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.
Ali, S.S.; Jafri, S.J.H.; Jamil, M.; Ijaz, M.
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)
Dec 17, 2007 ... The role of 20E in plant physiology including seed germination is not studied. ..... GA3, ABA and CKs on lettuce Lactuca sativa seed germination are ..... Practical uses for ecdysteroids in mammals and humans: an update. J.
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 ...
Dec 17, 2007 ... however, abscisic acid (ABA) can counter this effect by keeping seeds ... Tris-HCl buffer at pH 8.8, with constant current set at 20 mA/gel. The gels were ..... on plants is rarely studied and the importance of 20E in the life cycle ...
Deoli, Naresh; Hasenstein, Karl H.
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
Zhang, Ming; Gao, Bin, E-mail: firstname.lastname@example.org [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)
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.
Wang, T.T.; Chu, G.M.; Jiang, P.; Wang, M.
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)
Philip M. McDonald
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...
Verma, S K; Kingsley, K; Irizarry, I; Bergen, M; Kharwar, R N; White, J F
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.
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 ...
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 ...
Heneghan, J B; Robinson, J W; Menge, H; Winistörfer, B
Mechanical occlusions were created in the intestines of four germ-free dogs. At the time of the operation, a control loop of mid-intestine was perfused in vivo and then excised for examinations in vitro, which included the determination of the equilibrium uptake of phenylalanine and of beta-methyl-glucoside, the influx kinetics of phenylalanine and morphometric analysis of the mucosa by microdissection and stereological techniques. Seven days after establishment of the occlusion the abdomen was reopened, and loops above and below the occlusion were perfused, and then excised for the same tests in vitro. Unlike occluded loops of conventional dogs, the intestine of the germ-free animal above the occlusion does not secrete water and electrolytes into the lumen. Its transport properties in vitro do not differ from those of the control loop, and the morphometric analyses reveal only slight changes in villus structure. The loop below the obstruction undergoes marked atrophy, as has been observed in conventional dogs. The results suggest that the copious secretion that occurs above an intestinal obstruction in normal animals is due to the presence of an abundant bacterial population in the obstruction fluid.
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.
Tathiana Elisa Masetto
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.
Timothy B. Harrington
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...
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.
Joshua D. Klein
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.
Jiang, X.; Li, H.; Song, X.
The effects on seed germination and seedling growth in maize under salinity stress by seed priming with melatonin were investigated. Seeds of maize cultivar Nonghua101 were soaked in 0.4, 0.8 and 1.6 mM aerated solution of melatonin for 24 h, and primed seeds were germinated under the condition of 150 mM NaCl with paper media. The results showed seed priming with 0.8 mM melatonin was the best performance of all the treatments to seed germination and seedling growth in maize under salinity stress. Then primed with 0.8 mM melatonin or water for 24 h and unprimed seeds were germination under the condition of 150 mM NaCl with sand media. The results showed seed priming with 0.8 mM melatonin significantly improved germination energy, germination percentage, seedling vigor index, shoot and root lengths, seedling fresh and dry weights, K/sup +/ content, relative water content, proline and total phenolic contents, superoxide dismutase, catalase and phenylalanin ammonia lyase activities; and significantly decreased mean emergence time, Na/sup +/ content, electrolyte leakage and malondialdehyde content compared with untreated seeds under salinity stress. These results suggest that seed priming with melatonin alleviates the salinity damage to maize and seed priming with melatonin may be an important alternative approach to decrease the impact of salinity stress in maize. (author)
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.
Seed is the basic and most critical input for seed propagated agricultural crops: seed quality and seedling vigour determine plant establishment, growth and development in both natural and agricultural ecosystems. Seed quality and seedling vigour are mainly
Ordoñez-Salanueva, C A; Orozco-Segovia, A; Canales-Martínez, M; Seal, C E; Pritchard, H W; Flores-Ortiz, C M
Soil seed banks are essential elements of plant population dynamics, enabling species to maintain genetic variability, withstand periods of adversity and persist over time, including for cactus species. However knowledge of the soil seed bank in cacti is scanty. In this study, over a 5-year period we studied the seed bank dynamics, seedling emergence and nurse plant facilitation of Polaskia chende, an endemic columnar cactus of central Mexico. P. chende seeds were collected for a wild population in Puebla, Mexico. Freshly collected seeds were sown at 25 °C and 12-h photoperiod under white light, far-red light and darkness. The collected seeds were divided in two lots, the first was stored in the laboratory and the second was use to bury seeds in open areas and beneath a shrub canopy. Seeds were exhumed periodically over 5 years. At the same time seeds were sown in open areas and beneath shrub canopies; seedling emergence and survival were recorded over different periods of time for 5 years. The species forms long-term persistent soil seed banks. The timing of seedling emergence via germination in the field was regulated by interaction between light, temperature and soil moisture. Seeds entered secondary dormancy at specific times according to the expression of environmental factors, demonstrating irregular dormancy cycling. Seedling survival of P. chende was improved under Acacia constricta nurse plants. Finally, plant facilitation affected the soil seed bank dynamics as it promoted the formation of a soil seed bank, but not its persistence. © 2017 German Society for Plant Sciences and The Royal Botanical Society of the Netherlands.
Ortmans, William; Mahy, Grégory; Monty, Arnaud
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.
Full Text Available A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.. Results indicated that the seeds primed by gibberellins (GA, NaCl, and polyethylene glycol (PEG reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P<0.05. The recommended prime reagents were GA at 10 mg/L, NaCl at 50 mM, and PEG at 15% on account of germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM, or PEG (15% significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method.
Tian, Yu; Guan, Bo; Zhou, Daowei; Yu, Junbao; Li, Guangdi; Lou, Yujie
A series of seed priming experiments were conducted to test the effects of different pretreatment methods to seed germination, seedling growth, and seed yield traits in maize (Zea mays L.). Results indicated that the seeds primed by gibberellins (GA), NaCl, and polyethylene glycol (PEG) reagents showed a higher imbibitions rate compared to those primed with water. The final germination percentage and germination rate varied with different reagents significantly (P germination experiment. 15% PEG priming reagent increased shoot and root biomass of maize seedling. The shoot biomass of seedlings after presoaking the seeds with NaCl reagent was significantly higher than the seedlings without priming treatment. No significant differences of plant height, leaf number, and hundred-grain weight were observed between control group and priming treatments. Presoaking with water, NaCl (50 mM), or PEG (15%) significantly increased the hundred-grain weight of maize. Therefore, seed pretreatment is proved to be an effective technique to improve the germination performance, seedling growth, and seed yield of maize. However, when compared with the two methods, if immediate sowing is possible, presoaking is recommended to harvest better benefits compared to priming method.
Nyoka, Betserai I.; Roshetko, James M.; Jamnadass, Ramni
through a legal framework or voluntary. A few countries in Africa, Asia and Latin America have developed protocols for certification of tree seeds based on the OECD. Some germplasm suppliers use branding as a way of differentiating their germplasm as having superior quality. To enhance the use of high...... quality germplasm, there is a need to demonstrate the value of using such germplasm and raise awareness of germplasm quality among the farmers and policy-makers....
Bapat, V.A.; Rao, P.S.
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
D.A. Agboola; A.A. Ajiboye; O.O. Fawibe; M.O. Atayese
Studies were made on some aspects of the seed germination and seedling growth of two multipurpose trees. These include the effect of pre sowing treatments, seed sizes and gibberellic acid on the germination of seeds and seedling growth. The tree species include Prosopis africana (Guil & Perr) Taub and Dialium guineense (wild). Two seed sizes designated small- size (Ss) and Big-size (Bs) were identified in the seed. The effect of gibberellic acid (GA3) had a greater significance effect (P < 0....
DRAGANIC, Ivana; LEKIC, Slavoljub
The results of studying the effects of sunflower seed priming with an aqueous solution of ascorbic acid (A), tocopherol (T), and glutathione (G) performed prior to accelerated ageing and a cold test are presented in this paper. Germination, the percentage of abnormal seedlings, and the lengths of both roots and shoots were monitored. The results showed that the cold test caused a drastic drop in germination, an adverse effect on the shoot length, an increase in the percentage of abnormal seed...
Gomaa, Nasr H; Picó, F Xavier
Water-limited hot environments are good examples of hyper-aridity. Trees are scarce in these environments but some manage to survive, such as the tree Moringa peregrina. Understanding how trees maintain viable populations in extremely arid environments may provide insight into the adaptive mechanisms by which trees cope with extremely arid weather conditions. This understanding is relevant to the current increasing aridity in several regions of the world. Seed germination experiments were conducted to assess variation in seed mass, seed germination, and seedling traits of Moringa peregrina plants and the correlations among these traits. A seed burial experiment was also designed to study the fate of M. peregrina seeds buried at two depths in the soil for two time periods. On average, seeds germinated in three days and seedling shoots grew 0.7 cm per day over three weeks. Larger seeds decreased germination time and increased seedling growth rates relative to smaller seeds. Seeds remained quiescent in the soil and germination was very high at both depths and burial times. The after-ripening time of Moringa peregrina seeds is short and seeds germinate quickly after imbibition. Plants of M. peregrina may increase in hyper-arid environments from seeds with larger mass, shorter germination times, and faster seedling growth rates. The results also illustrate the adjustment in allocation to seed biomass and correlations among seed and seedling traits that allows M. peregrina to be successful in coping with aridity in its environment.
El Atta, H.A.; Areef, I.M.; Ahmed, A.I.
Dry tropical forests are characterized by unpredictable spells of drought and climate change. Saudi Arabia mostly falls within the arid zone and some few scattered areas fall in the semiarid zone mainly in the South Western region. Rainfall is sparse and with sporadic distribution. Drought is the most critical factor for restoration of the tree cover. Within a tree, seeds vary in size from large to small seeds. Although several researchers have studied the effect of within species variation in seed size on seedlings growth parameters, however there is a lack of knowledge regarding the effect of seed size on stress tolerance (Khurana and Singh 2000). We assumed that seedlings grown from different seed sizes from the same tree species may influence their response to water stress. Seeds of Acacia asak (Forssk.) Willd. were categorized into large, medium and small seeds on the basis of the seed weight. Seedlings from the three seed sizes were grown in potted soil and subjected to 5 levels of field water capacity (FC) (100, 75, 50, 25 and 15 percent) in the greenhouse. The Objective was to evaluate the response of seedling grown (from different seed sizes) to water stress and to understand the acclimation of seedlings to water stress. Water stress significantly reduced RWC, leaf area, and shoot length, fresh and dry weight. Significant correlations between growth parameters and water stress level were recorded. Seedlings from large seeds were heavier and comparatively less affected by drought compared to seedlings from smaller seeds. In all seedlings root length increased significantly and more biomass was allocated to roots than to shoots. However, at severe water stress (15 percent FC) no significant differences were reported between the three seedling categories. Therefore, raising of seedlings from large seeds is more appropriate for tree restoration programs under drought conditions. (author)
Parrado Rosselli, Angela
The spatial patterns of seed and seedling distribution relative to parent trees (seed and seedling shadow, respectively) were studied for Dacryodes chimantensis (Burseraceae) and Brosimum utile (Moraceae), two common tree species of terra firme forests of Colombian Amazonia. The general objective was to assess whether the patterns imposed by seed dispersal change or persist in subsequent life stages occurring during the transition from seeds/saplings to adult stages. Seed and seedling shadows on the ground were characterized for each tree species along four 50-m radial transects from the base of the parent tree. Causes of seed and seedling predation as a function of distance to the parent tree were determined, as well as the spatial consistency between life stages. Results showed that seed density of both Dacryodes and Brosimum declined leptokurtically with distance, and it was skewed towards the parent tree. However, seed density was more skewed and leptokurtic in Dacryodes than in Brosimum. The overall trend was maintained in the seedling stage of both species and was positively correlated with the distribution patterns of seeds. Seed and seedling predation were positively correlated with density and negatively correlated with the distance from the parent tree. Factors that could be generating the high consistency between the spatial patterns of seed and seedling distribution are discussed, as well as its implications in the population structure of both species and the debate on the factors that influence the spatial distribution of plant species in tropical rain forests.
Maria Elane de Carvalho Guerra
Full Text Available The knowledge of seed and seedling morphology are extremely important to the identification and preservation of plant species. In order to studying seed and seedling morphology and seed germination of copaiba (Copaifera langsdorfii Desf seeds, experiments were conducted at the Laboratory of Seed Analysis and Laboratory of Botany of the Federal University of Ceará. In copaíba seeds the characteristics studied were shape, size (length, width, thickness and morphology. The kind of germination, the root systems, hypocotyls, epicotyls and first leaves were the characteristics evaluated in copaiba seedlings. Ruler and pachimeter were used to make the measurements, as well as optical microscope and magnifying glass. The seeds are exalbumin kind, have neuter photoblastism and epigeous germination. Seed coat shows a palisade cell layer with a conspicuous light line. The seedlings have compound first leaves and axial root system.
Dec 17, 2008 ... Key words: Juglone, muskmelon, seedling growth, protein content, polyphenol oxidase activity. INTRODUCTION ... Juglone has been isolated from many plants in the .... In pea seeds, a relation between PPO activity and seed.
Seed treatments have been used to manage corn seedling diseases since the 1970’s and they contain a combination of active ingredients with specificity towards different pathogens. We hypothesized that using different seed treatment combinations and assessing seedling disease incidence and severity ...
Bowers, Janice E.; Pierson, E.A.
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.
Khan, M. L.
I examined the effects of seed mass on performance of seedlings of Artocarpus heterophyllus L. (Moraceae), a large evergreen late successional shade-tolerant tree species in three contrasting light conditions. Seed mass varied many fold from 1.5 to 14 g in A. heterophyllus. Germination and germination time showed a significant correlation with seed mass. Germination differed significantly among three light regimes (50%, 25% and 3%). Seed mass and light level significantly affected seedling survival. The seedlings that emerged from large seeds survived better than those from small seeds under all light regimes. Survival of seedlings was maximum in 25% light regime for all seed mass classes but did not differ significantly from that at 50% light regime. Survival was significantly lower in 3% light as compared to 50% and 25% light regimes. Seedling vigor (expressed in terms of seedling height, leaf area and dry weight) was also significantly affected by seed mass and light regimes. Seedlings that emerged from larger seeds and grew under 50% light regime produced the heaviest seedlings, while those resulting from smaller seeds and grown under 3% light regime produced the lightest seedlings. Resprouting capacity of seedlings after clipping was significantly affected by seed mass and light regime. Seedlings emerging from larger seeds were capable of resprouting several times successively. Resprouting was more pronounced under 50% and 25% light regimes as compared to 3% light. Success of A. heterophyllus regeneration appears to be regulated by an interactive effect of seed mass and light regime.
Full Text Available Studies were made on some aspects of the seed germination and seedling growth of two multipurpose trees. These include the effect of pre sowing treatments, seed sizes and gibberellic acid on the germination of seeds and seedling growth. The tree species include Prosopis africana (Guil & Perr Taub and Dialium guineense (wild. Two seed sizes designated small- size (Ss and Big-size (Bs were identified in the seed. The effect of gibberellic acid (GA3 had a greater significance effect (P < 0.05 on seed germination of both D. guineense and P. africana seeds. The big size seeds had a significant effect (P < 0.05 on the seed germination when compared to the small size seeds. The hydration/dehydration, pre sowing treatments on the seeds did not have any significant effects on germination.
Cardona, M.,E.; Kozáková, Hana; Collinder, E.; Persson, A.-K.; Midtvedt, T.; Norin, E.
Roč. 52, - (2005), s. 109-113 ISSN 1548-9213 R&D Projects: GA AV ČR IAA5020101 Institutional research plan: CEZ:AV0Z5020903 Keywords : germ-free * minipigs * ex-germ-free Subject RIV: EE - Microbiology, Virology Impact factor: 2.111, year: 2005
Kamila Cardoso Pereira
Full Text Available The objective was to evaluate the effect of Mentha piperita, Cymbopogon nardus and Eucalyptus globules essential oils, in sanitary and physiological quality of Schinus molle L. seeds and seedlings. The seeds were treated with essential oils at concentrations of 10%, on 1 μL g-1, 20%, on 2 μL g-1, 30% , on 3 μL g-1 and control. After treatments, seeds were evaluated by sanity test, using filter paper method (“blotter test” and by germination test, where the seeds were placed between vermiculite substrate. For counts, sprouted and dead seeds were considered. Shoot length, root, total height and stem diameter were measured for seedlings evaluation. The use of citronella and mint essential oils reduced the incidence of different pathogens in S. molle seeds. Mint essential oil at 20% and 30% were effective to promote seeds germination. Eucalyptus essential oil in any concentration was efficient to increase seedlings growth.
Ma, Wan Zheng; Ma, Wan Min; Du, Ying Ying; Dan, Qiong Peng; Yin, Bing; Dai, Shan Shan; Hao, Xiang
The impact of Cr6+ on the growth of lactuca sativa in Greenhouse Cucumber was investigated. The seeds of lacuna sativa Italian bolting resistance lettuce were treated by different Cr6+ concentration to study the effects on its seed germination and seedling growth. The results showed that the seed germination rate, vigor index of seedlings decreased with increment of Cr6+ concentration to varying degrees, and vigor germination, vigor index, raw weight, root length significantly lower. The absorption of lettuce seedlings on different nutrient elements is impacted by the concentration of Cr6+.
Jeremy J. James; Tony Svejcar
Seeding rangeland following wildfire is a central tool managers use to stabilize soils and inhibit the spread of invasive plants. Rates of successful seeding on arid rangeland, however, are low. The objective of this study was to determine the degree to which water availability, invasive plant abundance, and seeding technology influence postfire seedling establishment...
Khan, N.; Kazmi, R.H.; Willems, L.A.J.; Heusden, van A.W.; Ligterink, W.; Hilhorst, H.W.M.
The success of germination, growth and final yield of every crop depends to a large extent on the quality of the seeds used to grow the crop. Seed quality is defined as the viability and vigor attribute of a seed that enables the emergence and establishment of normal seedlings under a wide range of
Li, Ying; Huang, Lu-Qi; Zhang, Xiao-Bo; Wang, Hui; Cheng, Meng; Zhang, Tian; Yang, Guang
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.
Clark D. Fleege
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).
C. M. Ocamb; J. Juzwik; F. B. Martin
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...
ter Heerdt, G.N.J.; Bekker, R.M.; Bakker, J.P.; Verweij, G.L.
1. The seedling emergence method for assessing the size of the seed bank is improved by washing soil samples on a fine sieve and spreading the thus concentrated samples in a 3-5 mm thick layer on sterilized potting compost. 2. The method largely increases the number of seedlings that emerge as
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...
Full Text Available Pongamia (Pongamia pinnata (L. Pierre is one of a potential tree species to produce biodiesel. Pongamia-based biodiesel development program is still constrained by the availability of quality and quantity seeds due to the limited of seed sources. The purpose of this research was to identify the morphological diversity of fruits, seeds and seedlings from 5 populations in Java Island. Randomized completely design and randomized block design were used to assess the difference of fruits, seeds and seedlings morphological characteristics among populations. Principal component and hierarchy cluster analysis were used to explain variation pattern among populations. The results showed that the difference of populations was significantly affected by the difference of fruits, seeds, and seedlings morphology of pongamia. Seeds from Carita population showed good quality seed indicators with moisture content of 19.31%, and germination capacity of 74.50%. Sturdiness quotient of the seedling was 10.78. Contribution of genetic factor was higher than environtment factor is relation to the differences of morphological characteristics of fruits, seeds and seedlings of pongamia. Morphological character of the five populations can be divided into 3 groups, i.e. the first group of Batukaras and Kebumen, second group of Alas Purwo and Baluran, and group 3 was Carita.
Christiana O. ADEYEMI
Full Text Available The effect of daylight, continuous illumination and acid scarification on the seed germination and seedling vegetative growth (epicotyl and hypocotyl lengths, and number of secondary roots of different Parkia biglobosawere investigated in the Plant Physiology Laboratory University of Ilorin, Ilorin Kwara State Nigeria. Seeds from two out of the twenty six Parkia tree samples (trees B and T germinated within 24 hours of planting in the daylight germination study while seeds from another tree (Q did not germinate until the third week after planting (3WAP. Some seeds have higher germination percentage both in the daylight (preliminary germination study and in the continuous light (illuminated study. The treatment with concentrated Sulphric acid (conc. H2SO4was effective in breaking the seed dormancy as seeds from eight (8 trees produced one hundred percent (100% germination. At p= 0.05 the length of epicotyl and hypocoty1 lengths were significantly different as seedling vegetative growth were long in the seedlings from the daylight experiment than the continuous light experiment. The vegetative growths of the seedlings from the scarified seed were longer at 15min of scarification in all except in trees F and Z. It was observed that the time of scarification affect the both seed germination and seedling development.
Edicléia Aparecida Iensen Cherobini
Full Text Available This research aimed to study the vigor and the quality of Schizolobium parahyba seeds from samples of three differentstates, Rio Grande do Sul (RS, Santa Catarina (SC and Paraná (PR and to evaluate the seedlings quality produced by these seeds.The seeds were submitted to evaluations of moisture content, germination, vigor and healthy. The seedlings quality was evaluated byhard seeds, dead seeds, emergence, seedling height, root length, collar diameter, fresh and dry weight of seedlings. On the seedsevaluations, the samples from SC and PR presented better results for first count of germination, dry matter and accelerate aging. Thefungi associated to the seeds were Aspergillus sp., Alternaria sp., Penicillium sp. and Trichoderma sp. About the seedlings evaluations,seeds from PR showed the bests results when the differences between tests were significant (emergence, root length and dry weight ofseedlings. Some of the labs variables had correlation with the seedlings variables.
Full Text Available Early emergence and stand establishment of cowpea are considered to be the most important yield-contributing factors in rainfed areas. Laboratory tests and afield experiment were conducted in RCB design in 2011 at a research farm in Ramhormoz, Iran, to evaluate the effects of hydropriming (8, 12 and 16 hours duration and halo priming (solutions of 1.5% KNO3 and 0.8% NaCl on seedling vigor and field establishment of cowpea. Analysis of variance of laboratory data showed that hydropriming significantly improved germination rate, seed vigor index, and seedling dry weights. However, germination percentage for seeds primed with KNO3 and non-primed seeds were statistically similar, but higher than those for NaCl priming. Overall, hydropriming treatment was comparatively superior in the laboratory tests. Invigoration of cowpea seeds by hydropriming and NaCl priming resulted in higher seedling emergence and establishment in the field, compared to control and seed priming with KNO3. Seedling emergence rate was also enhanced by priming seeds with water, suggesting that hydropriming is a simple, low cost and environmentally friendly technique for improving seed and seedling vigor of cowpea.
Foster, Mercedes S.
The relative effectiveness of arboreal or terrestrial birds at dispersing seeds of Ormosia macrocalyx and O. bopiensis (Fabaceae: Papilionoideae) were studied in south-eastern Peru. Seeds of both species were either scarified, to represent seed condition after dispersal by terrestrial birds, or left intact, to represent seed condition after dispersal by arboreal birds. Seeds were distributed along forest transects, and germination, seedling development and mortality were monitored to determine the successes of the two groups at producing seedlings. Scarified seeds germinated with the early rains of the dry-to-wet-season transition, when erratic rainfall was interspersed with long dry spells. Intact seeds germinated 30 d later when the rain was more plentiful and regular. Intact seeds of O. macrocalyx gave rise to significantly more seedlings (41.1% vs. 25.5%) than did scarified seeds, in part, because significantly more seedlings from scarified seeds (n = 20) than from intact seeds (n = 3) died from desiccation when their radicles failed to enter the dry ground present during the dry-to-wet-season transition. Also, seedlings from scarified seeds were neither larger nor more robust than those from intact seeds despite their longer growing period. Results are consistent with the hypothesis that dispersal effectiveness of arboreal birds, at least for O. macrocalyx, is greater than that of terrestrial birds. Screen-house experiments in which seedlings developed under different watering regimes supported this result. Numbers of seedlings developing from intact and scarified seeds of O. bopiensis did not differ significantly.
Moori, S.; Eisv, H.R.
