubation periods. 4. Radioactive volatile fraction increased in the presence of the rice seedlings. 5. Pyrimidinol was unique conversion product of diazinon in rice seedlings and paddy soils. 6. Pyrimidinol applied to paddy soil is readily absorbed by rice seedlings. (Author)

  18. Produção de mudas de rúcula em bandejas com substratos a base de resíduos orgânicos Production of rocket (Eruca sativa seedlings with substrates composed of organic waste

    Directory of Open Access Journals (Sweden)

    Lya Januária Beiruth da Silva

    2009-10-01

    Full Text Available Com o objetivo de avaliar o efeito de diferentes substratos na produção de biomassa vegetal em mudas de rúcula, cv. cultivada, foi conduzido um experimento na Universidade Federal do Acre, no período de setembro a novembro de 2006, utilizando os seguintes tratamentos: T1 Plantmax® (Tratamento padrão; T2 composto orgânico (CO + casca de coco maduro triturado (CCMT (1:1 v/v; T3 CO + cama de aviário (CA + casca-de-arroz carbonizada (CAC (1:1:1 v/v; T4 CO + esterco bovino (EB + CAC (1:1:1 v/v; T5 - CO + coprólitos de minhoca (CM + CAC (1:1:1 v/v; T6 CO + CM + caroço de açaí triturado (CAT (1:1:1 v/v; T7 - CO + CM + CCMT (1:1:1 v/v; T8 - CO + EB + CCMT (1:1:1 v/v. Foram acrescidos, 10% de carvão vegetal triturado, 1,0 kg m-3 de calcário dolomitico e 1,5 kg m-3 de termofosfato, exceto no substrato T1. A semeadura foi feita utilizando-se três sementes por células em bandejas de poliestireno expandido, contendo os diferentes tratamentos e oito dias após a semeadura, foi feito o desbaste deixando-se apenas uma planta por célula. Aos 26 dias após a semeadura, foram avaliados a massa da matéria fresca da parte aérea, massa da matéria seca da parte aérea, raiz e total da planta. O delineamento experimental foi inteiramente casualizado, com três repetições, sendo cada unidade experimental constituída de 4 plantas. Os tratamentos T4 ,T5 e T7 foram os que promoveram maior massa fresca e seca das plantas e não diferiram estatisticamente entre si e do tratamento padrão (T1, para todas as características avaliados.With the objective of evaluating the effect of different substrates in the production of vegetable biomass on rocket (Eruca sativa seedlings cv. cultivated, an experiment was carried out at the Federal University of Acre, in the period from September to November of 2006, using the following treatments: T1 - Plantmax® (control, T2 - organic compost + triturated ripe coconut shells (1:1 v/v, T3 organic compost + poultry

  19. Características físicas e químicas de substratos para produção de mudas de Ilex paraguariensis St. Hil. Physical and chemical characteristics of substrates for the production of Ilex paraguariensis St. Hil. seedlings

    Directory of Open Access Journals (Sweden)

    Ivar Wendling

    2007-04-01

    Full Text Available Neste trabalho, objetivou-se avaliar as propriedades físicas e químicas de diferentes materiais e suas combinações, bem como sua influência na produção de mudas de erva-mate em tubetes plásticos. O trabalho foi conduzido no viveiro da Empresa Baldo S.A., em São Mateus do Sul, PR. Utilizaram-se seis materiais: esterco bovino curtido, serragem semidecomposta, palito de erva-mate picado, terra de subsolo, substrato comercial à base de casca de pinus e húmus de minhoca, com os quais foram formulados 14 tratamentos. Os resultados indicaram que os tratamentos que continham serragem, palito de erva-mate e, principalmente, esterco bovino, além de serem mais econômicos, mostraram bons resultados na qualidade das mudas produzidas. Dentre esses tratamentos, aquele composto de 40% de esterco bovino e 60% de serragem se destacou, em vista da boa relação custo-benefício apresentada e da sua facilidade de preparo. As características químicas dos substratos não interferiram nas suas características físicas, assim como a influência das características físicas na produção de mudas de erva-mate depende da variável analisada.This work aimed to evaluate the physical and chemical properties of different materials and their compositions, as well as their efficiency in the production of Ilex paraguariensis seedlings in plastic tubes. The work was conducted at the Baldo S.A. Company nursery in São Mateus do Sul, PR, Brazil. Six materials were used to formulate 14 treatments: cattle manure, semi-decomposed sawdust, Ilex paraguariensis chopped stems, underground earth, commercial substrate based on pinus bark and earthworm humus. The results indicated that the treatments containing sawdust, Ilex paraguariensis stems and mainly cattle manure, besides being more economical, produced good quality seedlings. The treatments consisting of 40% cattle manure and 60% sawdust stood out because of the good cost-benefit ratio and the easiness of

  20. Growth, water relations and photosynthesis of seedlings and resprouts after fire

    Science.gov (United States)

    Clemente, Adelaide S.; Rego, Francisco C.; Correia, Otília A.

    2005-05-01

    Seasonal patterns of growth, water relations, photosynthesis and leaf characteristics were compared between obligate seeders ( Cistus monspeliensis and Cistus ladanifer) and resprouters ( Arbutus unedo and Pistacia lentiscus) from the first to the second year after fire. We hypothesized that seedlings would be more water-limited than resprouts due to their shallower root systems. Regarding water use strategies, Cistus species are drought semi-deciduous and A. unedo and P. lentiscus are evergreen sclerophylls, therefore, comparisons were based on the relative deviation from mature conspecific plants. Seedlings and resprouts had higher shoot elongation and leaf production than mature plants, and over an extended period. Differences from mature plants were larger in resprouts, with two-fold transpiration, leaf conductance and photosynthesis in late spring/early summer. Seedlings of C. monspeliensis exhibited higher transpiration and leaf conductance than mature plants, while those of C. ladanifer only exhibited higher water potential. Growth increments and ameliorated water relations and photosynthesis after fire were attributed to an increase in water and nutrient availability. The small differences in water relations and photosynthesis between seedlings and mature conspecifics are in accordance with the prediction of seedlings experiencing higher water limitation than resprouts. We attribute these results to differences in root systems: resprouters benefited from an increase in root/shoot ratios and the presence of deep roots whereas Cistus seedlings relied on very shallow roots, which cannot provide assess to deep water during summer. Nevertheless, seedlings did not show evidence of experiencing a more severe water limitation than mature conspecifics, which we attributed to the presence of efficient mechanisms of avoiding and tolerating water stress. The results are discussed in relation to post-fire demography of seeders and resprouters in Mediterranean

  1. Nitric oxide induces the alternative oxidase pathway in Arabidopsis seedlings deprived of inorganic phosphate.

    Science.gov (United States)

    Royo, Beatriz; Moran, Jose F; Ratcliffe, R George; Gupta, Kapuganti J

    2015-10-01

    Phosphate starvation compromises electron flow through the cytochrome pathway of the mitochondrial electron transport chain, and plants commonly respond to phosphate deprivation by increasing flow through the alternative oxidase (AOX). To test whether this response is linked to the increase in nitric oxide (NO) production that also increases under phosphate starvation, Arabidopsis thaliana seedlings were grown for 15 d on media containing either 0 or 1mM inorganic phosphate. The effects of the phosphate supply on growth, the production of NO, respiration, the AOX level and the production of superoxide were compared for wild-type (WT) seedlings and the nitrate reductase double mutant nia. Phosphate deprivation increased NO production in WT roots, and the AOX level and the capacity of the alternative pathway to consume electrons in WT seedlings; whereas the same treatment failed to stimulate NO production and AOX expression in the nia mutant, and the plants had an altered growth phenotype. The NO donor S-nitrosoglutathione rescued the growth phenotype of the nia mutants under phosphate deprivation to some extent, and it also increased the respiratory capacity of AOX. It is concluded that NO is required for the induction of the AOX pathway when seedlings are grown under phosphate-limiting conditions. © The Author 2015. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  2. Bioprospecção de isolados de Trichoderma spp. para o controle de Rhizoctonia solani na produção de mudas de pepino Bioprospection of Trichoderma spp. isolates to control Rhizoctonia solani on cucumber seedling production

    Directory of Open Access Journals (Sweden)

    Cleusa Maria Mantovanello Lucon

    2009-03-01

    Full Text Available O objetivo deste trabalho foi selecionar e identificar isolados de Trichoderma spp. para o controle do tombamento causado por Rhizoctonia solani (AG-4 em plântulas de pepino (Cucumis sativus L., além de avaliar o efeito de concentrações crescentes e de combinações dos isolados mais eficientes no controle da doença. Os experimentos foram conduzidos em casa de vegetação, com 490 isolados. O tombamento das mudas foi avaliado uma semana após a aplicação à base das plântulas de substrato infestado com antagonista (1% e patógeno (1%. Os doze isolados que proporcionaram mais de 85% de redução da doença foram testados em concentrações crescentes para o controle do patógeno (1%: 0,5, 1, 2, 3 e 4%. Também foi avaliado o efeito das combinações dos cinco isolados mais promissores. Os isolados mais efetivos foram identificados pelo sequenciamento da região espaçadores internos transcritos (ITS do DNA ribossômico. Dos 490 isolados testados 44 (9% reduziram o tombamento. As concentrações de antagonistas superiores a 2% foram as mais efetivas no controle da doença. Apenas duas combinações resultaram no aumento do controle da doença. Os isolados mais efetivos foram identificados como T. hamatum (IB08, IB30, IB60, T. harzianum (IB34, IB35, T. atroviride (IB13, T. spirale (IB16, IB24 e T. asperellum (IB44. Não foi possível a identificação da espécie de três isolados.The objective of this work was to select and identify Trichoderma spp. isolates for the control of Rhizoctonia solani (AG-4 damping-off on cucumber (Cucumis sativus L. seedlings, as well as to evaluate the effects of increasing concentrations and different combinations of the most efficient isolates in the disease control. The experiments were carried out in a greenhouse with 490 isolates. The disease on cucumber seedlings was evaluated one week after the application of a commercial substrate infested with both antagonist (1% and pathogen (1% to the seedlings

  3. Sites of infection by pythium species in rice seedlings and effects of plant age and water depth on disease development.

    Science.gov (United States)

    Chun, S C; Schneider, R W

    1998-12-01

    ABSTRACT Seedling disease, caused primarily by several species of Pythium, is one of the major constraints to water-seeded rice production in Louisiana. The disease, also known as water-mold disease, seed rot, and seedling damping-off, causes stand reductions and growth abnormalities. In severe cases, fields must be replanted, which may result in delayed harvests and reduced yields. To develop more effective disease management tactics including biological control, this study was conducted primarily to determine sites of infection in seeds and seedlings; effect of plant age on susceptibility to P. arrhenomanes, P. myriotylum, and P. dissotocum; and minimum exposure times required for infection and seedling death. In addition, the effect of water depth on seedling disease was investigated. Infection rates of seed embryos were significantly higher than those of endosperms for all three Pythium spp. The development of roots from dry-seeded seedlings was significantly reduced by P. arrhenomanes and P. myriotylum at 5 days after planting compared with that of roots from noninoculated controls. Susceptibility of rice to all three species was sharply reduced within 2 to 6 days after planting, and seedlings were completely resistant at 8 days after planting. There was a steep reduction in emergence through the flood water, relative to the noninoculated control, following 2 to 3 days of exposure to inoculum of P. arrhenomanes and P. myriotylum. In contrast, P. dissotocum was much less virulent and required longer exposure times to cause irreversible seedling damage. Disease incidence was higher when seeds were planted into deeper water, implying that seedlings become resistant after they emerge through the flood water. These results suggest that disease control tactics including flood water management need to be employed for a very short period of time after planting. Also, given that the embryo is the primary site of infection and it is susceptible for only a few days, the

  4. Formação de mudas de cafeeiro em substratos oriundos de diferentes métodos de desinfestação Coffee seedlings production potting mixtures from disinfestations methods

    Directory of Open Access Journals (Sweden)

    Gustavo Rabelo Botrel Miranda

    2006-01-01

    Full Text Available Objetivando verificar o desenvolvimento de cafeeiro oriundos de diferentes métodos de tratamento de substratos utilizados na produção de mudas em saquinhos de polietileno, instalou-se em maio/2004 em um viveiro na Universidade Federal de Lavras o presente experimento. Foram utilizados treze tratamentos para a desinfestação de substratos, sendo utilizado o padrão para mudas de café com solo coletado de uma lavoura cafeeira de 20 anos. Utilizou-se a cultivar paraíso H 419-1. Avaliou-se o crescimento das plantas de cafeeiro quando estavam com 5 pares de folhas verdadeiras, sendo: altura de plantas (cm, diâmetro de caule (mm, massa seca do sistema radicular (g, massa seca da parte aérea (g, número de nós da inserção foliar do ramo ortotrópico da muda e área foliar total (cm². Concluiu-se que o uso do coletor solar é promissor para a desinfestação de substratos por proporcionar bom desenvolvimento de mudas de cafeeiro, a exemplo do brometo de metila.The objective of this work was to evaluate the development of coffee seedlings grown in bag mixture disinfested by different methods. The work was carried out in a high cover coffee nursery at Federal University of Lavras, State of Minas Gerais, Brazil, in May/2004. The bag mixture was prepared using soil from a 20 years old coffee field. Thirteen disinfestations methods were used in bag mixture. The cultivar paraíso H 419-1 was used in all treatments. The growth was evaluated when the plants had five pairs of mature leaves. The following parameters were analyzed: height (cm, girth diameter (mm, root and shoot dry weight (g, number of orthotropic nodes, and total leaf area (cm². It was concluded that methyl bromide promoted the best coffee seedlings development. The use of the solar collector was also considered promising for substrate disinfestations in commercial nurseries, as observed for the methyl bromide.

  5. 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.

  6. 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 ...

  7. Physiological aspects underlying the improved outplanting performance of Pinus pinaster Ait. seedlings associated with ectomycorrhizal inoculation.

    Science.gov (United States)

    Sanchez-Zabala, Joseba; Majada, Juan; Martín-Rodrigues, Noemí; Gonzalez-Murua, Carmen; Ortega, Unai; Alonso-Graña, Manuel; Arana, Orats; Duñabeitia, Miren K

    2013-11-01

    Mycorrhizal inoculation of conifer roots is a key strategy to optimize establishment and performance of forest tree species under both natural and cultivated conditions and also to mitigate transplantation shock. However, despite being a common practice, inoculation in outdoor nursery conditions has been poorly studied. Here, we have evaluated effectiveness of four fungal species (Lactarius deliciosus, Lactarius quieticolor, Pisolithus arhizus, and Suillus luteus) in the production of mycorrhizal Pinus pinaster seedlings in an outdoor commercial nursery and their ability to improve seedling physiology and field performance. All inoculated seedlings showed a significant increase in growth at the end of the nursery stage and these differences remained after 3 years of growth in the field. Differences observed in the content of malondialdehyde, total chlorophyll, carotenoids, anthocyanins, and phenolic compounds from needles of mycorrhizal and control seedlings may reflect a different sensitivity to photo-oxidative damage. We conclude that ectomycorrhizal inoculation improves adaptability to changeable growing conditions of an outdoor nursery and produces a higher quality nursery stock, thereby enhancing seedling performance after planting.

  8. Node Detection and Internode Length Estimation of Tomato Seedlings Based on Image Analysis and Machine Learning

    Directory of Open Access Journals (Sweden)

    Kyosuke Yamamoto

    2016-07-01

    Full Text Available Seedling vigor in tomatoes determines the quality and growth of fruits and total plant productivity. It is well known that the salient effects of environmental stresses appear on the internode length; the length between adjoining main stem node (henceforth called node. In this study, we develop a method for internode length estimation using image processing technology. The proposed method consists of three steps: node detection, node order estimation, and internode length estimation. This method has two main advantages: (i as it uses machine learning approaches for node detection, it does not require adjustment of threshold values even though seedlings are imaged under varying timings and lighting conditions with complex backgrounds; and (ii as it uses affinity propagation for node order estimation, it can be applied to seedlings with different numbers of nodes without prior provision of the node number as a parameter. Our node detection results show that the proposed method can detect 72% of the 358 nodes in time-series imaging of three seedlings (recall = 0.72, precision = 0.78. In particular, the application of a general object recognition approach, Bag of Visual Words (BoVWs, enabled the elimination of many false positives on leaves occurring in the image segmentation based on pixel color, significantly improving the precision. The internode length estimation results had a relative error of below 15.4%. These results demonstrate that our method has the ability to evaluate the vigor of tomato seedlings quickly and accurately.

  9. GARDEN CRESS GERMINABILITY AND SEEDLING VIGOUR AFTER TREATMENT WITH PLANT EXTRACTS

    Directory of Open Access Journals (Sweden)

    Miroslav Lisjak

    2015-12-01

    Full Text Available The usage of biologically active and environmentally friendly compounds has increasingly important role in the primary food production. This study was conducted in order to examine the impact of five commercial plant extracts on the seed vigour of garden cress (Lepidium sativum L.. The applied plant extracts significantly increased the germination. The highest fresh weight of seedlings, and also the lowest dry matter accumulation were observed in the treatment KE-plantasalva® without the sea salt addition. Equisetum extract inhibited the root elongation and resulted in the highest percentage of dry matter accumulated in seedlings, but also the lowest fresh weight.

  10. Association analysis of salt tolerance in cowpea (Vigna unguiculata (L.) Walp) at germination and seedling stages

    Science.gov (United States)

    Cowpea is one of the most important cultivated legumes in Africa. The worldwide annual production in cowpea dry seed is 5.4 million metric tons. However, cowpea is unfavorably affected by salinity stress at germination and seedling stages, which is exacerbated by the effects of climate change. The l...

  11. Nursery temperature as a factor in root elongation of ponderosa pine seedlings

    Science.gov (United States)

    Gilbert H. Schubert; Frank J. Baron

    1965-01-01

    Greenhouse and nursery studies suggest that graphs of "effective" day and night temperatures provide a convenient method to compare nursery sites and to evaluate the effects of temperature on seedling root growth. Comparisons of root response under different natural temperature regimes should provide inforrnation use ful 'for the production of higher...

  12. The genetic and economic effect of preliminary culling in the seedling orchard

    Science.gov (United States)

    Don E. Riemenschneider

    1977-01-01

    The genetic and economic effects of two stages of truncation selection in a white spruce seedling orchard were investigated by computer simulation. Genetic effects were computed by assuming a bivariate distribution of juvenile and mature traits and volume was used as the selection criterion. Seed production was assumed to rise in a linear fashion to maturity and then...

  13. Evaluation of RPM™ oak seedlings in afforesting floodplain crop fields along the Missouri River

    Science.gov (United States)

    Daniel C. Dey; John M. Kabrick; Michael A. Gold

    2005-01-01

    Regenerating oaks in agricultural floodplains is problematic because of their slow juvenile shoot growth, intense plant competition, seasonal flooding, and browsing by wildlife. Planting large nursery stock has been recommended to increase the competitiveness of oak seedlings. The Forrest Keeling Nursery in Missouri developed the Root Production Method (RPM™)...

  14. Natural seedlings and sprouts after regeneration cuttings in old-growth redwood

    Science.gov (United States)

    Kenneth N. Boe

    1975-01-01

    Natural regeneration of harvested old-growth stands of redwood (Sequoia sempervirens) is one way to start a new forest that is needed quickly for continuous timber production. Natural seedlings and sprouts developing after stands were cut were studied on the Redwood Experimental Forest, northern California. Three types of regeneration cuttings were...

  15. Influence of stomatic aperture on photosynthetic activity of bean-seedlings leaves

    International Nuclear Information System (INIS)

    Suarez Moya, J.; Fernandez Gonzalez, J.

    1984-01-01

    The present paper contains the data of photosynthetic activity and stomatic aperture of bean-seedlings Ieaves, and the relations obtained with both results. It has been observed that the product of photosynthetic activity by the resistance; to transpiration measured by a promoter ia a constant, between some limits. (Author) 45 refs

  16. 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...

  17. Efeito de recipientes e substratos utilizados na produção de mudas de cafeeiro no desenvolvimento inicial em casa de vegetação, sob estresse hídrico Effect of different recipients and substrata used in the production of coffee tree seedlings in the initial development in greenhouse under water stress

    Directory of Open Access Journals (Sweden)

    Haroldo Silva Vallone

    2010-04-01

    Full Text Available Com o objetivo de avaliar os efeitos de recipientes e substratos no desenvolvimento inicial de cafeeiros (Coffea arabica L. plantados em vasos dentro de casa de vegetação, sob diferentes níveis de estresse hídrico, foi conduzido um experimento no Setor de Cafeicultura da Universidade Federal de Lavras - UFLA, no período de janeiro a maio de 2004. O delineamento experimental utilizado foi em blocos casualizados (DBC em esquema fatorial (3 x 3 x 4, sendo o primeiro fator constituído de três recipientes utilizados na produção das mudas, tubetes de polietileno rígido de 50 mL; tubetes de 120 mL; e saquinhos de polietileno, nas dimensões de 20 cm de altura por 10 cm de largura e capacidade volumétrica, aproximada, de 700 mL; o segundo fator constituído de três substratos utilizados na produção das mudas, substrato alternativo, composto por 65% de casca de arroz carbonizada + 35% de substrato comercial; substrato comercial Plantmax hortaliças HT; e substrato padrão, composto por 70% de terra + 30% de esterco bovino peneirados e o terceiro fator foi constituído por quatro intervalos entre irrigações, 2, 6, 10 e 14 dias. Observa-se que os recipientes de capacidades volumétricas diferentes e os substratos utilizados influenciam, significativamente, o desenvolvimento dos cafeeiros, sendo que, após 120 dias do transplante das mudas para vasos em casa de vegetação com diferentes níveis de estresse hídrico, as plantas provenientes de mudas produzidas em saquinhos de polietileno e tubetes de 120 mL contendo substratos alternativo e comercial apresentaram melhor desenvolvimento.With the aim of evaluating the effects of different recipients and substrata in the production of coffee tree seedlings (Coffea arabica L., planted in pots inside the greenhouse, under different water stress levels, an experiment was carried out in the Section of Coffee of Department of Agriculture of Universidade Federal de Lavras - UFLA, in the period from

  18. 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.

  19. Modulation in radiation-induced changes in peroxidase activity with gibberellic acid in seedling's growth in chickpea (Cicer arietinum L.)

    International Nuclear Information System (INIS)

    Khan, M.R.; Qureshi, A.S.

    2002-01-01

    Changes in the effects of gamma irradiation (10 to 110 Kr) with gibberellic acid (GA/sub 3/) for peroxidase activity, in relation to early days of seedling's growth in Kabulic chickpea cultivar, Noor-91, were evaluated. Stimulation in peroxidase activity over control was recorded at all the irradiation treatments from 3rd to 8th day of seedling's development. Increase in peroxidase activity at 10 and 20 Kr was due to the increase in metabolic activity, while higher doses of gamma radiation account for the damaging action and production of peroxy radicals. However, stimulation in fresh weight was observed only at 10 Kr of gamma irradiation. Postmutagenic application of Ga/sub 3/ protect the seedlings from radiation injury, by increasing the peroxides activity, and increased the fresh weight of chickpea seedlings. (author)

  20. 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...

  1. 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 ...

  2. 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...

  3. Gas exchange, dry weights, and chlorophyll contents of Populus tremuloides seedlings grown from gamma-irradiated seeds

    International Nuclear Information System (INIS)

    Salmonson, B.J.; Zavitkovski, J.

    1977-01-01

    Photosynthesis and respiration rates of Populus tremuloides seedlings grown from seeds acutely irradiated with gamma rays (at levels of 0, 0.47, 0.94, 1.8, 3.7, 7.5, and 15 kr) were measured using a closed system and infrared (IR) gas analyzer. Dry weights of seedling roots and shoots and chlorophyll contents were also determined. In general, gamma irradiation of seed had little effect on subsequent gas-exchange processes in the plant. Net photosynthesis and dark respiration rates of the seedling at any radiation level were not significantly different from those of the control group. Pooled net photosynthesis of all irradiated seedlings was nonsignificantly lower than that of the control seedlings. The data suggested a slight stimulation in dry-matter production of shoots by low levels of gamma radiation. At the highest levels of radiation, shoot dry weight was significantly reduced. Root production displayed a pattern similar to that of shoots. No trends different from controls were evident in the shoot/root ratios. Total chlorophyll concentrations of the seedling increased over the controls by radiation treatment. Age and radiation effects were evident in the chlorophyll a/b ratios. The chlorophyll a/b ratios decreased with age in both the control and treatment groups. Although in seedlings 39 through 46 days old chlorophyll a/b ratios were higher in the control, chlorophyll a/b ratios were significantly higher in the treatment seedlings at 68 days. Changes in chlorophyll a were primarily responsible for this change

  4. Morphophysiological Behavior and Cambial Activity in Seedlings of Two Amazonian Tree Species under Shade

    Directory of Open Access Journals (Sweden)

    Monyck Jeane dos Santos Lopes

    2015-01-01

    Full Text Available Variations in light intensity can lead to important anatomical and morphophysiological changes in plants. Aiming to increase knowledge about the Amazonian tree species, this study examines the influence of shade on the cambial activity and development of Parkia gigantocarpa Ducke and Schizolobium parahyba var. amazonicum (Huber ex Ducke Barneby seedlings. Seedlings of the two species were grown in a nursery under four shade intensities (treatments: full sun, low, moderate, and high shade (resp., 0%, 23%, 67%, and 73% of shade, or 2000, 1540, 660, and 540 µmol·m−2·s−1 obtained with polyethylene screens. We measured plant height, stem diameter, biomass production, stomatal conductance (gs, transpiration (E, photosynthesis (A, and cambial activity (CA (xylem, cambium, and phloem. Also, we calculated the Dickson Quality Index (DQI. The highest values of biomass production, gs,  E, A, and DQI, were found under full sun, in P. gigantocarpa, and under low shade intensity in S. parahyba. In both species high shade intensity reduced CA. We concluded that the CA and the physiological and morphological attributes work together, explaining the radial growth and increasing seedlings quality, which optimized efficient seedling production under full sun, in P. gigantocarpa, and under low shade intensity in S. parahyba.

  5. Quantitative trait loci associated with seed and seedling traits in Lactuca.

    Science.gov (United States)

    Argyris, Jason; Truco, María José; Ochoa, Oswaldo; Knapp, Steven J; Still, David W; Lenssen, Ger M; Schut, Johan W; Michelmore, Richard W; Bradford, Kent J

    2005-11-01

    Seed and seedling traits related to germination and stand establishment are important in the production of cultivated lettuce (Lactuca sativa L.). Six seed and seedling traits segregating in a L. sativa cv. Salinas x L. serriola recombinant inbred line population consisting of 103 F8 families revealed a total of 17 significant quantitative trait loci (QTL) resulting from three seed production environments. Significant QTL were identified for germination in darkness, germination at 25 and 35 degrees C, median maximum temperature of germination, hypocotyl length at 72 h post-imbibition, and plant (seedling) quality. Some QTL for germination and early seedling growth characteristics were co-located, suggestive of pleiotropic loci regulating these traits. A single QTL (Htg6.1) described 25 and 23% of the total phenotypic variation for high temperature germination in California- and Netherlands-grown populations, respectively, and was significant between 33 and 37 degrees C. Additionally, Htg6.1 showed significant epistatic interactions with other Htg QTL and a consistent effect across all the three seed production environments. L. serriola alleles increased germination at these QTL. The estimate of narrow-sense heritability (h2) of Htg6.1 was 0.84, indicating potential for L. serriola as a source of germination thermotolerance for lettuce introgression programs.