This study attempted to examine the effect of seed priming using plant growth regulators and vitamin C on the physiological traits of non-aged and aged seeds of wheat and their obtained seedlings. Accelerated aging (AA) method (40 degree C, RH=100% for 72h) was used for aging seeds. The seeds were pre-treated by gibberellin (GA), salicylic acid (SA), brassinosteroid (BR), and ascorbic acid (AS). Some seed traits such as germination and electric conductivity (EC) and seedling traits such as malondialdehyde (MDA) content, activity of some antioxidant enzymes, soluble protein content (SP), soluble sugar (SS), and proline were measured seven days after germination. The results showed that accelerated aging of seeds reduces the germination percentage and speed, increases soluble sugar, and reduces soluble protein, activity of catalase (CAT), peroxidase (POD) and superoxide dismutase (SOD) in the seedling. Pre-treatment of the aged seed by GA had the maximum positive impact on seed germination and seedling growth. Priming improved germination indices, quality of seedling, and seedling resistance against the oxidative stress caused by AA. It also improved cell membrane integrity and thus reduced seeds’ EC. Priming increased the activity of CAT, POD and SOD enzymes in both aged and non-aged seeds. When the deteriorated seeds were primed, proline and SS contents of the seedling increased significantly, but SP and MDA decreased. In general, pre-treatment of the non-aged and aged seeds by gibberellin improved the physiological quality of the seed and seedling. (author)
Full Text Available Seedling characteristics of different sunflower (Helianthus annus L. cultivars under drought stress and inoculation with the Azospirillum lipoferum in a spilt-factorial layout based on randomized complete block design with three replications were evaluated. Treatments included dehydration stress (seed produced on maternal plants which irrigated after 60 (desirable irrigation, 120 (medium stress, 180 mm (severe stress evaporation from evaporation pan class A, different sunflower cultivars (Lakomka, Master, Favorite, Soor and Armavirosky and inoculation with bacteria (Azospirillum lipoferum and control. Bacteria allocated in the main plots and seeds which derived from dehydration stress conditions and different cultivars were allocated in sub plots as a factorial layout. Results showed that the time of seedling emergence, seedling vigor index, leaf petiole, stem and seedling dry weight were increased 14, 44, 30, 31, 22 and 27 percent by inoculating with bacteria, respectively. The percent of Seedling emergence of seeds derived from medium stress 48 percent was more than optimal irrigation conditions. Final appearance, speed of emergence, emergence index, dry weight and stamina seedling resulting from severe stress conditions were decreased compared with optimal irrigation. Seedling emergence of seeds derived from medium stress which inoculated with bacteria increased by 9 percent. Emergence speed index, appearance, stamina and seedling dry weights of seeds which inoculated with bacteria increased at medium and sever water stress. With consideration of the effect of dehydration stress on germination and seedling emergence, seed inoculation with bacteria improved seedling emergence and seedling vigor of seeds derived from dehydration stress conditions.
1. Seeding native plants is a key management practice to counter land degradation across the globe, yet the majority of seeding efforts fail, limiting the ability of this tool to accelerate ecosystem recovery. 2. Seedling recruitment requires transitions through several life stages, some of which ma...
van Zanten, Martijn; Zöll, C.; Wang, Z.; Philipp, C.; Carles, A.; Li, Y.; Kornet, N.G.; Liu, Y.; Soppe, W.J.J.
Plant life is characterized by major phase changes. We studied the role of histone deacetylase (HDAC) activity in the transition from seed to seedling in Arabidopsis. Pharmacological inhibition of HDAC stimulated germination of freshly harvested seeds. Subsequent analysis revealed that histone
Galdiano, Renato Fernandes; de Macedo Lemos, Eliana Gertrudes; de Faria, Ricardo Tadeu; Vendrame, Wagner Aparecido
Vitrification, a simple, fast, and recommended cryopreservation method for orchid germplasm conservation, was evaluated for Dendrobium hybrid "Dong Yai" mature seeds. The genetic stability of regenerated seedlings was also evaluated using flow cytometry. Mature seeds from this hybrid were submitted to plant vitrification solution (PVS2) for 0, 0.5, 1, 2, 3, 4, 5, or 6 h at 0 °C. Subsequently, they were plunged into liquid nitrogen (LN) at -196 °C for 1 h and recovered in half-strength Murashige and Skoog culture medium (1/2 MS), and seed germination was evaluated after 30 days. Seeds directly submitted to LN did not germinate after cryopreservation. Seeds treated with PVS2 between 1 and 3 h presented the best germination (between 51 and 58%), although longer exposure to PVS2 returned moderated germination (39%). Germinated seeds were further subcultured in P-723 culture medium and developed whole seedlings in vitro after 180 days, with no abnormal characteristics, diseases, or nutritional deficiencies. Seedlings were successfully acclimatized under greenhouse conditions with over 80% survival. Flow cytometry analysis revealed no chromosomal changes on vitrified seedlings, as well as seedlings germinated from the control treatment (direct exposure to LN). These findings indicate that vitrification is a feasible and safe germplasm cryopreservation method for commercial Dendrobium orchid hybrid conservation.
Dong, W.; Jun, Z.Y.; Lin, W.G.; Jin, F.
Relative performance of seedlings of species with different seed sizes may vary in response to resource availability, and may affect seedling growth. The objective was to test this hypothesis from alpine forbs species in the Qinghai-Tibetan Plateau. We examined the relative growth rate, allocation and performances of eight native forbs species covering a wide range of seed size in response to four light and three nutrient regimes. Light availability had a significant effect on seedling emergence time, but not on other seedling morphological performances. Seedling emergence time and seed size were negatively correlated with each other for three species within Asteraceae family, i.e. heaviest seeds emerged earlier. Seed size, nutrient availability and their interaction affected most of studied morphological and growth traits of seedlings. Fertilisation modified the relationship between seed size and seedling biomass. Our study showed that seed size and nutrient availability had significant effects on seedling performance in alpine meadows. Seedlings from the larger-seed species presented stronger advantage in initial seedling mass and height under most of resources conditions. (author)
Waaij, D. van der; Andres, A.H.
The efficacy of horizontal and vertical laminar flow units (equipped with high-efficiency air filters) in the prevention of cross-contamination between cages and of contamination from outside has been demonstrated. With germ-free mice and using germ-free standard techniques for sterilization and for
Yadollhhi Nooshabadi S.J.
Full Text Available Seed aging is the main problem of seed storage. Changes of bio-chemical and reduction of seedling growth are consequence of seed deterioration. An experiment was conducted to evaluate the effects of accelerated aging on soybean seed germination indexes and enzyme activity. Seeds were incubated in closed plastic boxes for the accelerated aging treatments. Three accelerate aging regimes were performed by placing seeds at 41°C and relative humidity (RH of 90-100 % for 0, 2, 4, 6 and 8 days periods. Our results showed that increasing aging duration resulted higher reduction in germination characteristics, catalase and ascorbate peroxidase. Germination percentage, means time to germination, germination index, normal seedling percentage and enzyme activity decrease significantly.
Silva, Rafael de C; Camillo, Julcéia; Scherwinski-Pereira, Jonny E
Actually, the germplasm of Jatropha spp. is conserved as whole plants in field collections. Under this storage method, the genetic resources are exposed to disease, pest and natural hazards such as human error, drought and weather damage. Besides, field genebanks are costly to maintain and with important requirements of trained personnel. Thus, the development of efficient techniques to ensure its safe conservation and regeneration is therefore of paramount importance. In this work we describe a method for Jatropha curcas seeds cryoexposure and seedling recovery after thawed. In a first experiment, an efficient protocol for in vitro plant recovery was carried out using zygotic embryo or seeds with or without coat. In a second experiment, desiccated seeds with or without coat were exposed to liquid nitrogen and evaluated after cryoexposure. Germination percentages were variable among treatments, and seeds demonstrated tolerance to liquid nitrogen exposure under certain conditions. Seeds of J. curcas presented up to 99.6% germination after seed coat removal. Seeds with coat cultured in vitro did not germinate, and were 60% contaminated. The germination of the zygotic embryos was significantly higher in the 1/2 MS medium (93.1%) than in WPM medium (76.2%), but from zygotic embryo, abnormal seedlings reached up to 99%. Seeds with coat exposed to liquid nitrogen showed 60% germination in culture after coat removal with good plant growth, and seeds cryopreserved without coat presented 82% germination, but seedlings showed a reduced vigor and a significant increase in abnormal plants. Seeds cultured in vitro with coat did not germinate, independently of cryoexposure or not. This study reports the first successful in vitro seedling recovery methodology for Jatropha curcas seeds, after a cryopreservation treatment, and is recommended as an efficient procedure for in vitro plant recovery, when seeds are conserved in germplasm banks by low or cryotemperatures.
Rafael de C. Silva
Full Text Available Actually, the germplasm of Jatropha spp. is conserved as whole plants in field collections. Under this storage method, the genetic resources are exposed to disease, pest and natural hazards such as human error, drought and weather damage. Besides, field genebanks are costly to maintain and with important requirements of trained personnel. Thus, the development of efficient techniques to ensure its safe conservation and regeneration is therefore of paramount importance. In this work we describe a method for Jatropha curcas seeds cryoexposure and seedling recovery after thawed. In a first experiment, an efficient protocol for in vitro plant recovery was carried out using zygotic embryo or seeds with or without coat. In a second experiment, desiccated seeds with or without coat were exposed to liquid nitrogen and evaluated after cryoexposure. Germination percentages were variable among treatments, and seeds demonstrated tolerance to liquid nitrogen exposure under certain conditions. Seeds of J. curcas presented up to 99.6% germination after seed coat removal. Seeds with coat cultured in vitro did not germinate, and were 60% contaminated. The germination of the zygotic embryos was significantly higher in the ½ MS medium (93.1% than in WPM medium (76.2%, but from zygotic embryo, abnormal seedlings reached up to 99%. Seeds with coat exposed to liquid nitrogen showed 60% germination in culture after coat removal with good plant growth, and seeds cryopreserved without coat presented 82% germination, but seedlings showed a reduced vigor and a significant increase in abnormal plants. Seeds cultured in vitro with coat did not germinate, independently of cryoexposure or not. This study reports the first successful in vitro seedling recovery methodology for Jatropha curcas seeds, after a cryopreservation treatment, and is recommended as an efficient procedure for in vitro plant recovery, when seeds are conserved in germplasm banks by low or cryotemperatures.
Full Text Available We investigated if seeds of Agave lechuguilla from contaminated sites with heavy metals were more tolerant to Cd ions than seeds from noncontaminated sites. Seeds from a highly contaminated site (Villa de la Paz and from a noncontaminated site (Villa de Zaragoza were evaluated. We tested the effect of Cd concentrations on several ecophysiological, morphological, genetical, and anatomical responses. Seed viability, seed germination, seedling biomass, and radicle length were higher for the non-polluted site than for the contaminated one. The leaves of seedlings from the contaminated place had more cadmium and showed peaks attributed to chemical functional groups such as amines, amides, carboxyl, and alkenes that tended to disappear due to increasing the concentration of cadmium than those from Villa de Zaragoza. Malformed cells in the parenchyma surrounding the vascular bundles were found in seedlings grown with Cd from both sites. The leaves from the contaminated place showed a higher metallothioneins expression in seedlings from the control group than that of seedlings at different Cd concentrations. Most of our results fitted into the hypothesis that plants from metal-contaminated places do not tolerate more pollution, because of the accumulative effect that cadmium might have on them.
Haque, M. M.; Diez, J. J.
Phytophthora alni is a highly destructive host specific pathogen to alders (Alnus spp.) spreading all over Europe. Recently this pathogen has been reported to cause diseases in common alder (Alnus glutinosa) in Spain. Seeds and seedlings of A. glutinosa were tested in vitro for their susceptibility to alder Phytophthora and other Phytophthora species. Isolates of P. alni ssp. alni, P. cinnamomi, P. citrophthora, P. nicotianae and P. palmivora were used in the experiments. Seeds and seedlings were inoculated with a zoospore suspension and uniform mycelial blocks of agar of the Phytophthora species. Susceptibility was calculated in terms of pathogen virulence on seed germination and seedling mortality 42 and 67 days after inoculation respectively. Seed germination and seedling mortality rates varied differently among the isolates used. Results implied that common alder and its seeds and seedlings are at risk to be infected by P. alni. In addition, other Phytophthora species are able to infect this kind of material showing their relative host non-specificity. This is one important finding concerning alder regeneration in infected areas, and the possibility of disease spread on this plant material. (Author) 42 refs.
Tiago Zanatta Aumonde; Emanuela Garbin Martinazzo; Tiago Pedó; Junior Borella; Luciano do Amarante; Francisco Amaral Villela; Dario Munt de Moraes
The work was conducted to evaluate the effect of different Philodendron bipinnatifidum Schott. extract concentrations on the physiology and enzymatic metabolism of lettuce seeds and seedlings. The treatments extracts of mature leaves at concentrations of 0, 6, 12, 25 and 50%. Were evaluated the germination, first count germination, speed and germination speed index, length of shoot and primary root, seedling total dry mass, electrical conductivity, chlorophyll content, activity of the enzymes...
Marques, M C M; Oliveira, P E A M
Seasonal tropical forests show rhythms in reproductive activities due to water stress during dry seasons. If both seed dispersal and seed germination occur in the best environmental conditions, mortality will be minimised and forest regeneration will occur. To evaluate whether non-seasonal forests also show rhythms, for 2 years we studied the seed rain and seedling emergence in two sandy coastal forests (flooded and unflooded) in southern Brazil. In each forest, one 100 x 30-m grid was marked and inside it 30 stations comprising two seed traps (0.5 x 0.5 m each) and one plot (2 x 2 m) were established for monthly monitoring of seed rain and a seedling emergence study, respectively. Despite differences in soil moisture and incident light on the understorey, flooded and unflooded forests had similar dispersal and germination patterns. Seed rain was seasonal and bimodal (peaks at the end of the wetter season and in the less wet season) and seedling emergence was seasonal and unimodal (peaking in the wetter season). Approximately 57% of the total species number had seedling emergence 4 or more months after dispersal. Therefore, both seed dormancy and the timing of seed dispersal drive the rhythm of seedling emergence in these forests. The peak in germination occurs in the wetter season, when soil fertility is higher and other phenological events also occur. The strong seasonality in these plant communities, even in this weakly seasonal climate, suggests that factors such as daylength, plant sensitivity to small changes in the environment (e.g. water and nutrient availability) or phylogenetic constraints cause seasonal rhythms in the plants.
Juan, Traba; Sagrario, Arrieta; Jesús, Herranz; Cristina, Clamagirand M.
Seeds of the Mediterranean Hackberry Celtis australis are often encountered in fox faeces. In order to evaluate the effect of gut transit on the size of seeds selected, the rates and speed of germination and on the survival of the seedlings, Mediterranean Hackberry seeds from fox faeces were germinated in a greenhouse. The results were compared with those of seeds taken from ripe, uneaten fruits. Fox-dispersed seeds were smaller and lighter than the control ones and had higher (74% vs. 57%) and more rapid germination (74.5 days vs. 99.2 days). Seedlings from fox-dispersed seeds showed significantly greater survival by the end of the study period (74.1% vs. 43.6%) than the control ones. Survival in seedlings from fox-dispersed seeds was related to germination date, late seedlings showing poorer survival. This relationship was not observed away in the control seedlings. Seed mass did not affect seedling survival. Seedling arising from fox-dispersed seeds grew faster than control ones. These results suggest that fox can play a relevant role as seed disperser of Mediterranean Hackberry.
Imran, Muhammad; Garbe-Schönberg, Dieter; Neumann, Günter
Zinc (Zn) priming is a technique used to increase seed Zn reserves for improving seed quality, crop growth, and enhancing stress tolerance in crop plants. The present study demonstrated the effect of water and Zn priming on the distribution and accumulation of endogenous and primed Zn in maize...... seeds (Zea mays L.). Zn concentration in unprimed, water and Zn primed seeds and germinated seedlings were analyzed by ICP-MS (Inductivity Coupled Plasma Mass Spectroscopy). DTZ (Diphenyle Thio-Carbazone) staining method and LA-ICP-MS (Laser Ablation Inductivity Coupled Plasma Mass Spectroscopy...
Demarne, Y.; Corring, T.; Pihet, A.; Sacquet, E.
Bile duct ligation was performed in germ-free and conventional rats in order to study the effects of bile deprivation on the absorption of dietary lipids and the excretion of faecal lipids in the presence or the absence of gastrointestinal flora. The main consequence of bile duct ligation in conventional rats was decrease of about 50% in the apparent absorption of dietary lipids (peanut oil). In germ-free rats, absorption decreased by only about 25%.In conventional as well as in germ-free con...
Vieira Roberval Daiton
Full Text Available Vigor of soybean [Glycine max (L. Merrill] seeds can be evaluated by measuring the electrical conductivity (EC of the seed soaking solution, which has shown a satisfactory relationship with field seedling emergence, but has not had aproper definition of range yet. This work studies the relationship between EC and soybean seedling emergence both in the field and laboratory conditions, using twenty two seed lots. Seed water content, standard germination and vigor (EC, accelerated aging and cold tests were evaluated under laboratory conditions using -0.03; -0.20; -0.40 and -0.60 MPa matric potentials, and field seedling emergence was also observed. There was direct relationship between EC and field seedling emergence (FE. Under laboratory conditions, a decreasing relationship was found between EC and FE as water content in the substrate decreased. Relationships between these two parameters were also found when -0.03; -0.20 and -0.40 MPa matric potentials were used. EC tests can be used successfully to evaluate soybean seed vigor and identify lots with higher or lower field emergence potential.
Full Text Available Rapeseed soil seed bank development and volunteer plant establishment represent substantial risk for crop infestation and GM contamination. This study was designed to complement such investigations with novel understanding from high latitude conditions. Four experiments were designed to characterise seed loss at harvest, persistence, viability and capacity for volunteer seedling establishment, as well as impact of management measures on soil seed bank dynamics. Oilseed rape was the primary crop investigated due to the availability of GM cultivars and because of the increasing importance. Harvest losses and soil seed bank development were significant. Volunteer seedlings emerged at reasonably high rates, especially in the first autumn after harvest, but about 10% of buried seeds maintained their viability for at least three years. Soil incorporation methods had no major effect on numbers of volunteer seedlings, but herbicide treatments controlled volunteer seedlings efficiently, though not completely, due to irregular timing of seedling emergence.
Full Text Available This study was conducted to test the effect of a priming combination on the seed germination percentage and seedling emergence performance of purslane under climate chamber and field conditions. Four purslane seed lots were treated according five different methods, which were T1: Seeds kept at a hundred percent relative humidity for four hours at 20 °C; T2: Seeds kept at a hundred percent relative humidity for four hours at 20 °C, and then soaked in distilled water for 8 hours at 5 °C; T3: Seeds kept at a hundred percent relative humidity for four hours at 20 °C, and then soaked in distilled water for 8 hours at 20 °C; T4: Seeds soaked in distilled water for 8 hours at 5 °C; T5: Seeds soaked in distilled water for 8 hours at 20 °C; and C: Control (untreated. Seed germination was calculated for 14 days at 20 °C, seedling emergence percentages were calculated in the climatically-controlled chamber for 21 days at 22 °C, and in the field for 35 days at 15-25 °C. The highest seed germination (94% and seedling emergence in the climatically-controlled chamber (87% and field (82% were obtained from seeds that had been kept at a hundred percent relative humidity for four hours at 20 °C, then soaked in distilled water for eight hours at 5 °C. Results indicated that farm-priming, can be an efficient priming method in purslane seeds.
Wandrag, Elizabeth M; Dunham, Amy E; Duncan, Richard P; Rogers, Haldre S
Dispersal is thought to be a key process underlying the high spatial diversity of tropical forests. Just how important dispersal is in structuring plant communities is nevertheless an open question because it is very difficult to isolate dispersal from other processes, and thereby measure its effect. Using a unique situation, the loss of vertebrate seed dispersers on the island of Guam and their presence on the neighboring islands of Saipan and Rota, we quantify the contribution of vertebrate seed dispersal to spatial patterns of diversity of tree seedlings in treefall gaps. The presence of vertebrate seed dispersers approximately doubled seedling species richness within canopy gaps and halved species turnover among gaps. Our study demonstrates that dispersal plays a key role in maintaining local and regional patterns of diversity, and highlights the potential for ongoing declines in vertebrate seed dispersers to profoundly alter tropical forest composition.
Full Text Available Both soil and water salinity is one of the main reasons in decreasing germination, seedling growth and establishment in many arid and semiarid parts of world especially in our country. For this reason in order to evaluate the effect of lentil seed size on germination and seedling growth properties that was under effect of salinity stress, a completely randomized design with factorial arrangement and 3 replications conducted using two lentils genotypes (Robatt and Gachsaran, two small and large seed sizes (34.8 and 59 mg in Robatt and 41.5 and 69 mg in Gachsaran per seed, respectively and five drought levels (0, 0.5, 0.8, 1.2 and 1.7 percent of NaCl in 2008s. Results showed that Robatt genotype had higher germination rate and salinity tolerance than Gachsaran. In addition seed size had significant different (P
Wang Wen'en; Zhang Junwei; Bao Manzhu
The dry seeds of Buchloe dactyloides were irradiated by γ-ray at dose of 25-300 Gy. Seed germination and seedling characters were surveyed in laboratory and field. The results indicated that radiation could promote seed germination, and the optimum dose was 100 Gy. The dose of 150 Gy was the up limit to germination rate, root length and seedling height in field. When the radiation dose was bellow 100 Gy, the fresh weight of stems, leaves and roots of seedlings were increased. From this study, the recommended radiation does for Buchloe dactyloides dry seeds treatment was between 100-150 Gy for the purpose of promoting germination. (authors)
Souza, Aline Das Graças; Smiderle, Oscar Jose; Bianchi, Valmor Joao
This study aimed to evaluate the efficiency of using the computerized imaging seed analysis system (SAS) in the biometric and morphophysiological characterization of seeds and the initial growth of seedlings from peach rootstocks. The experimental design was completely randomized with five replicates of 20 seeds. The variables analyzed were degree of seed humidity, length and width of seeds measured by SAS technology and manual measurements, mean germination time, germination percentage, radicle length and width, taproot length, length of the aerial part and taproot/aerial part ratio. The highest seed length, germination percentage (100%) and lower germination time (11.3), were obtained with the cv. Capdeboscq while, 'Tsukuba 1', 2' and 3' had intermediate seedlings length, varying from 1.55 to 1.65 cm with mean germination times between 14.5 and 18.0 days and average germination percentage of 96%. The computerized analysis of images is fast and efficient for biometric evaluations such as seed width and length, as well as initial growth of peach tree seedlings. The cvs Capdeboscq, Flordaguard and Tsukuba 2 presented greater radicle width, length and a mean taproot/aerial part ratio equal to 2, as well as higher number of adventitious roots, which indicated a strong positive correlation between radicle length, taproot length and initial seedling growth. The continuity of the research will certainly allow the development of reliable procedures for other species, besides allowing the identification of wider alternatives for the use of this system for the expansion of knowledge in the areas of physiology and evaluation of the physiological potential of seeds. Copyright© Bentham Science Publishers; For any queries, please email at email@example.com.
Verma, S K; White, J F
This study was conducted to investigate indigenous seed endophyte effects on browntop millet seedling development. We report that seed-inhabiting bacterial endophytes are responsible for promoting seedling development, including stimulation of root hair formation, increasing root and shoot length growth and increasing photosynthetic pigment content of seedlings. Bacterial endophytes also improved resistance of seedlings to disease. A total of four endophytic bacteria were isolated from surface-sterilized seeds and identified by 16S rDNA sequencing as Curtobacterium sp. (M1), Microbacterium sp. (M2), Methylobacterium sp. (M3) and Bacillus amyloliquefaciens (M4). Removal of bacteria with streptomycin treatment from the seeds compromised seedling growth and development. When endophytes were reinoculated onto seeds, seedlings recovered normal development. Strains M3 and M4 were found to be most potent in promoting growth of seedlings. Bacteria were found to produce auxin, solubilize phosphate and inhibit fungal pathogens. Significant protection of seedlings from Fusarium infection was found using strain M4 in microcosm assays. The antifungal lipopeptide genes for surfactin and iturin were detected in M4; culture extracts of M4 showed a positive drop collapse result for surfactins. This study demonstrates that browntop millet seeds vector indigenous endophytes that are responsible for modulation of seedling development and protection of seedlings from fungal disease. This study is significant and original in that it is the first report of seed-inhabiting endophytes of browntop millet that influence seedling development and function in defence against soilborne pathogens. This study suggests that conservation and management of seed-vectored endophytes may be important in development of more sustainable agricultural practices. © 2017 The Society for Applied Microbiology.
Baradjanegara, A.A.; Fujii, Taro; Amano, Etsuo
Seeds of rice c.v. Norin-8 and two radiation induced dwarf mutants MGS-46 and -96 were used to investigate the effects of gamma- and 14 MeV neutron-radiations in different culture systems. Seedling growth of irradiated seeds in soil, and in two types of synthetic media, modified White's (M-W) or modified Eriksson's (M-E), as well as the callus growth on 2.4-D supplemented media were measured as an index of radiation damage. Comparing the seedling height about two types of media, the M-E promoted the plant growth than the M-W in irradiated as well as non-irradiated lots of the three strains studied. The callus growth on M-E surpassed by more 10 times that obrained on the M-W in all the lots. The M-E medium seem to be appropriate for both the seedling and callus growth of rice. (auth.)
Mohd Yusof, A.; Grunewald, R.
The effect of the gamma ( 137 Cs) total exposure rate of 25 kR delivered at three different exposure rates (887 R/min, 159 R/min and 48 R/min) on soybean seeds was studied by measuring seedling height, cotyledon area, fresh weight, dry weight, Co 2 fixation and RuDP carboxylase activity. The dry weight, CO 2 fixation and irradiated imbibed groups did not show any correlation with exposure rate. Exposure rate effect was shown for the first stage out, no further correlation was observed in the subsequent stages, probably due to the recovery and repair mechanisms that take place as the seedling increases with age. The absence of an exposure rate effect on irradiated imbibed group may be explained in terms of non-detectable damage at a very high dose, since these seedlings exhibited effects that are similar to the effects of seeds exposed to an acute radiation dose. (author)
Andreza M. Martins; Fernanda M. Abilio; Plinio Gonçalves de Oliveira; Raquel Partelli Feltrin; Fernanda Scheffer Alves de Lima; Priscilla de O. Antonelli; Daniela Teixeira Vilela; Carl G. Smith III; Collin Tidwell; Paul Hamel; Margaret Devall; Kristina Connor; Theodor Leininger; Nathan Schiff; A. Dan Wilson
Pondberry (Lindera melissifolia(Walter) Blume) is an endangered dioecious, clonal shrub that grows in periodically flooded forests of the southeastern United States. The probability of survival of dispersed pondberry seeds and new germinants is unknown, but few seedlings are noted in the forest. This study was undertaken to: (1) identify herbivores...