  6. 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 ...

  7. 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...

  8. 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...

  9. 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

  10. The role of onion-associated fungi in bulb mite infestation and damage to onion seedlings.

    Science.gov (United States)

    Ofek, Tal; Gal, Shira; Inbar, Moshe; Lebiush-Mordechai, Sara; Tsror, Leah; Palevsky, Eric

    2014-04-01

    In Israel Rhizoglyphus robini is considered to be a pest in its own right, even though the mite is usually found in association with fungal pathogens. Plant protection recommendations are therefore to treat germinating onions seedlings, clearly a crucial phase in crop production, when mites are discovered. The aim of this study was to determine the role of fungi in bulb mite infestation and damage to germinating onion seedlings. Accordingly we (1) evaluated the effect of the mite on onion seedling germination and survival without fungi, (2) compared the attraction of the mite to species and isolates of various fungi, (3) assessed the effect of a relatively non-pathogenic isolate of Fusarium oxysporum on mite fecundity, and (4) determined the effects of the mite and of F. oxysporum separately and together, on onion seedling germination and sprout development. A significant reduction of seedling survival was recorded only in the 1,000 mites/pot treatment, after 4 weeks. Mites were attracted to 6 out of 7 collected fungi isolates. Mite fecundity on onion sprouts infested with F. oxysporum was higher than on non-infested sprouts. Survival of seedlings was affected by mites, fungi, and their combination. Sprouts on Petri dishes after 5 days were significantly longer in the control and mite treatments than both fungi treatments. During the 5-day experiment more mites were always found on the fungi-infected sprouts than on the non-infected sprouts. Future research using suppressive soils to suppress soil pathogens and subsequent mite damage is proposed.

  11. Growth of seedlings of Corymbia citriodora as a function of hydrogel use and fertilization

    Directory of Open Access Journals (Sweden)

    Marlon Rodrigo Bernardi

    2012-03-01

    Full Text Available Corymbia citriodora, also known as lemon eucalyptus, is one of the most cultivated species for extraction of essential oils. Seedling production for this species, however, is more difficult than for other species, considering its slower growth, higher susceptibility to disease and nutrition requirements. As regards top dressing in particular, no established routine is available so far to ensure fertilizer savings and good seedling development. Slow growth reduces seedling capability to absorb nutrients before leaching starts, and a potential alternative to that is to add water-retaining polymers to the substrate so as to facilitate absorption of the fertilizers applied and their slow release in seedling tubes. The objective of this study was to evaluate the effect of different fertilizer dosages, as applied to substrates containing water-retaining polymers, on the growth of Corymbia citriodora seedlings. A completely randomized design was used, with four replicates, consisting of a control treatment with routine substrate and fertilizer used by a commercial nursery, plus five treatments with top dressing dosages ranging from 80% to 20% of commercial dosage plus addition of a polymer (6 g L-1. After 126 days, seedlings were evaluated for height, stem base diameter and ratio of height to stem base diameter. After analysis, it was concluded that the use of a water-retaining polymer had a positive effect on the height, stem base diameter and ratio of shoot height to stem base diameter, and that it helped reduce by at least 20% the amount of routine fertilizer used by the commercial nursery, whether basic fertilizer or top dressing.

  12. 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.

  13. Effect of Acinetobacter sp on metalaxyl degradation and metabolite profile of potato seedlings (Solanum tuberosum L. alpha variety.

    Directory of Open Access Journals (Sweden)

    Fabiola G Zuno-Floriano

    Full Text Available One of the most serious diseases in potato cultivars is caused by the pathogen Phytophthora infestans, which affects leaves, stems and tubers. Metalaxyl is a fungicide that protects potato plants from Phytophthora infestans. In Mexico, farmers apply metalaxyl 35 times during the cycle of potato production and the last application is typically 15 days before harvest. There are no records related to the presence of metalaxyl in potato tubers in Mexico. In the present study, we evaluated the effect of Acinetobacter sp on metalaxyl degradation in potato seedlings. The effect of bacteria and metalaxyl on the growth of potato seedlings was also evaluated. A metabolite profile analysis was conducted to determine potential molecular biomarkers produced by potato seedlings in the presence of Acinetobacter sp and metalaxyl. Metalaxyl did not affect the growth of potato seedlings. However, Acinetobacter sp strongly affected the growth of inoculated seedlings, as confirmed by plant length and plant fresh weights which were lower in inoculated potato seedlings (40% and 27%, respectively compared to the controls. Acinetobacter sp also affected root formation. Inoculated potato seedlings showed a decrease in root formation compared to the controls. LC-MS/MS analysis of metalaxyl residues in potato seedlings suggests that Acinetobacter sp did not degrade metalaxyl. GC-TOF-MS platform was used in metabolic profiling studies. Statistical data analysis and metabolic pathway analysis allowed suggesting the alteration of metabolic pathways by both Acinetobacter sp infection and metalaxyl treatment. Several hundred metabolites were detected, 137 metabolites were identified and 15 metabolic markers were suggested based on statistical change significance found with PLS-DA analysis. These results are important for better understanding the interactions of putative endophytic bacteria and pesticides on plants and their possible effects on plant metabolism.

  14. Acorn fall and weeviling in a northern red oak seedling orchard

    Science.gov (United States)

    Daniel R. Miller; Scott E. Schlarbaum

    2005-01-01

    In 2000, we determined levels of damage by acorn weevils (Curculio spp.) and patterns of acorn fall in a northern red oak (Quercus rubra L.) seedling orchard in eastern Tennessee. The mean (±SE) production of acorns among 43 selected trees was 5,930 ± 586 acorns per tree with a maximum production level of 16,969 acorns for one tree...

  15. Final Report: N-Acylethanolamine metabolism and the acquisition of photoautotrophy during seedling establishment

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, Kent

    2018-01-29

    Research in our labs, supported since 2005 by Basic Energy Sciences, has led to the discovery of a new lipid mediator pathway that influences phytohormone-mediated regulation of plant growth and development—the so-called N-acylethanolamine (NAE) regulatory pathway. This pathway in plants shares conserved metabolic machinery with the endocannabinoid signaling system of vertebrates that regulates a multitude of physiological and behavioral processes in mammals, suggesting that the metabolism of NAEs is an important regulatory feature of eukaryotic biology. Current evidence in plants points to interactions between NAE metabolism, abscisic acid (ABA) signaling and light signaling to modulate seedling establishment and the acquisition of photoautotrophic growth. The proposed research fits well within the mission of Photosynthetic Systems and Physical Biosciences which seek “to understand the processes by which plants, algae and non-medical microbes capture, convert and/or store energy”. The fundamental regulatory processes that govern seedling establishment directly influence the assembly of photosynthetic energy conversion systems in essentially all higher plants. Our main hypothesis is that seedlings coordinate the metabolic depletion of NAEs during seedling establishment through a complex interaction of hydrolysis (by fatty acid amide hydrolase, FAAH) and oxidation (by lipoxygenases, LOX) and that newly-reported oxylipin metabolites of polyunsaturated NAEs help to coordinate seedling development and acquisition of photoautotrophy in response to appropriate environmental cues. Evidence suggests that ethanolmide oxylipins derived from NAEs can reversibly accumulate in seedlings and adjust/arrest seedling establishment and chloroplast development in conjunction with ABA signaling and light-signaling pathways. Our results provide important new information linking the production of small molecule lipid mediators in seedlings to the coordinated development of

  16. 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.

  17. [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

  18. Effect of ethephon on hardening of Pachystroma longifolium seedlings

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    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.

  19. Effects of space environment on biological characters of cultured rose seedlings

    Science.gov (United States)

    Min, L.; Huai, X.; Jinying, L.; Yi, P.; Chunhua, Z.

    Cultured rose seedlings were carried into space by SHENZHOU-4 spacecraft and then used as the experimental material to investigate effects of the space environmental conditions on morphology cytology physiology and molecular biology of the seedlings After loaded on the space flight the plant s height number of leaves and fresh weight per seedling were all increased significantly compared to the ground controls The content of chlorophyll was basically unchanged In some cells the ultrastructural changes involved twist contraction and deformation of cell wall curvature and loose arrangement of lamellae of some chloroplasts and a significant increase in number of starch grains per chloroplast In addition the number of mitochondria increased but some mitochondrial outer membrane broke and some mitochondrial cristae disappeared The activities of the defense enzymes such as superoxide dismutase peroxidase and catalyse in rose leaves increased and the content of malondialdehyde decreased In the RAPD analysis with 40 10-mer primers 36 primers generated 148 DNA bands from both of the space flight treated seedlings and the ground controls and five primers amplified polymorphic products The rate of DNA variation was 6 34

  20. Various compositions containing organic substrates to produce Eugenia uniflora L. seedlings

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    Licielo Romero Vieira

    2015-09-01

    Full Text Available The use of substrates formulated with agro-industrial residues, such as coconut shell fiber, sawdust, and carbonized rice husk, is among the sustainable alternatives to decrease the production costs of seedlings of plant species. This study aimed to evaluate the use of various substrates for obtaining high quality Eugenia uniflora L. seedlings. The experiment was conducted at the Federal University of Pampa (UNIPAMPA – Campus in São Gabriel, Rio Grande do Sul, Brazil, by sowing directly into 200 cm3 polypropylene tubes, testing various substrates (50% commercial substrate Plantmax® + 50% rice husk; commercial substrate Plantmax®; 50% commercial substrate Plantmax® + 50% coconut shell fiber; and 50% commercial substrate Plantmax® + 50% sawdust. Every 3 days, the number of emerged seedlings was evaluated and, after 180 days, the following morphological features were analyzed: shoot height, stem diameter, number of leaves, root and total fresh weight, shoot, root, and total dry weight, and Dickson’s quality index. The results indicate that all substrates were suitable for Eugenia uniflora emergence, but that containing 50% commercial substrate Plantmax® + 50% sawdust provided a delay in the emergence of this Myrtaceae; also, substrates containing 50% commercial substrate Plantmax® + 50% husk rice and 50% commercial substrate Plantmax® + 50% coconut shell fiber showed to be satisfactory for the growth of Eugenia uniflora seedlings.

  1. Physiological aspects of seedling development of coffee grown under colored screens

    International Nuclear Information System (INIS)

    Henrique, Paola de Castro; Alves, Jose Donizeti; Livramento, Darlan Einstein do; Goulart, Patricia de Fatima Pereira

    2011-01-01

    The objective of this work was to evaluate the physiological aspects of the development of coffee seedlings grown under colored screens with different spectral characteristics. Seedlings of Catucai Amarelo 2SL, in the stage known as 'orelha de onca', were arranged in a randomized block design, with five replicates, under structures individually covered with blue, white, gray, black or red screens with 50% shade. Four months after, evaluations were done for seedling growth, pigment content of the leaves, total soluble sugars and starch contents of the leaves and roots. The red screen was the most effective in promoting growth in four out of the seven studied traits: plant height, leaf area and leaf dry weight and total dry matter. For the other characteristics, there was no difference among the screens. The pigment analysis showed that, except for the gray screen, the other ones did not differ for this trait. In leaves, the red screen promoted higher levels of carbohydrates and starch. At the root, carbohydrate contents were higher under the red and black screens. Among the five screen colors, the red one was the most efficient in the production of coffee seedlings with higher vigor and quality, with outstanding carbohydrate contents and biomass. (author)

  2. Screening selected genotypes of cowpea [Vigna unguiculata (L.) Walp.] for salt tolerance during seedling growth stage.

    Science.gov (United States)

    Gogile, A; Andargie, M; Muthuswamy, M

    2013-07-15

    The environmental stress such as, salinity (soil or water) are serious obstacles for field crops especially in the arid and semi-arid parts of the world. This study was conducted to assess the potential for salt tolerance of cowpea genotypes during the seedling stage. The experimental treatments were 9 cowpea genotypes and 4 NaCl concentrations (0, 50, 100 and 200 mM) and they were tested in greenhouse. The experimental design was completely randomized design in factorial combination with three replications. Data analysis was carried out using SAS (version 9.1) statistical software. Seedling shoots and root traits, seedling shoots and root weight, number of leaves and total biological yield were evaluated. The analyzed data revealed highly significant (p cowpea genotypes, treatments and their interactions. It is found that salt stress significantly decreased root length, shoot length, seedling shoot and root weight of cowpea genotypes. The extent of decrease varied with genotypes and salt concentrations. Most genotypes were highly susceptible to 200 mM NaCl concentration. The correlation analysis revealed positive and significant association among most of the parameters. Genotypes 210856, 211557 and Asebot were better salt tolerant. The study revealed the presence of broad intra specific genetic variation in cowpea varieties for salt stress with respect to their early biomass production.

  3. Photoinduced toxicity of fluoranthene on germination and early development of plant seedling.

    Science.gov (United States)

    Kummerová, Marie; Kmentová, Eva

    2004-07-01

    The influence of light on phytotoxicity of increased concentration (2, 5, 10 mg/l) of intact fluoranthene (FLT) and photomodified fluoranthene (phFLT) diluted in experimental solutions was investigated. The germination rate of lettuce (Lactuca sativa L.), onion (Allium cepa L.) and tomato (Lycopersicum esculentum L.) seeds and some parameters of seedlings primary growth of these plant species were used as laboratory indicators of phytotoxicity. Among them a length of root and shoot, their dry weight and a content of photosynthetic pigments in shoot were measured. The results demonstrated that the higher concentration (5 and 10 mg/l) of FLT and especially of phFLT significantly inhibited the germination rate of seeds and the length of root and shoot seedlings of all plant species. Decreased production of biomass expressed by dry weight of root and shoot was found in lettuce seedlings under the inhibitory effect of FLT and phFLT. An increased concentration of FLT and phFLT did not exhibit an unambiguous effect on the content of photosynthetic pigments in shoot of experimental plants. Only the highest concentration (10 mg/l) of FLT significantly increased content of chlorophylls a and b in lettuce, onion and tomato plants and content of carotenoids in lettuce and onion. Light intensified a significant inhibitory effect of phFLT in the most testified parameters of germination and seedling growth.

  4. Efeitos da aplicação da escória de siderurgia ferrocromo no solo, no estado nutricional e na produção de matéria seca de mudas de maracujazeiro Aplication of basic slag iron-chromium in soil in nutritional state and dry matter production of passion fruit seedlings

    Directory of Open Access Journals (Sweden)

    Renato de Mello Prado

    2004-04-01

    2,8 dm³, cultivating them per 85 days. The application of the siderurgy slag iron-chromium promoted the neutralization of the acidity of the soil, however, in doses relatively low (360 kg ha-1 resulted in reduction in the nutrients and the production of dry matter of passion seedlings.

  5. 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...

  6. Produção de fôlhas de diferentes variedades de amoreiras, durante o período de formação das mudas nos sistemas de cepo e fuste Leaf production of different mulberry tree varieties, during the period of seedlings formation by the systems "cepo" and "fuste"

    Directory of Open Access Journals (Sweden)

    António Castilho Rúbia

    1966-01-01

    Full Text Available São apresentados resultados experimentais da produção de fôlhas em amoreiras de variedades comuns, durante o período de formação das mudas, com os sistemas denominados de cepo e fuste, em duas regiões, Limeira e Tatuí, do planalto paulista. Os resultados quanto à produção de fôlhas, em dois anos em cada região, permitiram as conclusões: Em Limeira, para a variedade Calabreza, o sistema de fuste foi muito superior ao de cepo. Para as variedades Fernão Dias e Lopes Lins, o sistema de fuste foi também superior, porém, de forma menos acentuada. Em Tatuí, no caso das variedades Calabreza e Fernão Dias, o sistema de cepo mostrou-se, ao contrário, mais produtivo. Para a variedade Lopes Lins, não houve diferença entre os dois sistemas de cultivo experimentados.In this paper the experimental results are reported on trials with leaf production carried out with common varieties of mulberry trees (Morus albaduring the period of seedlings formatioin by the systems known as "cepo" and "fuste", in two regions of the Paulista Plateau, namely Limeira and Tatuí. Regarding leaf production, in two years, for the regions, results allowed to reach the following conclusions: In Limeira, for the variety Calabreza, the system "fuste" showed highly superior to that named "cepo". As to the varieties Fernão Dias and Lopes Lins, the "fuste" system was also very satisfactory but not in a remarkable manner. In Tatui, as for the varieties Calabreza and Fernão Dias, the "cepo" system, on the contrary, showed to be more productive. Considering the variety Lopes Lins, there was not found any difference between the two tested cultivation systems.

  7. Observações sôbre a produtividade de seringueiras (Hevea brasiliensis muell.-arg. plantadas de sementes: II - Produtividade de 100 plantas do seringal mirim, em Manaus Observations on the latex production of seedlings of rubber trees (Hevea brasiliensis muell.-arg.: II - Study of 100 rubber trees of the seringal mirim, Manaus

    Directory of Open Access Journals (Sweden)

    Luiz O. T. Mendes

    1960-01-01

    Full Text Available No presente trabalho é feito um estudo da produtividade de 100 seringueiras plantadas de sementes, existentes no Seringal Mirim, em Manaus, Estado do Amazonas, quando tinham a idade de 30 anos. Os resultados se referem à produção obtida de sangrias feitas a meia espiral, em dois regimes de trabalho: a sangria todos os dias (de maio a julho de 1943; b sangria em dias alternados (de agôsto a dezembro de 1943. Tais resultados mostram que, no conjunto de plantas estudado, as de maior produção logo se sobressairam das demais, em qualquer dos regimes de sangria a que foram submetidas; mostram também que, de um modo geral, a mudança do regime de sangria todos os dias para o de sangria em dias alternados provocou um aumento na produção individual, por sangria, tanto mais pronunciado quanto menor foi a produtividade da planta no regime de sangria diária. É também apresentado o resultado do estudo da distribuição, dentro da população, das plantas e conjuntos de plantas classificadas de acordo com sua produtividade, por onde se verifica que umo quarta parte da população foi responsável pela produção de quase 60% do látex total colhido em qualquer dos regimes de sangria adotados. Êsses resultados mostram a possibilidade da formação de seringais de produção relativamente boa, a partir de sementes não selecionadas, desde que plantados inicialmente com densidades bastante elevadas, que permitam posteriores desbastes para a eliminação da maior parte da população, representada pelas plantas de baixa produção.The results of eight month tappings (half-spiral cut of 100 seedlings of rubber trees, 30 years old, are presented. From May to July 1943 the trees were tapped every day; from August to December, every other day. The change of the tapping system, from daily to every other day, caused an increase in the individual yield, per tapping; this yield increase was more pronounced in the low production plants. The study of the

  8. The Control of Fungus Uromycladium tepperianum on Seedling of Sengon (Falcataria moluccana (Miq. Barneby & J.W.Grimes in a nursery

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    Kurniawati Purwaka Putri

    2017-08-01

    Full Text Available Sengon (Falcataria moluccana (Miq. Barneby & J.W.Grimes is one of timber producing species of high economic value. Recently, sengon productivity decreases due to pests and diseases, attack is caused by the fungus Uromycladium tepperianum (SACE. McAlp. The control of gall rust disease at seedling level is important, because the stadia nursery are the most vulnerable. The aim of this research was to determine the effectiveness of the type of control in supressing the fungus of U. tepperianum and the growth of sengon in a nursery. The research design used a completely randomized design (CRD with five treatments of gall rust disease control types i.e. control ; biological fertilizer of Plant Growth Promoting Rhizobacteria (PGPR (5 g -L of water, biofungicide (5 g-L of water; chemical fungicide (2 g-L of water; and boron (300 ppm. Each treatment consisted of 20 seedlings repeated 4 times. The observed response were the number of fungal spores, diameter and height of seedlings. In addition, calculation of the effectiveness of the type of controller was counted. The results showed that after two weeks of fungal infections, the highest seedling growth was the seedling treated with fungicide (0.53 cm, while the lowest was the seedling treated with biological fungicide (0.32 cm. PGPR, fungicide biological, chemical fungicides and boron did not effective to the attack of fungus and to increase the growth of height and diameter of sengon seedling after the 4th week of the fungus infection.

  9. Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings 1

    Science.gov (United States)

    Creelman, Robert A.; Mason, Hugh S.; Bensen, Robert J.; Boyer, John S.; Mullet, John E.

    1990-01-01

    Roots often continue to elongate while shoot growth is inhibited in plants subjected to low-water potentials. The cause of this differential response to water deficit was investigated. We examined hypocotyl and root growth, polysome status and mRNA populations, and abscisic acid (ABA) content in etiolated soybean (Glycine max [L.] Merr. cv Williams) seedlings whose growth was inhibited by transfer to low-water potential vermiculite or exogenous ABA. Both treatments affected growth and dry weight in a similar fashion. Maximum inhibition of hypocotyl growth occurred when internal ABA levels (modulated by ABA application) reached the endogenous level found in the elongating zone of seedlings grown in water-deficient vermiculite. Conversely, root growth was affected to only a slight extent in low-water potential seedlings and by most ABA treatments (in some, growth was promoted). In every seedling section examined, transfer of seedlings into low-water potential vermiculite caused ABA levels to increase approximately 5- to 10-fold over that found in well-watered seedlings. Changes in soluble sugar content, polysome status, and polysome mRNA translation products seen in low-water potential seedlings did not occur with ABA treatments sufficient to cause significant inhibition of hypocotyl elongation. These data suggest that both variation in endogenous ABA levels, and differing sensitivity to ABA in hypocotyls and roots can modulate root/shoot growth ratios. However, exogenous ABA did not induce changes in sugar accumulation, polysome status, and mRNA populations seen after transfer into low-water potential vermiculite. Images Figure 6 Figure 7 PMID:16667248

  10. 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.

  11. Quality of jackfruit seedlings under saline water stress and nitrogen fertilisation

    Directory of Open Access Journals (Sweden)

    Francisco Ítalo Fernandes de Oliveira

    2017-08-01

    Full Text Available The lack of good quality water for agriculture purposes regarding salts and quantity in relation to demand for the plants has, for more than 30 years, been forcing the use of restrictive water because of salinity issues in agricultural production systems worldwide. In Brazil, the situation is no different, in the semi-arid areas, there are reports of losses of seed germination, initial growth of seedlings and yield of crops of commercial importance due to the salinity of the water used in irrigation systems. Therefore, an experiment was carried out from June to September/2014 in a protected environment, with a plastic film on the upper base and a thin screen against insects on the sides, to evaluate the effects of salinity interaction between water irrigation and nitrogen fertilisation sources on soil salinity, initial plant growth and the quality of the jackfruit seedlings. The treatments were distributed in randomised blocks, in the factorial scheme 5 × 3, reference irrigation water of 0.3, 1.0, 2.0, 3.0 and 4.0 dS m-1, in soil with and without ammonium sulfate and urea. An increase in the salinity of the irrigation water to 1.32 and 1.70 dS m-1 on the substrate without nitrogen stimulated an increase in the number of leaves and leaf area of the jackfruit seedlings. The ammonium sulfate was the nitrogen source that mainly contributed to the increase of soil salinity and to the reduction of the quality index of the seedlings. Despite the reduction of the Dickson quality index due to the salinity of the irrigation water and the nitrogen sources, the seedlings were suitable for cultivation.

  12. Germination and seedling frost tolerance differ between the native and invasive range in common ragweed.

    Science.gov (United States)

    Leiblein-Wild, Marion Carmen; Kaviani, Rana; Tackenberg, Oliver

    2014-03-01

    Germination characteristics and frost tolerance of seedlings are crucial parameters for establishment and invasion success of plants. The characterization of differences between populations in native and invasive ranges may improve our understanding of range expansion and adaptation. Here, we investigated germination characteristics of Ambrosia artemisiifolia L., a successful invader in Europe, under a temperature gradient between 5 and 25 °C. Besides rate and speed of germination we determined optimal, minimal and maximal temperature for germination of ten North American and 17 European populations that were sampled along major latitudinal and longitudinal gradients. We furthermore investigated the frost tolerance of seedlings. Germination rate was highest at 15 °C and germination speed was highest at 25 °C. Germination rate, germination speed, frost tolerance of seedlings, and the temperature niche width for germination were significantly higher and broader, respectively, for European populations. This was partly due to a higher seed mass of these populations. Germination traits lacked evidence for adaptation to climatic variables at the point of origin for both provenances. Instead, in the native range, seedling frost tolerance was positively correlated with the risk of frosts which supports the assumption of local adaptation. The increased frost tolerance of European populations may allow germination earlier in the year which may subsequently lead to higher biomass allocation--due to a longer growing period--and result in higher pollen and seed production. The increase in germination rates, germination speed and seedling frost tolerance might result in a higher fitness of the European populations which may facilitate further successful invasion and enhance the existing public health problems associated with this species.

  13. 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.

  14. H and Al ionic toxicity in seedlings of spruce and beech trees

    Energy Technology Data Exchange (ETDEWEB)

    Rost-Siebert, K.

    1985-01-01

    The influence of aluminium and hydrogen on seedlings of spruce and beech trees was tested. Parameters as root growth, state of health, minerals content and production of dry matter were measured. The results are discussed and show that ion concentrations of hydrogen and aluminium, average for todays forest soils, reduce root growth, damage roots and disturb the uptake of Ca/sup 2+/ and Mg/sup 2+/.

  15. 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.

  16. 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

  17. 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.

  18. How does solar ultraviolet-B radiation improve drought tolerance of silver birch (Betula pendula Roth.) seedlings?

    Science.gov (United States)

    Robson, T Matthew; Hartikainen, Saara M; Aphalo, Pedro J

    2015-05-01

    We hypothesized that solar ultraviolet (UV) radiation would protect silver birch seedlings from the detrimental effects of water stress through a coordinated suite of trait responses, including morphological acclimation, improved control of water loss through gas exchange and hydraulic sufficiency. To better understand how this synergetic interaction works, plants were grown in an experiment under nine treatment combinations attenuating ultraviolet-A and ultraviolet-B (UVB) from solar radiation together with differential watering to create water-deficit conditions. In seedlings under water deficit, UV attenuation reduced height growth, leaf production and leaf length compared with seedlings receiving the full spectrum of solar radiation, whereas the growth and morphology of well-watered seedlings was largely unaffected by UV attenuation. There was an interactive effect of the treatment combination on water relations, which was more apparent as a change in the water potential at which leaves wilted or plants died than through differences in gas exchange. This suggests that changes occur in the cell wall elastic modulus or accumulation of osmolites in cells under UVB. Overall, the strong negative effects of water deficit are partially ameliorated by solar UV radiation, whereas well-watered silver birch seedlings are slightly disadvantaged by the solar UV radiation they receive. © 2014 John Wiley & Sons Ltd.

  19. Studies on the growth and indole-3-acetic acid and abscisic acid content of Zea mays seedlings grown in microgravity

    Science.gov (United States)

    Schulze, A.; Jensen, P. J.; Desrosiers, M.; Buta, J. G.; Bandurski, R. S.

    1992-01-01

    Measurements were made of the fresh weight, dry weight, dry weight-fresh weight ratio, free and conjugated indole-3-acetic acid, and free and conjugated abscisic acid in seedlings of Zea mays grown in darkness in microgravity and on earth. Imbibition of the dry kernels was 17 h prior to launch. Growth was for 5 d at ambient orbiter temperature and at a chronic accelerational force of the order of 3 x 10(-5) times earth gravity. Weights and hormone content of the microgravity seedlings were, with minor exceptions, not statistically different from seedlings grown in normal gravity. The tissues of the shuttle-grown plants appeared normal and the seedlings differed only in the lack of orientation of roots and shoots. These findings, based upon 5 d of growth in microgravity, cannot be extrapolated to growth in microgravity for weeks, months, and years, as might occur on a space station. Nonetheless, it is encouraging, for prospects of bioregeneration of the atmosphere and food production in a space station, that no pronounced differences in the parameters measured were apparent during the 5 d of plant seedling growth in microgravity.

  20. Morphological changes of Paulownia seedlings infected phytoplasmas reveal the genes associated with witches' broom through AFLP and MSAP.

    Directory of Open Access Journals (Sweden)

    Xibing Cao

    Full Text Available Paulownia witches' broom (PaWB caused by phytoplasma might result in devastating damage to the growth and wood production of Paulownia. To study the effect of phytoplasma on DNA sequence and to discover the genes related to PaWB occurrence, DNA polymorphisms and DNA methylation levels and patterns in PaWB seedlings, the ones treated with various concentration of methyl methane sulfonate (MMS and healthy seedlings were investigated with amplified fragment length polymorphism (AFLP and methylation-sensitive amplification polymorphism (MSAP. Our results indicated that PaWB seedlings recovered a normal morphology, similar to healthy seedlings, after treatment with more than 20 mg · L-1 MMS; Phytoplasma infection did not change the Paulownia genomic DNA sequence at AFLP level, but changed the global DNA methylation levels and patterns; Genes related to PaWB were discovered through MSAP and validated using quantitative real-time PCR (qRT-PCR. These results implied that changes of DNA methylation levels and patterns were closely related to the morphological changes of seedlings infected with phytoplasmas.

  1. Molecular interaction between Methylobacterium extorquens and seedlings: growth promotion, methanol consumption, and localization of the methanol emission site.

    Science.gov (United States)

    Abanda-Nkpwatt, Daniel; Müsch, Martina; Tschiersch, Jochen; Boettner, Mewes; Schwab, Wilfried

    2006-01-01

    Four Methylobacterium extorquens strains were isolated from strawberry (Fragaria x ananassa cv. Elsanta) leaves, and one strain, called ME4, was tested for its ability to promote the growth of various plant seedlings. Seedling weight and shoot length of Nicotiana tabacum, Lycopersicon esculentum, Sinapis alba, and Fragaria vesca increased significantly in the presence of the pink-pigmented facultative methylotroph (PPFM), but the germination behaviour of seeds from six other plants was not affected. The cell-free supernatant of the bacterial culture stimulated germination, suggesting the production of a growth-promoting agent by the methylotroph. Methanol emitted from N. tabacum seedlings, as determined by proton-transfer-reaction mass spectrometry (PTR-MS), ranged from 0.4 to 0.7 ppbv (parts per billion by volume), while significantly lower levels (0.005 to 0.01 ppbv) of the volatile alcohol were measured when the seedlings were co-cultivated with M. extorquens ME4, demonstrating the consumption of the gaseous methanol by the bacteria. Additionally, by using cells of the methylotrophic yeast Pichia pastoris transformed with the pPICHS/GFP vector harbouring a methanol-sensitive promoter in combination with the green fluorescence protein (GFP) reporter gene, stomata were identified as the main source of the methanol emission on tobacco cotyledons. Methylobacterium extorquens strains can nourish themselves using the methanol released by the stomata and release an agent promoting the growth of the seedlings of some crop plants.

  2. 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.

  3. 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 ...

  4. 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 ...

  5. 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 ...

  6. 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 ...

  7. (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 ...

  8. 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 ...

  9. 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.

  10. 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 ...

  11. 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 ...

  12. Rational use of electrical energy in artificial light in the production of chrysanthemum seedlings in greenhouse; Uso racional de energia eletrica em iluminacao artificial na producao de mudas de crisantemo em ambiente protegido

    Energy Technology Data Exchange (ETDEWEB)

    David, Eduardo [Universidade Estadual de Campinas (FEA/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola], e-mail: eduardo.david@gr.unicamp.br; Rossi, Luiz Antonio [Universidade Estadual de Campinas (DEA/UNICAMP), SP (Brazil). Dept. de Engenharia Agricola], e-mail: rossi@agr.unicamp.br

    2008-07-01

    The type of artificial illumination employed for chrysanthemum cultivation in greenhouses to induce photo period effect will determine its growing rate as well as the energy consumption. Incandescent filament is currently employed for artificial illumination in chrysanthemum nursery to induce photo period effect. Nowadays new illumination technology is being tested aiming energy consumption reduction. The application of illumination based on electrical discharge in sodium or mercury vapor, as well as tubular or integrated compact fluorescent bulbs in chrysanthemum cultivation is identified as the objective of this research work. The experimental part of this work was carried out in a commercial greenhouse model employing five chrysanthemum variety as Papiro, Lindy White, Mona Lisa Rose, Euro Speedy and Stateman during winter and summer period. Parameters employed to the study variety behavior included: production per area, fresh matter weight, presence of flower sprouts and moisture content. The parameters known as electrical variables, like consumption, demand and power factor, together with the treatment energy efficiency index were used to analyze the employed illumination technologies and light bulbs type. Results showed differences between weight of fresh flowers and moisture content for the flowers variety under consideration. Productivity per unit area was noticed to be larger for discharge technology when compared with filament bulbs, for both varieties being tested. The lowest flower sprout occurrence was associated to the discharge technology with the exception of the variety Stateman produced with incandescent bulbs of 100 W in the winter plot. The unique exception related to discharge technology was associated to the White 23 W Integrated Compact Fluorescent bulb yielding 2.4% of flower sprouts compared with 0% of other bulb types associated to the production of the variety Euro Speedy. It was noticed from the results that the yellow integrated compact

  13. Effect of temperature on biomass allocation in seedlings of two contrasting genotypes of the oilseed crop Ricinus communis

    NARCIS (Netherlands)

    Ribeiro de Jesus, P.R.; Zanotti, R.F.; Deflers, C.; Fernandez, L.G.; Castro, De R.D.; Ligterink, W.; Hilhorst, H.W.M.

    2015-01-01

    Ricinus communis is becoming an important crop for oil production, and studying the physiological and biochemical aspects of seedling development may aid in the improvement of crop quality and yield. The objective of this study was to assess the effect of temperature on biomass allocation in two R.

  14. Pre-sowing application of ascorbic acid and salicylic acid to seed of pumpkin and seedling response to salt

    International Nuclear Information System (INIS)

    Rafique, N.; Raza, S.H.; Qasim, M.; Iqbal, N.

    2011-01-01

    The effects of seed soaking with salicylic acid or ascorbic acid on pumpkin seedlings growth under saline (10 dS m/sup -1/) conditions were investigated. Seedlings fresh weight, protein contents, protease and nitrate reductase activities were significantly affected by 15 and 30 mg L/sup -1/ salicylic acid and 30 mg L/sup -1/ ascorbic acid priming treatments, under both normal and saline conditions. Priming reduced the severity of the salt stress, the amelioration was better due to 30 mg L/sup -1/ ascorbic acid or 30 mg L/sup -1/ salicylic acid treatments as these treatments showed best results on seedling growth, fresh and dry matter production under non-saline and saline environments. Application of seed priming with ascorbic acid and salicylic acid in pumpkin ameliorate the adverse effects of salt stress. (author)

  15. 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

  16. 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.

  17. 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.

  18. Efecto del Compost de Biosólidos en la producción de plantines de Austrocedrus Chilensis (ciprés de la cordillera Effect of Biosolids Compost on seedling production of Austrocedrus Chilensis (ciprés de la cordillera

    Directory of Open Access Journals (Sweden)

    Gustavo Basil

    2009-06-01

    during the subsequent two years of a unique treatment with 50% compost on the posterior growth and nutritional status of the seedlings. Diameter and height were measured after 18, 25 and 37 months, shoot and root biomass after 25 and 37 months, and the foliar concentrations of C, N, P, K, Ca and Mg after 37 months. Although all initial treatments were treated with 50% compost after one year, significant differences of diameter, height, and biomass of shoots and roots were found among the original treatments in all analyzed dates, values being higher in the compost treatments. At the end of the experiment, foliar nutrient concentrations were similar, except for Mg that was higher in the original treatment with 50% compost. Results show the importance of the initial growth on the posterior development of cypress seedlings, and the potential value of biosolids compost as a substrate for the containerized production of this species.

  19. Isolamento, seleção de bactérias e efeito de Bacillus spp. na produção de mudas orgânicas de alface Isolation, selection of bacteria, and effect of Bacillus spp. in the production of organic lettuce seedlings

    Directory of Open Access Journals (Sweden)

    Andréa M.A. Gomes

    2003-12-01

    Full Text Available Isolados bacterianos epifíticos e endofíticos, obtidos de plantas sadias de alface, foram avaliados para promoção de crescimento de mudas e plantas, respectivamente em estufa e campo de cultivo orgânico (Chã Grande-PE. Nos experimentos em estufa, foi utilizada a cultivar Verônica e em campo, as cultivares Verdinha e Verônica. Os isolados foram aplicados por bacterização simultânea nas sementes e substrato. Em campo, foram utilizados os isolados mais eficientes, C25 (Bacillus thuringiensis subvar. kenyae e C116 (Bacillus pumilus, separadamente e em mistura, após teste de compatibilidade. Em estufa, foram avaliadas a matéria fresca de raízes (MFR, da parte aérea (MFPA e total (MFT, 21 dias após a bacterização. Em campo, foi determinado o peso da matéria fresca total de plantas comercializáveis 21 e 28 dias após o transplante, respectivamente para as cultivares Verdinha e Verônica. Os mecanismos de ação de BPCP analisados foram produção de ácido indol acético, ácido cianídrico, solubilização de fosfatos e alterações dos teores foliares dos macronutrientes, N, P, K, Ca e Mg. Em estufa, as mudas apresentaram aumento significativo em relação à testemunha para MFR, MFPA e MFT quando foi utilizado o isolado C116 e para MFR e MFT utilizando-se o C25. No campo, não houve promoção significativa no crescimento nas plantas das cultivares Verdinha e Verônica, tratadas com C25 e C116 separadamente ou em mistura. Dos mecanismos de ação analisados verificou-se apenas elevação significativa (P=0,05 do teor foliar de N pelo isolado C25.Epiphytic and endophytic bacterial strains isolated from healthy lettuce plants were evaluated for growth promotion of seedlings and plants respectively under greenhouse and field conditions of organic production of lettuce, in Brazil. The cultivar Verônica was utilized in the greenhouse experiments and cvs. Verônica and Verdinha were evaluated in the field. The strains were applied by

  20. 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....

  1. Produção de frutanos em calos e plântulas clonadas in vitro de Viguiera discolor Baker (Asteraceae Fructan production in callus and in vitro cloned seedlings of Viguiera discolor Baker (Asteraceae

    Directory of Open Access Journals (Sweden)

    Nair Massumi Itaya

    2005-09-01

    Full Text Available Viguiera discolor Baker é uma espécie nativa do cerrado, cuja sobrevivência está ameaçada pela invasão de espécies exóticas. Considerando sua elevada produção e a vasta aplicação de frutanos, o presente trabalho foi conduzido visando à obtenção in vitro dessa espécie e à prospecção desses carboidratos nessas condições. Sementes foram germinadas in vitro, em meio MS modificado, e após cinco semanas de incubação, nós caulinares foram isolados e incubados no mesmo meio adicionado de 0,5 mg L-1 de ANA, regenerando plantas uniformes, raízesnão espessadas, raízes tuberosas e estruturas semelhantes a calo (calo tipo1, formadas na região caulinar basal. Análise desse material evidenciou a presença de frutanos do tipo inulina nas raízes tuberosas e nos calos tipo 1. Na presença de 2,4-D obteve-se a formação de calos friáveis (calo tipo 2, nos quais também foram detectados frutanos e suas enzimas de síntese sacarose: sacarose 1-frutosiltransferase (SST e frutano: frutano 1-frutosiltransferase (FFT. Embora em concentrações menores às observadas nas plantas cultivadas sob condições naturais, o material produzido in vitro apresentou frutanos do mesmo tipo e razão SST/FFT menor do que um. Em meio de cultura sem hormônios, foi verificada a regeneração de 50% de plantas a partir dos nós caulinares. A propagação de V. discolor in vitro pode viabilizar a multiplicação e a preservação da espécie, bem como a produção de frutanos nessas condições.Viguiera discolor Baker is a herbaceous species, native to cerrado and its survival has been threatened by the invasion of exotic species. Considering its high production and the wide application of fructans, the present work has aimed to establish in vitro culture of this species and to investigate the presence of fructans under these conditions. Seeds were germinated in vitro on modified MS medium and after plant growth, stem nodes were isolated and incubated on

  2. Implications of Child Labour for Agricultural Production, Productivity ...

    African Journals Online (AJOL)

    2008-05-02

    May 2, 2008 ... Cameroon confirms that the productivity of food crop-based and cash crop-based ... crops approximately 46% women contributed to the total labour required as against 33% ..... capital, seedlings, maintenance and marketing.

  3. Degradation of 14C-Lindane(gamma-hexachlorocyclohexane) in Corn and Soya Bean Seedlings

    International Nuclear Information System (INIS)

    Afifi, M.L.

    2003-01-01

    The degradation of lindane (gamma-hexachlorocyclohexane,(gamma-HCH) by corn and soya bean seedlings has been studied. Following root application, anumber of metabolic products were identified utilizing Gas-liquid chromatography and GLC-mass spectrometry. In corn seedlings, these metabolites proved to be m-dichlorobenzene;1,2,4-trichlorobenzene; 1,2,4,5-tetrachlorobenzene; 2,4,5-and 2,3,5-trichlorophenols and gamma-pentachlorocyclohex-1-ene as compared with the standards. In soya bean seedlings, however, while 1,2,3,4-tetrachlorobenzene and 2,3,5-trichlorophenol were missing, 1,2,3-trichlorobenzene and 2,4,6-trichlorophenol were produced. Of the total chlorinated compounds found in hexane extracts, these metabolic products accounted for 30-35%. The amount of trichlorophenols which contributed to 38% and 16% of the metabolic output in corn and peas respectively, provided futher evidence that the degrading pathways in monocots might differ from these in dicots. The results also show that in both plant tissues dechlorination generally took place and represented adominant intermediary detoxification process

  4. Arsenic toxicity in Acacia mangium willd. and mimosa Caesalpiniaefolia benth. seedlings

    Directory of Open Access Journals (Sweden)

    Henrique Nery Cipriani

    2013-10-01

    Full Text Available Acacia mangium and Mimosa caesalpiniaefolia are fast-growing woody fabaceous species that might be suitable for phytoremediation of arsenic (As-contaminated sites. To date, few studies on their tolerance to As toxicity have been published. Therefore, this study assessed As toxicity symptoms in A. mangium and M. caesalpiniaefolia seedlings under As stress in a greenhouse. Seedlings of Acacia mangium and M. caesalpiniaefolia were grown for 120 d in an Oxisol-sand mixture with 0, 50, 100, 200, and 400 mg kg-1 As, in four replications in four randomized blocks. The plants were assessed for visible toxicity symptoms, dry matter production, shoot/root ratio, root anatomy and As uptake. Analyses of variance and regression showed that the growth of A. mangium and M. caesalpiniaefolia was severely hindered by As, with a reduction in dry matter production of more than 80 % at the highest As rate. The root/shoot ratio increased with increasing As rates. At a rate of 400 mg kg-1 As, whitish chlorosis appeared on Mimosa caesalpiniaefolia seedlings. The root anatomy of both species was altered, resulting in cell collapse, death of root buds and accumulation of phenolic compounds. Arsenic concentration was several times greater in roots than in shoots, with more than 150 and 350 mg kg-1 in M. caesalpiniaefolia and A. mangium roots, respectively. These species could be suitable for phytostabilization of As-contaminated sites, but growth-stimulating measures should be used.

  5. Characterization of nutrient deficiency in Hancornia speciosa Gomes seedlings by omitting micronutrients from the nutrient solution

    Directory of Open Access Journals (Sweden)

    Layara Alexandre Bessa

    2013-06-01

    Full Text Available Hancornia speciosa Gomes (Mangaba tree is a fruit tree belonging to the Apocynaceae family and is native to Brazil. The production of seedlings of this species is limited by a lack of technical and nutritional expertise. To address this deficiency, this study aimed to characterize the visual symptoms of micronutrient deficiency and to assess growth and leaf nutrient accumulation in H. speciosa seedlings supplied with nutrient solutions that lack individual micronutrients. H. speciosa plants were grown in nutrient solution in a greenhouse according to a randomized block design, with four replicates. The treatments consisted of a group receiving complete nutrient solution and groups treated with a nutrient solution lacking one of the following micronutrients: boron (B, copper (Cu, iron (Fe, manganese (Mn, zinc (Zn, and molybdenum (Mo. The visual symptoms of nutrient deficiency were generally easy to characterize. Dry matter production was affected by the omission of micronutrients, and the treatment lacking Fe most limited the stem length, stem diameter, root length, and number of leaves in H. speciosa seedlings as well as the dry weight of leaves, the total dry weight, and the relative growth in H. speciosa plants. The micronutrient contents of H. speciosa leaves from plants receiving the complete nutrient solution treatment were, in decreasing order, Fe>Mn>Cu>Zn>B.

  6. Association and mycorrhizal dependency in Jatropha curcas L. seedlings under salt stress

    Directory of Open Access Journals (Sweden)

    Dilliani Felipe Barros de Oliveira

    Full Text Available ABSTRACT The cultivation of Jatropha curcas L. for biodiesel production is possible in salinized areas; however, biomass production is limited in these soils. Arbuscular mycorrhizal fungi (AMF are a promising alternative for bioremediation in salinized soils. Yet, salinity also affects the AMF at the time of colonization and, in this case, the symbiosis is not always established. Therefore, the aim of this study was to test the hypotheses that three AMF species commonly found in saline soils are associated with J. curcas and if seedlings previously inoculated with these AMF are more tolerant to salt stress. Two trials were performed: the first one was carried out in a completely randomized design with five treatments (control, Rhizophagus intraradices, Gigaspora albida, Claroideoglomus etunicatum, and the three species together and six repetitions to investigate the formation of symbiosis among species; and the second trial was carried out in randomized blocks in a 4 × 2 factorial scheme (2, 5, 8, and 10 dS m-1, with and without mycorrhizae with eight repetitions to verify the development and mycorrhizal dependency (MD of the seedlings previously inoculated, in salinized environment. The three species of AMF are associated with J. curcas both alone and together. Mycorrhizal dependency increased with salinity, indicating that J. curcas is a facultative species. The pre-colonized seedlings with AMF are an alternative to the establishment of J. curcas in salinized soils.

  7. Produção de mudas de espécies forrageiras no sistema hidropônico de leito flutuante (floating com solução nutritiva à base de biofertilizante ou adubo solúvel = Production of seedlings of forage species in floating hydroponics system with biofertilizer or soluble fertilizer

    Directory of Open Access Journals (Sweden)

    Ricardo Probst

    2009-10-01

    Full Text Available Neste trabalho objetivou-se avaliar a sobrevivência das estacas e a produção de matéria seca na fase de cultivo de mudas das espécies forrageiras missioneira gigante (Axonopus catharinensis, amendoim forrageiro (Arachis pintoi e maku (Lotus uliginosus cv. Maku. No sistema hidropônico de leito flutuante com solução nutritiva à base de biofertilizante ou adubo solúvel. O delineamento experimental adotado foi o de blocos ao acaso em esquema fatorial 3 x 2, sendo três espécies forrageiras e duas soluções nutritivas. As espécies não apresentaram diferença quanto à sobrevivência (p = 0,225, independentemente do tipo de fertilizante (p = 0,92. No entanto, quando se quantificou a produção de MS planta-1 proporcionada por cada uma dessas espécies, o maku (p = 0,001 obteve as maiores quantidades (47,18 g, enquanto o amendoim forrageiro (19,90 g e a missioneira gigante (16,81 g foram semelhantes entre si (p = 0,227, tendo o mesmo ocorrido entre os fertilizantes (p = 0,559. Deste modo, as três espécies possuem condições semelhantes de sobrevivência, independentemente da concentração de nutrientes da solução nutritiva, com o maku proporcionando a maior produção de MS planta-1.The aim of this work was to evaluate the survival and dry matter production during the seedling culture phase of three forage species: Axonopus catharinensis, forage peanut (Arachis pintoi, and greater lotus (Lotus uliginosus cv. Maku, in a floating hydroponic system using biofertilizer or soluble fertilizer. The experimental design adopted was randomized blocks in a 3 x 2 factorial scheme, with three forage species and two fertilizers. There was no difference between species with regard to survival (p = 0.225, regardless of the fertilizer used (p = 0.92. However, when dry matter production was considered, Maku (P=0,001 showed greater weight (47.18 g, while there was no difference (p = 0.227 in weight between Arachis pintoi (19.90 g and Axonopus

  8. 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.

  9. 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.

  10. 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

  11. Bacillus subtilis and Enterobacter cloacae endophytes from healthy Theobroma cacao L. trees can systemically colonize seedlings and promote growth.

    Science.gov (United States)

    Leite, Hianna Almeida Câmara; Silva, Anderson Barbosa; Gomes, Fábio Pinto; Gramacho, Karina Peres; Faria, José Cláudio; de Souza, Jorge Teodoro; Loguercio, Leandro Lopes

    2013-03-01

    Clonal genotypes resistant to fungal diseases are an important component of the cocoa production system in southeastern Bahia state (Brazil), so that technologies for faster production of stronger and healthier plantlets are highly desirable. In this study, the effects of inoculated bacterial endophytes isolated from healthy adult cacao plants on seedlings, and aspects related to inoculation methods, colonization patterns, and photosynthesis were investigated. Sequencing of 16S rRNA, hsp-60, and rpo-B genes placed the wild-type isolates within the species Enterobacter cloacae (isolates 341 and 344) and Bacillus subtilis (isolate 629). Spontaneous rifampicin-resistant (rif(R)) variants for 344 were also produced and tested. Endophytic application was either by immersion of surface sterilized seeds in bacterial suspensions or direct inoculation into soil, 20 days after planting non-inoculated seeds into pots. Results from in vitro recovery of inoculated isolates showed that the wild-type endophytes and rif(R) variants systemically colonized the entire cacao seedlings in 15-20 days, regardless of the inoculation method. Some endophytic treatments showed significant increases in seedlings' height, number of leaves, and dry matter. Inoculation methods affected the combined application of endophytes, which maintained the growth-promotion effects, but not in the same manner as in single applications. Interestingly, the 344-3.2 rif(R) variant showed improved performance in relation to both the wild type and another related variant. Photosynthetic rates and stomatal conductance increased significantly for some endophytic treatments, being partially associated with effects on growth and affected by the inoculation method. The results suggest that E. cloacae and B. subtilis endophytes from healthy adult plants (not transmitted by seeds) were able to promote vegetative growth on cacao seedlings. The development of products for large-scale use in seedlings

  12. Drought stress leads to systemic induced susceptibility to a nectrotrophic fungus associated with mountain pine beetle in Pinus banksiana seedlings.

    Science.gov (United States)

    Klutsch, Jennifer G; Shamoun, Simon Francis; Erbilgin, Nadir

    2017-01-01

    Conifers have complex defense responses to initial attacks by insects and pathogens that can have cascading effects on success of subsequent colonizers. However, drought can affect a plant's ability to respond to biotic agents by potentially altering the resources needed for the energetically costly production of induced defense chemicals. We investigated the impact of reduced water on induced chemical defenses of jack pine (Pinus banksiana) seedlings from initial attack by biotic agents and resistance to subsequent challenge inoculation with a pathogenic fungal associate of mountain pine beetle (Dendroctonus ponderosae), Grosmannia clavigera. Applications of phytohormones (methyl salicylate and methyl jasmonate) and G. clavigera were used for initial induction of defenses. Monoterpene concentrations varied with initial induction from fungal and phytohormone application while watering treatment had no effect. Seedlings treated with G. clavigera and methyl jasmonate had the greatest monoterpene concentrations compared to the control and methyl salicylate-treated seedlings. However, the monoterpene response to the challenge inoculation varied with watering treatments, not with prior induction treatments, with lower monoterpene concentrations in fungal lesions on seedlings in the low to moderate watering treatments compared to normal watering treatment. Furthermore, prior induction from phytohormones resulted in systemic cross-induction of resistance to G. clavigera under normal watering treatment but susceptibility under low watering treatment. Seedlings stressed by low water conditions, which also had lower stomatal conductance than seedlings in the normal watering treatment, likely allocated resources to initial defense response but were left unable to acquire further resources for subsequent responses. Our results demonstrate that drought can affect interactions among tree-infesting organisms through systemic cross-induction of susceptibility.

  13. 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.

  14. Anatomical and morphological features of seedlings of some Cactoideae Eaton (Cactaceae Juss. species

    Directory of Open Access Journals (Sweden)

    Halyna Kalashnyk

    2016-12-01

    Full Text Available Three-month-old seedlings of 11 species of the subfamily Cactoideae (Melocactus bahiensis, Melocactus curvispinus, Echinopsis eyriesii, E. mirablis, E. peruviana, Oreocereus celsianus, Rebutia flavistyla, Rebutia minuscula, Astrophytum myriostigma, Mamillaria columbiana, and M. prolifera have been studied. These plants exhibit a uniseriate epidermis, covered by a thin cuticle. Except for E. peruviana and A. myriostigma, no hypodermis could be detected. The shoots of all studied specimens consist mainly of cortex parenchyma with large thin-walled cells. The pith parenchyma is composed of much smaller cells. Due to the fact that the cortex parenchyma comprises the largest portion of the cross-sectional area, it can be concluded that it is the main water-storing tissue. The extent of vascular tissue development varies. Collateral vascular bundles are present in the stele. The studied seedlings contain various ergastic substances, in particular inclusions of calcium oxalate (all studied species, starch (Mammillaria prolifera, E. mirabilis, and the genus Melocactus, inulin-like inclusions, and occasionally lipid drops (some Echinopsis species. Thus, it was found that all studied plants have a highly specialized anatomical and morphological structure. At the same time, the epidermis and hypodermis are poorly developed. Accordingly, the adaptation to arid conditions of the examined seedlings involves an increased growth of the water-storing tissue and the production of ergastic substances.