M. Esther Puente; Ching Y. Li; Yoav Bashan
A plant-bacterium association between the giant cardon cactus Pachycereus pringlei and endophytic bacteria help seedlings establish and grow on barren rock, This cactus, together with other desert plants, is responsible for weathering ancient lava flows in the Baja California Peninsula of Mexico.When cardon seeds are inoculated with endophytic...
Effects of salt stress on seed germination, early seedling growth and some physiological characteristics were evaluated for four cauliflower species in seven treatments of salinity including 0 (control), 34, 68, 102, 136, 170 and 204 mM NaCl in a three replicated randomized completely block design (RCBD). This result shows ...
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
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.
Silva, Anderson Tadeu; Ribone, Pamela A; Chan, Raquel L; Ligterink, Wilco; Hilhorst, Henk W M
The transition from a quiescent dry seed to an actively growing photoautotrophic seedling is a complex and crucial trait for plant propagation. This study provides a detailed description of global gene expression in seven successive developmental stages of seedling establishment in Arabidopsis (Arabidopsis thaliana). Using the transcriptome signature from these developmental stages, we obtained a coexpression gene network that highlights interactions between known regulators of the seed-to-seedling transition and predicts the functions of uncharacterized genes in seedling establishment. The coexpressed gene data sets together with the transcriptional module indicate biological functions related to seedling establishment. Characterization of the homeodomain leucine zipper I transcription factor AtHB13, which is expressed during the seed-to-seedling transition, demonstrated that this gene regulates some of the network nodes and affects late seedling establishment. Knockout mutants for athb13 showed increased primary root length as compared with wild-type (Columbia-0) seedlings, suggesting that this transcription factor is a negative regulator of early root growth, possibly repressing cell division and/or cell elongation or the length of time that cells elongate. The signal transduction pathways present during the early phases of the seed-to-seedling transition anticipate the control of important events for a vigorous seedling, such as root growth. This study demonstrates that a gene coexpression network together with transcriptional modules can provide insights that are not derived from comparative transcript profiling alone. © 2016 American Society of Plant Biologists. All Rights Reserved.
Full Text Available To study the effect of salinity stress on seed germination and seedling growth of four medicinal plants, Nigella sativa L., Cannabis sativa L., Trigonella foenum graecum and Cynara scolymus L. an experiment was conducted in the botany laboratory of Islamic Azad University, Birjand branch. A completely randomized design (CRD with 3 replications was used as separately for each species. Treatments were consisted of six salinity (NaCl concentrations (0, 4, 8, 12, 16 and 20 dS m-1. The measured traits were root, shoot and seedling length, dry and fresh weight of seedling, germination rate and percent, seed vigor index, seedling water content and root/ shoot ratio. Salinity stress reduced significantly shoot, root and seedling length of the species. Increasing of salinity stress declined dry and fresh weight of Trigonella foenum and Nigella sativa L. and dry weight of Cannabis sativa L.. Seedling water content and root/ shoot ratio of Nigella sativa L. increased in salinity treatments. Increasing of salinity stress declined germination rate and percent in Nigella sativa L., but in other species (Cannabis sativa L., Trigonella foenum graecum and Cynara scolymus only germination rate decreased. Trigonella foenum graecum germinated completely (%100 in all salinity treatments. Increasing of salinity until 16 dS m-1 reduced seed germination of Nigella sativa. Seed germination of Nigella sativa did not occurred in the highest salinity stress (20 dS m-1. Totally the results showed that in the germination stage, Trigonella foenum graecum and Cannabis sativa were relatively tolerate to salinity stress but Nigella sativa L. was the most sensitive one
Oct 20, 2008 ... (M) and Knudson 'C' (KC) were evaluated for seed germination and early ... running tap water and Teepol. ... blade. The powdery seeds were inoculated on the surface of agar ... an interval of one week to trace different stages of development of .... round in shape and radially symmetrical that turned to.
Shearin, Zackery R. C.; Filipek, Matthew; Desai, Rushvi; Bickford, Wesley A.; Kowalski, Kurt P.; Clay, Keith
Background and aimsWe characterized fungal endophytes of seeds of invasive, non-native Phragmites from three sites in the Great Lakes region to determine if fungal symbiosis could contribute to invasiveness through their effects on seed germination and seedling growth.MethodsField-collected seeds were surface sterilized and plated on agar to culture endophytes for ITS sequencing. Prevalence of specific endophytes from germinated and non-germinated seeds, and from seedlings, was compared.ResultsOne-third of 740 seeds yielded endophyte isolates. Fifteen taxa were identified with Alternaria sp. representing 54% of all isolates followed by Phoma sp. (21%) and Penicillium corylophilum (12%). Overall germination of seeds producing an isolate (36%) was significantly higher than seeds not producing an isolate (20%). Penicillium in particular was strongly associated with increased germination of seeds from one site. Sixty-three isolates and 11 taxa were also obtained from 30 seedlings where Phoma, Penicillium and Alternaria respectively were most prevalent. There was a significant effect of isolating an endophyte from the seed on seedling growth.ConclusionsThese results suggest that many endophyte taxa are transmitted in seeds and can increase seed germination and seedling growth of invasive Phragmites. The role of fungal endophytes in host establishment, growth and invasiveness in nature requires further research.
Yang, Fen; Svensson, Birte; Finnie, Christine
involved in primary metabolism and detoxification whereas the majority of down-regulated proteins were plant protease inhibitors. The results suggest that there is a link between increased energy metabolism and oxidative stress in the germinating barley seeds in response to F. graminearum infection, which......Fusarium seedling blight in cereals can result in significant reductions in plant establishment but has not received much attention. The disease often starts during seed germination due to sowing of the seeds infected by Fusarium spp. including Fusarium graminearum. In order to gain the first...
Yasur, Jyothsna; Rani, Pathipati Usha
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.
Xiao Wen Hu
Full Text Available Studying seed dormancy and its consequent effect can provide important information for vegetation restoration and management. The present study investigated seed dormancy, seedling emergence and seed survival in the soil seed bank of Stipa bungeana, a grass species used in restoration of degraded land on the Loess Plateau in northwest China. Dormancy of fresh seeds was determined by incubation of seeds over a range of temperatures in both light and dark. Seed germination was evaluated after mechanical removal of palea and lemma (hulls, chemical scarification and dry storage. Fresh and one-year-stored seeds were sown in the field, and seedling emergence was monitored weekly for 8 weeks. Furthermore, seeds were buried at different soil depths, and then retrieved every 1 or 2 months to determine seed dormancy and seed viability in the laboratory. Fresh seeds (caryopses enclosed by palea and lemma had non-deep physiological dormancy. Removal of palea and lemma, chemical scarification, dry storage (afterripening, gibberellin (GA3 and potassium nitrate (KNO3 significantly improved germination. Dormancy was completely released by removal of the hulls, but seeds on which hulls were put back to their original position germinated to only 46%. Pretreatment of seeds with a 30% NaOH solution for 60 min increased germination from 25% to 82%. Speed of seedling emergence from fresh seeds was significantly lower than that of seeds stored for 1 year. However, final percentage of seedling emergence did not differ significantly for seeds sown at depths of 0 and 1 cm. Most fresh seeds of S. bungeana buried in the field in early July either had germinated or lost viability by September. All seeds buried at a depth of 5 cm had lost viability after 5 months, whereas 12% and 4% seeds of those sown on the soil surface were viable after 5 and 12 months, respectively.
Panuccio, M.R.; Jacobsen, Sven-Erik; Saleem Akhtar, Saqib
with their high protein content and unique amino acid composition. Although the species has been described as a facultative halophyte, and its tolerance to salt stress has been investigated, its physiological and molecular responses to seawater (SW) and other salts have not been studied. We evaluated the effects...... been carried out to investigate the mechanisms used by quinoa, a facultative halophytic species, in order to cope with high salt levels at various stages of its develop- ment. Quinoa is regarded as one of the crops that might sustain food security in this century, grown primarily for its edible seeds...... of SW and different salts on seed germination, seedling emergence and the antioxidative pathway of quinoa. Seeds were germi- nated in Petri dishes and seedlings grown in pots with SW solutions (25, 50, 75 and 100 %) and NaCl, CaCl2, KCl and MgCl2 individually, at the concentrations in which...
peptidohydrolase (8.0%) from mung bean seedlings. (Baumgartner and Chrispeels, 1977), EP-HG (4.5%) from horse gram seedlings ( Rajeswari, 1997), acidic protease (15%) from germinating winged-bean seeds. (Usha and Singh, 1996) and EP-1 (1.6%) from barley seedlings and GA3-induced cysteine protease (3.38%).
Full Text Available Two rice varieties, Xiushui 110 with high cadmium (Cd tolerance and Xiushui 11 with low Cd tolerance were used to study the effects of Cd stress on seed germination, seedling growth and amylase activities. The low cadmium concentration had little effect on seed germination rate. However, cadmium stress could significantly inhibit plumule and radicle growth, especially for radicle growth. Germination index, vigour index, radicle length and amylase activities of Xiushui 11 decreased more significantly with the increasing cadmium level compared with Xiushui 110. The cadmium content in seedlings of Xiushui 11 was higher than that in Xiushui 110 when the cadmium concentration exceeded 5 μmol/L, which caused lower mitotic index in root tips and amylase activities, and more serious cadmium toxicity in Xiushui 11.
Seeber, R.G. Jr.
This investigation sought to follow the uptake of the cytokinin, 14 C-8N 6 -benzyladenine (BAP), by lettuce seeds through time, trace the movement of the metabolites through several areas of the seedling, and identify the BAP metabolites. Lettuce seeds (Lactuca sativa L. cv. Grand Rapids) were exposed to a two hour pulse of the radioactive BAP. These seeds were harvested at 4 hour intervals from 2-48 hours. Seedlings incubated from 36-48 hours were cut in two; root, stem, shoot tip and seed coats. Each of these groups were extracted in 70% methanol and their radioactive isolated by high performance liquid chromatography. Radioactive fractions were pooled and reduced for further analysis by thin layer chromatography. The major compound identified throughout the time periods was BAP, exclusively found from 2-20 hours. BAP riboside was found in addition to BAP from 24-32 hours. The 40 and 44 hour extracts contained BAP and its riboside in the shoot and BAP in the seed coat. The 48 hours extract contained BAP and its riboside in both the shoot tip and the seed coat. This study produced information on the following points. A cytokinin exposure of 2 hours or less is needed to break dormancy in these seeds
Full Text Available Effect of free and symbiotic nitrogen fixing bacteria on seed and seedling produced seeds under deficit irrigation was conducted in laboratory and field experiments in 2006. In laboratory of karaj’s Seed and Plant Research and Certificate Institute an experiment was conducted based on factorial in form of completely randomized design with four replications and in field’s of Islamic Azad University, Varamin Branch were split factorial in form of randomized completely block design with three replications. Treatments included water stress [Irrigation after 50 (Normal irrigation, 100 (Middle stress, 150 (Severe stress mm evaporation from pan class A], Cultivar [Manokin & Williams and SRF×T3 Line] and inoculation [Inoculation with Bradyrhizobium japonicum, Bradyrhizobium japonicum co-inoculated with Azotobacter chroococcum, No seed inoculation]. Results showed that drought stress decreased the uniformity and germination speed and seedling emergence. Bacteria increased leaf dry weight, stem dry weight, leaf area and seedling vigor index but had no effect on emergence. In irrigation levels inoculated treatments had higher seedling length, leaf, stem, seedling dry weight and seedling vigor. Severs stress seeds inoculated with Bradyrhizobium japonicum had higher root dry weight than control. Therefore in seeds which were produced under deficit irrigation conditions, bacteria increased seedlings vigor.
Basnet, R.K.; Duwal, A.; Tiwari, D.N.; Xiao, D.; Monakhos, S.; Bucher, J.; Visser, R.G.F.; Groot, S.P.C.; Bonnema, A.B.; Maliepaard, C.A.
The genetic basis of seed germination and seedling vigour is largely unknown in Brassica species. We performed a study to evaluate the genetic basis of these important traits in a B. rapa doubled haploid population from a cross of a yellow-seeded oil-type yellow sarson and a black-seeded
Narang, Kamlesh; Prakash, G.
Increase in dose of gamma irradiation caused a progressive decrease in seed germination and seedling length in all the seven taxa. Percentage germination varied from species to species. A positive correlation was observed between lengths of primary root and hypocotyl (r = 1.00), root and cotyledon (r = + 0.97), hypocotyl and cotyledon (r = + 0.96), root and lateral root (r = + 0.96), hypocotyl and lateral root (r = + 0.97), cotyledon and lateral root (r = 0.91) but a negative correlation was between fresh and dry weight (r = -0.97) of seedlings. (author)
Young, Hillary S; McCauley, Douglas J; Guevara, Roger; Dirzo, Rodolfo
Positive density-dependent seed and seedling predation, where herbivores selectively eat seeds or seedlings of common species, is thought to play a major role in creating and maintaining plant community diversity. However, many herbivores and seed predators are known to exhibit preferences for rare foods, which could lead to negative density-dependent predation. In this study, we first demonstrate the occurrence of increased predation of locally rare tree species by a widespread group of insular seed and seedling predators, land crabs. We then build computer simulations based on these empirical data to examine the effects of such predation on diversity patterns. Simulations show that herbivore preferences for locally rare species are likely to drive scale-dependent effects on plant community diversity: at small scales these foraging patterns decrease plant community diversity via the selective consumption of rare plant species, while at the landscape level they should increase diversity, at least for short periods, by promoting clustered local dominance of a variety of species. Finally, we compared observed patterns of plant diversity at the site to those obtained via computer simulations, and found that diversity patterns generated under simulations were highly consistent with observed diversity patterns. We posit that preference for rare species by herbivores may be prevalent in low- or moderate-diversity systems, and that these effects may help explain diversity patterns across different spatial scales in such ecosystems.
Wang, Guang Chen; Song, Yuan; Yan, Qiao Ling; Zhang, Jin Xin
Two typical broadleaved trees (i.e., Fraxinus rhynchophylla and Acer mono) with wind-dispersed seeds in Northeast China were selected in this study. A method of 15 N isotope labeling was used to explore the accumulation responses of seeds and seedlings to 15 N-urea soaking concentration (0, 0.05, 0.1 and 0.2 g·L -1 ), soaking time (4, 8 and 12 days) and leaf stage (2, 4, 6, and 8 leaves). The results showed that 15 N-urea soaking concentration and soaking time had significantly positive effects on δ 15 N values of seeds, i.e., higher 15 N-urea concentration and longer period of soaking (0.2 g·L -1 +12 d) were contributed to more 15 N accumulation of seeds. The maximum multiples of 15 N accumulation in F. rhynchophylla seeds and A. mono seeds were observed in 0.1 g·L -1 + (4 d, 8 d) and 0.05 g·L -1 + (4 d, 8 d), respectively. The loss rate of δ 15 N values decreased markedly from 2 leaves to 6 leaves and then kept relatively stable with the increasing seedling height, and the total δ 15 N values of seedlings started to decline at the stage of 8 leaves. These results suggested that seedlings with 6 leaves were more suitable for tracking seedling source. The δ 15 N values in leaves of seedlings were significantly positively correlated with 15 N-urea concentration level, soaking time and δ 15 N values of seeds. Overall, the accumulation of 15 N-urea could be found in seeds and seedlings of F. rhynchophylla and A. mono. The combination of 15 N-urea concentration (0.1 g·L -1 ), soaking time (8 d) and leaf stage (6 leaves) was the most suitable for tracking the seeds and seedlings of these two broadleaved trees.
These are available in June-. September when other fruits are scarce, and people cherished eating the succulent seeds. As documented by Irvine (1990) the plant which is a perennial is also a climber requiring support of woody sticks to climb, grow and survive. The plant start flowering between 1.5 to 2 years after planting.
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
Full Text Available Poor seed germination and early seedling growth associated with urea-induced soil ammonia volatilization are major constraints in the adoption of dry direct-seeded rice. To directly examine soil ammonia volatilization and its damage to seed germination and early seedling growth of dry direct-seeded rice when urea is applied at seeding, two Petri-dish incubation experiments and a field experiment were conducted. Ammonia volatilization due to urea application significantly reduced seed germination and early seedling growth of dry direct-seedling rice. NBPT significantly reduced ammonia volatilization following urea application. The application of ammonium sulfate, instead of urea at seeding, may mitigate poor crop establishment of dry direct-seeded rice. Root growth of dry direct-seeded rice was more seriously inhibited by soil ammonia volatilization than that of shoot. Results suggest that roots are more sensitive to soil ammonia toxicity than shoots in dry direct-seeded rice system when N is applied as urea at seeding.
Urva; Shafique, Hina; Jamil, Yasir; Haq, Zia Ul; Mujahid, Tamveel; Khan, Aman Ullah; Iqbal, Munawar; Abbas, Mazhar
Recently, laser application in agriculture has gained much attention since plant characteristics were improved significantly in response of pre-sowing seed treatment. Pre-sowing laser seed treatment effects on germination, seedling growth and mineral profile were studied in Moringa olifera. M. olifera healthy seeds were exposed to 25, 50, 75mJ low power continuous wave laser light and grown under greenhouse conditions. The seedling growth and biochemical attributes were evaluated from 10-day-old seedlings. The germination parameters (percentage, mean germination time), vigor index, seedling growth (root length, seedling length, shoot fresh weight, root fresh weight, shoot dry weight, root dry weight) enhanced considerably. The laser energy levels used for seed irradiation showed variable effects on germination, seedling growth and mineral profile. The mineral contents were recorded to be higher in seedling raised from laser treated seeds, which were higher in roots versus shoots and leaves. The effect of laser treatment on seedling fat, nitrogen and protein content was insignificant and at higher energy level both nitrogen and protein contents decreased versus control. Results revealed that M. olifera germination, seedling growth and mineral contents were enhanced and optimum laser energy level has more acceleratory effect since at three laser energy levels the responses were significantly different. Overall the laser energy levels effect on germination and seedling growth was found in following order; 75mJ>50mJ>25mJ, where as in case of fat, protein and nitrogen contents the trend was as; 25mJ>50mJ and 75mJ. However, this technique could possibly be used to improve the M. olifera germination, seedling growth, and minerals contents where germination is low due to unfavorable conditions. Copyright © 2017 Elsevier B.V. All rights reserved.
Article presents the results of research on the effect of chronic γ-irradiation in small doses on A. Thaliana seedlings and seeds growth and development. Exposure rate for the seeds was 0,45 mGy/h (total absorbed dose 30 cSv) and 0,18 mGy/h for seedlings (total absorbed dose 3 cSv). Statistically significant differences in the germination capacity, in the time of primary leaf rosette formation, in the hypocotyl length were revealed between irradiated and control seedlings. Plants from irradiated seeds differed by the higher growth rate of stem, they flowered and fruited earlier, but they also characterized on average shorter vegetative cycle in comparison with control plants. In our experiments it is shown significant impact of chronic low doses of γ-irradiation of seeds and seedlings on the ontogeny in A. Thaliana and on the parameters that reflect the growth and development of the irradiated plants
Silva, Anderson Tadeu; Ribone, Pamela A.; Chan, Raquel L.; Ligterink, Wilco; Hilhorst, Henk W.M.
The transition from a quiescent dry seed to an actively growing photoautotrophic seedling is a complex and crucial trait for plant propagation. This study provides a detailed description of global gene expression in seven successive developmental stages of seedling establishment in Arabidopsis
Boedeltje, G; ter Heerdt, GNJ; Bakker, JP
Seed bank studies focused on submerged aquatic plants are generally performed under submerged conditions, using the seedling-emergence method. However, if a study targets at both submerged species and helophytes, submerged conditions are generally not suitable. We tested the emergence of seedlings
Diane L. Haase; Nabil Khadduri; Euan Mason; Kas Dumroese
Douglas-fir (Pseudotsuga menziesii [Mirb.] Franco) seedlings from three nurseries in the Pacific Northwest United States were lifted on five dates from mid-October through mid-December 2006. Each nursery provided seedlings from a low- and a high-elevation seed lot. Photoperiod and accumulated chilling hours (calculated using two methods) were evaluated...
Lin, C.; Guan, Y. J.; Fu, H.; Hu, J.; Tian, Y. X.
The present study investigates the effects of seed soaking in varying concentration of rhodamine B (RB) or safranine T (ST) solutions on germination and seedling growth of pea seeds. The fluorescence in pea seedling at different developmental stages was observed. The results indicate that there were no adverse effects of seed soaking in RB (0.1mg/ml) and ST (0.5, 0.3, 0.1mg/ml) solutions on germination, seedling growth, antioxidant enzyme activities, malondialdehyde (MDA) and chlorophyll contents. The seeds treated with RB showed bright red and orange fluorescence under green (546 nm) and blue (495 nm) light excitation, respectively while no red or orange color was observed in the control seeds. In addition, the vascular bundles of stem, seedling roots and aerial parts of seedlings treated with RB all emitted brilliant fluorescence for a longer time as compared with that treated with ST. It can be concluded that pea seed labeled with RB by seed soaking at appropriate concentration could be used as a potential anti-counterfeiting technique in pea seeds. (author)
Thimmaiah, S.K.; Mahadevu, P; Srinivasappa, K.N.; Shankara, A.N.
Cowpea [Vigna unguiculata (L.) Walp.) is regarded as hardy and one of the important tropical legumes. The plants respond differently to mutagenic treatments. Ionizing radiations affect a wide range of physiological and biochemical activities of plants. The purpose of this paper is to report the effect of gamma radiation on seed germination and seedling vigour of two important cowpea varieties viz., KBC-1 and TVX-994-02E in M 1 generation under laboratory conditions. (author)
Tiago Zanatta Aumonde
Full Text Available The work was conducted to evaluate the effect of different Philodendron bipinnatifidum Schott. extract concentrations on the physiology and enzymatic metabolism of lettuce seeds and seedlings. The treatments extracts of mature leaves at concentrations of 0, 6, 12, 25 and 50%. Were evaluated the germination, first count germination, speed and germination speed index, length of shoot and primary root, seedling total dry mass, electrical conductivity, chlorophyll content, activity of the enzymes ?-amilase, superoxide dismutase, catalase and ascorbarto peroxidase, lipid peroxidation, hydrogen peroxide content and seedling emergence, length of shoot and total dry mass of emerged seedlings. There was a reduction of germination, germination speed index and total dry mass by increasing the concentration of the extract. While the content of hydrogen peroxide, lipid peroxidation and activity of superoxide dismutase, catalase and peroxidase ascorbarto increased with concentration. The increasing of concentration the leaf extracts of the P. bipinnatifidum negatively affects the activity of the enzyme ?-amylase and causes increase in the activity of antioxidant enzymes, affecting the physiologic performance and growth of lettuce seedlings.
Full Text Available Pollen pattern dispersal in seedling seed orchard (SSO is an essential part of a tree-improvement program. Two SSOs of Acacia mangium in South Kalimantan and South Sumatra that represent similar resources in different environments were used in this study. Genotypes of all trees and seeds from a subset of 10 mother trees in each orchard were determined for 12 microsatellite loci, and parentage analysis was carried out. The results shows that the pollen dispersal pattern in both SSOs decrease with distance from mother tree. Patterns of pollen dispersal, dispersal distance and cumulative frequency of pollen dispersal distance were similar in both SSOs. Random pollen dispersal were found in both SSOs. About 80% of all crosses were found within a 40-m distance range with the most frequent pollination distance between mother tree and male male parents was 0-10 m. No self-pollinated seed was detected. Application of all these aspects found in this study such as random pollen dispersal and the effective pollen dispersal distance can be useful for establishing seedling seed orchard, clonal seed orchard and in other tree improvement activities of A. mangium.
Juhr, N.C.; Franke, J.
This report deals with the utilization of UC-labelled urea in conventional, defined associated and germ-free rats. With conventional animals 71.44% of the administered UC dose can be demonstrated in the exhaled air, 0.47% in organs and 27.35% in the urine. 1.04% was found in the intestinal and fecal contents. Animals mono-associated with Proteus mirabilis have nearly the same utilization rate (59.15, 0.34, 35.98, 2% resp.). In germ-free animals 1.21% of the activity appeared in the exhaled air and showed a small part of non-enzymatic hydrolysis of urea. The excretion of 97.70% in the urine shows that urea is absorbed from the intestine in germ-free animals.
Fabiana Soledad Ojeda
Full Text Available Four neotropical species of Vigna Savi (Leguminosae, Phaseolinae have potential value as forage crops or ornamentals and could be cultivated in tropical or subtropical areas, even on floodplains. In order to obtain useful data for their culture and taxonomy, the seed morphology, germination pattern (hypogeal or epigeal and seedling development were studied. The studied species belong to different sections of the genus: V. adenantha (G.F.W. Meyer Maréchal, Mascherpa & Stainier (Sect. Leptospron; V. candida (Vell. Maréchal, Mascherpa & Stainier (Sect. Sigmoidotropis; V. caracalla (L. Verdc. (Sect. Caracallae and V. luteola (Jacq. Benth. (Sect. Vigna. The seeds were collected during fieldwork conducted in northwestern and northeastern Argentina. The qualitative and quantitative characters of the seeds were registered, after which they were sown. The development of the emerged seedlings was followed, first in a greenhouse and thereafter in open field. We recorded the type of germination, the thigmotropic movements of the hypocotyl and of the stem, seedling architecture and plant longevity. These traits allowed us to differentiate the species and construct an identification key that could be useful for agronomic or floricultural purposes. The data obtained partially support the current taxonomic treatment of the genus.