  15. Utilization of wood ash as seedling media of Cocoa (Theobroma cacao

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    Fitria Nugraheni Sukmawati

    2016-12-01

    Full Text Available An effort to increase productivity is provision of inorganic fertilizers. Inorganic fertilizer application in longtem as found to attenuate the availability of micronutrients and to decrease soil fertility. One possibility to replace inorganic fertilizer is the use of ash derived from plants, such as wood ash. The purpose of this study was to determine the effect of wood ash on soil K availability and to optimize the dose of wood ash which can give good influence on the growth of cocoa seedlings. The experiment was conducted at the experimental station Polytechnic LPP in Wedomartani, Sleman, Yogyakarta. The design used is non factorial randomized block design with 5 treatments, which is the ratio of ash and soil 0: 1 (A1 / Control; 0.25: 1 (A2; 0.5: 1 (A3; 0.75: 1 (A4; and 1: 1 (A5. Observations of treatment effects were made on the seedling height, number of leaves, stem diameter, wet weight and dry weight. Soil analysis was conducted to determine the content of macro elements, micro elements, and pH media. The results showed that ash increases the pH of the media to alkaline range and increase the availability of P and K soil to toxic range. Giving ash reduced the availability of N and caused chlorosis on cocoa seedlings.

  16. Environmental effects of nanosilver: impact on castor seed germination, seedling growth, and plant physiology.

    Science.gov (United States)

    Yasur, Jyothsna; Rani, Pathipati Usha

    2013-12-01

    Increasing use of nanoparticles in daily products is of great concern today, especially when their positive and negative impact on environment is not known. Hence, in current research, we have studied the impact of silver nanoparticle (AgNPs) and silver nitrate (AgNO3) application on seed germination, root, and shoot length of castor bean, Ricinus communis L. plant. Silver nanoparticles had no significant effects on seedling growth even at higher concentration of 4,000 mg L(-1), while the silver in bulk form as AgNO3 applied on the castor bean seeds inhibited the seed germination. Silver uptake in seedlings of the castor seeds on treatment with both the forms of silver was confirmed through atomic absorption spectroscopy studies. The silver nanoparticle and silver nitrate application to castor seeds also caused an enhanced enzymatic activity of ROS enzymes and phenolic content in castor seedlings. High-performance liquid chromatography analysis of individual phenols indicated enhanced content of parahydroxy benzoic acid. These kinds of studies are of great interest in order to unveil the movement and accumulation of nanoparticles in plant tissues for assessing future applications in the field or laboratory.

  17. Coupling effects of water and fertilizer on the growth characteristics of Catalpa bungei seedlings

    International Nuclear Information System (INIS)

    Jiyue, Q.; HE, J.W.Q.; Dong, L.

    2015-01-01

    In pot experiments using a rotatable central composite design, the effects of soil water content and fertilizer application, and their connection to seedling stem height (SH), ground diameter (GD), biomass yield (BY), and leaf area (LA), were examined in seedlings of Catalpa bungei clone 004-1 using response surface methodology. Our results indicated that nitrogen application (N) and the soil water content (W) had positive effects on all four growth parameters. The size sequence of the effects was N>W; however, phosphorus application (P) exerted significantly positive effects only on BY and LA. A monofactor effects analysis indicated that changes in the four parameters with increases in W, N, and P were all parabolic. Moreover, the interactions of W*N were found to have significantly positive effects on the four growth parameters, which initially increased and then decreased with increasing N when W was fixed, and with increasing W when N was fixed. The interaction of W*P had a significantly positive effect on SH. The optimized combination was determined by establishing a multi-objective decision model based on the four parameters, when the actual W, N, and P values reached 74.605% of the field capacity, 4.710 g plant-1, and 2.009 g plant-1, respectively. Under these conditions, C. bungei seedlings achieved maximum growth. These recommendations will conserve water and improve production, and they provide a basic theory for seedling culture and afforestation of C. bungei. In addition, our model fitting results showed that the biomass yield of fine roots (diameter = 2 mm) was closely correlated with SH and GD. (author)

  18. 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.

  19. Effect of Trichoderma on horticultural seedlings' growth promotion depending on inoculum and substrate type.

    Science.gov (United States)

    Marín-Guirao, J I; Rodríguez-Romera, P; Lupión-Rodríguez, B; Camacho-Ferre, F; Tello-Marquina, J C

    2016-10-01

    The biostimulant effect of Trichoderma spp. on horticultural crops are highly variable. Thus, practical use of Trichoderma sp. requires feasible formulated products and suitable substrates. This study evaluates the survival and the growth-promotion effect of a Trichoderma saturnisporum rice formulation compared with a nonformulated conidia suspension (seven treatments in total), on tomato, pepper and cucumber seedlings grown in two substrates: (i) rich in organic matter (OM) and (ii) mineral substrate without OM. The results showed beneficial effects on seedling growth in the OM-rich substrate when T. saturnisporum rice formulation (mainly at maximum concentration) was applied, but the effects were opposite when the mineral substrate without OM was used. The effects were closely linked to the level of inoculum in the substrate, which was greater upon application of the formulated inoculum as opposed to the nonformulated one. The use of rice to prepare the inoculum of T. saturnisporum seems to be promising for seedling growth in the nursery when it is applied in a substrate that is rich in organic matter, but it must be considered that under certain conditions of food shortage, Trichoderma sp. could show pathogenicity to seedlings. This study provides evidence of the complexity inherent in the use of micro-organisms in agriculture, while also confirming that the activity of the biofertilizers based on Trichoderma depends on the type of inoculum and its concentration, as well as the properties of the medium in which the fungi develop. Further studies assessing the effectiveness or possible pathogenicity of Trichoderma in different soils under greenhouse conditions must be addressed. © 2016 The Society for Applied Microbiology.

  20. Effect of SiO2 nanoparticles on drought resistance in hawthorn seedlings

    Directory of Open Access Journals (Sweden)

    Ashkavand Peyman

    2015-12-01

    Full Text Available Drought is a significant factor limiting crop production in arid regions while hawthorns (Crataegus sp. are an important component of such region’s forests. Therefore, treatments that increase hawthorn drought resistance may also increase transplanting success. Thus, the physiological and biochemical responses of hawthorn seedlings to a factorial combination of different concentrations of silica nanoparticles (SNPs at 0, 10, 50 and 100 mg L−1 and three soil moisture treatments (without stress, moderate stress and severe stress were investigated. Seedlings were irrigated with one of the four concentrations of SNPs for 45 days before exposing them to drought stress. Photosynthesis parameters, malondialdehyde (MDA, relative water content (RWC, membrane electrolyte leakage (ELI as well as chlorophyll, carotenoid, carbohydrate and proline content were determined. At the end of the experiment, positive effects by SNP pre-treatment on physiological indexes were observed during drought stress. Under drought conditions, the effect of SNPs on photosynthetic rate and stomatal conductance was evident. Although the SNPs increased plant biomass, xylem water potential and MDA content, especially under drought conditions, RWC and ELI were not affected by the SNP pre-treatments. Seedlings pre-treated with SNPs had a decreased carbohydrate and proline content under all water regimes, but especially so under drought. Total chlorophyll content and carotenoid content did not change among the treatments. Generally, the findings imply that SNPs play a positive role in maintaining critical physiological and biochemical functions in hawthorn seedlings under drought stress conditions. However, more studies are needed before the physiological and biochemical basis of induced drought resistance can be determined.

  1. 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...

  2. 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...

  3. 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.

  4. 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.

  5. 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.

  6. 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 ...

  7. 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.

  8. 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.

  9. 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).

  10. 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 ...

  11. 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...

  12. 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...

  13. 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.

  14. 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...

  15. Produção de mudas de espécies forrageiras no sistema hidropônico de leito flutuante (floating com solução nutritiva à base de biofertilizante ou adubo solúvel - DOI: 10.4025/actascianimsci.v31i4.4290 Production of seedlings of forage species in floating hydroponics system with biofertilizer or soluble fertilizer - DOI: 10.4025/actascianimsci.v31i4.7459

    Directory of Open Access Journals (Sweden)

    Júlio Graeff Erpen

    2009-10-01

    Full Text Available Neste trabalho objetivou-se avaliar a sobrevivência das estacas e a produção de matéria seca na fase de cultivo de mudas das espécies forrageiras missioneira gigante (Axonopus catharinensis, amendoim forrageiro (Arachis pintoi e maku (Lotus uliginosus cv. Maku. No sistema hidropônico de leito flutuante com solução nutritiva à base de biofertilizante ou adubo solúvel. O delineamento experimental adotado foi o de blocos ao acaso em esquema fatorial 3 x 2, sendo três espécies forrageiras e duas soluções nutritivas. As espécies não apresentaram diferença quanto à sobrevivência (p = 0,225, independentemente do tipo de fertilizante (p = 0,92. No entanto, quando se quantificou a produção de MS planta-1 proporcionada por cada uma dessas espécies, o maku (p = 0,001 obteve as maiores quantidades (47,18 g, enquanto o amendoim forrageiro (19,90 g e a missioneira gigante (16,81 g foram semelhantes entre si (p = 0,227, tendo o mesmo ocorrido entre os fertilizantes (p = 0,559. Deste modo, as três espécies possuem condições semelhantes de sobrevivência, independentemente da concentração de nutrientes da solução nutritiva, com o maku proporcionando a maior produção de MS planta-1.Production of seedlings of forage species in floating hydroponics system with biofertilizer or soluble fertilizer. The aim of this work was to evaluate the survival and dry matter production during the seedling culture phase of three forage species: Axonopus catharinensis, forage peanut (Arachis pintoi, and greater lotus (Lotus uliginosus cv. Maku, in a floating hydroponic system using biofertilizer or soluble fertilizer. The experimental design adopted was randomized blocks in a 3 x 2 factorial scheme, with three forage species and two fertilizers. There was no difference between species with regard to survival (p = 0.225, regardless of the fertilizer used (p = 0.92. However, when dry matter production was considered, Maku (p = 0,001 showed greater

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Effects of Drought Stress and Ozone Exposure on Isoprene Emissions from Oak Seedlings in Texas

    Science.gov (United States)

    Madronich, M. B.; Harte, A.; Schade, G. W.

    2014-12-01

    Isoprene is the dominant hydrocarbon emitted by plants to the atmosphere with an approximate global emission of 550 Tg C yr-1. Isoprene emission studies have elucidated plants' isoprene production capacity, and the controlling factors of instantaneous emissions. However, it is not yet well understood how long-term climatic factors such as drought and increasing ozone concentrations affect isoprene emission rates. Drought reduces photosynthetic activity and is thus expected to reduce isoprene emission rate, since isoprene production relies on photosynthates. On the other hand, ozone is also known to negatively affect photosynthesis rates, but can instead increase isoprene emissions. These apparent inconsistencies and a lack of experimental data make it difficult to accurately parameterize isoprene emission responses to changing environmental conditions. The objective of this work is to reduce some of these uncertainties, using oak seedlings as a study system. Our project focuses on isoprene emission responses of oak trees to typical summer drought and high ozone conditions in Texas. We report on experiments conducted using a laboratory whole-plant chamber and leaf-level data obtained from greenhouse-grown seedlings. The chamber experiment studied the effects of ozone and drought on isoprene emissions from >3 year old oak seedlings under controlled conditions of photosynthetically active radiation (PAR), temperature, soil-moisture and the chamber's air composition. Stress in plants was induced by manipulating potted soil-moisture and ozone concentration in the chamber. The greenhouse study focused on understanding the effects of drought under Texas climatic conditions. For this study we used two year old seedlings of water oak (Quercus nigra) and post oak (Quercus stellata). Temperature, humidity and light in the greenhouse followed local conditions. Leaf-level conductance, photosynthesis measurements and isoprene sampling were carried out under controlled leaf

  1. The effect of container volume on seedling production and initial growth of Jatropha curcas L. on the Western ParanaEfeito do volume do recipiente na produção de mudas e no crescimento inicial de Jatropha curcas L. no Oeste Paranaense

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    Michelle Cristina Ajala

    2012-12-01

    Full Text Available The effect of container volume on seedling production and initial growth of Jatropha curcas L. on the Western ParanaEste trabalho objetivou comparar a influência do volume de recipientes na produção de mudas e no crescimento, durante o primeiro ano, de pinhão manso no oeste paranaense. A produção de mudas no viveiro utilizou saco plástico de 1.178 cm3 e tubetes de 120 e 180 cm3 preenchidos com substrato comercial. As mensurações quinzenais incluíram os incrementos em altura, diâmetro do coleto e área foliar. Após o plantio foram avaliados os incrementos no número de folhas, de ramificações e a porcentagem de sobrevivência trimestral. Ao final da fase de viveiro, o maior incremento em altura (1,56 cm e em diâmetro do coleto (1,3 mm foi obtido nas mudas de J. curcas conduzidas em saco plástico com volume de 1.178 cm3, enquanto que os valores para mudas em tubetes de 180 cm3 e 120 cm3 resultaram em 1,24 cm e 1,2 mm e 1,48 cm e 1,1 mm, respectivamente. Após o plantio, não foram verificadas diferenças nos incrementos trimestrais em altura, diâmetro de colo, número de folhas, número de ramos (primários e secundários e porcentagem de mortalidade em função do volume dos recipientes utilizados para a formação das mudas. Os incrementos observados no primeiro trimestre após o plantio apresentaram os maiores valores em diâmetro do coleto, número de folhas, e mortalidade. Mudas de J.curcas semeadas no final de agosto, conduzidas em viveiro de setembro a novembro em tubetes de 120 cm3, e plantadas em dezembro em solo PVd da região oeste do Estado do Paraná resultam em crescimento equivalente ao de mudas produzidas em recipientes de maior volume com economia de substrato, espaço de viveiro e esforço no plantio.

  2. QTLs for seedling traits under salinity stress in hexaploid wheat

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    Yongzhe Ren

    2018-03-01

    Full Text Available ABSTRACT: Soil salinity limits agricultural production and is a major obstacle for increasing crop yield. Common wheat is one of the most important crops with allohexaploid characteristic and a highly complex genome. QTL mapping is a useful way to identify genes for quantitative traits such as salinity tolerance in hexaploid wheat. In the present study, a hydroponic trial was carried out to identify quantitative trait loci (QTLs associated with salinity tolerance of wheat under 150mM NaCl concentration using a recombinant inbred line population (Xiaoyan 54×Jing 411. Values of wheat seedling traits including maximum root length (MRL, root dry weight (RDW, shoot dry weight (SDW, total dry weight (TDW and the ratio of TDW of wheat plants between salt stress and control (TDWR were evaluated or calculated. A total of 19QTLs for five traits were detected through composite interval mapping method by using QTL Cartographer version 2.5 under normal and salt stress conditions. These QTLs distributed on 12 chromosomes explained the percentage of phenotypic variation by individual QTL varying from 7.9% to 19.0%. Among them, 11 and six QTLs were detected under normal and salt stress conditions, respectively and two QTLs were detected for TDWR. Some salt tolerance related loci may be pleiotropic. Chromosome 1A, 3A and 7A may harbor crucial candidate genes associated with wheat salt tolerance. Our results would be helpful for the marker assisted selection to breed wheat varieties with improved salt tolerance.

  3. Dormancy overcome and seedling quality of pecan in nursery

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    Tales Poletto

    Full Text Available ABSTRACT: This study evaluated the efficiency of methods to overcome seed dormancy in different storage periods in the production of pecan seedlings. Seeds were submitted to the following treatments: T1, T4 and T7 - control treatments (seeds with no treatment, stored at room temperature for 30, 60 and 90 days, respectively, T2, T5 and T8 - stratification (seeds were distributed in boxes with wet sand maintained at a temperature of 4°C for 30, 60 and 90 days, respectively, T3, T6 and T9 - scarification + stratification (seeds scarified with sandpaper n.80 and stratified by 30, 60 and 90 days, respectively, in completely random experimental design. Plant height, stem diameter, number of leaves, full emergence and emergence speed index (ESI were evaluated after 14 weeks of sowing. The best development of pecan 'plants, their emergence, and ESI were observed in the stratification treatment for 90 day as well as in the scarification + stratification treatment for 90 day. Storing seeds in uncontrolled environment reduced their viability.

  4. Substrates of Mauritia flexuosa and wastewater from pig farming on growth and quality in seedlings of Acacia mangium

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    Emanuel França Araújo

    Full Text Available ABSTRACT Sustainable alternatives should be adopted to minimise the negative environmental impacts of agricultural activities. The use of wastewater as well as organic waste, from agricultural activities or found naturally, such as the decomposed stems of the Buriti palm (Mauritia flexuosa, can be a sustainable alternative in the production of seedlings for the reforestation of areas in the process of degradation or desertification, common in the State of Piauí, Brazil. The aim of this study was to evaluate growth and quality in seedlings of Acacia mangium Willd grown in substrates with different proportions of decomposed stems of Mauritia flexuosa (DSB, and irrigated with wastewater from pig farming (WPF. The experimental design was completely randomised, arranged in a 5 x 2 factorial scheme, corresponding to five proportions of DSB and soil (v/v,% - 0:100, 20:80, 40:60, 60:40, 80:20, and two sources of irrigation water (well water and WPF, with four replications. At 100 days after sowing (DAS, the seedlings were collected to measure the variables related to growth, quality and nodulation. Height, root collar diameter, shoot dry weight, leaf area and nitrogen accumulation in the shoots were significantly influenced (p≤0.05 by the interaction between substrate and source of irrigation water. The WPF had no significant influence on the growth or quality of the Acacia mangium Willd seedlings. The best ratio between DSB substrate and soil was 46:54, considered the most suitable for seedling production in Acacia mangium Willd.

  5. 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)

  6. Effects of sodium nitroprusside (SNP) pretreatment on UV-B stress tolerance in lettuce (Lactuca sativa L.) seedlings.

    Science.gov (United States)

    Esringu, Aslıhan; Aksakal, Ozkan; Tabay, Dilruba; Kara, Ayse Aydan

    2016-01-01

    Ultraviolet-B (UV-B) radiation is one of the most important abiotic stress factors that could influence plant growth, development, and productivity. Nitric oxide (NO) is an important plant growth regulator involved in a wide variety of physiological processes. In the present study, the possibility of enhancing UV-B stress tolerance of lettuce seedlings by the exogenous application of sodium nitroprusside (SNP) was investigated. UV-B radiation increased the activities of superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX), peroxidase (POD) and total phenolic concentrations, antioxidant capacity, and expression of phenylalanine ammonia lyase (PAL) gene in seedlings, but the combination of SNP pretreatment and UV-B enhanced antioxidant enzyme activities, total phenolic concentrations, antioxidant capacity, and PAL gene expression even more. Moreover, UV-B radiation significantly inhibited chlorophylls, carotenoid, gibberellic acid (GA), and indole-3-acetic acid (IAA) contents and increased the contents of abscisic acid (ABA), salicylic acid (SA), malondialdehyde (MDA), hydrogen peroxide (H2O2), and superoxide radical (O2•(-)) in lettuce seedlings. When SNP pretreatment was combined with the UV-B radiation, we observed alleviated chlorophylls, carotenoid, GA, and IAA inhibition and decreased content of ABA, SA, MDA, H2O2, and O2•(-) in comparison to non-pretreated stressed seedlings.

  7. Responses of neotropical mangrove seedlings grown in monoculture and mixed culture under treatments of hydroperiod and salinity

    Science.gov (United States)

    Cardona-Olarte, P.; Twilley, R.R.; Krauss, K.W.; Rivera-Monroy, V.

    2006-01-01

    We investigated the combined effects of salinity and hydroperiod on seedlings of Rhizophora mangle and Laguncularia racemosa grown under experimental conditions of monoculture and mixed culture by using a simulated tidal system. The objective was to test hypotheses relative to species interactions to either tidal or permanent flooding at salinities of 10 or 40 g/l. Four-month-old seedlings were experimentally manipulated under these environmental conditions in two types of species interactions: (1) seedlings of the same species were grown separately in containers from September 2000 to August 2001 to evaluate intraspecific response and (2) seedlings of each species were mixed in containers to evaluate interspecific, competitive responses from August 2002 to April 2003. Overall, L. racemosa was strongly sensitive to treatment combinations while R. mangle showed little effect. Most plant responses of L. racemosa were affected by both salinity and hydroperiod, with hydroperiod inducing more effects than salinity. Compared to R. mangle, L. racemosa in all treatment combinations had higher relative growth rate, leaf area ratio, specific leaf area, stem elongation, total length of branches, net primary production, and stem height. Rhizophora mangle had higher biomass allocation to roots. Species growth differentiation was more pronounced at low salinity, with few species differences at high salinity under permanent flooding. These results suggest that under low to mild stress by hydroperiod and salinity, L. racemosa exhibits responses that favor its competitive dominance over R. mangle. This advantage, however, is strongly reduced as stress from salinity and hydroperiod increase. ?? Springer 2006.

  8. Produção de mudas de dois genótipos de alecrim-de-tabuleiro (Lippia gracilis Schauer em função de fertilizante mineral, calcário, substratos e recipientes Seedling production of two "alecrim-de-tabuleiro" (Lippia gracilis Schauer genotypes under mineral fertilizer, limestone, substrates and containers

    Directory of Open Access Journals (Sweden)

    A.C.L Oliveira

    2011-01-01

    produção de mudas de L. gracilis via estaquia.Commonly known as "alecrim-de-tabuleiro", Lippia gracilis Schauer (Verbenaceae has moderate antibacterial, antimicrobial and antiseptic activity. This study aimed to evaluate the effect of doses of mineral fertilizer, limestone, substrates and containers on seedling production of two "alecrim-de-tabuleiro" genotypes, using cuttings. In experiment 1, apical cuttings were distributed on expanded polystyrene trays of 128 cells containing coir + sand (1:1, using three replicates of eight cuttings each. Experimental design was in randomized blocks, in a 4x2x2 factorial arrangement, i.e. four doses of fertilizer (6-24-12 + micronutrients (1, 2, 3 and 4 g L-1, two doses of limestone (0 and 1 g L-1 and two genotypes (LGRA106 and LGRA201. At 35 days after planting, we evaluated survival (%, rooting (%, root length (cm and root dry matter (mg. In experiment 2, three replicates of eight cuttings each were used. Experimental design was in randomized blocks, in a split-plot scheme. In the plots, we tested two containers (expanded polystyrene tray of 128 cells and 110 cm³ tubets. In the subplots, we tested four substrate combinations [coir, coir + sand (1:1, coir + sand (2:1 and coir + sand (3:1] and two genotypes (LGRA106 and LGRA201. At 35 days after planting, the same variables of experiment 1 were evaluated, besides shoot length (cm and shoot dry matter (mg. The use of 1 g L-1 fertilizer without limestone was effective for plant survival and cutting rooting. Based on these experiments, the genotype LGRA106 is superior to LGRA201 as to the evaluated variables and the expanded polystyrene tray is recommended for the production of L. gracilis seedlings through cuttings.

  9. 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

  10. Water Deficit and Abscisic Acid Cause Differential Inhibition of Shoot versus Root Growth in Soybean Seedlings : Analysis of Growth, Sugar Accumulation, and Gene Expression.

    Science.gov (United States)

    Creelman, R A; Mason, H S; Bensen, R J; Boyer, J S; Mullet, J E

    1990-01-01

    Roots often continue to elongate while shoot growth is inhibited in plants subjected to low-water potentials. The cause of this differential response to water deficit was investigated. We examined hypocotyl and root growth, polysome status and mRNA populations, and abscisic acid (ABA) content in etiolated soybean (Glycine max [L.] Merr. cv Williams) seedlings whose growth was inhibited by transfer to low-water potential vermiculite or exogenous ABA. Both treatments affected growth and dry weight in a similar fashion. Maximum inhibition of hypocotyl growth occurred when internal ABA levels (modulated by ABA application) reached the endogenous level found in the elongating zone of seedlings grown in water-deficient vermiculite. Conversely, root growth was affected to only a slight extent in low-water potential seedlings and by most ABA treatments (in some, growth was promoted). In every seedling section examined, transfer of seedlings into low-water potential vermiculite caused ABA levels to increase approximately 5- to 10-fold over that found in well-watered seedlings. Changes in soluble sugar content, polysome status, and polysome mRNA translation products seen in low-water potential seedlings did not occur with ABA treatments sufficient to cause significant inhibition of hypocotyl elongation. These data suggest that both variation in endogenous ABA levels, and differing sensitivity to ABA in hypocotyls and roots can modulate root/shoot growth ratios. However, exogenous ABA did not induce changes in sugar accumulation, polysome status, and mRNA populations seen after transfer into low-water potential vermiculite.

  11. 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.

  12. Substratos alternativos e métodos de quebra de dormência para produção de mudas de canafístula Alternative substrates and methods of breaking dormancy for the production of canafístula seedlings

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    Tiago Reis Dutra

    2013-02-01

    Full Text Available O objetivo deste estudo foi avaliar o efeito de diferentes métodos de quebra de dormência e o uso do bagaço de cana para composição de substratos alternativos, constituídos a partir da mistura de um substrato comercial, na produção de mudas de canafístula (Peltophorum dubium (Sprengel Taubert. O experimento foi conduzido em delineamento de blocos casualizados, no esquema fatorial 5 x 4, sendo cinco substratos, Bioplant®; 75% Bioplant® + 25% Bagaço de cana (75B+25BC; 50% Bioplant® + 50% Bagaço de cana (50B+50BC; 25% Bioplant® + 75% Bagaço de cana (25B+75BC; Bagaço de cana (100%, e quatro métodos de quebra de dormência (testemunha, escarificação com o uso de lixa, imersão em água quente e escarificação com ácido sulfúrico com três repetições. Foram avaliados o índice de velocidade de emergência (IVE; o tempo médio de emergência (TME; a percentagem de germinação; a altura da parte aérea; o diâmetro do coleto; a massa seca da parte aérea; a massa seca de raiz; a massa seca total; a relação altura da parte aérea/diâmetro do coleto; a relação altura da parte aérea/massa seca da parte aérea; o índice de qualidade de Dickson; a taxa de crescimento absoluto e a taxa de crescimento relativo. Os tratamentos de imersão em água quente e de escarificação com ácido sulfúrico foram responsáveis pelos maiores percentuais de emergência e IVE, além dos de menor TME. O uso do bagaço de cana mostrou-se tecnicamente viável na composição dos substratos 75B+25BC e 50B+50BC, que, juntamente ao Bioplant®, proporcionaram as maiores taxas de crescimento e os maiores índices de qualidade das mudas de canafístula.This study aimed to evaluate the effect of different methods to break dormancy and the use of sugarcane bagasse in the composition of alternative substrates made from a mixture of commercial substrate, in canafistula (Peltophorum dubium (Sprengel Taubert seedling production The experiment was carried

  13. Nitrogênio, fósforo e potássio na nutrição e no crescimento de mudas de laranjeiravalência, enxertadas sobre limoeiro cravo Effect of nitrogen, phosphorus, and potassium levels on nutrition and production of seedlings of 'Valencia' sweet orange grafted on 'cravo' lemon rootstock

    Directory of Open Access Journals (Sweden)

    Renato de Mello Prado

    2009-12-01

    (Citrus limonia Osbeck, in response to Nitrogen, Phosphorus, and Potassium levels. The experimental design was entirely randomized, in factorial scheme 3³ + 1, being 3 factors (Nitrogen, Phosphorus, and Potassium -NPK, 3 levels and a control (without fertilization with 3 replications. The experimental unit constituted of a 'Valencia' sweet orange grafted on 'Cravo' lemon rootstock in a plastic bag with 2,5 kg of substratum. The treatments consisted of half, one, and two times the standard recommended dose for production of orange seedlings (4,590, 920, and 4,380 mg bag-1 of N, P, and K, respectively. Fertilization with N and K was carried out by three weekly fertirrigations, and the P was added to the substratum of Pinus spp. bark and vermiculite before sowing. After 424 days, the plants were subdivided in roots and aerial parts for determination of dry matter, height, leaf area, diameter of stem, and nutrient content. Fertilization with N, P, and K provided for greater development and greater accumulation of these macronutrients in the aerial part and root of the 'Valencia' sweet orange grafted on 'Cravo' lemon rootstock. There was adequate development of the plants with half the recommended dose of N, P, and K according to literature, approximately of 918, 184, and 876 mg dm-3 of N, P, and K, respectively. Satisfactory development was obtained with half the recommended dose of N, P and K, in general. Slightly greater development occurred in the recommended dose of 4,590, 920, and 4,380 mg bag-1 or 918, 184, and 876 mg dm-3 of substratum, respectively.

  14. 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.

  15. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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.

  18. Allelopathic Responses of Rice Seedlings under Some Different Stresses

    Directory of Open Access Journals (Sweden)

    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.

  19. 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

  20. Effects of elevated CO2 concentration on growth and water usage of tomato seedlings under different ammonium/nitrate ratios

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Increasing atmospheric CO2 concentration is generally expected to enhance photosynthesis and growth of agricultural C3 vegetable crops,and therefore results in an increase in crop yield.However,little is known about the combined effect of elevated CO2 and N species on plant growth and development.Two growth-chamber experiments were conducted to determine the effects of NH4+/NO3- ratio and elevated CO2 concentration on the physiological development and water use of tomato seedlings.Tomato was grown for 45 d in containers with nutrient solutions varying in NH4+/NO3- ratios and CO2 concentrations in growth chambers.Results showed that plant height,stem thickness,total dry weight,dry weight of the leaves,stems and roots,G value (total plant dry weight/seedling days),chlorophyll content,photosynthetic rate,leaf-level and whole plant-level water use efficiency and cumulative water consumption of tomato seedlings were increased with increasing proportion of NO3- in nutrient solutions in the elevated CO2 treatment.Plant biomass,plant height,stem thickness and photosynthetic rate were 67%,22%,24% and 55% higher at elevated CO2 concentration than at ambient CO2 concentration,depending on the values of NH4+/NO3- ratio.These results indicated that elevating CO2 concentration did not mitigate the adverse effects of 100% NH4+-N (in nutrient solution) on the tomato seedlings.At both CO2 levels,NH4+/NO3- ratios of nutrient solutions strongly influenced almost every measure of plant performance,and nitrate-fed plants attained a greater biomass production,as compared to ammonium-fed plants.These phenomena seem to be related to the coordinated regulation of photosynthetic rate and cumulative water consumption of tomato seedlings.

  1. Putrescine catabolism via DAO contributes to proline and GABA accumulation in roots of lupine seedlings growing under salt stress

    Directory of Open Access Journals (Sweden)

    Jolanta Legocka

    2017-09-01

    Full Text Available The levels of polyamines (PAs, proline (Pro, and γ-aminobutyric acid (GABA as well as the activity of diamine oxidase (DAO; EC 1.4.3.6 were studied in the roots of 2-day-old lupine (Lupinus luteus L. ‘Juno’ seedlings treated with 200 mM NaCl for 24 h. The effect of adding 1 mM aminoguanidine (AG, an inhibitor of DAO activity, was also analyzed. It was found that in roots of lupine seedlings growing under salt stress, a negative correlation between Pro accumulation and putrescine (Put content takes place. Pro level increased in roots by about 160% and, at the same time, Put content decreased by about 60%, as a result of ca. twofold increase of DAO activity. The AG added to the seedlings almost totally inhibited the activity of DAO, increased Put accumulation to control level, decreased Pro content by about 25%, and reduced GABA level by about 22%. Addition of 50 mM GABA to the lupine seedlings growing in the presence of AG and NaCl restored Pro content in roots to its level in NaCl-treated plants. In this research, the clear correlation between Put degradation and GABA and Pro accumulation was shown for the first time in the roots of seedlings growing under salt stress. This could be considered as a short-term response of a plant to high salt concentration. Our findings indicate that during intensive Pro accumulation in roots induced by salt stress, the pool of this amino acid is indirectly supported by GABA production as a result of Put degradation.

  2. Cytokinin-producing, plant growth-promoting rhizobacteria that confer resistance to drought stress in Platycladus orientalis container seedlings.

    Science.gov (United States)

    Liu, Fangchun; Xing, Shangjun; Ma, Hailin; Du, Zhenyu; Ma, Bingyao

    2013-10-01

    One of the proposed mechanisms through which plant growth-promoting rhizobacteria (PGPR) enhance plant growth is the production of plant growth regulators, especially cytokinin. However, little information is available regarding cytokinin-producing PGPR inoculation on growth and water stress consistence of forest container seedlings under drought condition. This study determined the effects of Bacillus subtilis on hormone concentration, drought resistance, and plant growth under water-stressed conditions. Although no significant difference was observed under well-watered conditions, leaves of inoculated Platycladus orientalis (oriental thuja) seedlings under drought stress had higher relative water content and leaf water potential compared with those of noninoculated ones. Regardless of water supply levels, the root exudates, namely sugars, amino acids and organic acids, significantly increased because of B. subtilis inoculation. Water stress reduced shoot cytokinins by 39.14 %. However, inoculation decreased this deficit to only 10.22 %. The elevated levels of cytokinins in P. orientalis shoot were associated with higher concentration of abscisic acid (ABA). Stomatal conductance was significantly increased by B. subtilis inoculation in well-watered seedlings. However, the promoting effect of cytokinins on stomatal conductance was hampered, possibly by the combined action of elevated cytokinins and ABA. B. subtilis inoculation increased the shoot dry weight of well-watered and drought seedlings by 34.85 and 19.23 %, as well as the root by 15.445 and 13.99 %, respectively. Consequently, the root/shoot ratio significantly decreased, indicative of the greater benefits of PGPR on shoot growth than root. Thus, inoculation of cytokinin-producing PGPR in container seedlings can alleviate the drought stress and interfere with the suppression of shoot growth, showing a real potential to perform as a drought stress inhibitor in arid environments.

  3. Deposit of pesticides without and with adjuvants on citrus seedlings following different intervals of artificial rain

    Directory of Open Access Journals (Sweden)

    Ricardo Augusto Decaro

    2016-01-01

    Full Text Available ABSTRACT: For a crop protection product to achieve its goal, the product must be applied and remain on the leaves until it is absorbed. This situation may be compromised due to rainfall after spraying, thus necessitating reapplication which increase the overall cost. Application technology research has focused on alternatives and solutions to mitigate this effect through the use of adjuvants. The objective of this research was to evaluate the deposit of spraying liquid on citrus seedlings using the products spirodiclofen, propargite, imidacloprid, lambda cyhalothrin, copper oxychloride, and copper hydroxide with water mixed with the adjuvants polydimethylsiloxane and phosphatidylcholine. Seedlings were subjected to simulated rains of 10mm at intervals of 1, 6, 12 and 24h after spraying, and the remaining deposits of spraying liquid per leaf area were analyzed by spectrophotometry by assessing a metallic marker previously added in the spraying liquids. Variables were subjected to analysis of variance and Tukey's test (P<0.05. The rains that occurred soon after spraying resulted in decreased spraying liquids deposits on citrus leaves. Adjuvant phosphatidylcholine promoted the greatest retention of spraying liquid on citrus leaves after rainfall.

  4. The Application of Homogenate and Filtrate from Baltic Seaweeds in Seedling Growth Tests

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    Izabela Michalak

    2017-02-01

    Full Text Available Algal filtrate and homogenate, obtained from Baltic seaweeds, were applied in seedling growth tests. Radish seeds were used in order to assess algal products phytotoxicity and their biostimulant effect on growth and nutrient uptake. Algal filtrate, at concentrations ranging from 5.0% to 100% was used for seed soaking and as a liquid biostimulant (soil and foliar application. Algal homogenate was developed for seed coating. Algal filtrate and homogenate were also enriched with Zn(II ions in order to examine the influence on metal ion complexation. The optimal doses of algal filtrate and homogenate, as well as soaking time were established. Multi-elemental analyses of the raw biomass, filtrate, homogenate, and radish were also performed using ICP-OES (Inductively Coupled Plasma—Optical Emission Spectrometry. The best results in terms of seedlings’ length and weight were obtained using clear filtrate at a concentration of 50% applied to the soil and for homogenate applied at a dose of 50 mg/g of seeds. Clear filtrate at a concentration of 50% used for seed soaking for one hour showed the best results. The applied algal products increased the content of elements in seedlings. Among the tested products, a concentration of 50% algal filtrate is recommended for future pot and field experiments.

  5. Initial Response of Pine Seedlings and Weeds to Dried Sewage Sludge in Rehabilitation of an Eroded Forest Site

    Science.gov (United States)

    Charles R. Berry

    1977-01-01

    Dried sewage sludge was applied at rates of 0, 17, 34, and 69 metric tons/ha on a badly eroded forest site in the Piedmont region of northeast Georgia. Production of weed bio mass varied directly with amount of sludge applied. Heigh growth for both shortleafand loblolly pine seedlings appeared to be greater on plots receiving 17 metric tons of sludge/ha, bu differences...

  6. Cadmium and lead interactive effects on oxidative stress and antioxidative responses in rice seedlings.

    Science.gov (United States)

    Srivastava, Rajneesh Kumar; Pandey, Poonam; Rajpoot, Ritika; Rani, Anjana; Dubey, R S

    2014-09-01

    Interactive effects of two heavy metal pollutants Cd and Pb in the growth medium were examined on their uptake, production of reactive oxygen species (ROS), induction of oxidative stress and antioxidative defence responses in Indica rice (Oryza sativa L.) seedlings. When rice seedlings in sand culture were exposed to 150 μM Cd (NO3)2 or 600 μM Pb (CH3COO)2 individually or in combination for 8-16 days, a significant reduction in root/shoot length, fresh weight, relative water content, photosynthetic pigments and increased production of ROS (O2˙- and H2O2) was observed. Both Cd and Pb were readily taken up by rice roots and localisation of absorbed metals was greater in roots than in shoots. When present together in the growth medium, uptake of both the metals Cd and Pb declined by 25-40%. Scanning electron microscope (SEM) imaging of leaf stomata revealed that Pb caused more distortion in the shape of guard cells than Cd. Dithizone staining of roots showed localisation of absorbed Cd on root hairs and epidermal cells. Both Cd and Pb caused increased lipid peroxidation, protein carbonylation, decline in protein thiol and increase in non-protein thiol. The level of reduced forms of non-enzymic antioxidants glutathione (GSH) and ascorbate (AsA) and their redox ratios (GSH/AsA) declined, whereas the activities of antioxidative enzymes superoxide dismutase (SOD) and guaiacol peroxidase (GPX) increased in metal treated seedlings compared to controls. In-gel activity staining also revealed increased intensities of SOD and GPX isoforms with metal treatments. Catalase (CAT) activity increased during early days (8 days) of metal exposure and declined by 16 days. Results suggest that oxidative stress is an important component in expression of Cd and Pb toxicities in rice, though uptake of both metals gets reduced considerably when present together in the medium.

  7. THE EFFECT OF MAGNETIC LIQUIDS IN SOME TREE SEEDLINGS

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    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.

  8. 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

  9. Phylloplane bacteria of Jatropha curcas: diversity, metabolic characteristics, and growth-promoting attributes towards vigor of maize seedling.

    Science.gov (United States)

    Dubey, Garima; Kollah, Bharati; Ahirwar, Usha; Mandal, Asit; Thakur, Jyoti Kumar; Patra, Ashok Kumar; Mohanty, Santosh Ranjan

    2017-10-01

    The complex role of phylloplane microorganisms is less understood than that of rhizospheric microorganisms in lieu of their pivotal role in plant's sustainability. This experiment aims to study the diversity of the culturable phylloplane bacteria of Jatropha curcas and evaluate their growth-promoting activities towards maize seedling vigor. Heterotrophic bacteria were isolated from the phylloplane of J. curcas and their 16S rRNA genes were sequenced. Sequences of the 16S rRNA gene were very similar to those of species belonging to the classes Bacillales (50%), Gammaproteobacteria (21.8%), Betaproteobacteria (15.6%), and Alphaproteobacteria (12.5%). The phylloplane bacteria preferred to utilize alcohol rather than monosaccharides and polysaccharides as a carbon source. Isolates exhibited ACC (1-aminocyclopropane-1-carboxylic acid) deaminase, phosphatase, potassium solubilization, and indole acetic acid (IAA) production activities. The phosphate-solubilizing capacity (mg of PO 4 solubilized by 10 8 cells) varied from 0.04 to 0.21. The IAA production potential (μg IAA produced by 10 8 cells in 48 h) of the isolates varied from 0.41 to 9.29. Inoculation of the isolates to maize seed significantly increased shoot and root lengths of maize seedlings. A linear regression model of the plant-growth-promoting activities significantly correlated (p < 0.01) with the growth parameters. Similarly, a correspondence analysis categorized ACC deaminase and IAA production as the major factors contributing 41% and 13.8% variation, respectively, to the growth of maize seedlings.

  10. 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.

  11. 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

  12. 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.

  13. Fontes e proporção de material orgânico para a produção de mudas de cafeeiro em tubetes Sources and proportions of organic components for production of coffee tree seedling (Coffea arabica L. in small plastic containers

    Directory of Open Access Journals (Sweden)

    Ricardo Dias

    2009-06-01

    Full Text Available Neste trabalho, objetivou-se avaliar a qualidade das mudas de cafeeiro (Coffea arabica L. produzidas em tubetes com substrato artificial suplementado com fontes de material orgânico em diferentes proporções. O experimento foi conduzido sob delineamento experimental de blocos casualizados em esquema fatorial 3 x 6, com quatro repetições em parcelas formadas por seis tubetes. O primeiro fator correspondeu às fontes de material orgânico (esterco bovino, húmus de minhoca e cama de peru e o segundo, suas proporções (0, 20, 40, 60, 80 e 100% no substrato artificial (BioPlant-café fertilizado com osmocote® (NPK 15-09-12. As características avaliadas foram: altura da muda, diâmetro de caule, número de pares de folhas, área foliar e massa seca da parte aérea e do sistema radicular. Pode-se concluir que o húmus de minhoca adicionado ao substrato artificial na proporção de 80% ou em uso exclusivo (100% aumentou a área foliar das mudas de cafeeiro e, como conseqüência proporcionou um maior acúmulo de massa seca da parte aérea. O uso de esterco bovino (acima de 30% e a cama de peru não alterou ou reduziu as características vegetativas das mudas de cafeeiro (altura da muda, diâmetro de caule, número de pares de folhas e área foliar e diminuiu o acúmulo de massa seca.This work aimed to evaluate the quality of coffee seedlings (Coffea arabica L. produced in small plastic containers with artificial substrate supplemented with sources of organic components in different proportions. The experiment was carried out using the randomized block design, in a 3 x 6 factorial structure, with four replications in plots composed of small plastic containers. The first factor corresponded to the sources (cattle manure, earthworm casting, and turkey manure and the second to the proportions (0, 20, 40, 60, 80, and 100% in the artificial substrate (BioPlant-café® fertilized with osmocote® (NPK 15-09-12. The characteristics evaluated were

  14. Seedling Growth Strategies in Bauhinia Species: Comparing Lianas and Trees

    Science.gov (United States)

    Cai, Zhi-Quan; Poorter, Lourens; Cao, Kun-Fang; Bongers, Frans

    2007-01-01

    Background and Aims Lianas are expected to differ from trees in their growth strategies. As a result these two groups of woody species will have different spatial distributions: lianas are more common in high light environments. This study determines the differences in growth patterns, biomass allocation and leaf traits in five closely related liana and tree species of the genus Bauhinia. Methods Seedlings of two light-demanding lianas (Bauhinia tenuiflora and B. claviflora), one shade-tolerant liana (B. aurea), and two light-demanding trees (B. purpurea and B. monandra) were grown in a shadehouse at 25 % of full sunlight. A range of physiological, morphological and biomass parameters at the leaf and whole plant level were compared among these five species. Key Results The two light-demanding liana species had higher relative growth rate (RGR), allocated more biomass to leaf production [higher leaf mass fraction (LMF) and higher leaf area ratio (LAR)] and stem mass fraction (SMF), and less biomass to the roots [root mass fraction (RMF)] than the two tree species. The shade-tolerant liana had the lowest RGR of all five species, and had a higher RMF, lower SMF and similar LMF than the two light-demanding liana species. The two light-demanding lianas had lower photosynthetic rates per unit area (Aarea) and similar photosynthetic rates per unit mass (Amass) than the trees. Across species, RGR was positively related to SLA, but not to LAR and Aarea. Conclusions It is concluded that the faster growth of light-demanding lianas compared with light-demanding trees is based on morphological parameters (SLA, LMF and LAR), and cannot be attributed to higher photosynthetic rates at the leaf level. The shade-tolerant liana exhibited a slow-growth strategy, compared with the light-demanding species. PMID:17720978

  15. Arbuscular mycorrhizal fungi increase salt tolerance of apple seedlings.

    Science.gov (United States)

    Yang, Shou-Jun; Zhang, Zhong-Lan; Xue, Yuan-Xia; Zhang, Zhi-Fen; Shi, Shu-Yi

    2014-12-01

    Apple trees are often subject to severe salt stress in China as well as in the world that results in significant loss of apple production. Therefore this study was carried out to evaluate the response of apple seedlings inoculated with abuscular mycorrhizal fungi under 0, 2‰, 4‰ and 6‰ salinity stress levels and further to conclude the upper threshold of mycorrhizal salinity tolerance. The results shows that abuscular mycorrhizal fungi significantly increased the root length colonization of mycorrhizal apple plants with exposure time period to 0, 2‰ and 4‰ salinity levels as compared to non-mycorrhizal plants, however, percent root colonization reduced as saline stress increased. Salinity levels were found to negatively correlate with leaf relative turgidity, osmotic potential irrespective of non-mycorrhizal and mycorrhizal apple plants, but the decreased mycorrhizal leaf turgidity maintained relative normal values at 2‰ and 4‰ salt concentrations. Under salt stress condition, Cl - and Na + concentrations clearly increased and K + contents obviously decreased in non-mycorrhizal roots in comparison to mycorrhizal plants, this caused mycorrhizal plants had a relatively higher K + /Na + ratio in root. In contrast to zero salinity level, although ascorbate peroxidase and catalase activities in non-inoculated and inoculated leaf improved under all saline levels, the extent of which these enzymes increased was greater in mycorrhizal than in non-mycorrhizal plants. The numbers of survived tree with non-mycorrhization were 40, 20 and 0 (i.e., 66.7%, 33.3% and 0) on the days of 30, 60 and 90 under 4‰ salinity, similarly in mycorrhization under 6‰ salinity 40, 30 and 0 (i.e., 66.7%, 50% and 0) respectively. These results suggest that 2‰ and 4‰ salt concentrations may be the upper thresholds of salinity tolerance in non-mycorrhizal and mycorrhizal apple plants, respectively.

  16. Influence of stomatic aperture on photosynthetic activity of bean-seedlings leaves; Influencia de la apertura estomatica sobre la actividad fotosintetica de las hojas de plantas de judias

    Energy Technology Data Exchange (ETDEWEB)

    Suarez Moya, J; Fernandez Gonzalez, J

    1984-07-01

    The present paper contains the data of photosynthetic activity and stomatic aperture of bean-seedlings Ieaves, and the relations obtained with both results. It has been observed that the product of photosynthetic activity by the resistance; to transpiration measured by a promoter ia a constant, between some limits. (Author) 45 refs.

  17. Identification of Sweet Sorghum accessions with seedling cold tolerance using both lab cold germination test and field early Spring planting evaluation

    Science.gov (United States)

    Cultivars with quick seedling emergence and stand establishment at early spring cold conditions may be planted early in the same region with an extended period of plant growth and can potentially increase either grain yield, stem sugar yield, or biomass production of sorghum. Planting cultivars with...

  18. 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...

  19. Performance of container-grown seedlings of American chestnut backcross hybrids BC3 F3 generation in central Louisiana

    Science.gov (United States)

    Shi-Jean Susana Sung; Stacy L. Clark; Scott Schlarbaum; Daniel C. Dey; Daniel J. Leduc

    2016-01-01

    Seedlings from two families of the BC3F3 backcross generation of the American chestnut (Castanea dentata) and Chinese chestnut (C. mollissima) were cultured in 2013 in Missouri using the Root Production Method®, a container-based system used to avoid disease problems associated with...

  20. 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.

  1. 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.

  2. 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

  3. Efeito do tipo de substrato e da presença de adubação suplementar sobre o crescimento vegetativo, nutrição mineral, custo de produção e intensidade de cercosporiose em mudas de cafeeiro formadas em tubetes Effects of substrate type and supplementary fertilization on vegetative growth, mineral nutrition, production costs, and brown eye spot of coffee seedlings in stiff plastic containers

    Directory of Open Access Journals (Sweden)

    Adélia Aziz Alexandre Pozza

    2007-06-01

    Full Text Available A utilização de tubetes para produzir mudas de cafeeiro (Coffea arabica L. tornou-se uma realidade. Objetivando avaliar o uso de substratos adubados ou não com fertilizante de liberação gradual e seus efeitos na nutrição, na formação, na cercosporiose e nos custos de produção de mudas de cafeeiro em tubetes, conduziu-se um experimento em viveiro, em esquema fatorial (4x2 com quatro substratos combinados com duas adubações, tendo quatro repetições. As parcelas foram constituídas por 16 tubetes de 120 mL, considerando-se como plantas úteis as seis centrais. Os tratamentos consistiram dos substratos S1= Substrato comercial I, S2 = Substrato comercial II, S3 = Substrato de eucalipto e S4 = 80% esterco de curral + 20% terra de subsolo, todos com e sem adubação com fertilizante de liberação gradual. No geral, os melhores substratos para formação de mudas de cafeeiro em tubetes foram os substratos não comerciais ou orgânicos, independentemente de receberem ou não adubação suplementar. Observou-se redução da cercosporiose com a nutrição mineral, principalmente com o cálcio. Com a utilização de todos os substratos houve ganho econômico em relação ao custo por milheiro de mudas. A maior economia foi obtida com o substrato S4, seguida do substrato S3, com melhor relação custo/benefício.The utilization of stiff plastic containers for producing coffee seedlings (Coffea arabica L. is a reality. Aiming to evaluate the effects of substrate type enriched or not with slow-release fertilizer on vegetative growth, mineral nutrition, production cost and, brown eye spot of coffee seedlings, an experiment was conducted in the plant nursery. The experimental design was a factorial scheme with four substrates in the presence and absence of supplementary fertilization, with four replicates. The plots were made of 16 containers of 120 ml, using six central plants for evaluation. The treatments consisted of S1 = Commercial Substrate

  4. Technical and economic feasibility of the use of discharge lamps in replacement of filament for induction of photoperiod in chrysanthemum seedlings production; Viabilidade tecnico-economica do uso de lampadas de descarga em substituicao as de filamento para inducao de fotoperiodo na producao de mudas de crisantemos

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Luiz A.; David, Eduardo [Universidade Estadual de Campinas (FEAGRI/UNICAMP), SP (Brazil). Fac. de Engenharia Agricola], E-mail: rossi@feagri.unicamp.br; Pagliardi, Odail [Faculdade Municipal Prof. Franco Montoro (FMPFM), Mogi Guacu, SP (Brazil); Sarubbi, Juliana [Universidade Federal de Santa Maria (CESNORS/UFSM), Palmeira das Missoes, RS (Brazil). Centro de Educacao Superior Norte-RS

    2010-07-01

    Due to its physiological characteristics, the seedlings of chrysanthemums require supplemental light to prevent bud formation, that is done at night. This article examines the technical and economic valuation to replace the current technology of artificial lighting used by producers (incandescent bulbs) for the purpose of inducing photoperiod in a protected environment for cutting-discharge lamps, with the goal of reducing the consumption electricity used in the process. The analysis showed that the integrated compact fluorescent yellow lamp 23W is the technically and economically feasible for such replacement. (author)

  5. 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

  6. 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...

  7. 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,...

  8. 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...

  9. 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.

  10. 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.

  11. 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...

  12. 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...

  13. Changes in the glucosinolate-myrosinase defense system in Brassica juncea cotyledons during seedling development.

    Science.gov (United States)

    Wallace, S K; Eigenbrode, Sanford D

    2002-02-01

    Optimal defense theory (ODT) predicts that plant defenses will be allocated to plant organs and tissues in proportion to their relative fitness values and susceptibilities to attack. This study was designed to test ODT predictions on the myrosinase-glucosinolate defense system in Brassica juncea by examining the relationships between the fitness value of B. juncea cotyledons and the levels and effectiveness of cotyledon defenses. Specifically, we estimated fitness value of cotyledons during plant development by measuring plant growth and seed production after cotyledon damage or removal at successive seedling ages. Cotyledon removal within five days of emergence had a significant impact on growth and seed production, but cotyledon removal at later stages did not. Consistent with ODT, glucosinolate and myrosinase levels in cotyledons also declined with seedling age, as did relative defenses against a generalist herbivore, Spodoptera eridania, as estimated by bioassay. Declines in glucosinolates were as predicted by a passive, allometric dilution model based on cotyledon expansion. Declines in myrosinase activity were significantly more gradual than predicted by allometric dilution, suggesting active retention of myrosinase activity as young cotyledons expand.