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.
Full Text Available The success of seed germination and the establishment of a normal seedling are key determinants of plant species propagation. At present, only few studies have focused on the genetic control of the seed germination by proteomic approach in Brassica napus. In the present study, the protein expression pattern of seed germination was investigated using differential fluorescence two-dimensional gel electrophoresis (2-D DIGE in B. napus. One hundred thirteen differentially expressed proteins (DEPs, which were mainly involved in storage proteins (23.4%, energy metabolism (18.9%, protein metabolism (16.2%, defense/disease (12.6%, seed maturation (11.7%, carbohydrate metabolism (4.5%, lipid metabolism (4.5%, amino acids metabolism (3.6%, cell growth/division (3.6%, and some unclear proteins (2.7% were observed by proteomic analysis. Seventeen genes corresponding to 11 DEPs were identified within or near the associated linkage disequilibrium regions related to seed germination and vigor quantitative traits reported in B. napus in previous studies. The expression pattern of proteins showed the heterotrophic metabolism could be activated in the process of seed germination and the onset of defense system might start during seed germination. These findings will help us more in-depth understanding of the mobilization of seed storage reserves and regulation mechanisms of germination process in B. napus.
Griffiths, Hannah M; Bardgett, Richard D; Louzada, Julio; Barlow, Jos
Anthropogenic activities are causing species extinctions, raising concerns about the consequences of changing biological communities for ecosystem functioning. To address this, we investigated how dung beetle communities influence seed burial and seedling recruitment in the Brazilian Amazon. First, we conducted a burial and retrieval experiment using seed mimics. We found that dung beetle biomass had a stronger positive effect on the burial of large than small beads, suggesting that anthropogenic reductions in large-bodied beetles will have the greatest effect on the secondary dispersal of large-seeded plant species. Second, we established mesocosm experiments in which dung beetle communities buried Myrciaria dubia seeds to examine plant emergence and survival. Contrary to expectations, we found that beetle diversity and biomass negatively influenced seedling emergence, but positively affected the survival of seedlings that emerged. Finally, we conducted germination trials to establish the optimum burial depth of experimental seeds, revealing a negative relationship between burial depth and seedling emergence success. Our results provide novel evidence that seed burial by dung beetles may be detrimental for the emergence of some seed species. However, we also detected positive impacts of beetle activity on seedling recruitment, which are probably because of their influence on soil properties. Overall, this study provides new evidence that anthropogenic impacts on dung beetle communities could influence the structure of tropical forests; in particular, their capacity to regenerate and continue to provide valuable functions and services. © 2016 The Author(s).
Ferreras, Ana Elisa; Galetto, Leonardo
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.
Full Text Available Interactions among metabolic pathways are important in plant biology. At present, not much is known about how folate metabolism affects other metabolic pathways in plants. Here we report a T-DNA insertion mutant (atdfb-3 of the plastidial folylpolyglutamate synthetase gene (AtDFB was defective in seed reserves and skotomorphogenesis. Lower carbon (C and higher nitrogen (N content in the mutant seeds than that of the wild type were indicative of an altered C and N partitioning capacity. Higher levels of organic acids and sugars were detected in the mutant seeds compared with the wild type. Further analysis revealed that atdfb-3 seeds contained less total amino acids and individual Asn and Glu as well as NO3-. These results indicate significant changes in seed storage in the mutant. Defects in hypocotyl elongation were observed in atdfb-3 in darkness under sufficient NO3- conditions, and further enhanced under NO3- limited conditions. The strong expression of AtDFB in cotyledons and hypocotyl during early developmental stage was consistent with the mutant sensitivity to limited NO3- during a narrow developmental window. Exogenous 5-formyl-tetrahydrofolate completely restored the hypocotyl length in atdfb-3 seedlings with NO3- as the sole N source. Further study demonstrated that folate profiling and N metabolism were perturbed in atdfb-3 etiolated seedlings. The activity of enzymes involved in N reduction and assimilation was altered in atdfb-3. Taken together, these results indicate that AtDFB is required for seed reserves, hypocotyl elongation and N metabolism in darkness, providing novel insights into potential associations of folate metabolism with seed reserve accumulation, N metabolism and hypocotyl development in Arabidopsis.
The effects of a seed treatment on early season growth, seedling disease development, incidence Fusarium spp. infection, and photosynthetic performance of maize were evaluated at two locations in Iowa in 2007. Maize seed was either treated with Cruiser 2Extreme 250 ® (fludioxonil + azoxystrobin + me...
Šplíchalová, Alla; Slavíková, Renata; Šplíchalová, Zdislava; Šplíchal, Igor
Roč. 9, FEB 14 (2018), č. článku 220. ISSN 1664-3224 R&D Projects: GA ČR GA13-14736S Institutional support: RVO:61388971 Keywords : preterm * enterocyte * germ-free Subject RIV: EC - Immunology OBOR OECD: Immunology Impact factor: 6.429, year: 2016
Lundberg, Randi; Toft, Martin Fitzner; August, Benjamin
We recently investigated the applicability of antibiotic-treated recipient mice for transfer of different gut microbiota profiles. With this addendum we elaborate on perspectives and limitations of using antibiotics as an alternative to germ-free (GF) technology in microbial transplantation studies...
Eva-Guadalupe LIZ(A)RRAGA-PAUL(I)N; Susana-Patricia MIRANDA-CASTRO; Ernesto MORENO-MART(I)NEZ; Alma-Virginia LARA-SAGAH(O)N; Irineo TORRES-PACHECO
Objective:To evaluate the effect of chitosan(CH)and hydrogen peroxide(H2O2)seed coatings and seedling sprinklings on two different maize varieties by measuring their phenology,the H2O2 presence,the catalase (CAT)activity,and the protein quantity.Methods:Seven groups of ten seeds for each maize variety were treated with CH(2％(20 g/L)and 0.2％(2 g/L))or H2O2(8 mmol/L)by coating,sprinkling,or both.Germination and seedling growth were measured.One month after germination,the presence of H2O2 in seedlings in the coated seed treatments was evaluated.Protein content and CAT activity were determined under all treatments.Results:H2O2 seed coating enhanced the germination rate and increased seedling and stem length in the quality protein maize(QPM)variety.Seedlings had a higher emergence velocity under this treatment in both varieties.CH and H2O2 sprinklings did not have an effect on seedling phenology.Exogenous application of H2O2 promoted an increase of endogenous H2O2.CH and H2O2 seedling sprinkling increased the protein content in both maize varieties,while there was no significant effect on the CAT activity of treated seeds and seedlings.Conclusions:CH and H2O2 enhance some phenological and biochemical features of maize depending on their method of application.
Chen, Yen-Po; Chen, Ming-Ju
Lactobacillus kefiranofaciens M1 is a novel probiotic strain that was isolated from kefir grains. Previously, we have demonstrated the immunoregulatory, anti-allergic, anti-asthmatic and anti-colitis abilities of L. kefiranofaciens M1 in a number of in-vitro and in-vivo experiments. However, whether the effects of L. kefiranofaciens M1 are elicited directly on the host or act by regulating the host's microbiota remains unknown. A number of studies have used germ-free or gnotobiotic animals to investigate the relationship between probiotics and colitis; therefore the aim of this study was to investigate the effects of L. kefiranofaciens M1 on germ-free mice. Such an approach should help in determining the direct effects of L. kefiranofaciens M1 on the host itself. Four-week-old female germ-free mice were inoculated intragastrically with 2×10(8) CFU/mouse L. kefiranofaciens M1 once or at 2-day intervals for 14 days. Bacterial colonization, the Th1/Th2 cytokine profile of the mice's splenocytes and the anti-colitis effect of L. kefiranofaciens M1 were investigated. The strongest response in terms of splenic Th1 cytokine IFN-γ and IL-12 production upon TLR activation was detected in the continuous treatment group when comparing to the single inoculation group and the germ-free control. In addition, continuous inoculation with L. kefiranofaciens M1 was found to ameliorate the symptoms of DSS-induced colitis in germ-free mice. However, L. kefiranofaciens M1 failed to colonize the host. Thus it would seem that L. kefiranofaciens M1 is likely to act directly on the host and not be involved in microbiota regulation.
Full Text Available Lactobacillus kefiranofaciens M1 is a novel probiotic strain that was isolated from kefir grains. Previously, we have demonstrated the immunoregulatory, anti-allergic, anti-asthmatic and anti-colitis abilities of L. kefiranofaciens M1 in a number of in-vitro and in-vivo experiments. However, whether the effects of L. kefiranofaciens M1 are elicited directly on the host or act by regulating the host's microbiota remains unknown. A number of studies have used germ-free or gnotobiotic animals to investigate the relationship between probiotics and colitis; therefore the aim of this study was to investigate the effects of L. kefiranofaciens M1 on germ-free mice. Such an approach should help in determining the direct effects of L. kefiranofaciens M1 on the host itself. Four-week-old female germ-free mice were inoculated intragastrically with 2×10(8 CFU/mouse L. kefiranofaciens M1 once or at 2-day intervals for 14 days. Bacterial colonization, the Th1/Th2 cytokine profile of the mice's splenocytes and the anti-colitis effect of L. kefiranofaciens M1 were investigated. The strongest response in terms of splenic Th1 cytokine IFN-γ and IL-12 production upon TLR activation was detected in the continuous treatment group when comparing to the single inoculation group and the germ-free control. In addition, continuous inoculation with L. kefiranofaciens M1 was found to ameliorate the symptoms of DSS-induced colitis in germ-free mice. However, L. kefiranofaciens M1 failed to colonize the host. Thus it would seem that L. kefiranofaciens M1 is likely to act directly on the host and not be involved in microbiota regulation.
Cai Chunju; Gao Jian; Mu Shaohua
The dry seeds of Phyllostachys edulis were irradiated by different doses of 60 Co γ rays, the effects of the radiation on seed vigor and seedling growth characters were investigated by four testing methods, i.e. germination testing indoor, electrical conductivity, TTC vigor testing and growth classification of saddling. Results showed that the germination process and germination rate could be accelerated by doses of 60 Co γ rays (≤100 Gy), and higher doses of 60 Co γ rays (>100 Gy) could obviously inhibit the germination process and reduce seed vigor, while induce seed embryo broken, cell division, growth restrained, the height of young seedling and length of root decreasing. The inhibition effects were significantly increased with radiation dose increase. The optimal range of radiation dose for radiation breeding of Phyllostachys edulis dry seeds was 100 to 175 Gy. Linear relationships were existed in electrical conductivity after dipping in water for 24h in germination rate (G), germination index (GI), vigor index (VI), height of seedlings and length of root. EC after 24h and height of seedlings were chosen to test the change of seeds vigor and the effect of the radiation of 60 Co γ rays on Phyllostachys edulis. (authors)
Zhang, Hao; Yang, Minmin; Luan, Qian; Tang, Hu; Huang, Fenghong; Xiang, Xia; Yang, Chen; Bao, Yuping
Cellulose anionic hydrogels were successfully prepared by dissolving TEMPO-oxidized cellulose nanofibers in NaOH/urea aqueous solution and being cross-linked with epichlorohydrin. The hydrogels exhibited microporous structure and high hydrophilicity, which contribute to the excellent water absorption property. The growth indexes, including the germination rate, root length, shoot length, fresh weight, and dry weight of the seedlings, were investigated. The results showed that cellulose anionic hydrogels with suitable carboxylate contents as plant growth regulators could be beneficial for seed germination and growth. Moreover, they presented preferable antifungal activity during the breeding and growth of the sesame seed breeding. Thus, the cellulose anionic hydrogels with suitable carboxylate contents could be applied as soilless culture mediums for plant growth. This research provided a simple and effective method for the fabrication of cellulose anionic hydrogel and evaluated its application in agriculture.
Full Text Available Study of the effects of various media on growth of ebony (Diospyros celebica Bakh seedlings through seeds multiplication was carried out. The experiment used various media i.e. sands, soil (latosol, compost and EM Bokashi. The study was arranged by Factorial Randomized Block Design with 4 replications, growth parameters were observed i.e. growth percentage, plant height, total leaves, total roots and roots length. The results showed that the best medium of all parameter observed was EM Bokashi and the low results showed by latosol soil medium. Statistically all of parameter observed showed significant level at 5% Duncans’ tested to various media. The best media at the study was EM Bokashi, and could be recommended for media of ebony seed multiplication especially.
Pansing, Elizabeth R; Tomback, Diana F; Wunder, Michael B; French, Joshua P; Wagner, Aaron C
Tree recruitment is a spatially structured process that may undergo change over time because of variation in postdispersal processes. We examined seed pilferage, seed germination, and seedling survival in whitebark pine to determine whether 1) microsite type alters the initial spatial pattern of seed caches, 2) higher abiotic stress (i.e. higher elevations) exacerbates spatial distribution changes, and 3) these postdispersal processes are spatially clustered. At two study areas, we created a seed distribution pattern by burying seed caches in microsite types frequently used by whitebark pine's avian seed disperser (Clark's nutcracker) in upper subalpine forest and at treeline, the latter characterized by high abiotic environmental stress. We monitored caches for two years for pilferage, germination, and seedling survival. Odds of pilferage (both study areas), germination (northern study area), and survival (southern study area) were higher at treeline relative to subalpine forest. At the southern study area, we found higher odds of 1) pilferage near rocks and trees relative to no object in subalpine forest, 2) germination near rocks relative to trees within both elevation zones, and 3) seedling survival near rocks and trees relative to no object at treeline. No microsite effects were detected at the northern study area. Findings indicated that the microsite distribution of seed caches changes with seed/seedling stage. Higher odds of seedling survival near rocks and trees were observed at treeline, suggesting abiotic stress may limit safe site availability, thereby shifting the spatial distribution toward protective microsites. Higher odds of pilferage at treeline, however, suggest rodents may limit treeline recruitment. Further, odds of pilferage were higher near rocks and trees relative to no object in subalpine forest but did not differ among microsites at treeline, suggesting pilferage can modulate the spatial structure of regeneration, a finding supported by
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.
Valquíria Aparecida Mendes de Jesus
Full Text Available This work aimed to study the effect of the Calophyllum brasiliense seed coat on the seed germination process. To this end, three experiments were conducted in laboratory, greenhouse and screenhouse. From a total of six treatments, five are related to the seed coat (mechanical scarification; mechanical scarification followed by 2 hours in water, chemical scarification, hot water immersion and complete seed coat removal and one control. Laboratory and greenhouse experiments were conducted in a completely randomized design (CRD. Screenhouse experiment was conducted in a completely randomized block design (RBD. We evaluated the total percentage, the speed index and the average time of germination or emergence. Data were subjected to analysis of variance and means compared by LSD test, at 5%. Under the conditions of this work, it was possible to infer that, in laboratory, mechanical scarification followed by 2 hours in water increases the proportion and germination speed index (GSI, in the greenhouse, the complete seed coat removal increases the percentage and emergence speed index (ESI, and in the screenhouse, mechanical scarification followed by 2 hours in water and chemical scarification presented the best results. The average germination time was not significantly different in the three experiments evaluated.
Sayed, M. A.; Imam, R.; Siddiqui, M.N.
The aim of this study was to investigate the allelopathic effects of L. siribicus extract on seed germination and seedlings growth of wheat as well as to identify potential allelochemical. The different concentration (5, 10 and 15%) of aqueous extract were applied during the time of sowing and at 5 days after sowing of wheat seed. L. siribicus extract showed concentration and time - depending activity. Different concentration of aqueous extract inhibited seed germination, seedlings growth, when extracts were applied during the time of seed sowing. The stimulatory effect of seedlings growth were found for 5 % aqueous extract, in contrast 10 and 15% extract inhibited seedlings growth, when extracts were applied at 5 days after sowing. Apart from, 4-hydroxy benzoic acids affected seedlings growth irrespective of application time. The weight of dry matter of wheat seedlings were increased for 5% than 10 and 15% extracts. Thin layer chromatography suggested that the presence of 4-hydroxy benzoic acid including other allelopathic and growth regulatory compounds inhibited germination and seedlings growth. Mineral composition was determined and its might have some stimulatory effect on seedlings growth. It was interesting that 5% extract inhibited germination and seedlings growth, when it was applied during the time of seed sowing, but stimulated seedling growth, when it was applied at 5 days after sowing. The extract of this plants can be used either for bioherbicide as well as growth stimulatory agents for the organic farming system. To find out molecular mechanism behind it, further research is to be done. (author)
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.
Rogério Falleiros Carvalho
Full Text Available Seed priming with hormones has been an efficient method for increasing seed vigor as well as seedling growth under stressful conditions. These responses have in the past been attributed to the activation of antioxidant systems in a range of crops. The results described in this work show that hormonal priming with methyl jasmonate, salicylic acid or CEPA (chloroethylphosphonic acid, an ethylene (ET releaser, does not induce the antioxidant activity of superoxide dismutase, catalase, ascorbate peroxidase or glutathione reductase in maize seedlings subjected to salt stress. The enhanced biomass of maize seedlings under salt stress that was observed only from ET priming indicates that the stress tolerance in maize from ethylene priming is a fundamental process for stress tolerance acquisition, which is explained, however, by other biochemical mechanisms but not by changes in the antioxidant system.
Rafique, N.; Raza, S.H.; Qasim, M.; Iqbal, N.
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)
Rafael de C. Silva
Full Text Available Actually, the germplasm of Jatropha spp. is conserved as whole plants in field collections. Under this storage method, the genetic resources are exposed to disease, pest and natural hazards such as human error, drought and weather damage. Besides, field genebanks are costly to maintain and with important requirements of trained personnel. Thus, the development of efficient techniques to ensure its safe conservation and regeneration is therefore of paramount importance. In this work we describe a method for Jatropha curcas seeds cryoexposure and seedling recovery after thawed. In a first experiment, an efficient protocol for in vitro plant recovery was carried out using zygotic embryo or seeds with or without coat. In a second experiment, desiccated seeds with or without coat were exposed to liquid nitrogen and evaluated after cryoexposure. Germination percentages were variable among treatments, and seeds demonstrated tolerance to liquid nitrogen exposure under certain conditions. Seeds of J. curcas presented up to 99.6% germination after seed coat removal. Seeds with coat cultured in vitro did not germinate, and were 60% contaminated. The germination of the zygotic embryos was significantly higher in the ½ MS medium (93.1% than in WPM medium (76.2%, but from zygotic embryo, abnormal seedlings reached up to 99%. Seeds with coat exposed to liquid nitrogen showed 60% germination in culture after coat removal with good plant growth, and seeds cryopreserved without coat presented 82% germination, but seedlings showed a reduced vigor and a significant increase in abnormal plants. Seeds cultured in vitro with coat did not germinate, independently of cryoexposure or not. This study reports the first successful in vitro seedling recovery methodology for Jatropha curcas seeds, after a cryopreservation treatment, and is recommended as an efficient procedure for in vitro plant recovery, when seeds are conserved in germplasm banks by low or cryotemperatures
Selection responses in natural plant populations depend on how the phenotypic variation of traits is composed. The contributions of nuclear genetic, maternal, paternal, environmental and inbreeding effects to variation in time to germination, germination percentage, and seed- and seedling size were
Ribeiro de Jesus, P.R.
Biochemical, physiological and molecular responses of Ricinus communis seeds and seedlings to different temperatures: a multi-omics approach
by Paulo Roberto Ribeiro de Jesus
The main objective of this thesis was to provide a detailed
Salmonson, B.J.; Zavitkovski, J.
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
Ramlall, Chandika; Varghese, Boby; Ramdhani, Syd; Pammenter, Norman W; Bhatt, Arvind; Berjak, Patricia; Sershen
Increased air pollution in a number of developing African countries, together with the reports of vegetation damage typically associated with acid precipitation in commercial forests in South Africa, has raised concerns over the potential impacts of acid rain on natural vegetation in these countries. Recalcitrant (i.e. desiccation sensitive) seeds of many indigenous African species, e.g. must germinate shortly after shedding and hence, may not be able to avoid exposure to acid rain in polluted areas. This study investigated the effects of simulated acid rain (rainwater with pH adjusted to pH 3.0 and 4.5 with 70:30, H2 SO4 :HNO3 ) on germination, seedling growth and oxidative metabolism in a recalcitrant-seeded African tree species Trichilia dregeana Sond., growing in its natural seed bank. The results suggest that acid rain did not compromise T. dregeana seed germination and seedling establishment significantly, relative to the control (non-acidified rainwater). However, pH 3.0 treated seedlings exhibited signs of stress typically associated with acid rain: leaf tip necrosis, abnormal bilobed leaf tips, leaf necrotic spots and chlorosis, reduced leaf chlorophyll concentration, increased stomatal density and indications of oxidative stress. This may explain why total and root biomass of pH 3.0 treated seedlings were significantly lower than the control. Acid rain also induced changes in the species composition and relative abundance of the different life forms emerging from T. dregeana's natural seed bank and in this way could indirectly impact on T. dregeana seedling establishment success. © 2014 Scandinavian Plant Physiology Society.
Full Text Available The relative contributions of primary and secondary seed dispersal to plant demography have received little investigation. Evidence on these seed dispersal types, on seed fate and seedling recruitment of the tropical rain forest tree Dipteryx oleifera, is presented. The study was conducted in a 6.37ha permanent plot where seeds and seedlings were located and tagged for the 2007 cohort. A total of 2 814 seeds were threaded and their fate was followed one year after germination. Primary seed dispersal by bats protected seeds from insect larval predation below the adult tree. Bats congregated seeds in bat seed piles located at a mean distance of 40.94±1.48m from the nearest adult individual of D. oleifera. Terrestrial vertebrates congregated seeds in caches located 41.90±2.43m from the nearest adult individual of D. oleifera. The results of the fitted proportional hazard model suggested that primary seed dispersal decreased seed hazard probability by 1.12% for each meter from the adult conspecific (pPresentamos evidencia de la contribución relativa de la dispersión primaria y secundaria de semillas en la suerte que corren las mismas y en el reclutamiento de plántulas de la especie de bosque húmedo tropical Dipteryx oleifera. Este estudio fue realizado en una parcela permanente de 6.37 ha en la que semillas y plántulas del cohorte del 2007 fueron localizadas y mapeadas. Etiquetamos 2 814 semillas para evaluar su suerte un año después de la germinación. Encontramos que la dispersión primaria por murciélagos libera a las semillas de la depredación bajo la copa del árbol adulto causada por la fase larval de un insecto. Los murciélagos dispersan semillas bajo la copa de palmas usadas como comederos, localizados a 40.94±1.48m del árbol de D. oleifera más cercano y vertebrados terrestres congregaran las semillas en caches localizados aproximadamente a 41.90±2.43m del árbol de D. oleifera. Un modelo proporcional de riesgos fue ajustado
Radhakrishnan, Ramalingam; Kumari, Bollipo Dyana Ranjitha
The effects of pulsed magnetic field (PMF) treatment of soybean (Glycine max L. cv CO3) seeds were investigated on rate of seed germination, seedling growth, physico-chemical properties of seed leachates and soil microbial population under laboratory conditions. Seeds were exposed to PMF of 1500 nT at 0.1, 1.0 10.0 and 100.0 Hz for 5 h per day for 20 days, induced by enclosure coil systems. Non-treated seeds were considered as controls. All PMF treatments significantly increased the rate of seed germination, while 10 and 100 Hz PMFs showed the most effective response. The 1.0 and 10 Hz PMFs remarkably improved the fresh weight of shoots and roots, leaf area and plant height from seedlings from magnetically-exposed seeds compared to the control, while 10 Hz PMF increased the total soluble sugar, total protein and phenol contents. The leaf chlorophyll a, b and total chlorophyll were higher in PMF (10 and 100 Hz) pretreated plants, as compared to other treatments. In addition, activities of alpha-amylase, acid phosphatase, alkaline phosphatase, nitrate reductase, peroxidase and polyphenoloxidase were increased, while beta-amylase and protease activities were declined in PMF (10 Hz)-exposed soybean plants. Similarly, the capacity of absorbance of water by seeds and electrical conductivity of seed leachates were significantly enhanced by 10 Hz PMF exposure, whereas PMF (10 Hz) pretreated plants did not affect the microbial population in rhizosphere soil. The results suggested the potential of 10 Hz PMF treatment to enhance the germination and seedling growth of soybean.
Full Text Available Effect of seed-priming with potassium (K sources (K-nano-chelate, KNC, and sulfate (0, 2 and 4 % under drought stress (DS conditions (0, -0.3, -0.6, -0.9, -1.2 and -1.5 MPa water potential on the corn seedling traits was studied. Drought stress decreased the germination indices and seedling vigor. The highest germination, seminal root fresh and dry mass (RFM and RDM was obtained in KNC primed seeds at -0.3 MPa DS. Mean germination time increased under DS conditions mainly in non-primed seeds. Increasing DS to -1.2 MPa led to decrease in RFM and RDM. Influence of DS on the fresh mass of shoots was more severe than on seminal roots. The highest shoots and seminal roots length was observed in 4 % KNC without any DS. Proper priming can be suggested to increase the plant tolerance under DS.