  14. Growth, physiological and biochemical responses of Camptotheca acuminata seedlings to different light environments

    Directory of Open Access Journals (Sweden)

    Xiaohua eMa

    2015-05-01

    Full Text Available Light intensity critically affects plant growth. Camptotheca acuminata is a light-demanding species, but its optimum light intensity is not known. To investigate the response of C. acuminata seedlings to different light intensities, specifically 100% irradiance (PAR, 1500±30 μmol m-2 s-1, 75% irradiance, 50% irradiance, and 25% irradiance, a pot experiment was conducted to analyze growth parameters, photosynthetic pigments, gas exchange, chlorophyll fluorescence, stomatal structure and density, chloroplast ultrastructure, ROS concentrations, and antioxidant activities. Plants grown under 75% irradiance had significantly higher total biomass, seedling height, ground diameter, photosynthetic capacity, photochemical efficiency and photochemical quenching than those grown under 100%, 25%, and 50% irradiance. Malondialdehyde (MDA content, relative electrolyte conductivity (REC, superoxide anion (O2.- production, and peroxide (H2O2 content were lower under 75% irradiance. The less pronounced plant growth under 100% and 25% irradiance was associated with a decline in photosynthetic capacity and photochemical efficiency, with increases in the activity of specific antioxidants (i.e., superoxidase dismutase, peroxidase, and catalase, and with increases in MDA content and REC. Lower levels of irradiance were associated with significantly higher concentrations of chlorophyll (Chl a and b and lower Chla/b ratios. Stomatal development was most pronounced under 75% irradiance. Modification of chloroplast development was found to be an important mechanism of responding to different light intensities in C. acuminata. The results indicated that 75% irradiance is optimal for the growth of C. acuminata seedlings. The improvement in C. acuminata growth under 75% irradiance was attributable to increased photosynthesis, less accumulation of ROS, and the maintenance of the stomatal and chloroplast structure.

  15. Assessing Nitrogen Treatment Efficiency in Schima Superba Seedlings Detected Using Hyperspectral Reflectance

    Directory of Open Access Journals (Sweden)

    Miaomiao Cheng

    2014-01-01

    Full Text Available The sharp change in nitrate (N deposition fluxes due to anthropogenic influences has major consequences for terrestrial plant productivity. Early detection of plants under nitrate stress is important for forest management in the subtropical region. This study used leaf-scale hyperspectral reflectance measurements to detect the seedling growth response of Schima superba (S. superba under simulated N deposition during a period of two years. Two-year-old S. superba seedlings were planted under natural field conditions and treated with four N treatments at CK, LN-6, MN-10, and HN-24g N m-2 year-1. The chlorophyll content and leaf reflectance were examined to detect the N addition temporal effects. Results indicated that S. superba responded significantly with differences in chlorophyll content and leaf reflectance to N additional treatment. Compared with the N deficiency (CK plots, plots with higher N addition rate (HN reduced the chlorophyll concentration of S. superba seedlings. However, the long-term observed impact of LN and MN treatments increased the S. superba chlorophyll during the two years. Nitrogen additional treatments can be distinguished using the hyperspectral indices (R700/R720, R695/R420, and R695/R760 retrieved from the differences in leaf reflectance at the green spectrum and the red spectrum. The derivative shift to longer wavelength peaks with increasing N supply, accompanied by the increase in chlorophyll content. Leaf reflectance at 559 nm was negatively correlated with leaf chlorophyll content (R = -0.77. The identified N specific spectral ratios may be used for image interpretation and plant N status diagnosis for site-specific N management.

  16. Genetics of drought tolerance at seedling and maturity stages in Zea mays L

    Energy Technology Data Exchange (ETDEWEB)

    Khan, N.H.; Ahsan, M.; Naveed, M.; Sadaqat, H.A.; Javed, I.

    2016-11-01

    Shortage of irrigation water at critical growth stages of maize is limiting its production worldwide. Breeding drought-tolerant cultivars is one possible solution while identification of potential genotypes is crucial for genetic improvement. To assess genetic variation for seedling-stage drought tolerance, we tested 40 inbred lines in a completely randomized design under glasshouse conditions. From these, two contrasting inbred lines were used to develop six basic generations (P1, P2, F1, F2, BC1F1, BC2F2). These populations were then evaluated in a triplicated factorial randomized complete block design under non-stressed and drought-stressed conditions. For statistical analyses, a nested block design was employed to ignore the replication effects. Significant differences (p=0.01) were recorded among the genotypes for investigated seedling-traits. Absolute values of fresh root length, fresh root weight, and dry root weight lead to select two genotypes, one tolerant (WFTMS) and one susceptible (Q66). Estimates of heritability, genetic advance, and genotypic correlation coefficients were higher and significant for most of the seedling-traits. Generation variance analysis revealed additive gene action. Narrow-sense heritability [F2 = 65; F8 = 79] revealed the same results. Generation mean analysis signified additive genetic effects in the inheritance of cob girth, non-additive for plant height, grains per ear row and grain yield per plant, and environmental for ear leaf area, cob length, grain rows per ear, biomass per plant, and 100-grain weight under drought-stressed conditions. For conferring drought-tolerance in maize, breeders can adopt the recombinant breeding strategy to pyramid the desirable genes. (Author)

  17. Photosynthesis in Norway spruce seedlings infected by the needle rust Chrysomyxa rhododendri.

    Science.gov (United States)

    Bauer, Helmut; Plattner, Karin; Volgger, Waltraud

    2000-02-01

    Chrysomyxa rhododendri (DC.) De Bary is a needle rust with a host shift between Rhododendron sp. and Norway spruce (Picea abies (L.) Karst.), penetrating only the new developing flushes of the conifer. Because little is known about its effects on trees, we investigated several parameters related to photosynthesis in artificially infected 3-year-old Norway spruce seedlings. The potential efficiency of photosystem II (PSII; derived from chlorophyll fluorescence measurements) was reduced in infected current-year needles as soon as disease symptoms were visible, about three weeks after inoculation. Two weeks later, photosynthetic O(2) evolution (P(max)) of infected needles was less than 20% of control needles, whereas respiratory O(2) uptake (R(D)) was about three times higher than that of control needles. Nonstructural carbohydrate concentrations were about 60% of control values in all parts of the shoots of infected trees. Photosynthetic inhibition was associated with marked decreases in chlorophyll concentration and chlorophyll a/b ratio but only a small reduction in carotenoid concentration. In infected trees, P(max) of noninfected 1-year-old and 2-year-old needles was 50 and 80% higher than in the corresponding age class of needles of control trees. Estimation of potential daily net dry mass production, based on P(max), R(D), specific leaf area, carbon content and needle biomass, indicated that seedlings infected once were able to produce 60%, and those infected twice only 25%, of the dry mass of controls. We conclude that afforestation and regeneration of Norway spruce is seriously impaired in regions where seedlings are frequently attacked by Chrysomyxa.

  18. Growth response of four species of Eastern hardwood tree seedlings exposed to ozone, acidic precipitation, and sulfur dioxide

    International Nuclear Information System (INIS)

    Davis, D.D. Skelly, J.M.

    1992-01-01

    In 1987 a study was conducted in controlled environment chambers to determine the foliar sensitivity of tree seedlings of eight species to ozone and acidic precipitation, and to determine the influence of leaf position on symptom severity. Jensen and Dochinger conducted concurrent similar studies in Continuously Stirred Tank Reactor (CSTR) chambers with ten species of forest trees. Based on the results of these initial studies, four species representing a range in foliar sensitivity to ozone were chosen: black cherry (Prunus serotina Ehrh.), red maple (Acer rubrum L.), northern red oak (Quercus rubra L.) and yellow-poplar (Liriodendron tulipifera L.). These species were also chosen because of their ecological and/or commercial importance in Pennsylvania. Seedlings were exposed in growth chambers simulated acid rain. In addition acute exposures to sulfur dioxide were conducted in a regime based on unpublished monitoring data collected near coal-fired power plants. The objective of this study was to determine if the pollutant treatments influenced the growth and productivity of seedlings of these four species. This information will help researchers and foresters understand the role of air pollution in productivity of eastern forests

  19. Effect of Salt Stress (NaCl on Germination and Early Seedling Parameters of Three Pepper Cultivars (Capsicum annuum L.

    Directory of Open Access Journals (Sweden)

    Aloui Hassen

    2014-03-01

    Full Text Available Salinity is one of the major environmental problem that lead to a deterioration of agricultural land and, as a result, to a reduction in crop productivity worldwide. This research tested the effect of different salinity levels on germination and early seedling growth of three pepper (Capsicum annuum L. cultivars which were "Beldi", "Baklouti" and "Anaheim Chili". Experimental treatment included 7 concentrations of NaCl (0, 2, 4, 6, 8, 10 and 12 g/l. Results indicated that all investigate traits were affected by salt stress. Salt stress affected on germination parameters and radicle and plumule length. Fresh weight and dry weight of evaluated seedlings was also affected. "Anaheim Chili" cultivar was shown to be the most restraint cultivar to salt stress in comparison to "Beldi" and "Baklouti" cultivars.

  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. 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...

  8. 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 ...

  9. 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 ...

  10. 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 ...

  11. 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 ...

  12. 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.

  13. 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...

  14. 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 ...

  15. 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.

  16. 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...

  17. 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 ...

  18. 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 ...

  19. 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 ...

  20. 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 ...

  1. 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.

  2. 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

  3. 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...

  4. 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

  5. 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 ...

  6. 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...

  7. 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.

  8. 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

  9. 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)

  10. Responses of secondary chemicals in sugar maple (Acer saccharum) seedlings to UV-B, springtime warming and nitrogen additions

    Energy Technology Data Exchange (ETDEWEB)

    Sager, E.P.S.; Hutchinson, T.C. [Trent Univ., Peterborough, ON (Canada). Environmental Studies

    2006-10-15

    Elevated UV-B radiation due to climatic change and ozone depletion may represent a significant springtime environmental stressor to germinating seedlings in temperate forest regions. This study aimed to determine the effects of UV-B, nitrogen (N) fertilization and climate warming on the concentrations of base cations and secondary metabolites in the foliage of sugar maple seedlings growing in acid or alkaline soils. The influence of measured flavonoids and phenolics on herbivore activity was examined, as well as the relationship between foliar concentrations of calcium (Ca); manganese (Mn); and N and the production of phenolic and flavonoid compounds. Experimental plots were established in mature hardwood forests in alkaline and acid soil locations in Bobcaygeon and Haliburton, Ontario. Pentagonal open-top chambers were used to lengthen the growing season and simulate an earlier spring. Ammonium nitrate was applied at a rate comparable with an additional deposition of 5 g N per m per year. Fertilizer was applied on 3 separate occasions. Ambient UV-B radiation was screened out with Mylar D polyester film. Sites, treatments and time of sampling had complex effects on foliar elemental chemistry, production of secondary compounds and herbivory. Foliar concentrations of individual phenols were higher in seedlings in the UV-B exclusion treatments. At both sites, removal of ambient UV-B led to increases in flavonoids and chlorogenic acid, and reduced herbivore activity. At Haliburton, ammonium nitrate fertilization led to further increases in foliar Mn. Nitrogen additions led to decreases in the concentrations of some flavonoids at both sites. It was concluded that the composition of the forest soil governs the response of seedlings when they are exposed to abiotic stressors. 63 refs., 5 tabs., 8 figs.

  11. Gas exchange, phisiological indexes and ionic accumulation in Annona emarginata (Schltdl. H. Rainer seedlings in nutrients solution

    Directory of Open Access Journals (Sweden)

    Daniel Baron

    2013-06-01

    Full Text Available "Araticum-de-terra-fria" (Annona emarginata (Schltdl. H. Rainer has been consider a good alternative in rootstock production for the main commercial Annonaceae species. Although this species develops in different soil and climate conditions, there is no understanding by the physiological responses of this species at different nutritional levels. Thus, the objective of this study was to evaluate the influence of different ionic strengths on development of vegetative species known as "Araticum-de-terra-fria". It was evaluated in seedlings grown in different ionic strengths (25% I, 50% I, 75% I and 100% I of the complete nutrient solution Hoagland and Arnon (1950 nº 2, for 140 days, the following characteristics: Gas Exchange (CO2 assimilation rate, stomatal conductance, internal CO2 concentration, transpiration rate, water use efficiency, Rubisco carboxylation efficiency; Vegetative growth characteristics (diameter, leaf number, dry matter; Physiological Indexes (leaf area ratio, specific leaf area, relative growth rate, net assimilation rate, leaf weight ratio and Ionic Accumulation (nutrients leaf analysis. Seedlings grown under 50% I showed the highest values of Leaf CO2 assimilation rate, water use efficiency, carboxylation efficiency, growth, relative growth rate, net assimilation rate and ionic accumulation in the total dry matter. So it is concluded that "Araticum-de-terra-fria" seedlings grown under intermediate nutrient concentrations of complete nutrient solution Hoagland and Arnon (1950 nº 2, explored more adequately their physiological potential that justify their adaptation in different nutritional conditions and allow reducing the amount of mineral nutrition of seedlings production.

  12. 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...

  13. 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)

  14. 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

  15. Crested wheatgrass-cheatgrass seedling competition in a mixed-density design

    Science.gov (United States)

    Francis, Mark G.; Pyke, David A.

    1996-01-01

    Plant competition experiments have historically used designs that are difficult to interpret due to confounding problems. Recently, designs based on a 'response function' approach have been proposed and tested in various plant mixture settings. For this study, 3 species were used that are important in current revegetation practices in the Intermountain West. 'Nordan' (Agropyron desertorum [Fish. ex Link] Shult.) and 'Hycrest' (A. cristatum [L.] Gaertn. x desertorum) crested wheatgrass are commonly-used revegetation species on rangelands susceptible to cheatgrass (Bromus tectorum L.) invasion, although little quantitative data exist that compare their competitive abilities. We evaluated the competitive ability of Hycrest and Nordan seedlings in 2-species mixtures with cheatgrass in a greenhouse study. Linear and nonlinear models were developed for a range of densities (130- 520 seeds m-2) for each species to predict median above-ground biomass and tiller numbers and to further test the usefulness of this design for evaluating species to rehabilitate rangelands. In both experiments, increasing Hycrest and Nordan densities reduced their own biomass and tiller production while increasing Hycrest densities reduced cheatgrass biomass and tiller production. Nordan did not affect cheatgrass biomass and tiller production. However, increasing cheatgrass densities reduced Hycrest and Nordan biomass and tiller production, and its own biomass and tiller production. The competition index i.e. substitution rate, indicated that Hycrest seedlings were better competitors with cheatgrass than Nordan, although in all mixtures, cheatgrass plants were the superior competitors. Further field research using this design, where environmental inputs are less optimal and diverse, is needed to validate these results and to further evaluate the use of this approach in examining effects of intra- and interspecific competition.

  16. 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. 

  17. Association analysis of salt tolerance in cowpea (Vigna unguiculata (L.) Walp) at germination and seedling stages.

    Science.gov (United States)

    Ravelombola, Waltram; Shi, Ainong; Weng, Yuejin; Mou, Beiquan; Motes, Dennis; Clark, John; Chen, Pengyin; Srivastava, Vibha; Qin, Jun; Dong, Lingdi; Yang, Wei; Bhattarai, Gehendra; Sugihara, Yuichi

    2018-01-01

    This is the first report on association analysis of salt tolerance and identification of SNP markers associated with salt tolerance in cowpea. Cowpea (Vigna unguiculata (L.) Walp) is one of the most important cultivated legumes in Africa. The worldwide annual production in cowpea dry seed is 5.4 million metric tons. However, cowpea is unfavorably affected by salinity stress at germination and seedling stages, which is exacerbated by the effects of climate change. The lack of knowledge on the genetic underlying salt tolerance in cowpea limits the establishment of a breeding strategy for developing salt-tolerant cowpea cultivars. The objectives of this study were to conduct association mapping for salt tolerance at germination and seedling stages and to identify SNP markers associated with salt tolerance in cowpea. We analyzed the salt tolerance index of 116 and 155 cowpea accessions at germination and seedling stages, respectively. A total of 1049 SNPs postulated from genotyping-by-sequencing were used for association analysis. Population structure was inferred using Structure 2.3.4; K optimal was determined using Structure Harvester. TASSEL 5, GAPIT, and FarmCPU involving three models such as single marker regression, general linear model, and mixed linear model were used for the association study. Substantial variation in salt tolerance index for germination rate, plant height reduction, fresh and dry shoot biomass reduction, foliar leaf injury, and inhibition of the first trifoliate leaf was observed. The cowpea accessions were structured into two subpopulations. Three SNPs, Scaffold87490_622, Scaffold87490_630, and C35017374_128 were highly associated with salt tolerance at germination stage. Seven SNPs, Scaffold93827_270, Scaffold68489_600, Scaffold87490_633, Scaffold87490_640, Scaffold82042_3387, C35069468_1916, and Scaffold93942_1089 were found to be associated with salt tolerance at seedling stage. The SNP markers were consistent across the three models and

  18. Physiological and biochemical responses of Ricinus communis seedlings to different temperatures: a metabolomics approach.

    Science.gov (United States)

    Ribeiro, Paulo Roberto; Fernandez, Luzimar Gonzaga; de Castro, Renato Delmondez; Ligterink, Wilco; Hilhorst, Henk W M

    2014-08-12

    Compared with major crops, growth and development of Ricinus communis is still poorly understood. A better understanding of the biochemical and physiological aspects of germination and seedling growth is crucial for the breeding of high yielding varieties adapted to various growing environments. In this context, we analysed the effect of temperature on growth of young R. communis seedlings and we measured primary and secondary metabolites in roots and cotyledons. Three genotypes, recommended to small family farms as cash crop, were used in this study. Seedling biomass was strongly affected by the temperature, with the lowest total biomass observed at 20°C. The response in terms of biomass production for the genotype MPA11 was clearly different from the other two genotypes: genotype MPA11 produced heavier seedlings at all temperatures but the root biomass of this genotype decreased with increasing temperature, reaching the lowest value at 35°C. In contrast, root biomass of genotypes MPB01 and IAC80 was not affected by temperature, suggesting that the roots of these genotypes are less sensitive to changes in temperature. In addition, an increasing temperature decreased the root to shoot ratio, which suggests that biomass allocation between below- and above ground parts of the plants was strongly affected by the temperature. Carbohydrate contents were reduced in response to increasing temperature in both roots and cotyledons, whereas amino acids accumulated to higher contents. Our results show that a specific balance between amino acids, carbohydrates and organic acids in the cotyledons and roots seems to be an important trait for faster and more efficient growth of genotype MPA11. An increase in temperature triggers the mobilization of carbohydrates to support the preferred growth of the aerial parts, at the expense of the roots. A shift in the carbon-nitrogen metabolism towards the accumulation of nitrogen-containing compounds seems to be the main biochemical

  19. 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)

  20. 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.

  1. 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.

  2. 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.

  3. Influence of biostimulants-seed-priming on Ceratotheca triloba germination and seedling growth under low temperatures, low osmotic potential and salinity stress.

    Science.gov (United States)

    Masondo, Nqobile A; Kulkarni, Manoj G; Finnie, Jeffrey F; Van Staden, Johannes

    2018-01-01

    Extreme temperatures, drought and salinity stress adversely affect seed germination and seedling growth in crop species. Seed priming has been recognized as an indispensable technique in the production of stress-tolerant plants. Seed priming increases seed water content, improves protein synthesis using mRNA and DNA and repair mitochondria in seeds prior to germination. The current study aimed to determine the role of biostimulants-seed-priming during germination and seedling growth of Ceratotheca triloba (Bernh.) Hook.f. (an indigenous African leafy vegetable) under low temperature, low osmotic potential and salinity stress conditions. Ceratotheca triloba seeds were primed with biostimulants [smoke-water (SW), synthesized smoke-compound karrikinolide (KAR 1 ), Kelpak ® (commercial seaweed extract), phloroglucinol (PG) and distilled water (control)] for 48h at 25°C. Thereafter, primed seeds were germinated at low temperatures, low osmotic potential and high NaCl concentrations. Low temperature (10°C) completely inhibited seed germination. However, temperature shift to 15°C improved germination. Smoke-water and KAR 1 enhanced seed germination with SW improving seedling growth under different stress conditions. Furthermore, priming seeds with Kelpak ® stimulated percentage germination, while PG and the control treatment improved seedling growth at different PEG and NaCl concentrations. Generally, high concentrations of PEG and NaCl brought about detrimental effects on seed germination and seedling growth. Findings from this study show the potential role of seed priming with biostimulants in the alleviation of abiotic stress conditions during seed germination and seedling growth in C. triloba plants. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Root-shoot relationships in four strains of field-grown Erianthus arundinaceus at seedling stage

    Directory of Open Access Journals (Sweden)

    Fumitaka Shiotsu

    2016-01-01

    Full Text Available The production of cellulosic bioethanol from non-edible plants is a potential countermeasure against global warming. Erianthus species provide cellulosic raw material for bioethanol because they have high biomass productivity and high tolerance to environmental stress, associated with their large, deep root systems. However, it is difficult to select Erianthus species for breeding by direct observation of their root systems because the roots are widely dispersed in the soil. Instead, we examined shoot morphological traits that could be closely related to root morphology to find effective reference indices for selection. The potential to evaluate root structure and function in Erianthus according to bleeding rate was also examined. An analysis of root–shoot relationships in seedlings indicated that root number and mean length were closely related to stem number and diameter, respectively. These results suggest that root–shoot relationships may provide useful criteria for selective breeding of root systems in Erianthus.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. [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.

  7. Morpho-physiological responses of alhagi sparsifolia shap. (leguminosae) seedlings to progressive drought stress

    International Nuclear Information System (INIS)

    Zeng, F.; Zhang, B.; Lu, Y.; Li, C.; Liu, B.; An, G.; Gao, X.

    2016-01-01

    Water is a key limiting factor influencing plant growth and development in arid ecosystem. To explore the mechanisms of the desert plant Alhagi sparsifolia seedlings to tolerate drought stress in extreme desert, an experiment was conducted from July to September in 2010 with four water treatments: 100 percent (W/sub 100/), 80 percent (W80), 60 percent (W60) and 45 percent (W/sub 45/) of water holding capacity (WHC). Plant growth, photosynthesis, nutrient content and water use efficiency (WUE) were measured. The Results showed that plant growth, branch number, biomass allocation, number of leaves and area per leaf as well as leaf area ratio with drought stress treatments (W/sub 80/, W/sub 60/ and W/sub 45/) decreased than W/sub 100/ treatment, while root/shoot ratio and specific leaf area increased gradually throughout the experimental duration. Furthermore, photosynthetic pigment content, light-saturated photosynthetic rate, and concentration of carbon and nitrogen in plant significantly decreased with increasing drought stress. The WUE at W/sub 100/ and W/sub 80/ treatments increased significantly at the beginning of drought stress treatment and then reduced with stress prolonged. In Conclusion, the desert plant A. sparsifolia can tolerate the progressive drought stress due to the strong plasticity of morphological and physiological traits. The critical level of soil WHC to limit the growth and dry mass production of A. sparsifolia seedlings in the southern fringe of the Taklimakan Desert was approximately at 45 percent. (author)

  8. Growth and biomass partitioning of mulungu seedlings in response to phosphorus fertilization and mycorrhizal inoculation

    Directory of Open Access Journals (Sweden)

    Tiago de Sousa Leite

    2014-12-01

    Full Text Available The objective of this work was to evaluate the initial growth and biomass partitioning of mulungu (Erythrina velutina Willd. seedlings under different rates of phosphorus in the presence and absence of arbuscular mycorrhizal fungi (FMA’s. A randomized blocks design in a 5 x 2 factorial arrangement was used, with four replicates and three plants per plot. Treatments consisted of five phosphorus rates (0, 50, 100, 150 and 200 mg.Kg soil-1, using as source the superphosphate fertilizer, and presence or absence of FMA’s. At 98 days after sowing (DAS, shoot height, stem diameter, leaf number, leaf chlorophyll index, leaf dry matter, stem dry matter, root dry matter, leaf area, Dickson quality index and height/stem diameter ratio were evaluated. The phosphorus rate of 200 mg.kg-1 proved to be the most efficient for production of Erythrina velutina seedlings, but with a significant reduction in the biological association of this plant with rhizobacteria. Biomass distribution within the different parts of the plants did not change with distinct rates of P, and there were no benefits in the use of FMA’s until 98 DAS.

  9. DNA damage, repair monitoring and epigenetic DNA methylation changes in seedlings of Chernobyl soybeans.

    Science.gov (United States)

    Georgieva, Mariyana; Rashydov, Namik M; Hajduch, Martin

    2017-02-01

    This pilot study was carried out to assess the effect of radio-contaminated Chernobyl environment on plant genome integrity 27 years after the accident. For this purpose, nuclei were isolated from root tips of the soybean seedlings harvested from plants grown in the Chernobyl area for seven generations. Neutral, neutral-alkaline, and methylation-sensitive comet assays were performed to evaluate the induction and repair of primary DNA damage and the epigenetic contribution to stress adaptation mechanisms. An increased level of single and double strand breaks in the radio-contaminated Chernobyl seedlings at the stage of primary root development was detected in comparison to the controls. However, the kinetics of the recovery of DNA breaks of radio-contaminated Chernobyl samples revealed that lesions were efficiently repaired at the stage of cotyledon. Methylation-sensitive comet assay revealed comparable levels in the CCGG methylation pattern between control and radio-contaminated samples with a slight increase of approximately 10% in the latter ones. The obtained preliminary data allow us to speculate about the onset of mechanisms providing an adaptation potential to the accumulated internal irradiation after the Chernobyl accident. Despite the limitations of this study, we showed that comet assay is a sensitive and flexible technique which can be efficiently used for genotoxic screening of plant specimens in natural and human-made radio-contaminated areas, as well as for safety monitoring of agricultural products. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Density Stress has Minimal Impacts on the Barley or Maize Seedling Transcriptome

    Directory of Open Access Journals (Sweden)

    Summer St. Pierre

    2011-03-01

    Full Text Available High planting density affects the morphology and productivity of many crop species. Our objectives were to examine the phenotypic and transcriptomic changes that occur during plant density stress in barley ( L. and maize ( L. seedlings. In maize and barley seedlings, density stress impacted several morphological traits. Gene expression profiles were examined in four barley and five maize genotypes grown at low and high plant densities. Only 221 barley and 35 maize genes exhibited differential expression in response to plant density stress. The majority of the gene expression changes were observed in a subset of the genotypes and reflected minor changes in the level of expression, indicating that the plant density stress imposed in this study did not result in major changes in gene expression. Also, little overlap was observed within barley or maize genotypes in gene expression during density stress, indicating that genotypic differences play a major role in the response to density stress. While it is clear that gene expression differences are involved in morphological changes induced by high plant densities, it is likely that many of these gene expression differences are subtle and restricted to particular tissues and developmental time.

  11. 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).

  12. Influence of light, UV-B radiation, and herbicides on wax biosynthesis of cucumber seedlings

    International Nuclear Information System (INIS)

    Tevini, M.; Steinmüller, D.