Full Text Available Among arid zone tree species, Acacia senegal and Prosopis cineraria are the most important dryland resources of Western Rajasthan desert ecosystem. Due to ecological, biological and molecular similarities, they are often studied together. The climatic conditions in this region restrict the build-up of soil organic matter and soils are generally deficient in nitrogen. Studies were carried out to isolate and molecularly characterize the diverse group of plant growth promoting rhizobacteria from root nodules of native A. senegal and P. cineraria and their effect on seed germination and seedling traits in two genotypes of A. senegal. The direct sequencing of 16S rDNA region resulted in molecular identification of plant growth promoting rhizobacteria as Bacillus licheniformis, Sinorhizobium saheli isolated from root nodules of A. senegal and S. kostiense and S. saheli isolated from root nodules of P. cineraria. The partial sequences of 16S rDNA were assigned Gen accession numbers HQ738496, HQ738499, HQ738506 and HQ738508. Scarification treatment with sulphuric acid (98% for 15 minutes was able to break the exogenous seed dormancy and enhanced germination percentage in control treatment to 90% and 92.5% in A. senegal in genotypes CAZRI 113AS and CAZRI 35AS, respectively. The treatments with Bacillus licheniformis or S. kostiense, either inoculated individually or as coinoculants, had positive effect on phenotypic traits of germination. Two A. senegal genotypes exhibited significant differences with regard to all the phenotypic traits. On the other hand, treatments with S. saheli isolated from either A. senegal or P. cineraria had negative effects on germination and related phenotypic traits. Values of the coeffivient of determination (R2 over 80% for root length versus shoot length, root/shoot ratio and seedling weight respectively validate that the observed attributes are inter-dependable and linear progression trend can be predicted.
Full Text Available Effects of seed soaking with plant growth regulators (IAA, GA3, kinetin or prostart on wheat (Triticum aestivum cv. Auqab-2000 emergence and seedling growth under normal (4 dS/cm and saline (15 dS/cm conditions were studied to determine their usefulness in increasing relative salt-tolerance. During emergence test, emergence percentage and mean emergence time (MET were significantly affected by most of priming treatments, however, root and shoot length, fresh and dry weight of seedlings were significantly increased by 25 ppm kinetin followed by 1% prostart for 2 h treatments under both normal and saline conditions. All pre-sowing seed treatments decreased the electrolyte leakage of steep water as compared to that of non-primed seeds even after 12 h of soaking. Seed soaking with 25 ppm kinetin induced maximum decrease in electrolyte leakage while an increase in electrolyte leakage was observed by 25, 50 or 100 ppm IAA treatments. It is concluded that priming has reduced the severity of the effect of salinity but the amelioration was better due to 25 ppm kinetin and 1% prostart (2 h treatments as these showed best results on seedling growth, fresh and dry weights under non-saline and saline conditions whereas seed soaking with IAA and GA3 were not effective in inducing salt tolerance under present experimental material and conditions.
Full Text Available Paphiopedilum spicerianum is listed as one of the country’s Wild Plants with Extremely Small Populations (PSESP. Procedures were developed for asymbiotic seed germination and seedling development aimed at producing seedlings for reintroduction. The highest germination was achieved in RECW with a 24 h dark cycle after pretreatment with 1% NaOCl for 40 min after 30 days from germination. However, these protocorms remained white and did not develop further. Although germination was lower under the same conditions in MSCW, it resulted in healthier and greener protocorms. Of four suitable media tested to promote seedling formation, Hyponex No 1 medium with 1.0mgl−1α-naphthalene acetic acid, 0.5gl−1 activated charcoal and 10% banana homogenate was the most effective. Advanced seedling development was seen in all six tested media during a 4 month growing period, with the highest leaf growth rate seen in the same media used for seedling formation, supplemented with 1.0mgl−16-benzyladenine added to promote leaf growth. Fluorescein diacetate (FDA tests on seeds showed that higher salt concentrations in the medium and longer duration of exposure to NaOCl reduce germination because of damaging effects on the testa and the embryo cells.
Shiels, Aaron B; Drake, Donald R
Mammalian herbivores can limit plant recruitment and affect forest composition. Loulu palms (Pritchardia spp.) once dominated many lowland ecosystems in Hawai'i, and non-native rats (Rattus spp.), ungulates (e.g. pigs Sus scrofa, goats Capra hircus) and humans have been proposed as major causes of their decline. In lowland wet forest, we experimentally determined the vulnerability of seeds and seedlings of two species of Pritchardia, P. maideniana and P. hillebrandii, by measuring their removal by introduced vertebrates; we also used motion-sensing cameras to identify the animals responsible for Pritchardia removal. We assessed potential seed dispersal of P. maideniana by spool-and-line tracking, and conducted captive-feeding trials with R. rattus and seeds and seedlings of both Pritchardia species. Seed removal from the forest floor occurred rapidly for both species: >50 % of Pritchardia seeds were removed from the vertebrate-accessible stations within 6 days and >80 % were removed within 22 days. Although rats and pigs were both common to the study area, motion-sensing cameras detected only rats (probably R. rattus) removing Pritchardia seeds from the forest floor. Captive-feeding trials and spool-and-line tracking revealed that vertebrate seed dispersal is rare; rats moved seeds up to 8 m upon collection and subsequently destroyed them (100 % mortality in 24-48 h in captivity). Surprisingly, seedlings did not suffer vertebrate damage in field trials, and although rats damaged seedlings in captivity, they rarely consumed them. Our findings are consistent with the hypothesis generated from palaeoecological studies, indicating that introduced rats may have assisted in the demise of native insular palm forests. These findings also imply that the seed stage of species in this Pacific genus is particularly vulnerable to rats; therefore, future conservation efforts involving Pritchardia should prioritize the reduction of rat predation on the plant recruitment stages
Shu, Y.; Zhou, Y.; Huang, S.; Chen, M.; Huang, L.; Ma, H.
The class I KNOX homeobox transcription factors are known to play an important role in maintenance of plant phenotype, especially leaves and flowers. In this study, a soybean KNOX I homeobox transcription factor, GmSBH1, was analyzed and confirmed to play important roles in the process of seed germination and developing. Real time quantitative PCR assay showed that the transcript level of GmSBH1 in soybean seedlings was modulated by plant hormones, such as IAA, GA, MeJA and ABA.Yeast one-hybrid assay showed that GmSBH1 could bind to the ABRE cis-element. Overexpression of GmSBH1 in Arabidopsis resulted in the abnormal phenotype of flowers and siliques. In GmSBH1 transgenic lines, both seed germination and seedlings growth showed hypersensitive to ABA. Moreover, the expression of ABA-responsive genes, such as ABI3 and ABI5, were increased in the transgenic line seedlings. Taken together, ectopic expression of GmSBH1 could alter the morphology and confer ABA sensitivity during seed germination and early seedling growth in transgenic Arabidopsis. (author)
Full Text Available In order to determine the relationships between salt tolerance, seed and seedling characteristics, 16 watermelon genotypes collected from various regions of Turkey, and 3 standard and 2 F1 hybrid varieties were used as material in the study. The seedlings were grown in Hoaglands nutrient solution in aqua culture in an atmospheric controlled climatic environment, and 100 mM NaCl salt stress was applied when the seedlings had 4-5 true leaves,. It has been understood that watermelon genotypes have different responses to salt stress in seedling growth and ion uptake. The watermelon genotypes 18, 22, 28, 31 and 41, with large seed weights and large cotyledon leaves were less affected from salt damage by being more selective in ion uptake. Watermelon genotypes 33, 38, 39, 40 and 44 with low seed weights and cotyledon leaf weights were not selective on ion uptake and were more affected by salt damage. It has been observed that the parameters used in the study have a high correlation with each other.
Masondo, Nqobile A; Kulkarni, Manoj G; Finnie, Jeffrey F; Van Staden, Johannes
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.
Full Text Available Abstract Background Bacteria grown on semi-solid media can build two types of multicellular structures, depending on the circumstances. Bodies (colonies arise when a single clone is grown axenically (germ-free, whereas multispecies chimeric consortia contain monoclonal microcolonies of participants. Growth of an axenic colony, mutual interactions of colonies, and negotiation of the morphospace in consortial ecosystems are results of intricate regulatory and metabolic networks. Multicellular structures developed by Serratia sp. are characteristically shaped and colored, forming patterns that reflect their growth conditions (in particular medium composition and the presence of other bacteria. Results Building on our previous work, we developed a model system for studying ontogeny of multicellular bacterial structures formed by five Serratia sp. morphotypes of two species grown in either "germ-free" or "gnotobiotic" settings (i.e. in the presence of bacteria of other conspecific morphotype, other Serratia species, or E. coli. Monoclonal bodies show regular and reproducible macroscopic appearance of the colony, as well as microscopic pattern of its growing margin. Standard development can be modified in a characteristic and reproducible manner in close vicinity of other bacterial structures (or in the presence of their products. Encounters of colonies with neighbors of a different morphotype or species reveal relationships of dominance, cooperation, or submission; multiple interactions can be summarized in "rock – paper – scissors" network of interrelationships. Chimerical (mixed plantings consisting of two morphotypes usually produced a “consortium” whose structure is consistent with the model derived from interaction patterns observed in colonies. Conclusions Our results suggest that development of a bacterial colony can be considered analogous to embryogenesis in animals, plants, or fungi: to proceed, early stages require thorough
Full Text Available Because of changes in climatic conditions, tree seeds originating from breeding programs may no longer be suited to sites where they are currently sent. As a consequence, new seed zones may have to be delineated. Assisted migration consists of transferring seed sources that match the future climatic conditions to which they are currently adapted. It represents a strategy that could be used to mitigate the potential negative consequences of climate change on forest productivity. Decisions with regard to the choice of the most appropriate seed sources have to rely on appropriate knowledge of morpho-physiological responses of trees. To meet this goal, white spruce (Picea glauca [Moench] Voss seedlings from eight seed orchards were evaluated during two years in a forest nursery, and at the end of the first growing season on three plantation sites located in different bioclimatic domains in Quebec.The morpho-physiological responses obtained at the end of the second growing season (2+0 in the nursery made it possible to cluster the orchards into three distinct groups. Modelling growth curves of these different groups showed that the height growth of seedlings from the second-generation and southern first-generation seed orchards was significantly higher than that of those from other orchards, by at least 6%. A multiple regression model with three climatic variables (average growing season temperature, average July temperature, length of the growing season showed that the final height of seedlings (2+0 from the first-generation seed orchards was significantly related to the local climatic conditions at the orchard sites of origin where parental trees from surrounding natural populations were sampled to provide grafts for orchard establishment. Seedling height growth was significantly affected by both seed source origins and planting sites, but the relative ranking of the different seed sources was maintained regardless of reforestation site. This
Yang, Xuejun; Baskin, Carol C; Baskin, Jerry M; Zhang, Wenhao; Huang, Zhenying
In contrast to the extensive understanding of seed mucilage biosynthesis, much less is known about how mucilage is biodegraded and what role it plays in the soil where seeds germinate. We studied seed mucilage biodegradation by a natural microbial community. High-performance anion-exchange chromatography (HPAEC) was used to determine monosaccharide composition in achene mucilage of Artemisia sphaerocephala. Mucilage degradation by the soil microbial community from natural habitats was examined by monosaccharide utilization tests using Biolog plates, chemical assays and phospholipid fatty acid (PLFA) analysis. Glucose (29.4%), mannose (20.3%) and arabinose (19.5%) were found to be the main components of achene mucilage. The mucilage was biodegraded to CO(2) and soluble sugars, and an increase in soil microbial biomass was observed during biodegradation. Fluorescence microscopy showed the presence of mucilage (or its derivatives) in seedling tissues after growth with fluorescein isothiocyanate (FITC)-labelled mucilage. The biodegradation also promoted early seedling growth in barren sand dunes, which was associated with a large soil microbial community that supplies substances promoting seedling establishment. We conclude that biodegradation of seed mucilage can play an ecologically important role in the life cycles of plants especially in harsh desert environments to which A. sphaerocephala is well-adapted. © 2011 Blackwell Publishing Ltd.
Full Text Available Inoculation of the bacterial cells of microbial seed coating agents (SCAs into the environment may result in limited survival and colonization. Therefore, the application efficacy of an encapsulated microbial seed coating agent (ESCA was investigated on potted cotton plants; the agent was prepared with polyvinyl alcohol, sodium dodecyl sulfate, bentonite, and microencapsulated Bacillus subtilis SL-13. Scanning electron micrography revealed that the microcapsules were attached to ESCA membranes. The ESCA film was uniform, bubble-free, and easy to peel. The bacterial contents of seeds coated with each ESCA treatment reached 106 cfu/seed. Results indicated that the germination rate of cotton seeds treated with ESCA4 (1.0% (w/v sodium alginate, 4.0% polyvinyl alcohol, 1.0% sodium dodecyl sulfate, 0.6% acacia, 0.5% bentonite, and 10% (v/v microcapsules increased by 28.74%. Other growth factors of the cotton seedlings, such as plant height, root length, whole plant fresh weight, and whole plant dry weight, increased by 52.70%, 25.13%, 46.47%, and 33.21%, respectively. Further analysis demonstrated that the peroxidase and superoxide dismutase activities of cotton seedlings improved, whereas their malondialdehyde contents decreased. Therefore, the ESCA can efficiently improve seed germination, root length, and growth. The proposed ESCA exhibits great potential as an alternative to traditional SCA in future agricultural applications.
Full Text Available Germ-free animals have been used to define the vital role of commensal bacteria on the maturation of the host immune system. However, the role of bacterial residues in diet in this setting is poorly understood. Here we investigated the effect of bacterial contamination in sterile diet on the level of allergic sensitization in germ-free mice. Sterile grain-based diets ST1 and R03 were tested for the level of bacterial contamination. ST1 contained higher amount of bacterial DNA, approximately ten times more endotoxin, and induced higher, TLR4-dependent, cytokine production in dendritic cells compared to R03. In a germ-free mouse model of sensitization to the major birch pollen allergen Bet v 1, feeding on ST1 for at least two generations was associated with decreased production of allergen-specific IgE and IgG1 antibodies in sera in comparison to R03. Furthermore, reduced levels of allergen-specific and ConA-induced cytokines IL-4, IL-5 and IL-13 accompanied by increased levels of IFN-γ were detected in splenocytes cultures of these mice. Our results show that contamination of experimental diet with bacterial residues, such as endotoxin, significantly affects the development of allergic sensitization in germ-free mice. Therefore, careful selection of sterile food is critical for the outcomes of germ-free or gnotobiotic experimental models of immune-deviated diseases.
Full Text Available Water or soil salinities are the most important factors that reduce the seed germination of plants. Ethephon can break seed dormancy in a variety of plants, such as cereals and speeds up germination. In some plants pretreatment of seeds with salicylic acid has increased the germination percentage. To study effect of salicylic acid and ethephon on seed germination of wheat (Seivand cultivar under salinity condition a factorial experiment in a completely randomized design with three replications was conducted at the Plant Research Laboratory of Neyshabur Branch of Islamic Azad University in 2011. Four salinity levels (0, 50, 100, 150 mM, three salicylic acid levels (0, 0.5, 1 mM and four ethephon levels (0, 0.5, 1, 2 mM were used. The results showed that at salinity condition seed germination rate and percentage, shoot and root length, their dry weight and α-amylase activity decreased and proline content increased. Pretreatment of seeds by salicylic acid increased seed germination percentage, some growth parameters, α-amylase activity and proline content under salinity condition. Moreover, pretreatment of seeds by ethephon decreased some growth parameters and increased proline content but its effect on germination and α-amylase activity were not significant. It seems that Salicylic acid as a plant growth regulator under salinity condition and ethephon convertion to ethylene, activated plant tolerance mechanisms to salinity condition and decrease damaging effect of salinity on seed germination and seedling growth of wheat.
Cao, D.; Zhang, Y.; Zhang, Y.; Guan, B.
Seed priming and nitrogen application can promote plant tolerance and resistance to salt stress. To explore the combined effects of these two factors on the growth of salt-stressed seedlings, four treatments (priming + nitrogen application, PN; priming + no nitrogen application, P; unprimed + nitrogen application, UPN; and control treatment unprimed + no nitrogen application, UP) were applied to evaluate the responses of plant morphology, antioxidase systems, physiological and biochemical parameters of the maize seedlings under different concentrations of salt stress (0, 100, 200, and 300 mM). The results indicated that under salt stress, the priming treatment facilitated the growth of seedlings of root and stems, increased the amount of osmoregulatory substances, and enhanced the antioxidase activity and resistance of the maize seedlings. After nitrogen application during the maize growth stage, the growth of young leaves was greatly promoted along with an increase in the soluble protein and chlorophyll content. The combination of seed priming and nitrogen application significantly improved the plant growth, antioxidase activities and physiological and biochemical parameters. (author)
Mulyadi A T
Full Text Available Acacia mangium Willd is one of the promising wood species, it is a fast growing species and can be used as raw materials for pulp, furniture and wood working. Musi Hutan Persada Company has planted Acacia mangium Willd in large scale for pulp processing raw materials and for wood working industry. The faculty of forestry of the Nusa Bangsa University in collaboration with the Musi Hutan Persada have examined the effect of “Sonic Bloom” to the Acacia mangium Willd germination and seedling growth. The results of the research are the following : (1 The seed germination with “Sonic Bloom” provided percented of germination of 82%, better than those without “Sonic Bloom”, i.e. only 34%; (2 With Sonic Bloom, the height of 80-days old seedling is 129.6 cm higher than those without “Sonic Bloom”of only 90.7 cm ; (3 the diameter of 80-days old seedling with “Sonic Bloom” is 0,24 cm higher than those without “Sonic Bloom” harving diameters of only 0.19 cm.The study concludes that sonic bloom treatment is very useful for the seed germination and the growth of Acacia mangium Willd seedling Key Words : Sonic Bloom, persemaian, Acacia mangium, perkecambahan, bibit Normal 0 false false false IN X-NONE X-NONE
Philip M. McDonald; Gary Fiddler; Martin Ritchie; Paula Anderson
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...
Jayabalan, N.; Rao, G.R.
Dry and healthy seeds of Lycopersicon esculentum Mill. var. Co-2 were irradiated with gamma rays at 10 KR, 20 KR, 30 KR, 40 KR and 50 KR. The percentage of seed germination was directly proportional to the dose given. The survival percentage decreased with higher doses. Concentration of EMS and NMU applied, ranged from 10 mM to 50 mM and 1 mM to 5 mM, respectively. The duration of soaking of seed was 4 hours in distilled water and 4 hours in mutagenic agents. In treated seeds, the percentage of germination and survival of seedlings decreased with an increase in concentration of these chemical mutagens. These observations are discussed in detail. (author). 11 refs
Juhr, N.C.; Franke, J.
This report deals with the utilization of 14 C-labelled urea in conventional, defined associated and germ-free rats. With conventional animals 71.44% of the administered 14 C dose can be demonstrated in the exhaled air, 0.47% in organs and 27.35% in the urine. 1.04% were found in the intestinal and fecal contents. Animals mono-associated with Proteus mirabilis have nearly the same utilization rate (59.15, 0.34, 35.98, 2% resp.). In germ-free animals 1.21% of the activity appeared in the exhaled air and showed a small part of non-enzymatic hydrolysis of urea. The excretion of 97.70% in the urine shows, that urea is absorbed from the intestine in germ-free animals. (author)
Wahid, Nadya; Bounoua, Lahouari
Selection of quality seeds in breeding programs can significantly improve seedling productivity. Germination and biochemical analyses on seeds from ten natural populations of maritime pine (Pinus pinaster Ait.) in Morocco reveals significant differences among populations in seed weight, germination characters and protein content in both dry seeds and megagametophytes. During germination, the mobilization of protein content in megagametophyte is significantly different among populations than sugar content. A strong positive correlation between the germination capacity and the protein content in both dry seeds and megagametophytes indicates that the best populations in term of germination capacity may also be the richest in protein content. The present study finds that seed weight is not a good indicator for quality seed selection, nor is it recommended to increase the degree of germinability. Our results suggest that the pine population in southern Morocco might have adapted to drought conditions as it is characterized by heavy seed weight and lower speed of protein content mobilization in megagametophyte compared to northern populations growing in temperate climate.
Parveen, Asra; Mazhari, Bi Bi Zainab; Rao, Srinath
Nanotechnology is leading towards the development of low cost applications to improve the cultivation and growth of plants. The use of nanotechnology in agriculture will leads to a significant effect on food industry along with opening a new area of research in agroecosystem. In this paper gold nanoparticles were biosynthesized with Cassia auriculata leaf extract at room temperature and characterized by UV-vis spectroscopy, X-ray diffraction and transmission electron microscopy. The objective of this study was to investigate effect of synthesized bio-nanogold on an important food and biofuel producing plant Pennisetum glaucum. Positive effects were observed on percentage of seed germination and growth of seedlings. Improved germination and increased plant biomass have high economic importance in production of biofuel or raw materials, agriculture and horticulture. Although the impact of nanoparticles on plants depends on concentration, size and shape. The biological synthesized AuNPs can replace the chemically synthesized AuNPs used in gene transfer method. The study gives brief insight on nanoparticles effects on plants, brings attention on both positive and negative side of nanomaterial which can resolve phytopathological infections by stimulating nutrition and growth. Copyright © 2016 Elsevier Inc. All rights reserved.
Tan, Mu-xiu; Zeng, Wen-wen; Wei, Peng-xiao; Mo, Qiao-cheng; Pu, Zu-ning; Cen, Xiu-fen; Shi, Feng-hua
To explore the germination conditions of Lonicera hypoglauca sand culture seeds and the effects of sand culture seedlings sterilization. 0.1% HgCl2 with different sterilization time, different illumination time and temperature culture condition were adopted to study the germination conditions of sand culture seeds. Different sterilization treatments and different hardening-seedling days were used to test the sterilization effect of sand culture seedlings. The sterilization effect of the combination of 75% ethanol 30 s + 0.1% HgCl2 5 min on Lonicera hypoglauca seeds was the optimum,with the average pollution rate of 15.56%, and the average germination rate reached 51.11%. The combination of varied temperature-room temperature under light for 12 h/d was the best, with the average germination rate peaked at 75.49%, and the average germination potential reached 68.36%. The treatment of detergent liquor scrub-tap water wash on the part above the hypocotyl, which was sand cultured under the opening condition and had no root, showed the best sterilization effect, with the average pollution rate was zero, and the average survival rate peaked at 100.00%. The sterilization effect of sand culture seedlings, which was disinfected after cleaning by detergent liquor scrub-tap water wash after hardening-seeding for 30 days, was the best, with the average pollution rate of 50.00%, and the average survival rate of 100.00%. The best sterilization effect is the combination of 75% ethanol 30 s + 0.1% HgCl2 5 min; Lighting for 12 h/d of varied temperature-room temperature is regarded as the optimum culture condition. The treatment of detergent liquor scrub-tap water wash treatment on the part above the hypocotyl,which is sand cultured under the opening condition and had no root, shows the best sterilization effect. For the sand culture seedlings, before inoculated in subculture medium, should be hardening-seedling for some days and sterilized after detergent liquor scrub-tap water wash.
Dutta, Bhabesh; Gitaitis, Ronald; Smith, Samuel; Langston, David
The ability of seed-borne bacterial pathogens (Acidovorax citrulli, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. tomato, Xanthomonas euvesicatoria, and Pseudomonas syringae pv. glycinea) to infest seeds of host and non-host plants (watermelon, tomato, pepper, and soybean) and subsequent pathogen transmission to seedlings was investigated. A non-pathogenic, pigmented strain of Serratia marcescens was also included to assess a null-interacting situation with the same plant species. Flowers of host and non-host plants were inoculated with 1 × 10(6) colony forming units (CFUs)/flower for each bacterial species and allowed to develop into fruits or umbels (in case of onion). Seeds harvested from each host/non-host bacterial species combination were assayed for respective bacteria by plating on semi-selective media. Additionally, seedlots for each host/non-host bacterial species combination were also assayed for pathogen transmission by seedling grow-out (SGO) assays under greenhouse conditions. The mean percentage of seedlots infested with compatible and incompatible pathogens was 31.7 and 30.9% (by plating), respectively and they were not significantly different (P = 0.67). The percentage of seedlots infested with null-interacting bacterial species was 16.8% (by plating) and it was significantly lower than the infested lots generated with compatible and incompatible bacterial pathogens (P = 0.03). None of the seedlots with incompatible/null-interacting bacteria developed symptoms on seedlings; however, when seedlings were assayed for epiphytic bacterial presence, 19.5 and 9.4% of the lots were positive, respectively. These results indicate that the seeds of non-host plants can become infested with incompatible and null-interacting bacterial species through flower colonization and they can be transmitted via epiphytic colonization of seedlings. In addition, it was also observed that flowers and seeds of non-host plants can be colonized by
Full Text Available The ability of seed-borne bacterial pathogens (Acidovorax citrulli, Clavibacter michiganensis subsp. michiganensis, Pseudomonas syringae pv. tomato, Xanthomonas euvesicatoria, and Pseudomonas syringae pv. glycinea to infest seeds of host and non-host plants (watermelon, tomato, pepper, and soybean and subsequent pathogen transmission to seedlings was investigated. A non-pathogenic, pigmented strain of Serratia marcescens was also included to assess a null-interacting situation with the same plant species. Flowers of host and non-host plants were inoculated with 1 × 10(6 colony forming units (CFUs/flower for each bacterial species and allowed to develop into fruits or umbels (in case of onion. Seeds harvested from each host/non-host bacterial species combination were assayed for respective bacteria by plating on semi-selective media. Additionally, seedlots for each host/non-host bacterial species combination were also assayed for pathogen transmission by seedling grow-out (SGO assays under greenhouse conditions. The mean percentage of seedlots infested with compatible and incompatible pathogens was 31.7 and 30.9% (by plating, respectively and they were not significantly different (P = 0.67. The percentage of seedlots infested with null-interacting bacterial species was 16.8% (by plating and it was significantly lower than the infested lots generated with compatible and incompatible bacterial pathogens (P = 0.03. None of the seedlots with incompatible/null-interacting bacteria developed symptoms on seedlings; however, when seedlings were assayed for epiphytic bacterial presence, 19.5 and 9.4% of the lots were positive, respectively. These results indicate that the seeds of non-host plants can become infested with incompatible and null-interacting bacterial species through flower colonization and they can be transmitted via epiphytic colonization of seedlings. In addition, it was also observed that flowers and seeds of non-host plants can be
Wahlström, Annika; Kovatcheva-Datchary, Petia; Ståhlman, Marcus
The gut microbiota influences the development and progression of metabolic diseases partly by metabolism of bile acids (BAs) and modified signaling through the farnesoid X receptor (FXR). In this study, we aimed to determine how the human gut microbiota metabolizes murine BAs and affects FXR...... signaling in colonized mice. We colonized germ-free mice with cecal content from a mouse donor or feces from a human donor and euthanized the mice after short-term (2 weeks) or long-term (15 weeks) colonization. We analyzed the gut microbiota and BA composition and expression of FXR target genes in ileum...... and liver. We found that cecal microbiota composition differed between mice colonized with mouse and human microbiota and was stable over time. Human and mouse microbiota reduced total BA levels similarly, but the humanized mice produced less secondary BAs. The human microbiota was able to reduce the levels...
Anderson, R.E.; Howarth, J.L.; Troup, G.M.
Radiation in sufficient amounts is carcinogenic, immunosuppressive, and results in a reduced life span. Similar consequences follow neonatal thymectomy (nTx) in some strains of rodents. The tumorigenic effects of irradiation appear to be partly mediated via suppression of the thymus-dependent portion of the immune response. Our purpose was to determine whether a similar relationship exists for radiation-induced accelerated aging. Female germ-free Charles River mice had neonatal or sham thymectomies within 24 hours of birth. Half of each group was exposed to 700 rads at 6 weeks of age. When mice with histologically malignant tumors were excluded, the combined life-shortening effects of nTx and irradiation were less pronounced than the sum of the individual effects. This suggests that some of the decreased longevity associated with irradiation may be mediated by T-cell injury
Paré, W P; Burken, M I; Allen, E D; Kluczynski, J M
Recent findings with respect to the role of spiral gram-negative bacteria in peptic ulcer disease have stimulated interest in discerning the role of these agents in stress ulcer disease. We tested the hypothesis that a standard restraint-cold ulcerogenic procedure would fail to produce ulcers in axenic rats. Axenic, as well as normal Sprague Dawley rats, were exposed to a cold-restraint procedure. The germ-free condition was maintained throughout the study in the axenic rats. Axenic rats had significantly fewer ulcers as compared to normal rats exposed to the standard cold-restraint procedure, as well as handling control rats. The data represent the first report suggesting a microbiologic component in the development of stress ulcer using the rat model.
Li, W.; Zhang, X.; Li, G.; Suo, H.; Ashraf, U.; Mo, Z.
Stress induced variations in seed germination of various crops has been well reported but germination potential of sweet corn seeds under osmotic stress with relation to time dynamics is still elusive. Present study explored the water absorption, germination potential and physiological indices and of sweet corn seeds exposed to five different levels of PEG-induced water stress i.e., 0, -0.3, -0.6, -0.9 and -1.2 M Pa water potential (Psi /sub w/) with respect to time dynamics. Results showed that enhanced water stress for prolonged time period (96 h) led to substantial reduction in water absorption and seed moisture contents, seed germination and vigor index as well as seedlings growth and fresh and dry biomass. Osmotic stress triggered antioxidant defense system like super-oxide dismutase (SOD), peroxidase (POD) and catalase (CAT) and accumulation of soluble sugars, proline and protein contents considerably. Initially, activities of SOD and CAT were higher but then reduced as stress persisted, however, POD showed a linear increase with respect to stress exposure time. Water stress also increased MDA contents up to 36 h then declined. Further, alpha-amylase activity and soluble protein showed significant correlations with maize seed germination. Overall, germination potential decreased with increase in osmotic stress in sweet corn seeds. (author)
Alencar, Nara L M; Innecco, Renato; Gomes-Filho, Enéas; Gallão, Maria Izabel; Alvarez-Pizarro, Juan C; Prisco, José T; Oliveira, Alexandre B De
Cereus jamacaru, a Cactaceae found throughout northeast Brazil, is widely used as cattle food and as an ornamental and medicinal plant. However, there has been little information about the physiological and biochemical aspects involved in its germination. The aim of this study was to investigate its reserve mobilization during germination and early seedling growth. For this, C. jamacaru seeds were germinated in a growth chamber and collected at 0, 2, 4, 5, 6, 8 and 12 days after imbibition for morphological and biochemical analyses. Dry seeds had wrinkled seed coats and large, curved embryos. Lipids were the most abundant reserve, comprising approximately 55% and 65% of the dry mass for cotyledons and the hypocotylradicle axis, respectively. Soluble sugars and starch were the minor reserves, corresponding to approximately 2.2% of the cotyledons' dry mass, although their levels showed significant changes during germination. Soluble proteins corresponded to 40% of the cotyledons' dry mass, which was reduced by 81% at the final period of germination compared to dry seeds. C. jamacaru seed can be classified as an oil seed due to its high lipid content. Moreover, lipids were the main reserve mobilized during germination because their levels were strongly reduced after seed germination, while proteins were the second most utilized reserve in this process.
Full Text Available The influence of 0, 0.1 mM, 0.5 mM, 1.0 mM, 4.0 mM, 8.0 mM fluoride (F concentration on seed germination, seedling growth of gram seeds (cv. Anuradha was studied under laboratory condition. At the end of 15 days of treatment, significant reduction in root length, shoot length, dry weight, fresh weight, % of germination, protein content, catalase activity, tolerance index, vigour index, germination rate, germination relative index, mean daily germination were observed at increasing fluoride concentration. Total soluble sugar content, proline content, peroxidase activity, ascorbic acid oxidase activity, % DFC, % phytotoxicity of root and shoot increased along with gradual increment of F concentration. 4.0 mM F concentration was found to be most sensitive for gram seeds. At 8.0 mM F concentration germination occurred but plants were totally dried after completion of treatment period.
Vilhena, Karyme S S; Guilhon, Giselle Maria Skelding Pinheiro; Zoghbi, Maria das Graças B; Santos, Lourivaldo Silva; Souza Filho, Antonio Pedro Silva
Chemical investigation of the rhizomes of Cyperus distans (Cyperaceae) led to the identification of α-ciperone, cyperotundone and scabequinone, besides other common constituents. Complete assignment of the (13)C NMR data of scabequinone is being published for the first time. The inhibitory effects of C. distans extracts and scabequinone on the seed germination and seedling growth of Mimosa pudica, Senna obtusifolia and Pueraria phaseoloides were evaluated. Seed germination inhibition bioassay revealed that S. obtusifolia (52-53%) was more sensitive to the hexane and the methanol extracts at 1% than M. pudica (0-10%). Scabequinone at 250 mg L⁻¹ displayed seed germination inhibitions more than 50% and radicle growth reduction of more than 35% of the test species S. obtusifolia and P. phaseoloides, while the hypocotyl growth of M. pudica was significantly affected (>50%) by the quinone at the same concentration. These results demonstrate that scabequinone contributes to the overall inhibitory activities of C. distans.
Shi, Yu; Zhang, Yi; Yao, Hejin; Wu, Jiawen; Sun, Hao; Gong, Haijun
The beneficial effects of silicon on plant growth and development under drought have been widely reported. However, little information is available on the effects of silicon on seed germination under drought. In this work, the effects of exogenous silicon (0.5 mM) on the seed germination and tolerance performance of tomato (Solanum lycopersicum L.) bud seedlings under water deficit stress simulated by 10% (w/v) polyethylene glycol (PEG-6000) were investigated in four cultivars ('Jinpengchaoguan', 'Zhongza No.9', 'Houpi L402' and 'Oubao318'). The results showed that the seed germination percentage was notably decreased in the four cultivars under water stress, and it was significantly improved by added silicon. Compared with the non-silicon treatment, silicon addition increased the activities of superoxide dismutase (SOD) and catalase (CAT), and decreased the production of superoxide anion (O2·) and hydrogen peroxide (H2O2) in the radicles of bud seedlings under water stress. Addition of silicon decreased the total phenol concentrations in radicles under water stress, which might contribute to the decrease of peroxidase (POD) activity, as observed in the in vivo and in vitro experiments. The decrease of POD activity might contribute to a less accumulation of hydroxyl radical (·OH) under water stress. Silicon addition also decreased the concentrations of malondialdehyde (MDA) in the radicles under stress, indicating decreased lipid peroxidation. These results suggest that exogenous silicon could improve seed germination and alleviate oxidative stress to bud seedling of tomato by enhancing antioxidant defense. The positive effects of silicon observed in a silicon-excluder also suggest the active involvement of silicon in biochemical processes in plants. Copyright © 2014 Elsevier Masson SAS. All rights reserved.
Greve, J. W.; Gouma, D. J.; Soeters, P. B.; Buurman, W. A.
The increased susceptibility to infections after surgery in jaundiced patients is considered to be caused by an impairment of cellular immunity and/or nutritional status. Endotoxins are suggested to play a role in the pathogenesis. However, the mechanism of action is unknown. Germ-free rats were
Yafizham; Herwibawa, B.
This study was aimed to determine the effects of sodium azide on the performance of chili pepper. Dry seeds from pure lines of chili pepper cv. Landung were used in this experiment. Each set containing 50 seeds was placed in nylon fishner bags, washed in flowing water and soaked in distilled water for four hours. After soaking, four sets of seeds were dabbed dry with tissue paper and were treated for two hours at 30 0C in appropriate solution of 0, 0.10, 0.20, 0.40, 0.80, 1.60 mM sodium azide with phosphate buffer at pH 3. After treatment, the seeds were germinated in plastic boxes containing sterilized sand and kept under laboratory condition by supplied with water everyday. The seeds for M1 germination percentage, seedling height, plant height and number of leaves were recorded 30 days and 60 days after treatment, respectively. Seeds which radicle emerged were considered germinated, the seedling and plant height were measured from the tip of primary root to the base of the first leaf pair, and the number of leaves were counted for only fully expanded leaves. A completely randomized block design in four replicates was used throughout the experiment. Data obtained were analysed for range, mean, standard of deviation, and percent of control using Microsoft Office Excel 2007 software. It was concluded that different doses of sodium azide influenced the performances of chili pepper cv. Landung. Very low doses of sodium azide (0-1.60 mM) might be used to study the improvement of chili pepper diversity.
Full Text Available There are now several examples of plant species engineered to synthesise and accumulate nutritionally important polyunsaturated fatty acids in their seed triacylglycerols (TAG. The utilization of such TAG in germinating seeds of such transgenic plants was unknown. In this study, we examined the TAG utilization efficiency during seed germination in transgenic Arabidopsis seeds containing several examples of these fatty acids. Seed TAG species with native fatty acids had higher utilization rate than the TAG species containing transgenically produced polyunsaturated fatty acids. Conversely, quantification of the fatty acid components remaining in the total TAG after early stages of seed germination revealed that the undigested TAGs tended to contain an elevated level of the engineered polyunsaturated fatty acids (PUFA. LC-MS analysis further revealed asymmetrical mobilization rates for the individual TAG species. TAGs which contained multiple PUFA fatty acids were mobilized slower than the species containing single PUFA. The mobilised engineered fatty acids were used in de novo membrane lipid synthesis during seedling development.
Kikuti,Ana Lúcia Pereira; Marcos-Filho,Júlio
Seed vigor testing is an important component of quality control programs adopted by seed industry. The software Seed Vigor Imaging System (SVIS) has been successfully used for seed vigor assessment in different species. The objective of this research was to verify the SVIS efficiency to assess okra seed vigor in comparison to other vigor tests used for this species. Five seed lots of 'Clemson Americano' and four of 'Santa Cruz' were submitted to germination (speed and percentage), cold germin...
Guerrero Rodriguez, Sandra Bibiana; Paz Camacho, Erika Andrea; Parrado Rosselli, Angela
Animals affect the spatial occupation patterns of tropical forest plants throughout the seed dispersal they perform. Therefore, changes in vertebrate populations by human disturbance might affect re generation dynamics of plant species. We studied differences in the spatial distribution of seeds and seedlings of the Andean oak (Quercus humboldtii) between two nearby forests with contrasting levels of anthropogenic influence in the Colombian Andes. Density and spatial distribution of seedlings were evaluated in 490 and 484 1 m2 plots located in a 28 ha area, in the high and low disturbed site, respectively. In each plot, all seedlings found were sampled and classified into three age categories. Density and spatial distribution of seeds were evaluated in 0.25 m 2s ubplots placed in the same plots described above. Results showed a higher number and density of seedlings in the high disturbed site, as well as a marked decrease in seedling density as age increases. Distances to the nearest neighbour were shorter in the high disturbed site for all seedlings and each age category, in contrast to the low disturbed site. Indexes of spatial distribution indicate an aggregated pattern in the most disturbed site, while a uniform pattern in the low disturbed one. Seeds also exhibited an aggregated pattern in the high disturbed site and a higher seed predation by invertebrates. Results seemed to be a consequence of forest fragmentation and a decrease of vertebrate seed dispersers, seed predators and herbivores associated to the regeneration processes of the species. These results provide important information for the forest management and restoration activities, since in order to maintain plant populations in the long term, presence and viable populations of seed dispersers should be also maintained.
el-Sheekh, M M; el-Saied A el-D
Crude extracts from three green seaweeds (Cladophora dalmatica, Enteromorpha intestinalis, Ulva lactuca) and the three red algae (Corallina mediterranea, Jania rubens, Pterocladia pinnate) were prepared. Their effects on germination, growth of seedlings, chlorophyll content and other metabolic activities of Vicia faba were investigated. The crude extract of C. dalmatica showed maximal activity, and it increased seed germination, length of main root and shoot systems and the number of lateral roots. All the crude extracts of seaweed increased protein content in both root and shoot systems, total soluble sugars and chlorophyll content in leaves. The cytokinin content of the green algae was higher than that in red algae. Growth of seedlings of V. faba was stimulated but to different degrees.
Chaudhuri, Sadhan K.
Germination efficiency and root/shoot length of germinated seedling is proposed to identify irradiated lentil seeds. Germination percentage was reduced above 0.2 kGy and lentil seeds were unable to germinate above 1.0 kGy dose. The critical dose that prevented the root elongation varied from 0.1 to 0.5 kGy. The sensitivity of lentil seeds to gamma irradiation was inversely proportional to moisture content of the seeds. Radiation effects could be detected in seeds even 12 months storage after gamma irradiation
Pre-sowing treatments were evaluated for Tetracarpidium conophorum. Mechanically scarified T. conophorum seeds soaked in indole acetic acid for 24 h yielded 90% seed germination. Smoked- and sun-dried seeds for 14 days yielded 73 and 33.3% seed germination, respectively. Poorest values were obtained from acid ...
Nascimento, Bruna B; Cartelle, Christiane T; Noviello, Maria de L; Pinheiro, Breno V; de Almeida Vitor, Ricardo W; Souza, Danielle da G; de Vasconcelos Generoso, Simone; Cardoso, Valbert N; Martins, Flaviano Dos S; Nicoli, Jacques R; Arantes, Rosa M E
Toxoplasmosis represents one of the most common zoonoses worldwide. Its agent, Toxoplasma gondii, causes a severe innate pro-inflammatory response. The indigenous intestinal microbiota promotes host animal homoeostasis and may protect the host against pathogens. Germ-free (GF) animals provide an important tool for the study of interactions between host and microbiota. In this study, we assessed the role of indigenous microorganisms in disease development utilizing a murine toxoplasmosis model, which includes conventional (CV) and GF NIH Swiss mice. CV and GF mice orally inoculated with T. gondii had similar survival curves. However, disease developed differently in the two animal groups. In CV mice, intestinal permeability increased and levels of intestinal pro-inflammatory cytokines were altered. In GF animals, there were discrete epithelial degenerative changes and mucosal oedema, but the liver and lungs displayed significant lesions. We conclude that, despite similar survival curves, CV animals succumb to an exaggerated inflammatory response, whereas GF mice fail to produce an adequate systemic response. © 2017 The Authors. International Journal of Experimental Pathology © 2017 International Journal of Experimental Pathology.
Zhou, Renwu; Zhou, Rusen; Zhang, Xianhui; Zhuang, Jinxing; Yang, Size; Bazaka, Kateryna; (Ken) Ostrikov, Kostya
Atmospheric-pressure N2, He, air, and O2 microplasma arrays have been used to investigate the effects of plasma treatment on seed germination and seedling growth of mung bean in aqueous solution. Seed germination and growth of mung bean were found to strongly depend on the feed gases used to generate plasma and plasma treatment time. Compared to the treatment with atmospheric-pressure O2, N2 and He microplasma arrays, treatment with air microplasma arrays was shown to be more efficient in improving both the seed germination rate and seedling growth, the effect attributed to solution acidification and interactions with plasma-generated reactive oxygen and nitrogen species. Acidic environment caused by air discharge in water may promote leathering of seed chaps, thus enhancing the germination rate of mung bean, and stimulating the growth of hypocotyl and radicle. The interactions between plasma-generated reactive species, such as hydrogen peroxide (H2O2) and nitrogen compounds, and seeds led to a significant acceleration of seed germination and an increase in seedling length of mung bean. Electrolyte leakage rate of mung bean seeds soaked in solution activated using air microplasma was the lowest, while the catalase activity of thus-treated mung bean seeds was the highest compared to other types of microplasma.
Tao, Jinghe; Zhang, Wenxu; Liang, Li; Lei, Ziqiang
Desertification is the degradation of land in arid and semi-arid areas. Nowadays, lack of water and desertification are extreme problems for plant survival and growth in the arid and semi-arid areas of the world. It becomes increasingly important as to how to let the plant absorb moisture more effectively for keeping growth strong. We synthesized superabsorbent polymers (SAPs) with carbohydrate and characterized them by Fourier transform infrared spectra analyses, scanning electron microscopy and thermogravimetric/differential thermal analyses. Then, a completely randomized experiment was conducted to assess the effect of carbohydrate-based SAPs on seed germination and seedling growth of maize in an artificial climate chest. The results showed that adding an appropriate amount of SAPs could improve root length, shoot length, total biomass, germination potential and germination rate. It indicates that this SAP is not toxic to plants and can promote seed germination, and at the same time provides a possibility of replacing other substrates.
Tao, Jinghe; Liang, Li; Lei, Ziqiang
Desertification is the degradation of land in arid and semi-arid areas. Nowadays, lack of water and desertification are extreme problems for plant survival and growth in the arid and semi-arid areas of the world. It becomes increasingly important as to how to let the plant absorb moisture more effectively for keeping growth strong. We synthesized superabsorbent polymers (SAPs) with carbohydrate and characterized them by Fourier transform infrared spectra analyses, scanning electron microscopy and thermogravimetric/differential thermal analyses. Then, a completely randomized experiment was conducted to assess the effect of carbohydrate-based SAPs on seed germination and seedling growth of maize in an artificial climate chest. The results showed that adding an appropriate amount of SAPs could improve root length, shoot length, total biomass, germination potential and germination rate. It indicates that this SAP is not toxic to plants and can promote seed germination, and at the same time provides a possibility of replacing other substrates. PMID:29515838
Full Text Available Hemp (Cannabis sativa L. cultivars grown for industrial use have recently emerged as a sustainable alternative source of industrial fibre and bioenergy, and is a highly valuable food and animal feed resource. The aim of the present study was to evaluate the effect of vermicompost extract, vermicompost mineral nutrient composition, and vermicompost-derived humic and fulvic acids on seed germination and growth of hemp seedlings. In general, separate application of all vermicompost components stimulated seed germination and hypocotyl and radicle growth, as well as increased chlorophyll concentration in cotyledons. Effective concentration range and the degree of stimulation varied significantly between the treatments. For practical purposes, application of vermicompost and vermicompost-derived extracts for stimulation of hemp growth could be useful at concentrations 5%, 0.05 mg·mL−1 and 1%, for vermicompost extract, humic acids and fulvic acids, respectively.
Full Text Available The influence of seed storage conditions and different temperatures (5˚C, 10˚C, 15˚C, 20˚C, 25˚C, 30˚C and 26˚C/21˚C during germination and seedling development on seed germination, shoot length and germination rate of wild oat (Avena fatua L. was examined. Germinated seeds were counted daily over a period of ten days and shoot length was measured on the last day, while germination rates were calculated from those measurements. The results showed that seed storage under controlled conditions (T1: temperature 24±1°C, humidity 40-50%; T2: temperature 26±1°C, humidity 70-80% and T3: temperature 4˚C for periods of 3 (t1 and 12 (t2 months had a significant influence on germination of wild oat seeds. The percentage of germinated seeds under all examined temperatures was higher when they were stored for 12 months under controlled temperature and humidity. The results also showed that temperature had a significant effect on the percentage of germination and germination rate of A. fatua seeds. The highest total germination occurred at 15˚C temperature (T1: t1 - 41.25%, t2 - 44.37%; T2: t1 - 28.13%, t2 - 34.37%; T3: t1 - 10.63%, t2 - 12.50%. Germination percentage under an alternating day /night photoperiod at 26˚C/21˚C temperature was higher in all treatment variants (T1: t1 - 8.13%, t2 - 10.00%; T2: t1 - 11.87%, t2 - 13.13%; T3: t1 - 2.42%, t2 - 2.70% than germination in the dark at 25˚C, 30˚C and 5˚C.
Blomquist, K.W.; Lyon, G.E.
The Nuclear Waste Policy Act, as amended in 1987, directs the US Department of Energy (DOE) to study Yucca Mountain, in southern Nevada, as a potential site for long-term storage of high-level nuclear waste. DOE policy mandates the restoration of all lands disturbed by site characterization activities and DOE has developed an environmental program that is to be implemented during site characterization activities at Yucca.Mountain. DOE is currently conducting reclamation feasibility trials as part of this environmental program. No topsoil was saved on disturbances during early site investigation and minimal soil remains at existing disturbances on Yucca Mountain. A study was developed to test the effects of soil quality and depth on seedling emergence and survival. A series of plots was established and two treatments were tested. The first treatment compared native topsoil to subsoil imported from a borrow pit. The second treatment compared four different depth ranges of both soil types. All plots received identical seeding treatments. Seedling density was measured after emergence. Overall seedling densities were low, averaging 10.3 ± 8.8 (SD) plants/m 2 . Statistical analysis revealed a significant interaction between the two treatment factors. The subsoil had increasing densities from the deep soil depths to the shallow depths while the topsoil had increasing densities from the shallow soil depths to the deep depths. The cause of this interaction may have resulted from the bedrock being close to the soil surface of the shallow plots
Full Text Available The objective of present study was to evaluate the response of the mung bean seeds of ‘Sonali B1’ variety primed with chitosan in four different concentrations (0, 0.1%, 0.2% and 0.5% under salinity stress of five different concentrations (i.e., 0, 4, 6, 8 and 12 dS*mm-1 and halotolerance pattern by applying Celite as matrix at three different moisture levels (5%, 10% and 20%. Improved germination percentage, germination index, mean germination time, coefficient of velocity of germination along with root and shoot length was observed comparing with control. Germination stress tolerance index (GSI, plant height stress tolerance index (PHSI and root length stress tolerance index (RLSI were used to evaluate the tolerance of the mung bean seeds against salinity stress induced by chitosan. Results of GSI, PHSI, RLSI showing noteworthy inhibitory effect of salinity stress in control set was significantly less pronounced in chitosan treated seedlings. Chitosan can remarkably alleviate the detrimental effect of salinity up to the level of 6 dS*m-1, beyond which no improvement was noticed. In conclusion present investigation revealed that chitosan is an ideal elicitor for enhancing the speed of germination and seedling invigoration that synchronize with emergence of radicle and salinity stress tolerance.
Liu Xiuqing; Zhang Tie
The seeds of Lactuca sativa were irradiated by different doses (10, 20, 30, 40, 50 Gy) of 60 Co γ-rays. The effects of low dose irradiation on seed germination, seedling growth and enzymes activity were investigated. The results indicated that low dose irradiation could promote germination rate, germinating viability, germination rate in the field, root length and height of seedling. The suitable dosage for low dose irradiation for Lactuca sativa was 30 Gy. POD activity after irradiation treatment in the range of 10 to 50 Gy and CAT activity after irradiation treatment in the range of 20 Gy to 40 Gy was lower than that of control. (authors)
Juhr, N.C.; Franke, J.; Ratsch, H.