    1987-01-01

    The behavior of cuticular alkane-1-ols and alkanes were studied in different developmental stages of cucumber seedlings grown in the dark or under white light, with or without UV-B radiation or in presence of wax biosynthesis inhibitors, trichloroacetic acid and metolachlor. Accumulation of alkane-1-ols increased light independently with seedling age. Synthesis of alkanes was strictly light and dose dependent. Addition of UV-B radiation did not alter the amounts of alkanes or alcohols, however, the distribution of homologues was shifted towards shorter chain homologues. Treatments with Cl 3 AcOH resulted in strong inhibition of alkane accumulation, whereas the amount of alkane-1-ols was changed neither at low nor at moderate concentrations of Cl 3 AcOH but their homologue distribution shifted towards longer chain lengths. This shifting was depressed in the presence of UV-B. At high concentrations of Cl 3 Ac0H similar homologue distributions as produced by UV-B (shift to shorter homologues) were observed. Metolachlor treatment resulted in an inhibition of alkane-1-ol production connected with rising amounts of alkanes, predominantly of short chain species. A simple model of wax biosynthesis is proposed which describes the interactions with white light, UV-B radiation and herbicides. (author)

  13. Methanol production from Eucalyptus wood chips. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Fishkind, H.H.

    1982-06-01

    This feasibility study includes all phases of methanol production from seedling to delivery of finished methanol. The study examines: production of 55 million, high quality, Eucalyptus seedlings through tissue culture; establishment of a Eucalyptus energy plantation on approximately 70,000 acres; engineering for a 100 million gallon-per-day methanol production facility; potential environmental impacts of the whole project; safety and health aspects of producing and using methanol; and development of site specific cost estimates.

  14. Uso de ácido giberélico em sementes de fruta-do-conde (Annona squamosa L. visando à produção de mudas em diferentes embalagens Giberellic acid use on sugar apple (Annona squamosa L. seeds aiming seedling production in different packs

    Directory of Open Access Journals (Sweden)

    GISELA FERREIRA

    2002-04-01

    Full Text Available O presente trabalho foi conduzido no laboratório de sementes e casa de vegetação da UNIOESTE -- Câmpus de Marechal Cândido Rondon -- PR, com o objetivo de avaliar o efeito de diferentes concentrações de ácido giberélico (GA3 na germinação de sementes e na emergência de plântulas de fruta-do-conde (Annona squamosa L., em diferentes recipientes, visando à produção de mudas. O experimento foi instalado em delineamento experimental inteiramente casualizado. Os tratamentos foram compostos pela embebição das sementes em sete concentrações de ácido giberélico (0; 50; 100; 250; 500; 750 e 1000 mg.L-1, por 5 horas, com 4 repetições de 25 sementes. No campo, os tratamentos foram constituídos das sete concentrações de GA3 e dois tipos de embalagens (bandejas de isopor e sacolas de polietileno, com 4 repetições de 25 sementes. As avaliações do laboratório constaram de porcentagem total de sementes germinadas, dormentes e mortas; porcentagem total de plântulas normais e anormais, e índice de velocidade de germinação (IVG e do campo, pela porcentagem total de plântulas emergidas; índice de velocidade de emergência de plântulas (IVE; altura de plântulas e número de folhas. Os dados foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey, a 5% de probabilidade. Verificou-se que o GA3 promoveu o incremento na germinação de sementes de Annona squamosa e que as sacolas de polietileno foram mais adequadas do que as bandejas no desenvolvimento das plântulas na fase inicial.The objetive of this experiment, was to evaluate the effect of giberellic acid (GA3 concentrations, on sugar apple (Annona squamosa L. seeds germination and seedlings emergence. The experiment was carried out in a completely randomized design. The treatments were composed of seeds soaking in 7 GA3 concentrations (0, 50, 100, 250, 500, 750 and 1.000 mg.L-1 of GA3, for 5 hours, with 4 replicates of 25 seeds, and kept at

  15. The differentiation of fibre- and drug type Cannabis seedlings by gas chromatography/mass spectrometry and chemometric tools.

    Science.gov (United States)

    Broséus, Julian; Anglada, Frédéric; Esseiva, Pierre

    2010-07-15

    Cannabis cultivation in order to produce drugs is forbidden in Switzerland. Thus, law enforcement authorities regularly ask forensic laboratories to determinate cannabis plant's chemotype from seized material in order to ascertain that the plantation is legal or not. As required by the EU official analysis protocol the THC rate of cannabis is measured from the flowers at maturity. When laboratories are confronted to seedlings, they have to lead the plant to maturity, meaning a time consuming and costly procedure. This study investigated the discrimination of fibre type from drug type Cannabis seedlings by analysing the compounds found in their leaves and using chemometrics tools. 11 legal varieties allowed by the Swiss Federal Office for Agriculture and 13 illegal ones were greenhouse grown and analysed using a gas chromatograph interfaced with a mass spectrometer. Compounds that show high discrimination capabilities in the seedlings have been identified and a support vector machines (SVMs) analysis was used to classify the cannabis samples. The overall set of samples shows a classification rate above 99% with false positive rates less than 2%. This model allows then discrimination between fibre and drug type Cannabis at an early stage of growth. Therefore it is not necessary to wait plants' maturity to quantify their amount of THC in order to determine their chemotype. This procedure could be used for the control of legal (fibre type) and illegal (drug type) Cannabis production. (c) 2010 Elsevier Ireland Ltd. All rights reserved.

  16. Biochemical toxicity and DNA damage of imidazolium-based ionic liquid with different anions in soil on Vicia faba seedlings.

    Science.gov (United States)

    Liu, Tong; Zhu, Lusheng; Wang, Jinhua; Wang, Jun; Zhang, Jun; Sun, Xi; Zhang, Cheng

    2015-12-17

    In the present study, the toxic effects of 1-octyl-3-methylimidazolium chloride ([Omim]Cl), 1-octyl-3-methylimidazolium bromide ([Omim]Br) and 1-octyl-3-methylimidazolium tetrafluoroborate ([Omim]BF4) in soil on Vicia faba (V. faba) seedlings at 0, 100, 200, 400, 600 and 800 mg kg(-1) were assessed for the first time at the cellular and molecular level. Moreover, the toxicity of these three ionic liquids (ILs) was evaluated, and the influence of anions on the toxicity of the ILs was assessed. The results showed that even at 100 mg kg(-1), the growth of V. faba seedlings was inhibited after exposure to the three ILs, and the inhibitory effect was enhanced with increasing concentrations of the three ILs. The level of reactive oxygen species (ROS) was increased after exposure to the three ILs, which resulted in lipid peroxidation, DNA damage and oxidative damage in the cells of the V. faba seedlings. In addition, the anion structure could influence the toxicity of ILs, and toxicity of the three tested ILs decreased in the following order: [Omim]BF4 > [Omim]Br > [Omim]Cl. Moreover, oxidative damage is the primary mechanism by which ILs exert toxic effects on crops, and ILs could reduce the agricultural productivity.

  17. Substrates with green manure compost and leaf application of biofertilizer on seedlings of yellow passion fruit plants

    Directory of Open Access Journals (Sweden)

    Cristiane Muniz Barbosa Barros

    2013-12-01

    Full Text Available Substrates and fertilization are fundamental for seedling production, which well nourished can produce earlier and are more resistant to stresses. Animal manures are often used in non-industrialized substrates with good results, but their costs are increasing. Other residues may be used for plant nutrition, in substrates or in leaf fertilization. The aim of this work was to evaluate substrates prepared with green manure composts and the leaf application of biofertilizer on the formation of yellow passion fruit seedlings. A greenhouse experiment was conducted between December 2009 and February 2010, with a split-plot random block design. Plots received or not leaf application of supermagro biofertilizer. Subplots consisted of different substrates: soil; soil + cattle manure; soil + cattle manure composted with black oats straw; soil + cattle manure composted with ryegrass straw; soil + cattle manure composted with turnip straw; and soil + cattle manure composted with vetch straw. There were three dates of leaf fertilization: 10, 25 and 40 days after emergence (DAE. At 50 DAE plants were collected for evaluation of growth and accumulation of biomass and nutrients: N, P, K, Ca, Mg, Cu, Mn and Zn. Data were submitted to analysis of variance and means compared by Tukey test. The substrate soil + cattle manure promoted higher stem diameter, plant height, leaf area, root length and volume and nutrient accumulation. Among substrates with green manure composts, those prepared with black oats and turnip straw outranked the others. The use of leaf biofertilizer showed diverse results on seedling formation, being beneficial when combined to substrates with black oats composted straw, and prejudicial when combined to soil + cattle manure and soil + turnip composted straw substrates. The accumulation of nutrients by the seedlings occurred in the following order: K>Ca>N>Mg>P>Zn>Cu=Mn.

  18. 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)

  19. 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.

  20. 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.

  1. 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.

  2. NO accumulation alleviates H2 O2 -dependent oxidative damage induced by Ca(NO3 )2 stress in the leaves of pumpkin-grafted cucumber seedlings.

    Science.gov (United States)

    Li, Lin; Shu, Sheng; Xu, Qing; An, Ya-Hong; Sun, Jin; Guo, Shi-Rong

    2017-05-01

    Nitric oxide (NO) and hydrogen peroxide (H 2 O 2 ), two important signaling molecules, are stimulated in plants by abiotic stresses. In this study, we investigated the role of NO and its interplay with H 2 O 2 in the response of self-grafted (S-G) and salt-tolerant pumpkin-grafted (Cucurbita maxima × C. moschata) cucumber seedlings to 80 mM Ca(NO 3 ) 2 stress. Endogenous NO and H 2 O 2 production in S-G seedlings increased in a time-dependent manner, reaching maximum levels after 24 h of Ca(NO 3 ) 2 stress. In contrast, a transient increase in NO production, accompanied by H 2 O 2 accumulation, was observed at 2 h in rootstock-grafted plants. N w -Nitro-l-Arg methyl ester hydrochloride (l-NAME), an inhibitor of nitric oxide synthase (NOS), tungstate, an inhibitor of nitrate reductase (NR), and 2-(4-carboxyphenyl)-4,4,5,5-tetramethy-limidazoline-1-oxyl-3-oxide (cPTIO), a scavenger of NO, were found to significantly inhibit NO accumulation induced by salt stress in rootstock-grafted seedlings. H 2 O 2 production was unaffected by these stress conditions. Ca(NO 3 ) 2 stress-induced NO accumulation was blocked by pretreatment with an H 2 O 2 scavenger (dimethylthiourea, DMTU) and an inhibitor of NADPH oxidase (diphenyleneiodonium, DPI). In addition, maximum quantum yield of PSII (Fv/Fm), as well as the activities and transcript levels of antioxidant enzymes, were significantly decreased by salt stress in rootstock grafted seedlings after pretreatment with these above inhibitors; antioxidant enzyme transcript levels and activities were higher in rootstock-grafted seedlings compared with S-G seedlings. These results suggest that rootstock grafting could alleviate the oxidative damage induced by Ca(NO 3 ) 2 stress in cucumber seedlings, an effect that may be attributable to the involvement of NO in H 2 O 2 -dependent antioxidative metabolism. © 2016 Scandinavian Plant Physiology Society.

  3. 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...

  4. 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)

  5. 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.

  6. NSP-Dependent Simple Nitrile Formation Dominates upon Breakdown of Major Aliphatic Glucosinolates in Roots, Seeds, and Seedlings of Arabidopsis thaliana Columbia-0.

    Science.gov (United States)

    Wittstock, Ute; Meier, Kathrin; Dörr, Friederike; Ravindran, Beena M

    2016-01-01

    One of the best-studied plant defense systems, the glucosinolate-myrosinase system of the Brassicales, is composed of thioglucosides known as glucosinolates and their hydrolytic enzymes, the myrosinases. Tissue disruption brings these components together, and bioactive products are formed as a consequence of myrosinase-catalyzed glucosinolate hydrolysis. Among these products, isothiocyanates have attracted most interest as chemical plant defenses against herbivores and pathogens and health-promoting compounds in the human diet. Previous research has identified specifier proteins whose presence results in the formation of alternative product types, e.g., nitriles, at the expense of isothiocyanates. The biological roles of specifier proteins and alternative breakdown products are poorly understood. Here, we assessed glucosinolate breakdown product profiles obtained upon maceration of roots, seedlings and seeds of Arabidopsis thaliana Columbia-0. We identified simple nitriles as the predominant breakdown products of the major endogenous aliphatic glucosinolates in root, seed, and seedling homogenates. In agreement with this finding, genes encoding nitrile-specifier proteins (NSPs) are expressed in roots, seeds, and seedlings. Analysis of glucosinolate breakdown in mutants with T-DNA insertions in any of the five NSP genes demonstrated, that simple nitrile formation upon tissue disruption depended almost entirely on NSP2 in seeds and mainly on NSP1 in seedlings. In roots, about 70-80% of the nitrile-forming activity was due to NSP1 and NSP3 . Thus, glucosinolate breakdown product profiles are organ-specifically regulated in A. thaliana Col-0, and high proportions of simple nitriles are formed in some parts of the plant. This should be considered in future studies on biological roles of the glucosinolate-myrosinase system.

  7. NSP-dependent simple nitrile formation dominates upon breakdown of major aliphatic glucosinolates in roots, seeds, and seedlings of Arabidopsis thaliana Columbia-0

    Directory of Open Access Journals (Sweden)

    Ute Wittstock

    2016-12-01

    Full Text Available One of the best-studied plant defense systems, the glucosinolate-myrosinase system of the Brassicales, is composed of thioglucosides known as glucosinolates and their hydrolytic enzymes, the myrosinases. Tissue disruption brings these components together, and bioactive products are formed as a consequence of myrosinase-catalyzed glucosinolate hydrolysis. Among these products, isothiocyanates have attracted most interest as chemical plant defenses against herbivores and pathogens and health-promoting compounds in the human diet. Previous research has identified specifier proteins whose presence results in the formation of alternative product types, e.g. nitriles, at the expense of isothiocyanates. The biological roles of specifier proteins and alternative breakdown products are poorly understood. Here, we assessed glucosinolate breakdown product profiles obtained upon maceration of roots, seedlings and seeds of Arabidopsis thaliana Columbia-0. We identified simple nitriles as the predominant breakdown products of the major endogenous aliphatic glucosinolates in root, seed, and seedling homogenates. In agreement with this finding, genes encoding nitrile-specifier proteins (NSPs are expressed in roots, seeds, and seedlings. Analysis of glucosinolate breakdown in mutants with T-DNA insertions in any of the five NSP genes demonstrated, that simple nitrile formation upon tissue disruption depended almost entirely on NSP2 in seeds and mainly on NSP1 in seedlings. In roots, about 70-80 % of the nitrile-forming activity was due to NSP1 and NSP3. Thus, glucosinolate breakdown product profiles are organ-specifically regulated in A. thaliana Col 0, and high proportions of simple nitriles are formed in some parts of the plant. This should be considered in future studies on biological roles of the glucosinolate-myrosinase system.

  8. 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.

  9. 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.

  10. 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 ...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. A halotolerant Enterobacter sp. displaying ACC deaminase activity promotes rice seedling growth under salt stress.

    Science.gov (United States)

    Sarkar, Anumita; Ghosh, Pallab Kumar; Pramanik, Krishnendu; Mitra, Soumik; Soren, Tithi; Pandey, Sanjeev; Mondal, Monohar Hossain; Maiti, Tushar Kanti

    2018-01-01

    Agricultural productivity is proven to be hampered by the synthesis of reactive oxygen species (ROS) and production of stress-induced ethylene under salinity stress. One-aminocyclopropane-1-carboxylic acid (ACC) is the direct precursor of ethylene synthesized by plants. Bacteria possessing ACC deaminase activity can use ACC as a nitrogen source preventing ethylene production. Several salt-tolerant bacterial strains displaying ACC deaminase activity were isolated from rice fields, and their plant growth-promoting (PGP) properties were determined. Among them, strain P23, identified as an Enterobacter sp. based on phenotypic characteristics, matrix-assisted laser desorption ionization-time of flight mass spectrometry data and the 16S rDNA sequence, was selected as the best-performing isolate for several PGP traits, including phosphate solubilization, IAA production, siderophore production, HCN production, etc. Enterobacter sp. P23 was shown to promote rice seedling growth under salt stress, and this effect was correlated with a decrease in antioxidant enzymes and stress-induced ethylene. Isolation of an acdS mutant strain enabled concluding that the reduction in stress-induced ethylene content after inoculation of strain P23 was linked to ACC deaminase activity. Copyright © 2017 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  17. 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

  18. EFFECT OF PLANTING MEDIA ON THE GROWTH OF Shorea pinanga Scheff. SEEDLINGS

    Directory of Open Access Journals (Sweden)

    Diana Prameswari

    2004-11-01

    Full Text Available Shoreapinanga Scheff.   is a major tropical plant species which has an important  economic  value not  only for timber,  but also as illipe nut  (called tengkawang  in local  name production.   This species   is suggested   for  land  rehabilitation    and  forest  conservation.    In rehabilitation   action, S. pi11a11ga is usually   planted   on the poor  and degraded  area.   Application   of  chemical  fertilizer and compost  is used to increase  the survival  and growth  of  the  seedlings.  Excessive chemical fertilizer  input  to soil, however,  may cause  negative  effect on  soil,  plant  and  environment. Conversely,  compost  may improve soil porosity, soil aggregate,  water absorption   and soil fertility. The objective  of  the study  was  to examine  effect  of  planting  media  on growth  of  S. pinanga  seedlings. Complete  randomized  design has been arranged with 5 treatments,  e.g. soil mixed with husk  (at the proportion   of  1:1, soil mixed with acacia compost  (1:1,   soil mixed with charcoal of  rice husk (1:1   and soil mixed with humic acid (1:1.    Another  treatment  was  soil alone  used as control.   The  result showed that  growth  of  both  stem  height   and  diameter,  and  index  of seedling  quality  were affected  significantly   by planting  media.    The mixture  of  soil and  acacia compost  (1 :1  was the best  planting media for the growth  of S. pinanga seedlings,  which resulted in the growth  of height  (24.19   cm and stem diameter  (0.246 cm.  Meanwhile, soil mixed with rice husk charcoal (1:1  gave the best result to the index of  seedling quality (ISQ = 1.34   and total dry weight (TOW=   15.93  g.

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. Study the effect of salinity levels and seed priming on germination and seedling properties of two medicinal plant species from Asteraceae family

    Directory of Open Access Journals (Sweden)

    M. Kafi

    2016-04-01

    Full Text Available Soil and water sources salinity are important constrains which threat the sustainable agriculture production in Iran. In order to evaluate the effect of different antioxidants and salinity levels on germination and seedling properties of two medicinal species (Cnicus benedictus L., and (Cichorium intybus L., an experiment was conducted using a factorial based on completely randomized design with four replications at Special Crops Laboratory of Ferdowsi University of Mashhad. The studied factor for each plant included: seed priming at 4 levels including control (distilled water, ascorbic acid (40 mM, gibberlic acid (75 mg.lit-1 and salicylic acid (1.5 mM, and five salinity levels according to electrical conductivity by adding NaCl to distilled water (control, 5,10,15 and 20 ds.m-1. According to results, pretreatment with salicylic acid improved all of the germination and seedling properties in Cnicus benedictus L. but gibberlic acid could to improved germination and seedling properties in Cichorium intybus L. species. There were strong correlation between germination rate and radical and caulicle length especially on Cichorium intybus species. Generally, seed priming with gibberlic acid and salicylic acid could improve germination and seedling properties of these two species. Both species showed a reliable tolerance to NaCl salinity at germination stage, and germination was 60% compared with control at 20 ds.m-1 treatment.

  4. Productivity

    DEFF Research Database (Denmark)

    Spring, Martin; Johnes, Geraint; Hald, Kim Sundtoft

    Productivity is increasingly critical for developed economies. It has always been important: as Paul Krugman puts it, “Productivity isn’t everything, but in the long run it is almost everything. A country’s ability to improve its standard of living over time depends almost entirely on its ability...... to raise its output per worker”(Krugman, 1994). Analyses of productivity have, by and large, been the preserve of economists. Operations Management (OM) is rooted in a similar concern for the efficient use of scarce resources; Management Accounting (MA) is concerned with the institutionalised measurement...... and management of productivity. Yet the three perspectives are rarely connected. This paper is a sketch of a literature review seeking to identify, contrast and reconcile these three perspectives. In so doing, it aims to strengthen the connections between policy and managerial analyses of productivity....

  5. Fungal disease prevention in seedlings of rice (Oryza sativa) and other grasses by growth-promoting seed-associated endophytic bacteria from invasive Phragmites australis

    Science.gov (United States)

    Verma, Satish K.; Kingsley, Kathryn L.; Bergen, Marshall S.; Kowalski, Kurt P.; White, James F.

    2018-01-01

    Non-cultivated plants carry microbial endophytes that may be used to enhance development and disease resistance of crop species where growth-promoting and protective microbes may have been lost. During seedling establishment, seedlings may be infected by several fungal pathogens that are seed or soil borne. Several species of Fusarium, Pythium and other water moulds cause seed rots during germination. Fusariumblights of seedlings are also very common and significantly affect seedling development. In the present study we screened nine endophytic bacteria isolated from the seeds of invasive Phragmites australis by inoculating onto rice, Bermuda grass (Cynodon dactylon), or annual bluegrass (Poa annua) seeds to evaluate plant growth promotion and protection from disease caused by Fusarium oxysporum. We found that three bacteria belonging to genus Pseudomonas spp. (SLB4-P. fluorescens, SLB6-Pseudomonas sp. and SY1-Pseudomonassp.) promoted seedling development, including enhancement of root and shoot growth, and stimulation of root hair formation. These bacteria were also found to increase phosphate solubilization in in vitro experiments. Pseudomonas sp. (SY1) significantly protected grass seedlings from Fusarium infection. In co-culture experiments, strain SY1 strongly inhibited fungal pathogens with 85.71% growth inhibition of F. oxysporum, 86.33% growth inhibition of Curvularia sp. and 82.14% growth inhibition of Alternaria sp. Seedlings previously treated with bacteria were found much less infected by F. oxysporum in comparison to non-treated controls. On microscopic observation we found that bacteria appeared to degrade fungal mycelia actively. Metabolite products of strain SY1 in agar were also found to inhibit fungal growth on nutrient media. Pseudomonas sp. (SY1) was found to produce antifungal volatiles. Polymerase chain reaction (PCR) amplification using specific primers for pyrrolnitirin synthesis and HCN (hydrogen cyanide) production

  6. Growth reponses of eggplant and soybean seedlings to mechanical stress in greenhouse and outdoor environments

    Science.gov (United States)

    Latimer, J. G.; Pappas, T.; Mitchell, C. A.

    1986-01-01

    Eggplant (Solanum melongena L. var. esculentum 'Burpee's Black Beauty') and soybean [Glycine max (L.) Merr. 'Wells II'] seedlings were assigned to a greenhouse or a windless or windy outdoor environment. Plants within each environment received either periodic seismic (shaking) or thigmic (flexing or rubbing) treatment, or were left undisturbed. Productivity (dry weight) and dimensional (leaf area and stem length) growth parameters generally were reduced more by mechanical stress in the greenhouse (soybean) or outdoor-windless environment (eggplant) than in the outdoor windy environment. Outdoor exposure enhanced both stem and leaf specific weights, whereas mechanical stress enhanced only leaf specific weight. Although both forms of controlled mechanical stress tended to reduce node and internode diameters of soybean, outdoor exposure increased stem diameter.

  7. Insecticidal activity of neem oil against Gyropsylla spegazziniana (Hemiptera: Psyllidae nymphs on Paraguay tea seedlings

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    M. A. Formentini

    Full Text Available Abstract Gyropsylla spegazziniana (Paraguay tea ampul is one of the most important pests of Paraguay tea plants, and prohibition of synthetic insecticide use for control of this pest has led to the search for alternative methods. This laboratory study aimed to compare different control strategies for G. spegazziniana, utilizing a commercial neem seed oil product. Paraguay tea seedlings were treated with neem oil solution both pre- and post-infestation with 5th instar nymphs. The systemic action of neem oil was also evaluated by treating plant soil with the neem oil solution, followed by transfer of the insects to plants 24 h post-treatment. Spray treatments were effective against the pest, especially post-infestation (80% mortality, demonstrating the potential of neem oil for control of the Paraguay tea ampul. No significant effects were observed with respect to systemic activity.

  8. Growth and Chemical Composition of Pistachio Seedlings under Different Levels of Manganese in Greenhouse Conditions

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    T. Poorbafrani

    2016-09-01

    Full Text Available Introduction: Pistachio is one of the most important crops in many regions of Iran with respect of production and export. There are more than 470000 ha of nonbearing and bearing pistachio trees mainly in Kerman province. Despite the economic importance of this crop, very little information is available on its nutritional requirements. Pistachio trees like other crops need to macro and micro nutrients. one of these elements is manganese (Mn. Manganese is an essential mineral nutrient, playing a key role in several physiological processes, particularly photosynthesis, respiration and nitrogen assimilation. This element is normally supplied to the plants by soil. Therefore, soil conditions affect its availability to plants. Soils with high pH, calcareous soils, especially those with poor drainage and high organic matter, are among the soils which produce Mn-deficient plants. Calcium carbonate is the major inactivation factor of Mn in calcareous soils. The soils of Iran are predominantly calcareous in which micronutrients deficiency, including Mn, is observed due to the high pH and nutrient fixation. The objective of this research was to examine the effect of manganese application on growth and chemical composition of pistachio seedlings in some calcareous soils with different chemical and physical properties. Materials and Methods: For this purpose a greenhouse experiment was carried out as factorial (two factors including soil type and Mn levels experiment in completely randomized design with three replications. Treatments were consisted of three levels of Mn (0, 10 and 20 mg Mn Kg-1 soil as Manganese sulfate and 12 different soils from Rafsanjan region in Southern Iran. Soil samples were air dried and crushed to pass through a 2-mm sieve, and some physical and chemical properties of soils such as texture, electrical conductivity, pH, organic matter content, calcium carbonate equivalent, cation exchange capacity and iron, manganese, copper and

  9. 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 ...

  10. 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...

  11. 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

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

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    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.

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

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    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

  14. 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.

  15. 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.

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

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    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.

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

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    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.