This report deals with the ultilization of 14 C-labelled cellulose in conventional, defined associated, and germ-free rats. With conventional animals 35.8% of the administered 14 C dose can be demonstrated in the exhaled air, 5.9% in organs, and 3.9% in the urine. 58.6% could be identified as not utilized in the intestinal and fecal contents. Animals mono-associated with Bacteroides succinogenes have about the same utilization rate. The appearance of 14 C in the exhaled air, in organs and the urine of germ-free animals is caused by a part of 14 C-labelled starch in the used test material. (author)
Lundberg, Randi; Toft, Martin Fitzner; August, Benjamin
Translational animal models are essential prerequisites in exploring functions and causality of the microbiome in human health and disease. Animal models targeted at microbiome research can be germ-free mice inoculated either with a monoculture or with defined (gnotobiotic) or undefined bacterial......, but there is a lack of knowledge on the stability of complex bacterial communities in IVCs. Germ-free SW mice were inoculated with a complex murine microbiota, housed in an isolator or in IVCs and bred for two generations, corresponding to a time course of 5 months. The gut microbiota was characterized by 16S...... Biosciences and Innovation Fund Denmark. The project is a collaboration between Taconic Biosciences, University of Copenhagen and the 3G Centre (Gut, Grain and Greens)....
Taking normal corn, waxy corn, pop corn, and sweet corn as test materials, this paper studied their seed germination and seedling growth under effects of simulated acid rain (pH 6.0, 5.0, 4.0, 3.0, 2.0, and 1.0). Simulated acid rain at pH 2.0-5.0 had no significant effects on the seed germination and seedling growth, but at pH 1.0, the germination rate of normal corn, waxy corn, pop corn, and sweet corn was 91.3%, 68.7%, 27.5%, and 11.7%, respectively. As compared with those at pH 6.0 (CK), the germination rate, germination index, vigor index, germination velocity, shoot height, root length, shoot and root dry mass, and the transformation rate of stored substances at pH 1.0 had significant decrease, and the average germination time extended apparently. At pH 1.0, the effects of acid rain were greater at seedling growth stage than at germination stage, and greater on underground part than on aboveground part. Due to the differences in gene type, normal corn and waxy corn had the strongest capability against acid rain, followed by pop corn, and sweet corn. It was suggested that corn could be categorized as an acid rain-tolerant crop, the injury threshold value of acid rain was likely between pH 1.0 and pH 2.0, and normal corn and waxy corn would be prioritized for planting in acid rain-stricken area.
Full Text Available The present investigation was carried out to study the response of different concentrations of treated petroleum sludge on seed germination, root and shoot length and tolerance of Vigna unguiculata (L. Walp. The biologically treated petroleum sludge with bacterial consortium showed 54.8% reduction in total petroleum hydrocarbons. Treated sludge was utilized with agricultural soil in known concentration for the assessment of growth of V. unguiculata. A remarkable absence of seed germination was observed at higher sludge concentration. The different concentrations of treated petroleum sludge showed severe decline on the length, weight and vigour index of the tested seedlings with increasing sludge concentrations. The results showed that the difference in rate of seed germination was significant among various concentrations. Under environmental stress condition, germination is the most critical phase of life cycle in crop plants. In this present study, the high oil content found to alter the osmotic relation between seed and water and thus reduce the amount of water absorbed. It was concluded that the concentration of nutrients and oil present in the treated sludge were toxic to the plant.
Full Text Available Two of the most troublesome weeds in soybean, cotton, and corn in cropping systems of mid-south United States (US are Senna obtusifolia and Xanthium strumarium. Understanding their population dynamics, particularly weed seedling emergence patterns, is important for the timely implementation and the success of weed management strategies. Identifying the sources of variation of emergence patterns could greatly improve our ability to predict emergence timing. A three-years field study was conducted to determine the effect of environmental conditions on S. obtusifolia and X. strumarium seedling emergence and seedbank potential. The experiment was conducted with two seed sources; X. strumarium burs and S. obtusifolia seeds from a single maternal plant source, and X. strumarium burs and S. obtusifolia seeds from multiple maternal plant sources, both being exposed either to 5 cm burial depth (buried or left on the soil surface (soil surface in the fallow or planted in spring after their storage under chilled (chill or room temperature (no chill conditions. X. strumarium and S. obtusifolia seedling emergence was lower from burs and seeds that were planted in the soil in September as compared with the chill and/or no chill seeds/burs stored for six months. X. strumarium seedling emergence was reduced from 37 to 1% when burs were left on the soil surface when compared to buried burs. S. obtusifolia seedling emergence was reduced from 47 to 13% when seeds were left on the soil surface as compared to buried. At the end of the experimental period, the soil seedbank of X. strumarium had been significantly depleted, whereas the remaining seeds of S. obtusifolia were viable.
Andresen, Marianne; Wulff, Ednar Gadelha; Mbega, Ernest R.
An aqueous extract of the sisal agave, A. sisalana, was prepared from dried stem tissue by boiling in water. The sisal extract (SE) displayed a broad inhibition of the seed-borne mycoflora when applied to farmer-saved seeds of Sorghum bicolor. Species of Fusarium (belonging to the Gibberella......-old plants (p agave, Yucca schidigera. Both extracts were found to reduce seed-borne Fusarium and crown rot more efficiently than fungicides based on tebuconazole, enilconazole...... and fludioxonil (p agave is a waste product in fiber production. From our findings A. sisalana stem appears to represent an abundant source of antifungal activity, simple to extract, easy to store and with a promising potential in biological seed treatment....
Full Text Available Abstract: The effects of gibberellic acid, kinetin, benzyladenine, ethylene, 24-epibrassinolide and polyamines (spermine, spermidine, putrescine, cadaverine on jasmonic acid inhibition of seed germination and seedling growth of barley were studied. All of the plant growth regulators studied were determined to have a succesful performance in reversing of the inhibitory effects of jasmonic acid on the seed germination and seedling growth. Moreover, the above mentioned growth regulators overcame the inhibitory effect of JA on the percentages of germination and coleoptile emergence in the same ratio, while GA3 was the most successful hormone on the fresh weight and radicle and coleoptile elongation in comparison with the other growth regulators. Key words: Barley, jasmonic acid, plant growth regulator, seed germination, seedling growth ARPANIN TOHUM ÇİMLENMESİ VE FİDE BÜYÜMESİNİN JASMONİK ASİT TEŞVİKLİ İNHİBİSYONU ÜZERİNE BAZI BİTKİ BÜYÜME DÜZENLEYİCİLERİNİN ETKİLERİ Özet: Arpanın tohum çimlenmesi ve fide büyümesinin jasmonik asit inhibisyonu üzerine gibberellik asit, kinetin, benziladenin, etilen, 24-epibrassinolit ve poliaminlerin (spermin, spermidin, putressin, kadaverin etkileri araştırılmıştır. Çalışılan bitki büyüme düzenleyicilerinin tümünün tohum çimlenmesi ve fide büyümesi üzerinde jasmonik asitin engelleyici etkisini tersine çevirmede başarılı bir performansa sahip oldukları belirlenmiştir. Dahası, yukarıda sözü edilen büyüme düzenleyicileri çimlenme ve koleoptil çıkış yüzdeleri üzerinde aynı oranda etkili olurken, taze ağırlık ve radikula ve koleoptil uzaması üzerinde diğer büyüme düzenleyicileri ile karşılaştırıldığında en başarılı hormon GA3 olmuştur. Anahtar kelimeler: Arpa, jasmonik asit, bitki büyüme düzenleyicisi, tohum çimlenmesi, fide büyümesi
Full Text Available The effects of small doses of gamma irradiation on the seed germination and seedling growth of Scotch pine and post-radiation action of water solutions of IAA, GA3 and kinetin have been investigated. Changes in the destructive action of ionizing-radiation toy gibberellic acid and its intensifying by IAA and kinetin has been found.
Investigating Seed Germination Indices and Absorption Rate of Sodium, Chloride, Calcium, and Potassium in Different Parts of Seedlings of Sweet Corn KSC 403 (Zea Mays L var. Saccharata Under Salinity Stress and Seed Priming
M. Nasrolah alhossini,
Full Text Available To investigate the effects of different levels of seed priming on germination indices and nutrient absorption at early growth stages of sweet corn (Golden Kernel Hybrid a factorial experiment based on completely randomized design was conducted with three replications in 2011. The experiment consists of 6 levels of primings (seeds without priming, priming with tap water, priming with distilled water, priming with sodium chloride, potassium chloride, and hydrous calcium chloride and five levels of salinity (zero, 4, 8, 12 and 16 ds/m sodium chloride. The characteristics studied were germination percentage, germination rate, root and shoot length, fresh weight and dry weight of seedling, root to shoot ratio and determination of sodium, chloride, calcium, and potassium concentration in different parts of seedlings (stems, roots and seed. The results indicated that increasing salinity stress levels decreased all parameters measured. Priming seeds with hydrated calcium chloride responded to significantly to salinity stress better than other treatments. Results also showed that increasing concentration of sodium chloride salt, increased absorption rate of sodium but concentration of calcium and potassium were reduced. Because application of hydrous calcium chloride stimulates cell in using calcium under salinity conditions it leads to improved seedling growth parameters. To achieve a more accurate results slicing interaction effect of seed priming×salinity levels was performed. Hydrous calcium chloride treatments improved all traits under study except sodium and potassium concentration. This represents a better performance of seeds germination under salinity stress when seeds primed with hydrous calcium chloride.
Philip M. McDonald; John C. Tappeiner
Although California black oak, tanoak, and Pacific madrone are the principal hardwood species in the forest zone of California and Oregon and are key components of many plant communities, their seed production, regeneration, and early growth requirements have received little study. Information is presented on seed production, storage, and germination, and on the...
One of the most important developmental processes in the life-cycle of higher plants is the transition from a seed to a plant and from a generative to a vegetative developmental program. The major hallmark or end-point of the transition from seed to plant is the onset of photosynthesis and the
Gallardo, K.; Job, C.; Groot, S.P.C.; Puype, M.; Demol, H.; VandeKerckhove, J.; Job, D.
Proteomics of Arabidopsis seeds revealed the differential accumulation during germination of two housekeeping enzymes. The first corresponded to methionine synthase that catalyses the last step in the plant methionine biosynthetic pathway. This protein was present at low level in dry mature seeds,
Baradjanegara, A.A.; Fujii, T.; Amano, E.
Seeds of rice c.v. Norin-8 and two radiation induced dwarf mutants MGS-46 and -96 were used to investigate the effects of gamma and 14 MeV neutron-radiations in different culture systems. Seeding growth of irradiated seeds in soil, and in two types of synthetic media, modified White's (M-W) or modified Erickson's (M-E), as well as the callus growth on 2,4-D supplemented media were measured as an index radiation damage. Comparing the seeding height about two types of media, the M-E promoted the plant growth than the M-W in irradiated as well as non irradiated lots of the three strains studied. The callus growth on M-E surpassed by more 10 times that obtained on the M-W in all the lots. The M-E medium seems to be appropriate for both the seeding and callus growth of rice. (author)
Alhadi Fatima A.
Full Text Available Plant seeds used rely on a wide range of internal mechanisms and physio-chemical factors to ensure their germination under favorable environmental conditions. Most plant seeds have complex process of germination, including water, oxygen, temperature availability, genome-wide gene expression, signal transduction, hormones stimulations, inhibitors removal and catalytic protein synthesis. In addition, influences of seeds nutrient values such as, protein, lipids, sugars and free amino acids have a special importance. Regarding, seeds free amino acids. Discussion of these individual factors needs to be put in context of their role in germination processes. Regarding, free amino acids seed storage, there is limited information about their relevant functions in activation and/or deactivation of required metabolic mechanisms and interactive compounds involved in this process in commercial plant cultivars. Therefore, current study was aimed to determine the probable influence of free amino acid compositions of seeds on germination process of two different (Punica granatum L. pomegranate cultivars including wild type Automi cultivar and edible Khazemi cultivar. In particular, we focused on the impact of amino acids contents variations on germination process and associated AAs compositional changes during various stages of germination and seedlings establishment. Amino acid analysis using HPLC detected all the essential and non-essential amino acids in the raw seeds of the studied cultivars, Automi and Khazemi along with AAs compositional changes occurred during different stages of seed germination. These AAs have been extensively analyzed in the context of their role in dormancy breaking capacities in plants species. Automi raw seeds are rich in Phe, that, is strongly related to ABA synthesis and hence might be responsible for the dormancy of Automi seeds, Khazemi raw seeds have sufficient levels of Arg, Glu and Met that have been reported to enhance
Full Text Available BACKGROUND: The plant hormone abscisic acid (ABA regulates diverse processes of plant growth and development. It has recently been proposed that GCR2 functions as a G-protein-coupled receptor (GPCR for ABA. However, the structural relationships and functionality of GCR2 have been challenged by several independent studies. A central question in this controversy is whether gcr2 mutants are insensitive to ABA, because gcr2 mutants were shown to display reduced sensitivity to ABA under one experimental condition (e.g. 22 degrees C, continuous white light with 150 micromol m(-2 s(-1 but were shown to display wild-type sensitivity under another slightly different condition (e.g. 23 degrees C, 14/10 hr photoperiod with 120 micromol m(-2 s(-1. It has been hypothesized that gcr2 appears only weakly insensitive to ABA because two other GCR2-like genes in Arabidopsis, GCL1 and GCL2, compensate for the loss of function of GCR2. PRINCIPAL FINDINGS: In order to test this hypothesis, we isolated a putative loss-of-function allele of GCL2, and then generated all possible combinations of mutations in each member of the GCR2 gene family. We found that all double mutants, including gcr2 gcl1, gcr2 gcl2, gcl1 gcl2, as well as the gcr2 gcl1 gcl2 triple mutant displayed wild-type sensitivity to ABA in seed germination and early seedling development assays, demonstrating that the GCR2 gene family is not required for ABA responses in these processes. CONCLUSION: These results provide compelling genetic evidence that GCR2 is unlikely to act as a receptor for ABA in the context of either seed germination or early seedling development.
Liu, Yan; Hou, Long-Yu; Li, Qing-Mei; Jiang, Ze-Ping; Gao, Wei-Dong; Zhu, Yan; Zhang, Hai-Bo
To investigate the effects of β-carboxyethyl germanium sequioxide (Ge-132) and germanium dioxide (GeO 2 ) on improving salt tolerance of evening primrose (Oenothera biennis L.), seed germination, seedling growth, antioxidase and malondialdehyde (MDA) were observed under treatments of various concentrations (0, 5, 10, 20, 30 μM) of Ge in normal condition and in 50 mM NaCl solution. The results showed that both Ge-132 and GeO 2 treatments significantly increased seed germination percentage and shoot length in dose-dependent concentrations but inhibited early root elongation growth. 5-30 μM Ge-132 and 10, 20 μM GeO 2 treatments could significantly mitigate even eliminate harmful influence of salt, representing increased percentage of seed germination, root length, ratio between length of root and shoot, and decreased shoot length. These treatments also significantly decreased peroxidase (POD) and catalase (CAT) activities and MDA content. The mechanism is likely that Ge scavenges reactive oxygen species - especially hydrogen peroxide (H 2 O 2 ) - by its electron configuration 4S 2 4P 2 so as to reduce lipid peroxidation. This is the first report about the comparison of bioactivity effect of Ge-132 and GeO 2 on seed germination and seedling growth under salt stress. We conclude that Ge-132 is better than GeO 2 on promoting salt tolerance of seed and seedling.
Koné, Mongomaké; Koné, Tchoa; Silué, Nakpalo; Soumahoro, André Brahima; Kouakou, Tanoh Hilaire
Bambara groundnut (Vigna subterranea (L.) Verdc.) is an indigenous grain legume. It occupies a prominent place in the strategies to ensure food security in sub-Saharan Africa. Development of an efficient in vitro regeneration system, a prerequisite for genetic transformation application, requires the establishment of optimal conditions for seeds germination and plantlets development. Three types of seeds were inoculated on different basal media devoid of growth regulators. Various strengths of the medium of choice and the type and concentration of carbon source were also investigated. Responses to germination varied with the type of seed. Embryonic axis (EA) followed by seeds without coat (SWtC) germinated rapidly and expressed a high rate of germination. The growth performances of plantlets varied with the basal medium composition and the seeds type. The optimal growth performances of plants were displayed on half strength MS basal medium with SWtC and EA as source of seeds. Addition of 3% sucrose in the culture medium was more suitable for a maximum growth of plantlets derived from EA.
Roager, Henrik Munch; Sulek, Karolina; Skov, Kasper
Every single species of the gut microbiota produce low-molecular-weight compounds that are absorbed constantly from the intestinal lumen and carried to systemic circulation where they play a direct role in health and disease. However, very few studies address the host metabolome as a function...... of colonizing bacteria. In this study the effect of the Lactobacillus acidophilus NCFM strain was investigated by comparing the metabolome of mono-colonized and germ-free mice in several compartments. By liquid-chromatography coupled to mass spectrometry, we were able to show that the metabolome differed...
Marieta Caixeta Dorneles
Full Text Available http://dx.doi.org/10.5902/1980509810541 The seed germination strategy is important for the survival of species, allowing their maintenance and regeneration in the environment. Seed germination and seedling emergence of Anadenanthera colubrina were studied to examine the reproductive efficiency of this species, typical of Cerrado biome. The fruits were collected in ‘Vale do Rio Araguari’, in MG state. The water content at 105 °C, the germination in controlled laboratory conditions and seedling emergence in semi-open greenhouse were analyzed. The seeds had low water content between 6.7 to 10.7%. The germinating ability and the emergence percentage were high for almost all studied individuals, being registered 68 for seeds of individual number 2 and 85 - 94% for the others; 38% (individual number 2 and 78 - 91% (for the others, respectively. The speed of the processes was high, with the end of germination within 12.8 days and emergence within 18.8 days. The processes were heterogeneous, with values of coefficient of variation of the germination or emergence time above 28.5%; asynchronous, with values of uncertainty above 1.5 bits and synchrony below 0.3812. The seeds of this species were efficient in both processes and the heterogeneity and asynchrony may indicate the effects of environmental fluctuations during the seed formation, besides the genetic variability, intrinsic to each individual of the population. The speed and the high potential of seed germination of this species may also facilitate the programs of reforestation with the production of large numbers of seedlings in short time.
Full Text Available We investigated the effects of seed burial depth and soil water content on seedling emergence and growth of Ulmus pumila var. sabulosa (sandy elm, an important native tree species distributed over the European-Asian steppe. Experimental sand burial depths in the soil were 0.5, 1.0, 1.5, 2.0 and 2.5 cm, and soil water contents were 4%, 8%, 12% and 16% of field capacity. All two-way ANOVA (five sand burial depths and four soil water contents results showed that seed burial depths, soil water content and their interactions significantly affected all the studied plant variables. Most of the times, seedling emergence conditions were greater at the lower sand burial depths (less than 1.0 cm than at the higher (more than 1.0 cm seed burial depths, and at the lower water content (less than 12% than at the higher soil water content. However, high seed burial depths (more than 1.5 cm or low soil water content (less than 12% reduced seedling growth or change in the root/shoot biomass ratios. In conclusion, the most suitable range of sand burial was from 0.5 to 1.0 cm soil depth and soil water content was about 12%, respectively, for the processes of seedling emergence and growth. These findings indicate that seeds of the sandy elm should be kept at rather shallow soil depths, and water should be added up to 12% of soil capacity when conducting elm planting and management. Our findings could help to create a more appropriate sandy elm cultivation and understand sparse elm woodland recruitment failures in arid and semi-arid regions.
Proteomic Comparison between Maturation Drying and Prematurely Imposed Drying of Zea mays Seeds Reveals a Potential Role of Maturation Drying in Preparing Proteins for Seed Germination, Seedling Vigor, and Pathogen Resistance
Wang, Wei-Qing; Ye, Jian-Qing; Rogowska-Wrzesinska, Adelina
We have studied the role(s) of maturation drying in the acquisition of germinability, seedling vigor and pathogen resistance by comparing the proteome changes in maize embryo and endosperm during mature and prematurely imposed drying. Prematurely imposed dried seeds at 40 days after pollination...... (DAP) germinated almost as well as mature seeds (at 65 DAP), but their seedling growth was slower and they were seriously infected by fungi. A total of 80 and 114 proteins were identified to change at least two-fold (p ... abundant in this group and may contribute to the acquisition of seed germinability. However, a relatively large number of proteins changed in the embryo (47 spots) and endosperm (76 spots) specifically during maturation drying. Among these proteins, storage proteins in the embryo and defense proteins...
Cyndi M. Smith; Graeme Poll; Cameron Gillies; Celina Praymak; Eileen Miranda; Justin Hill
Limber pine plays an important role in the harsh environments in which it lives, providing numerous ecological services, especially because its large, wingless seeds serve as a high energy food source for many animals. Limber pine populations are declining due to a combination of white pine blister rust, mountain pine beetle, drought, and fire suppression. Outplanting...
8 dS/m with three replications based on CRD design with factorial arrangement. Coefficent of equation was estimated with SAS software based on NLIN and REG procedure. Results and discussion Result showed that quinoa is sensitive in emergence stage is depends to substrate and 50 % of emergence reduction in soil and cocopit occurred at 6.35 and 15.04 dS/m. Threshold in soil and cocopit was 9.52 and 0.03 dS/m. Emergence rate and percentage of seeds under saline condition in cocpit did not have significant differences up to 12 dS/m and salinity above 4 dS/m delay emergence. Seedling emergence index under nonsaline condition was 0.96 but at 4, 8 and 12 dS/m in soil had 24, 48 and 84 % reduction. Seedling height in soil and cocopit at 12 dS/m reduced 91 and 30 %, respectively. Priming could not improve quinoa emergence although hydroprime improve emergence to some extent (8%. Quinoa is sensitive to salinity at seedling stage but after this stage could produce 2-3 t ha-1 seed yield with 15 dS/m saline water in Yazd. Since, in saline area farmers don’t have fresh water and quinoa is sensitive to saline water during emergence and early establishment. It would be better use transplanting method or not coverage of seed with soil.
Verma, Satish K.; Kingsley, Kathryn L.; Bergen, Marshall S.; Kowalski, Kurt P.; White, James F.
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
Simone M. Franzin
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
National Oceanic and Atmospheric Administration, Department of Commerce — Multiple experiments were conducted to determine the effects hydrogen sulfide had on seedlings and seed germination in the seagrass Zostera marina. One study...
Matwijczuk, A.; Kornarzyński, K.; Pietruszewski, S.
The impact of a variable magnetic field, magnetically treated water and a combination of both these factors on the germination of seeds and the final mass at the initial stage of growth sunflower plants was presented. Investigations were carried out in pots filled with sand, tin an air-conditioned plant house with no access to daylight using fluorescent light as illumination. A statistical significance positive impact was achieved for the samples subjected to the interaction of both stimulating factors simultaneously, the magnetic field and the impact of treated water several times on the speed of seed germination and final plant mass. Negative impacts were obtained for the majority of the test cases, for the magnetically treated water, the short duration of activity of the magnetic field and for the connection of the magnetic field and low-flow times.
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.
Chen Liyu; Zhang Shuqing; Li Jianfeng; Shi Shangli; Huo Pinghui
In order to study the effect of microwave irradiation on germination and growth physiological characteristics of seeds that stored for years, the irradiated alfalfa seeds that stored at room temperature for 2 years were used to conduct the germination and pot culture tests, and the germination rate, radical elongation, growth height, individual nodule, nitrogenase activity, chlorophyll content and chlorophyll fluorescence parameters were measured. On the 15th day of germination, the germination rates of all the treatments are higher than that of the control, which decrease with the elongation of time. On the llst day of germination, the radical length of all the treatments is lower than that of the control. Growth height, individual nodule, fresh weight and dry weight for the 40 s irradiation treatment are higher than that of the control. Nitrogenase activity of all the treatments is lower than that of the control (P < O.05). The chlorophyll content reaches its maximum when being irradiated for 10 s, and the variation for F 0 and F v /F m of all treatments indicates that the light conversion efficiency of the leaves derived from the irradiated alfalfa seeds that stored for 2 a at room temperature is still relatively stressed. (authors)
Wittstock, Ute; Meier, Kathrin; Dörr, Friederike; Ravindran, Beena M
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.
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.
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
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.
Full Text Available B12D belongs to a function unknown subgroup of the Balem (Barley aleurone and embryo proteins. In our previous work on rice seed germination, we identified a B12D-like protein encoded by LOC_Os7g41350 (named OsB12D1. OsB12D1 pertains to an ancient protein family with an amino acid sequence highly conserved from moss to angiosperms. Among the six OsB12Ds, OsB12D1 is one of the major transcripts and is primarily expressed in germinating seed and root. Bioinformatics analyses indicated that OsB12D1 is an anoxic or submergence resistance-related gene. RT-PCR results showed OsB12D1 is induced remarkably in the coleoptiles or roots by flooding during seed germination and early seedling growth. The OsB12D1-overexpressed rice seeds could protrude radicles in 8 cm deep water, further exhibiting significant flooding tolerance compared to the wild type. Moreover, this tolerance was not affected by the gibberellin biosynthesis inhibitor paclobutrazol. OsB12D1 was identified in the mitochondrion by subcellular localization analysis and possibly enhances electron transport through mediating Fe and oxygen availability under flooded conditions. This work indicated that OsB12D1 is a promising gene that can help to enhance rice seedling establishment in farming practices, especially for direct seeding.
Liddycoat, Scott M; Greenberg, Bruce M; Wolyn, David J
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.