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

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    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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. Effects of Pretreatment with Salicylic Acid on Growth and Nutrient Uptake of Sesame Seedlings under Salt Stress

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    H Safari

    2018-02-01

    Full Text Available Introduction Salinity stress is regarded as one of the most important abiotic factors limiting plant growth and agricultural products, particularly in arid and semi-arid regions. Sesame (Sesamum indicum L. is an important oilseed crop rated moderately salt tolerant and capable of producing profitable crops in saline conditions. Germination and seedling establishment are critical stages in the life cycle of plants especially under stress conditions. Different methodologies have been adopted by plant physiologists in different crops to alleviate salt stress. Seed priming has proven beneficial in this regard in many important agricultural crops. Salicylic acid is one of the physiological processes regulators that it increases resistant of plants to environmental stresses such as salinity stress. Materials and Methods To evaluate the effect of different levels of salinity and seed pretreatment with salicylic acid (SA, on some growth indices and nutrient uptake of sesame (Sesamum indicum L. seedling, a factorial experiment with completely randomized design and four replicates was conducted in Department of Agronomy, Rafsanjan University of Vali-e- Asr. Factors were seed pretreatment with three levels including, distilled water, 1 mM salicylic acid and 2.5 Mm salicylic acid and salinity at three levels: control (Hoagland standard solution, 2.5 dS.m-1, 6 and 9 dS.m-1. A dry seed treatment (no pretreatment was also added and considered as control. Results and Discussion Results showed that at 9 dS/m-1both SA concentrations caused significant increase in emergence percentage compared to dry seed and distilled water. Plant leaf area and SPAD values decreased along with salinity in dry seed and distilled water, nevertheless, at 2.5 mM SA, values were not significantly different between 6 and 9 dS.m-1. On the other hand, SA seed pretreatment decreased shoot Na and increased K content, although shoot Mg and P contents were the highest at 1 and 2.5 mM SA

  5. Nitrogênio, fósforo e potássio na nutrição e na produção de mudas de laranjeira 'Valência', enxertada sobre citrumeleiro 'Swingle' Nitrogen, phosphorus and potassium on nutrition and production of seedlings of 'Valencia' orange

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    Renato de Mello Prado

    2008-09-01

    Full Text Available O experimento foi conduzido em estufa telada na FCAV/Unesp Câmpus Jaboticabal-SP, durante o período de novembro de 2005 a janeiro de 2007. O estudo teve por objetivo avaliar componentes do desenvolvimento e do estado nutricional de mudas de laranjeira 'Valência', enxertada sobre citrumeleiro 'Swingle', cultivado em substrato, em função de doses de nitrogênio, fósforo e potássio. O delineamento experimental foi o inteiramente casualizado, em esquema fatorial 3³ + 1, sendo 3 fatores (nitrogênio, fósforo e potássio, 3 doses e uma testemunha (sem adubação, com 3 repetições. A unidade experimental foi constituída de uma muda de laranjeira por sacolas de 5 dm-3, contendo 2,5 kg de substrato casca de Pinus e vermiculita. Os tratamentos foram constituídos pela aplicação das seguintes doses de nutrientes em mg por dm³ de substrato: N1/2:459, N1:918 e N2:1836; P1/2:92, P1:184 e P2: 368; K1/2:438, K1:876 e K2:1752. Aos 424 dias após a semeadura, as plantas foram divididas em raízes e parte aérea para a determinação da massa da matéria seca, altura, área foliar, diâmetro do caule e conteúdo de nutrientes. As adubações com N, P e K proporcionaram maior crescimento e maior acúmulo de N, P e K na parte aérea e nas raízes das mudas de laranjeira, em substrato de casca de Pinus e vermiculita, em relação à testemunha. A dose de 459 mg dm-3 de N e as doses de P e K 184 e 876 mg dm-3, respectivamente, proporcionaram melhor crescimento da parte aérea das mudas; porém, na dose recomendada de N de 918 mg dm-3, ocorreu maior crescimento do sistema radicular.The experiment was led in a protected greenhouse in the FCAV/Unesp, Jaboticabal Campus -SP, during the period of November of 2005 to January of 2007. The study objective was to evaluate the development of components and the nutritional state of seedlings of 'Valencia' orange grafted on lemon tree citrumelo 'Swingle' rootstock, in function of nitrogen, phosphorus and potassium

  6. Evaluation of Cd effects on growth and some oxidative stress parameters of wheat cultivars during seedling stage

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    Ezatollah Esfandiari

    2016-03-01

    S-transferase, catalase and ascorbate peroxidase enzymes are probably the main reasons of the lipid peroxidation increase in Kohdasht cultivar. However, there was no damage on membranes of Izengran and Pishtase cultivars, which indicates the balance between production and scavenging of damaging factors of these cultivars. Generally, it can be stated that available Cd in medium was adsorbed and accumulated in wheat leaves resulting in reduction in dry matter of different parts and whole seedling of wheat which is due to susebtability of different cultivars to Cd. However, there were no oxidative stresses in leaves of Gaskogen, Agosta and MV17 cultivars due to their better defense mechanisms.

  7. Vegetative and seedling regeneration of pin cherry (Prunus pensylvanica): Efficacy of herbicide treatment. NODA note No. 21

    Energy Technology Data Exchange (ETDEWEB)

    Mallik, A U; Bell, F W; Peterson, G W

    1996-11-01

    Pin cherry (Prunus pensylvanica L.) is a major competing plant commonly found in young conifer plantations in both boreal and northern hardwood forests. This note describes and presents results of a study conducted to determine, for pin cherry, the ratio of the current year`s seedling recruitment versus the previous year`s stem density; seed production; the soil seed bank; and the efficacy of a glyphosate herbicide treatment to control this competitor. The study was carried out in a seven-year-old jack pine plantation north of Atikokan, Ontario.

  8. Nitric Oxide Regulates Seedling Growth and Mitochondrial Responses in Aged Oat Seeds

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    Chunli Mao

    2018-04-01

    Full Text Available Mitochondria are the source of reactive oxygen species (ROS in plant cells and play a central role in the mitochondrial electron transport chain (ETC and tricarboxylic acid cycle (TCA cycles; however, ROS production and regulation for seed germination, seedling growth, as well as mitochondrial responses to abiotic stress, are not clear. This study was conducted to obtain basic information on seed germination, embryo mitochondrial antioxidant responses, and protein profile changes in artificial aging in oat seeds (Avena sativa L. exposed to exogenous nitric oxide (NO treatment. The results showed that the accumulation of H2O2 in mitochondria increased significantly in aged seeds. Artificial aging can lead to a loss of seed vigor, which was shown by a decline in seed germination and the extension of mean germination time (MGT. Seedling growth was also inhibited. Some enzymes, including catalase (CAT, glutathione reductase (GR, dehydroascorbate reductase (DHAR, and monodehydroascorbate reductase (MDHAR, maintained a lower level in the ascorbate-glutathione (AsA-GSH scavenging system. Proteomic analysis revealed that the expression of some proteins related to the TCA cycle were down-regulated and several enzymes related to mitochondrial ETC were up-regulated. With the application of 0.05 mM NO in aged oat seeds, a protective effect was observed, demonstrated by an improvement in seed vigor and increased H2O2 scavenging ability in mitochondria. There were also higher activities of CAT, GR, MDHAR, and DHAR in the AsA-GSH scavenging system, enhanced TCA cycle-related enzymes (malate dehydrogenase, succinate-CoA ligase, fumarate hydratase, and activated alternative pathways, as the cytochrome pathway was inhibited. Therefore, our results indicated that seedling growth and seed germinability could retain a certain level in aged oat seeds, predominantly depending on the lower NO regulation of the TCA cycle and AsA-GSH. Thus, it could be concluded that the

  9. Combined Inoculation with Multiple Arbuscular Mycorrhizal Fungi Improves Growth, Nutrient Uptake and Photosynthesis in Cucumber Seedlings

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    Shuangchen Chen

    2017-12-01

    , Fe, Mn, Mg, and Zn in roots. Further analysis revealed that inoculation with VT had relatively better effect on growth of cucumber seedling followed by BF and Fm, indicating that AMF composition consisting of distant AMF species may have a better effect than a single or closely related AMF spp. This study advances the understanding of plant responses to different AM fungi toward development of strategies on AMF-promoted vegetable production.

  10. Observações sôbre a produtividade de seringueiras (Hevea brasiliensis muell.-arg. Plantadas de sementes: IV - Produtividade de 29 plantas existentes na travessa Itororó, Belém, Pá Observations on the latex production of seedlings of rubber trees (Hevea brasiliensis muell.-arg.: IV - Study of 29 rubber trees of the travessa Itororó, Belém, Pará

    Directory of Open Access Journals (Sweden)

    Luiz O. T. Mendes

    1960-01-01

    Full Text Available Neste trabalho são apresentados os resultados do estudo da produtividade de 29 seringueiras plantadas de sementes, existentes na Travessa Itororó, Belém, quando tinham a idade de 25 anos aproximadamente. Os resultados se referem à produção obtida de sangrias feitas a meia espiral, em dois regimes de trabalho: a em dias alternados, de 16 de setembro de 1943 a 31 de março de 1944; b todos os dias úteis, de 1.° de abril a 30 de setembro de 1944. Do conjunto de seringueiras estudadas os resultados mostram que a melhor planta logo após as primeiras sangrias já se classificara em primeiro lugar, quanto à produção. Os dados revelam também que houve pequena diminuição na produção média da população, ao passar para o regime de sangria diária; observou-se no entanto, que o decréscimo de produção foi mois pronunciado e freqüente entre as plantas de maior produtividade médio no regime de sangria em dias alternados. O estudo da população como um todo mostra que uma pequena parcela das plantas contribuiu com grande parte da produção; em ambos os regimes de trabalho, cerca de 25% da população de plantas foram responsáveis por aproximadamente 50% do produção de látex, e mais ou menos 50% da população de plantas produziram cerca de 75% da produção de látex. Tais resultados mostram a importância que se deve dar à eliminação precoce de plantas pouco produtivas, no caso de se fazerem plantações a partir de sementes não selecionadas.The results of 13 month tappings (half-spiral cut of 29 seedlings of rubber trees, approximately 25 years old, ore presented. From September 16, 1943 to March 31, 1944, the trees were tapped every other day; from Abril 1st, to September 30, 1944, every day. The change of the tapping system, from every other day to daily, caused a small decrease in the mean yield of the group, per tapping; this yield decrease was more pronounced and frequent in the high production plants. It must be

  11. Efeito da qualidade das sementes sobre a formação de mudas de alface Effect of seed quality on lettuce seedlings development

    Directory of Open Access Journals (Sweden)

    Simone M. Franzin

    2005-06-01

    Full Text Available Determinou-se o efeito da qualidade fisiológica das sementes sobre a formação de mudas de alface. Utilizaram-se dois lotes de sementes com diferentes níveis de qualidade inicial, das cultivares Regina e Vera, selecionados por meio dos testes de germinação, primeira contagem, envelhecimento acelerado, condutividade elétrica e emergência em "gerbox". Os efeitos dos níveis de qualidade sobre a produção de mudas foram avaliados por meio dos testes de índice de velocidade de emergência, número de folhas, altura da parte aérea, comprimento de raízes, massa úmida e seca das mudas e classificação do vigor das mudas. Utilizou-se o delineamento inteiramente casualizado, com os dados analisados pelo teste Tukey em 5% de probabilidade. Houve efeito favorável na qualidade das sementes das cultivares Regina e Vera para a formação de mudas aos 20 dias após a semeadura. Concluiu-se que sementes de alta qualidade fisiológica produzem maior percentagem de mudas vigorosas, com maior número de folhas, maior altura da parte aérea e comprimento de raízes e maior massa aos 20 dias de cultivo.The effect of the physiological quality of the seeds on lettuce seedlings was established. Two lots of lettuce seeds cv. Regina and Vera with different levels of initial quality were used. These lots were selected based upon germination tests: first score, fast aging, electrical conductivity and emergence in gerbox. The effects of the quality levels on the seedling production were evaluated through the parameters: speed rate emergence tests, number of leaves, height of the aerial part, root length, dry and wet mass of the seedlings and classification of the vitality of the seedlings. The experiment was carried out in a completely randomized design with four replications. Seed quality of the cultivars Regina and Vera have a positive effect on the formation of seedlings 20 days after sowing. High physiological quality seeds produce a higher percentage of

  12. The growth and uptake of Ga and In of rice (Oryza sative L.) seedlings as affected by Ga and In concentrations in hydroponic cultures.

    Science.gov (United States)

    Syu, Chien-Hui; Chien, Po-Hsuan; Huang, Chia-Chen; Jiang, Pei-Yu; Juang, Kai-Wei; Lee, Dar-Yuan

    2017-01-01

    Limited information is available on the effects of gallium (Ga) and indium (In) on the growth of paddy rice. The Ga and In are emerging contaminants and widely used in high-tech industries nowadays. Understanding the toxicity and accumulation of Ga and In by rice plants is important for reducing the effect on rice production and exposure risk to human by rice consumption. Therefore, this study investigates the effect of Ga and In on the growth of rice seedlings and examines the accumulation and distribution of those elements in plant tissues. Hydroponic cultures were conducted in phytotron glasshouse with controlled temperature and relative humidity conditions, and the rice seedlings were treated with different levels of Ga and In in the nutrient solutions. The growth index and the concentrations of Ga and In in roots and shoots of rice seedlings were measured after harvesting. A significant increase in growth index with increasing Ga concentrations in culture solutions (<10mgGaL -1 ) was observed. In addition, the uptake of N, K, Mg, Ca, Mn by rice plants was also enhanced by Ga. However, the growth inhibition were observed while the In concentrations higher than 0.08mgL -1 , and the nutrients accumulated in rice plants were also significant decreased after In treatments. Based on the dose-response curve, we observed that the EC 10 (effective concentration resulting in 10% growth inhibition) value for In treatment was 0.17mgL -1 . The results of plant analysis indicated that the roots were the dominant sink of Ga and In in rice seedlings, and it was also found that the capability of translocation of Ga from roots to shoots were higher than In. In addition, it was also found that the PT 10 (threshold concentration of phytotoxicity resulting in 10% growth retardation) values based on shoot height and total biomass for In were 15.4 and 10.6μgplant -1 , respectively. The beneficial effects on the plant growth of rice seedlings were found by the addition of Ga in

  13. [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.

  14. 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

  15. Antioxidant properties of soybean seedlings inoculated with Trichoderma asperellum

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    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

  16. Drought-Induced Leaf Proteome Changes in Switchgrass Seedlings

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    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

  17. 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...

  18. 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.

  19. 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)

  20. Superação de dormência na qualidade de sementes e mudas: influência na produção de Senna multijuga (L. C. Rich. Irwin & Barneby Overcoming of dormancy in the quality of seeds and seedlings: influence in the production of Senna multijuga (L.C. Rich. Irwin & barneby

    Directory of Open Access Journals (Sweden)

    Graziela Piveta

    2010-01-01

    Full Text Available O objetivo deste trabalho foi determinar a qualidade fisiológica e sanitária de sementes de Senna multijuga(L. C. Rich. Irwin & Barneby relacionada aos métodos de superação de dormência e à interferência na produção de mudas. As sementes foram submetidas aos seguintes métodos: imersão em água fervente, as sementes foram imersas em água, com temperatura de 100°C, até esfriar, por 24 horas; escarificação ácida, onde as sementes foram imersas em ácido sulfúrico (H2SO4 a 90%, por 10 e 20 minutos, e testemunha (sem tratamento. Foram realizados os testes de sanidade, germinação, tetrazólio e avaliação da qualidade das mudas. O delineamento experimental foi inteiramente casualizado. Para a avaliação da germinação foi utilizado um esquema fatorial (4 X 2, com quatro métodos de superação de dormência X dois fotoperíodos, para os substratos rolo-de-papel e vermiculita. A escarificação ácida constituiu-se no método mais eficiente para a superação da dormência das sementes de Senna multijuga. Penicillium sp. e Aspergillus sp. tiveram sua incidência aumentada quando o tegumento foi danificado pela escarificação ácida por 20 minutos. O controle de Fusarium spp. aumentou gradativamente com o aumento do tempo de exposição ao ácido sulfúrico.The objective of this work was to determine the physiological and sanitary quality of Senna multijugaseeds related to the methods of dormancy overcoming and the influence on the seedlings quality. The seeds had been submitted to the following methods :immersion in water fervent, the seeds had been immersed in water, at 100°C, until cooling for 24 hours; acid escarification, where the seeds had been immersed in sulfuric acid (H2SO4 90%, for 10 and 20 minutes, and control (without treatment. The tests of sanity, germination and tetrazolium had been carried through, and were evaluated the quality of the seedlings. For the germination of the evaluation an factorial project was

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

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    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.

  2. Foliar potassium nitrate application improves the tolerance of Citrus macrophylla L. seedlings to drought conditions.

    Science.gov (United States)

    Gimeno, V; Díaz-López, L; Simón-Grao, S; Martínez, V; Martínez-Nicolás, J J; García-Sánchez, F

    2014-10-01

    Scarcity of water is a severe limitation in citrus tree productivity. There are few studies that consider how to manage nitrogen (N) nutrition in crops suffering water deficit. A pot experiment under controlled-environment chambers was conducted to explore if additional N supply via foliar application could improve the drought tolerance of Citrus macrophylla L. seedlings under dry conditions. Two-month-old seedlings were subjected to a completely random design with two water treatments (drought stress and 100% water/field capacity). Plants under drought stress (DS) received three different N supplies via foliar application (DS: 0, DS + NH4NO3: 2% NH4NO3, DS + KNO3: 2% KNO3). KNO3-spraying increased leaf and stem DW as compared with DS + NH4NO3 and DS treatments. Leaf water potential (Ψw) was decreased by drought stress in all the treatments. However, in plants from DS + NH4NO and DS + KNO3, this was due to a decrease in the leaf osmotic potential, whereas the decrease in those from the DS treatment was due to a decrease in the leaf turgor potential. These responses were correlated with the leaf proline and K concentrations. DS + KNO3-treated plants had a higher leaf proline and K concentration than DS-treated plants. In terms of leaf gas exchange parameters, it was observed that net assimilation of CO2 [Formula: see text] was decreased by drought stress, but this reduction was much lower in DS + KNO3-treated plants. Thus, when all results are taken into account, it can be concluded that a 2% foliar-KNO3 application can enhance the tolerance of citrus plants to water stress by increasing the osmotic adjustment process. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  3. Behavior of Eucalyptus urophylla and Eucalyptus citriodora Seedlings Grown in Soil Contaminated by Arsenate

    Directory of Open Access Journals (Sweden)

    Roseli Freire Melo

    2016-01-01

    Full Text Available ABSTRACT Persistent areas of tailings and deposits from coal and gold mining may present high levels of arsenic (As, mainly in the arsenate form, endangering the environment and human health. The establishment of vegetation cover is a key step to reclaiming these environments. Thus, this study aimed to evaluate the potential of Eucalyptus urophylla and E. citriodora seedlings for use in phytoremediation programs of arsenate-contaminated areas. Soil samples were incubated at increasing rates (0, 50, 100, 200 and 400 mg dm-3 of arsenic (arsenate form, using Na2HAsO4 for 15 days. The seedlings were produced in a substrate (vermiculite + sawdust and were transplanted to the pots with soil three months after seed germination. The values of plant height and diameter were taken during transplanting and 30, 60 and 90 days after transplanting. In the last evaluation, the total leaf area and biomass of shoots and roots were also determined. The values of available As in soil which caused a 50 % dry matter reduction (TS50%, the As translocation index (TI from the roots to the shoot of the plants, and its bioconcentration factor (BF were also calculated. Higher levels of arsenate in the soil significantly reduced the dry matter production of roots and shoots and the height of both species, most notably in E. urophylla plants. The highest levels of As were found in the root, with higher values for E. citriodora (ranging from 253.86 to 400 mg dm-3. The TI and BF were also reduced with As doses, but the values found in E. citriodora were significantly higher than in E. urophylla. E. citriodora plants presented a higher capacity to tolerate As and translocate it to the shoot than E. urophylla. Although these species cannot be considered as hyperaccumulators of As, E. citriodora presented the potential to be used in phytoremediation programs in arsenate-contaminated areas due to the long-term growth period of this species.

  4. Pinus pinaster seedlings and their fungal symbionts show high plasticity in phosphorus acquisition in acidic soils.

    Science.gov (United States)

    Ali, M A; Louche, J; Legname, E; Duchemin, M; Plassard, C

    2009-12-01

    Young seedlings of maritime pine (Pinus pinaster Soland in Aït.) were grown in rhizoboxes using intact spodosol soil samples from the southwest of France, in Landes of Gascogne, presenting a large variation of phosphorus (P) availability. Soils were collected from a 93-year-old unfertilized stand and a 13-year-old P. pinaster stand with regular annual fertilization of either only P or P and nitrogen (N). After 6 months of culture in controlled conditions, different morphotypes of ectomycorrhiza (ECM) were used for the measurements of acid phosphatase activity and molecular identification of fungal species using amplification of the ITS region. Total biomass, N and P contents were measured in roots and shoots of plants. Bicarbonate- and NaOH-available inorganic P (Pi), organic P (Po) and ergosterol concentrations were measured in bulk and rhizosphere soil. The results showed that bulk soil from the 93-year-old forest stand presented the highest Po levels, but relatively higher bicarbonate-extractable Pi levels compared to 13-year-old unfertilized stand. Fertilizers significantly increased the concentrations of inorganic P fractions in bulk soil. Ergosterol contents in rhizosphere soil were increased by fertilizer application. The dominant fungal species was Rhizopogon luteolus forming 66.6% of analysed ECM tips. Acid phosphatase activity was highly variable and varied inversely with bicarbonate-extractable Pi levels in the rhizosphere soil. Total P or total N in plants was linearly correlated with total plant biomass, but the slope was steep only between total P and biomass in fertilized soil samples. In spite of high phosphatase activity in ECM tips, P availability remained a limiting nutrient in soil samples from unfertilized stands. Nevertheless young P. pinaster seedlings showed a high plasticity for biomass production at low P availability in soils.

  5. A New Strategy in Observer Modeling for Greenhouse Cucumber Seedling Growth

    Science.gov (United States)

    Qiu, Quan; Zheng, Chenfei; Wang, Wenping; Qiao, Xiaojun; Bai, He; Yu, Jingquan; Shi, Kai

    2017-01-01

    State observer is an essential component in computerized control loops for greenhouse-crop systems. However, the current accomplishments of observer modeling for greenhouse-crop systems mainly focus on mass/energy balance, ignoring physiological responses of crops. As a result, state observers for crop physiological responses are rarely developed, and control operations are typically made based on experience rather than actual crop requirements. In addition, existing observer models require a large number of parameters, leading to heavy computational load and poor application feasibility. To address these problems, we present a new state observer modeling strategy that takes both environmental information and crop physiological responses into consideration during the observer modeling process. Using greenhouse cucumber seedlings as an instance, we sample 10 physiological parameters of cucumber seedlings at different time point during the exponential growth stage, and employ them to build growth state observers together with 8 environmental parameters. Support vector machine (SVM) acts as the mathematical tool for observer modeling. Canonical correlation analysis (CCA) is used to select the dominant environmental and physiological parameters in the modeling process. With the dominant parameters, simplified observer models are built and tested. We conduct contrast experiments with different input parameter combinations on simplified and un-simplified observers. Experimental results indicate that physiological information can improve the prediction accuracies of the growth state observers. Furthermore, the simplified observer models can give equivalent or even better performance than the un-simplified ones, which verifies the feasibility of CCA. The current study can enable state observers to reflect crop requirements and make them feasible for applications with simplified shapes, which is significant for developing intelligent greenhouse control systems for modern

  6. A New Strategy in Observer Modeling for Greenhouse Cucumber Seedling Growth

    Directory of Open Access Journals (Sweden)

    Quan Qiu

    2017-08-01

    Full Text Available State observer is an essential component in computerized control loops for greenhouse-crop systems. However, the current accomplishments of observer modeling for greenhouse-crop systems mainly focus on mass/energy balance, ignoring physiological responses of crops. As a result, state observers for crop physiological responses are rarely developed, and control operations are typically made based on experience rather than actual crop requirements. In addition, existing observer models require a large number of parameters, leading to heavy computational load and poor application feasibility. To address these problems, we present a new state observer modeling strategy that takes both environmental information and crop physiological responses into consideration during the observer modeling process. Using greenhouse cucumber seedlings as an instance, we sample 10 physiological parameters of cucumber seedlings at different time point during the exponential growth stage, and employ them to build growth state observers together with 8 environmental parameters. Support vector machine (SVM acts as the mathematical tool for observer modeling. Canonical correlation analysis (CCA is used to select the dominant environmental and physiological parameters in the modeling process. With the dominant parameters, simplified observer models are built and tested. We conduct contrast experiments with different input parameter combinations on simplified and un-simplified observers. Experimental results indicate that physiological information can improve the prediction accuracies of the growth state observers. Furthermore, the simplified observer models can give equivalent or even better performance than the un-simplified ones, which verifies the feasibility of CCA. The current study can enable state observers to reflect crop requirements and make them feasible for applications with simplified shapes, which is significant for developing intelligent greenhouse control

  7. A New Strategy in Observer Modeling for Greenhouse Cucumber Seedling Growth.

    Science.gov (United States)

    Qiu, Quan; Zheng, Chenfei; Wang, Wenping; Qiao, Xiaojun; Bai, He; Yu, Jingquan; Shi, Kai

    2017-01-01

    State observer is an essential component in computerized control loops for greenhouse-crop systems. However, the current accomplishments of observer modeling for greenhouse-crop systems mainly focus on mass/energy balance, ignoring physiological responses of crops. As a result, state observers for crop physiological responses are rarely developed, and control operations are typically made based on experience rather than actual crop requirements. In addition, existing observer models require a large number of parameters, leading to heavy computational load and poor application feasibility. To address these problems, we present a new state observer modeling strategy that takes both environmental information and crop physiological responses into consideration during the observer modeling process. Using greenhouse cucumber seedlings as an instance, we sample 10 physiological parameters of cucumber seedlings at different time point during the exponential growth stage, and employ them to build growth state observers together with 8 environmental parameters. Support vector machine (SVM) acts as the mathematical tool for observer modeling. Canonical correlation analysis (CCA) is used to select the dominant environmental and physiological parameters in the modeling process. With the dominant parameters, simplified observer models are built and tested. We conduct contrast experiments with different input parameter combinations on simplified and un-simplified observers. Experimental results indicate that physiological information can improve the prediction accuracies of the growth state observers. Furthermore, the simplified observer models can give equivalent or even better performance than the un-simplified ones, which verifies the feasibility of CCA. The current study can enable state observers to reflect crop requirements and make them feasible for applications with simplified shapes, which is significant for developing intelligent greenhouse control systems for modern

  8. The effect of plant growth-promoting rhizobacteria on asparagus seedlings and germinating seeds subjected to water stress under greenhouse conditions.

    Science.gov (United States)

    Liddycoat, Scott M; Greenberg, Bruce M; Wolyn, David J

    2009-04-01

    Plant growth-promoting rhizobacteria (PGPR) can have positive effects on vigour and productivity, especially under stress conditions. In asparagus (Asparagus officinalis L.) field culture, seeds are planted in high-density nurseries, and 1-year-old crowns are transplanted to production fields. Performance can be negatively affected by water stress, transplant shock, and disease pressure on wounded roots. PGPR inoculation has the potential to alleviate some of the stresses incurred in the production system. In this study, the effects of PGPR (Pseudomonas spp.) treatment were determined on 3-week-old greenhouse-grown seedlings and germinating seeds of 2 asparagus cultivars. The pots were irrigated to a predetermined level that resulted in optimum growth or the plants were subjected to drought or flooding stress for 8 weeks. The cultivars responded differently to PGPR: single inoculations of seedlings enhanced growth of 'Guelph Millennium' under optimum conditions and 'Jersey Giant' seedlings under drought stress. Seed inoculations with PGPR resulted in a positive response only for 'Guelph Millennium', for which both single or multiple inoculations enhanced plant growth under drought stress.

  9. 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.

  10. 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, ...

  11. 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...

  12. 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

  13. 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...

  14. 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

  15. 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

  16. 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

  17. 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...

  18. 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...

  19. 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...

  20. 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...