Zhou, Zhong-Yu; Liu, Wan-Xue; Pei, Gang; Ren, Hui; Wang, Jing; Xu, Qiao-Lin; Xie, Hai-Hui; Wan, Fang-Hao; Tan, Jian-Wen
A bioassay-directed phytochemical study was conducted to investigate potential allelochemicals in the roots of the invasive plant Ageratina adenophora. Eleven phenolic compounds, including seven new ones, 7-hydroxy-8,9-dehydrothymol 9-O-trans-ferulate (1), 7-hydroxythymol 9-O-trans-ferulate (2), 7,8-dihydroxythymol 9-O-trans-ferulate (3), 7,8-dihydroxythymol 9-O-cis-ferulate (4), methyl (7R)-3-deoxy-4,5-epoxy-D-manno-2-octulosonate 8-O-trans-p-coumarate (5), methyl (7R)-3-deoxy-4,5-epoxy-D-manno-2-octulosonate 8-O-cis-p-coumarate (6), and 3-(2-hydroxyphenyl)propyl methyl malonate (7), were isolated from a bioactive subfraction of the ethanol extract of the roots of A. adenophora. The new structures were established on the basis of detailed spectroscopic analysis. The potential phytotoxic effects of these compounds on the germination of Arabidopsis thaliana seeds were tested by a filter paper assay. Compound 7 and known compounds 3-(2-hydroxyphenyl)-1-propanol (8) and o-coumaric acid (9) remarkably showed inhibition activity against Arabidopsis seed germination at a concentration of 1.0 mM. Compounds 1, 2, 5, 6, and 10 showed slight inhibitory activity at the test concentration after treatment for 3 days, while the other compounds showed no obvious inhibitory effects. Moreover, 7-9 were further found to show obvious inhibitory activity on retarding the seedling growth of Ar. thaliana cultured in soil medium.
Full Text Available In order to determine the effects of seed burial and flooding depths on the emergence and seedling growth of watergrass (Echinochloa oryzoides and barnyardgrass (E. crus-galli, this experiment was conducted in a covered free air condition, at the Rice Research Institute of Iran, Rasht in summer of 2009. The treatments included four seeding depths (0.1 (seeds were mixed with the top soil, 2, 4 and 6 cm, and four flooding depths (0.1 (saturated soil with no standing water, 3, 6, and 9 cm arranged as a factorial arrangement in a randomized complete block design with three replications. After 28 days, number of emergent seedlings, weed seedlings height, root and shoot fresh weight, leaf and root area were measured, and emergence percentage and root/shoot ratio were calculated. Since no germination of seeds was observed at the 6 cm sowing depth, this treatment wasn’t presented in results. Measured or calculated variable per unit was significantly different between two species and between various levels of seed burial and flooding depths. These variables also influenced by the interactions of the mentioned factors with an exception of emergence percentage. Emergence percentage and growth characteristics except for plant height were higher in E. oryzoides than E. crus-galli when weed seeds were located in the depth of 0.1 centimeter. In seeds located in the depth of 2 centimeters, all variables were higher in E. oryzoides than E. crus-galli. In both species, the higher values for mentioned variables was observed in the saturated condition of soil, when weed seeds were located at the depth of 0.1 centimeter and reduced with increasing flooding and seed burial depth. Results indicated that flooding condition with adequate height caused major limiting effects on emergence, establishment and growth of two Echinochloa species, especially when the seeds were deeply buried; but at decreased height specially saturated soils, emergence and growth of E
Pengaruh pemberian abu sekam padi sebagai bahan desikan pada penyimpanan benih terhadap daya tumbuh dan pertumbuhan bibit kakao (The effects of rice husk ash as desiccation material of seed storage on viability and cocoa seedling growth.
Full Text Available Rice husk ash as desiccation material can be used to maintain seed viability in storage through its ability to absorb humidity during its storage. High relative humidity caused seed moisture content to increase so the respiration rate of seed increases and uses faster food stock. Finally the viability of seed is lost. A research on use of rice husk ash as desiccation material of cocoa seed storage was conducted in Agronomy Laboratory and Kaliwining Experimental Station, Indonesian Coffee and Cocoa Research Institute. Completely Randomized Design was used in this research with treatment of rice husk ash application on cocoa seed as follows: 0 g/100 seeds (A, 5 g/100 seeds (B, 10 g/100 seeds (C, 15 g/100 seeds (D, and 20 g/100 seeds (E. This experiment used four replications. Cocoa seeds were stored in plastic bag within carton box in ambient temperature. The storage periods were 1, 2, and 3 weeks, and parameters of observation consisted of electrical conductivity of dipped water of cocoa seeds, percentage of seed germination, percentage of seed emergence, early growth parameters at one month old including seedlings height of seedling, diameter, leaf number, root length, and dry weight. The result of the experiment showed that the use of rice husk ash at 5-10 g/100 seeds could maintain electrical conductivity of dipped water at low level, percentage of seed germination at 99-100 % and percentage of seed emergence at 79-91% after two weeks storage. The use of rice husk ash at 5-10 g/100 seeds after two weeks storage affected height of cacao seedling, but did not affected stem diameters, leaf numbers, root lengths, and dry weights
Long branch-chains of amylopectin with B-type crystallinity in rice seed with inhibition of starch branching enzyme I and IIb resist in situ degradation and inhibit plant growth during seedling development : Degradation of rice starch with inhibition of SBEI/IIb during seedling development.
Pan, Ting; Lin, Lingshang; Wang, Juan; Liu, Qiaoquan; Wei, Cunxu
Endosperm starch provides prime energy for cereal seedling growth. Cereal endosperm with repression of starch branching enzyme (SBE) has been widely studied for its high resistant starch content and health benefit. However, in barley and maize, the repression of SBE changes starch component and amylopectin structure which affects grain germination and seedling establishment. A high resistant starch rice line (TRS) has been developed through inhibiting SBEI/IIb, and its starch has very high resistance to in vitro hydrolysis and digestion. However, it is unclear whether the starch resists in situ degradation in seed and influences seedling growth after grain germination. In this study, TRS and its wild-type rice cultivar Te-qing (TQ) were used to investigate the seedling growth, starch property changes, and in situ starch degradation during seedling growth. The slow degradation of starch in TRS seed restrained the seedling growth. The starch components including amylose and amylopectin were simultaneously degraded in TQ seeds during seedling growth, but in TRS seeds, the amylose was degraded faster than amylopectin and the amylopectin long branch-chains with B-type crystallinity had high resistance to in situ degradation. TQ starch was gradually degraded from the proximal to distal region of embryo and from the outer to inner in endosperm. However, TRS endosperm contained polygonal, aggregate, elongated and hollow starch from inner to outer. The polygonal starch similar to TQ starch was completely degraded, and the other starches with long branch-chains of amylopectin and B-type crystallinity were degraded faster at the early stage of seedling growth but had high resistance to in situ degradation during TRS seedling growth. The B-type crystallinity and long branch-chains of amylopectin in TRS seed had high resistance to in situ degradation, which inhibited TRS seedling growth.
Full Text Available A precondition necessary for creation and selection of genotypes tolerant of stress conditions is a study of physiological, biochemical and molecular bases of their adaptive reaction to stress. The study includes 40 lines of free pollination originating from 5 provenances: Sutjeska, Višegrad, Tara, Teslić and Durmitor (B&H, Serbia and Montenegro. Two populations were selected from each provenance, i.e.: 5 lines of free pollination represent the population growing on the cliffs and 3 lines of free pollination represent the population growing at the best site of Austrian pine. Specific characteristics of the studied provenances, populations, and free pollination lines were confirmed by the analyses in the salt-soluble proteins. The identical protein composition was proved in a small number of cases in the replicates of the same free pollination line, which indicates a high intra-line variability, which can be the result of the effect of father, as well as of heterozygosity of mother trees. The analyses of protein composition of seed showed considerable differences at provenance level. Inter-line, population and provenance differences, and also, the interaction between the origin and drought factor, were recorded for 9-day-old seedlings germinated in induced drought conditions and in normal conditions.
Hrncir, Tomas; Stepankova, Renata; Kozakova, Hana; Hudcovic, Tomas; Tlaskalova-Hogenova, Helena
Mammals are essentially born germ-free but the epithelial surfaces are promptly colonized by astounding numbers of bacteria soon after birth. The most extensive microbial community is harbored by the distal intestine. The gut microbiota outnumber ~10 times the total number of our somatic and germ cells. The host-microbiota relationship has evolved to become mutually beneficial. Studies in germ-free mice have shown that gut microbiota play a crucial role in the development of the immune system. The principal aim of the present study was to elucidate whether the presence of gut microbiota and the quality of a sterile diet containing various amounts of bacterial contaminants, measured by lipopolysaccharide (LPS) content, can influence maturation of the immune system in gnotobiotic mice. We have found that the presence of gut microbiota and to a lesser extent also the LPS-rich sterile diet drive the expansion of B and T cells in Peyer's patches and mesenteric lymph nodes. The most prominent was the expansion of CD4+ T cells including Foxp3-expressing T cells in mesenteric lymph nodes. Further, we have observed that both the presence of gut microbiota and the LPS-rich sterile diet influence in vitro cytokine profile of spleen cells. Both gut microbiota and LPS-rich diet increase the production of interleukin-12 and decrease the production of interleukin-4. In addition, the presence of gut microbiota increases the production of interleukin-10 and interferon-gamma. Our data clearly show that not only live gut microbiota but also microbial components (LPS) contained in sterile diet stimulate the development, expansion and function of the immune system. Finally, we would like to emphasize that the composition of diet should be regularly tested especially in all gnotobiotic models as the LPS content and other microbial components present in the diet may significantly alter the outcome of experiments.
Bojović Biljana M.
Full Text Available Allelopathy is the direct or indirect harmful effect which one plant produces on another through the production of chemical compounds that escape into the environment. In the presence paper allelopathic relationships were determined in three cereals - wheat (Triticum aestivum L., barley (Hordeum vulgare L., oat (Avena sativa L. and vegetable crops - spinach (Spinacia oleracea L., radish (Raphanus sativus L., pepper (Capsicum annum L.. In addition to the percentage of germination, allelopathic potential was tested measuring root and stem length of tested plant species germinated either alone or in combination with others. The obtained results showed that seed germination and plant growth of cereals and vegetables are depended on the presence of other plants in all tested combinations. In this study has proven largely inhibitory allelopathic effect on germination and plant growth.
Wang, Lu; Waters, Mark T; Smith, Steven M
The control of seed germination in response to environmental conditions is important for plant success. We investigated the role of the karrikin receptor KARRIKIN INSENSITIVE2 (KAI2) in the response of Arabidopsis seeds to osmotic stress, salinity and high temperature. Germination of the kai2 mutant was examined in response to NaCl, mannitol and elevated temperature. The effect of karrikin on germination of wild-type seeds, hypocotyl elongation and the expression of karrikin-responsive genes was also examined in response to such stresses. The kai2 seeds germinated less readily than wild-type seeds and germination was more sensitive to inhibition by abiotic stress. Karrikin-induced KAI2 signalling stimulated germination of wild-type seeds under favourable conditions, but, surprisingly, inhibited germination in the presence of osmolytes or at elevated temperature. By contrast, GA stimulated germination of wild-type seeds and mutants under all conditions. Karrikin induced expression of DLK2 and KUF1 genes and inhibited hypocotyl elongation independently of osmotic stress. Under mild osmotic stress, karrikin enhanced expression of DREB2A, WRKY33 and ERF5 genes, but not ABA signalling genes. Thus, the karrikin-KAI2 signalling system can protect against abiotic stress, first by providing stress tolerance, and second by inhibiting germination under conditions unfavourable to seedling establishment. © 2018 The Authors. New Phytologist © 2018 New Phytologist Trust.
Full Text Available Triazole derivatives are widely used in agriculture for seed protectant of cereals against seed and soil infection. Triazole derivatives can have an effect on the biochemical and physiological functions of plants. The tebuconazole-based protectant of seeds «Bunker» (content of tebuconazole 60 grams per liter, g/L is a systemic fungicide of preventive and therapeutic action. The effect of the seed treatment by «Bunker» preparation on the shoot growth and cell viability coleoptile, synthesis of dehydrins in shoots and frost resistance etiolated winter and spring wheat seedlings has been studied. It has been shown that treatment of winter and spring wheat seed by «Bunker» preparation induces similar concentration-dependent inhibition of the coleoptiles length. At the recommended dose (0,5 liter per tonne of seeds, L/t growth inhibition was 28 - 30%, at a concentration of 1 L/t – 33 - 36%, at a concentration of 1,5 L/t – 40 - 42%, at a concentration of 3 L/t – 43 - 47%, at a concentration of 4 L/t – 48 - 51% and at 5 L/t – 53 - 56%. The treatment of wheat seed by «Bunker» preparation had no phytotoxic effect on coleoptile cells in any of the studied concentrations, on the contrary, with increasing concentration of preparation observed the increase in cell viability, as measured by recovery of 2,3,5-triphenyltetrazolium chloride. We can assume that having retardant properties, tebuconazole not only inhibits the growth of plants, but also delays their aging. The treatment of seed protectant at a concentration of 1.5 L/t induced synthesis of the dehydrins with molecular masses about 19, 21, 22, 25 and 27 kD in winter wheat shoots and 18,6, 27 and 28,5 kD in spring wheat shoots during cold hardening. Among identified dehydrins the dehydrin of 27 kD is most significantly induced both in winter and spring wheat. The treatment of seed protectant «Bunker» in the same concentration increased the frost resistance of winter and spring wheat
Alexandra Augusti Boligon
Full Text Available There are various vigor tests for the evaluation of seeds physiological quality, however, few studies correlate this tests with plants emergency. This study aimed at identifying wheat (Triticum aestivum L. seed analysis variables that best predict seedling emergence. Wheat seeds (CEP 30 cultivar were divided into two batches, one initially subjected to the accelerated ageing process and forming the low-quality batch, and the other, without application of the accelerated ageing process, to compose a high-quality batch. The following seed test variables were evaluated: (i percentage of normal seedlings in the germination tests, (ii initial germination counting, (iii accelerated ageing, (iv cold test without soil, (v germination speed index, and (vi emergence of seedlings in sand after seven and 15 days. The following seedling characteristics were evaluated: root and shoot lengths, total length, and dry mass of the root and shoot. The characteristics evaluated for the seedlings were subjected to path analysis and the seed tests variables to stepwise multiple regression analysis, taking seedling emergence at seven days as the response variable. Factor analysis was also carried out on all variables. Dry mass of the shoot and root length presented the best correlation with seedling emergence for the high-quality batch, but this behavior was not observed for any variable in the low-quality batch. Accelerated ageing was the best seedling emergence estimator for both batches of the used cultivar.Existem inúmeros testes de vigor que podem ser utilizados na avaliação da qualidade fisiológica das sementes, porém, são poucos os estudos que relacionam estes testes com a emergência de plântulas das culturas. Identificaram-se variáveis da análise de sementes de trigo (Triticum aestivum L. que mais bem predizem a emergência de plântulas dessa cultura. Um lote de sementes de trigo do cultivar CEP 30 foi dividido em dois sublotes, sendo um submetido
Renard, H; Maro, D; Le Dizès, S; Escobar-Gutiérrez, A; Voiseux, C; Solier, L; Hébert, D; Rozet, M; Cossonnet, C; Barillot, R
Uncertainties remain regarding the fate of atmospheric tritium after it has been assimilated in grasslands (ryegrass) in the form of TFWT (Tissue Free Water Tritium) or OBT (Organically Bound Tritium). One such uncertainty relates to the tritium forms discrimination during transfer from TFWT to OBT resulting from photosynthesis (OBT photo ), corresponding to the OBT photo /TFWT ratio. In this study, the OBT/TFWT ratio is determined by experiments in the laboratory using a ryegrass model and hydroponic cultures, with constant activity of tritium in the form of tritiated water (denoted as HTO) in the "water" compartment (liquid HTO) and "air" compartment (HTO vapour in the air). The OBT photo /TFWT ratio and the exchangeable OBT fraction are measured for three parts of the plant: the leaf, seed and root. Plant growth is modelled using dehydrated biomass measurements taken over time in the laboratory and integrating physiological functions of the plant during the first ten days after germination. The results suggest that there is no measurable discrimination of tritium in the plant organic matter produced by photosynthesis. Copyright © 2017 Elsevier Ltd. All rights reserved.
BOS, NA; PLOPLIS, VA
The B cell immune response to 2,4-dinitrophenyl (DNP) keyhole limpet hemocyanin was compared in antigen-free, germ-free and conventional BALB/c mice. The numbers of total and of DNP-specific IgM-, IgG- and IgA-secreting cells in the spleen were determined by enzyme-linked immunosorbent plaque assays
Schwarzer, Martin; Šrůtková, Dagmar; Schabussova, I.; Hudcovic, Tomáš; Akgün, J.; Wiedermann, U.; Kozáková, Hana
Roč. 31, č. 46 (2013), s. 5405-5412 ISSN 0264-410X R&D Projects: GA ČR GA303/09/0449; GA MŠk 7AMB12AT020 Institutional support: RVO:61388971 Keywords : Allergy * Bifidobacterium * Germ-free mice Subject RIV: EC - Immunology Impact factor: 3.485, year: 2013
Full Text Available Seed germination under field conditions is highly influenced by the presence of other plants. Allelopathy is an important mechanism of plant competition, by producing phytotoxins to the plant environment in order to decline other plants growth. Soil sickness problem in farm lands is also known as an allelopathic effect or even autotoxicity. The toxicity of released allelochemicals by a plant in the environment is attributed to its function of concentration, age and metabolic stage. In this study we investigate the effect (5, 20, 35 and 50 g l-1 of leaf, stem and root water extract of sorghum on seed germination and seedling growth of mung bean. The results of the experiment showed that allelopathic effect of different concentrations was not significant for germination percentage, but germination rate and mean germination time decreased significantly by increasing the concentration of allelopathic extracts; also, there was a clear allelopathic effect of sorghum extract on seedling growth of mung bean. 50 g l-1 sorghum stem extract exhibited the highest inhibitory effect on root and shoot growth of mung bean. Among all parts of sorghum, stem extracts showed the highest allelopatic effect on seedling growth. Root extract showed higher inhibitory effect than leaf extracts.
Full Text Available Seed germination under field conditions is highly influenced by the presence of other plants. Allelopathy is an important mechanism of plant competition, by producing phytotoxins to the plant environment in order to decline other plants� growth. Soil sickness problem in farm lands is also known as an allelopathic effect or even autotoxicity. The toxicity of released allelochemicals by a plant in the environment is attributed to its function of concentration, age and metabolic stage. In this study we investigate the effect (5, 20, 35 and 50 g l-1 of leaf, stem and root water extract of sorghum on seed germination and seedling growth of mung bean. The results of the experiment showed that allelopathic effect of different concentrations was not significant for germination percentage, but germination rate and mean germination time decreased significantly by increasing the concentration of allelopathic extracts; also, there was a clear allelopathic effect of sorghum extract on seedling growth of mung bean. 50 g l-1 sorghum stem extract exhibited the highest inhibitory effect on root and shoot growth of mung bean. Among all parts of sorghum, stem extracts showed the highest allelopatic effect on seedling growth. Root extract showed higher inhibitory effect than leaf extracts.
Conceição Angelina dos Santos PEREIRA
Full Text Available O feijão (Phaseolus vulgaris, L. é uma leguminosa de grande importância para a dieta da população brasileira. No entanto, um de seus maiores problemas é representado pelo baixo valor nutricional de suas proteínas, decorrente, por um lado, da sua baixa digestibilidade e, de outro, do teor e biodisponibilidade reduzidos de aminoácidos sulfurados. Com o objetivo de avaliar a digestibilidade das proteínas albumina e globulina do feijão preto sem casca, foram realizados ensaios biológicos com camundongos isentos de germes e convencionais e com ratos (Wistar, recém-desmamados, com idade de 21 a 25 dias. Avaliou-se ainda o Escore Químico Corrigido pela Digestibilidade da Proteína. A digestibilidade verdadeira no experimento com camundongos isentos de germes foi de 90,21 e 90,00%, no teste com camundongos convencionais foi de 85,53 e 86,73%, e no experimento com ratos foi de 82,62 e 68,53%, para albumina e globulina, respectivamente. O Escore Químico Corrigido pela Digestibilidade da Proteína foi de 61,00% para a albumina e 51,00% para a globulina. A digestibilidade determinada em animais isentos de germes foi superior aos valores encontrados em animais convencionais, sugerindo que a flora intestinal esteja contribuindo para elevar o teor de nitrogênio nas fezes dos animais convencionais, e, portanto, esteja sendo subestimada a digestibilidade verdadeira do feijão.The bean (Phaseolus vulgaris, L. is a legume of great importance in the Brazilian typical diet. Nevertheless, it presents a low protein quality due to its poor digestibility and low levels and bioavailability of its sulfur aminoacids. The aim of this study was to evaluate the digestibility of albumin and globulin protein fractions of dehulled black beans in conventional and germ-free mice and also in weaning rats (Wistar of 21 to 25 days of age. Protein Digestibility Corrected Amino Acid Score was also determined. True digestibility values in germ-free mice were 90.21 and 90
Full Text Available Essential oil isolated from the aerial parts of Nepeta meyeri Benth. by hydrodistilation was analysed by GC and GC-MS methods. A total 18 components were identified in the oil representing 100.0% of the oil. Main components were 4aα,7α,7aβ-nepetalactone (80.3%, 4aα,7α,7aα–nepetalactone (10.3%, trans-pulegol (3.1%, 1, 8-cineole (3.0% and β-bourbonene (2.0%. In addition, n-hexane extract of N. meyeri was analysed by using GC and GC-MS methods and 18 components were identified. Likewise, nepetalactones, 4aα,7α,7aβ-nepetalactone (83.7%, 4aα,7α,7aα–nepetalactone (3.6%, 1, 8-cineole (1.9% and α-terpinene (1.5% were the predominat compounds in the hexane extract. Three concentrations (0.5, 1.0 and 2.0 mg/mL of the essential oil and n-hexane, chloroform, acetone and methanol extracts isolated from the aerial partsand roots were tested for the herbicidal effects on the germination of the seeds of four weed species including Amaranthus retroflexus L., Chenopodium album L., Cirsium arvense L. and Sinapsis arvensis L. The essential oil of N. meyeri completely inhibited the germination of all weed seeds whereas the extracts showed various inhibition effects on the germination of the weed species. Herbicidal effect was increased with the increasing application concentrations of the extracts. In general, the acetone extract was found to be more effective as compared to the other extracts. All extracts also exhibited various inhibition effects on the seedling growths of the weed species. All extracts also tested for their phytotoxic effects on the weeds at greenhouse condition and the results showed that the oil and extracts caused mortality with 22.00-66.00% 48h after the treatments. These findings suggest that the essential oil and the extracts of N. meyeri have potentials for use as herbicides against those weed species.
Otis Prud'homme, Guillaume; Lamhamedi, Mohammed S; Benomar, Lahcen; Rainville, André; DeBlois, Josianne; Bousquet, Jean; Beaulieu, Jean
With climate change, favorable growing conditions for tree species are shifting northwards and to higher altitudes. Therefore, local populations are becoming less adapted to their environment. Assisted migration is one of the proposed adaptive measures to reduce the vulnerability of natural populations and maintain forest productivity. It consists of moving genetic material to a territory where future climate conditions correspond to those of its current location. Eight white spruce ( Picea glauca [Moench] Voss) seed sources representing as many seed orchards were planted in 2013 at three forest sites simulating a south-north climatic gradient of 1.7°C in Québec, Canada. The objectives were to (1) evaluate the morpho-physiological responses of the different seed sources and (2) determine the role of genetic adaptation and physiological plasticity on the observed variation in morpho-physiological traits. Various seedling characteristics were measured, notably height growth from nursery to the fourth year on plantation. Other traits such as biomass and carbon allocation, nutritional status, and various photosynthetic traits before bud break, were evaluated during the fourth growing season. No interaction between sites and seed sources was observed for any traits, suggesting similar plasticity between seed sources. There was no change in the rank of seed sources and sites between years for height growth. Moreover, a significant positive correlation was observed between the height from the nursery and that after 4 years in the plantation. Southern seed sources showed the best height growth, while optimum growth was observed at the central site. Juvenile height growth seems to be a good indicator of the juvenile carbon sequestration and could serve as a selection criterion for the best genetics sources for carbon sequestration. Vector analysis showed no nitrogen deficiency 4 years after planting. Neither seed sources nor planting sites had a significant effect on
Guillaume Otis Prud'homme
Full Text Available With climate change, favorable growing conditions for tree species are shifting northwards and to higher altitudes. Therefore, local populations are becoming less adapted to their environment. Assisted migration is one of the proposed adaptive measures to reduce the vulnerability of natural populations and maintain forest productivity. It consists of moving genetic material to a territory where future climate conditions correspond to those of its current location. Eight white spruce (Picea glauca [Moench] Voss seed sources representing as many seed orchards were planted in 2013 at three forest sites simulating a south-north climatic gradient of 1.7°C in Québec, Canada. The objectives were to (1 evaluate the morpho-physiological responses of the different seed sources and (2 determine the role of genetic adaptation and physiological plasticity on the observed variation in morpho-physiological traits. Various seedling characteristics were measured, notably height growth from nursery to the fourth year on plantation. Other traits such as biomass and carbon allocation, nutritional status, and various photosynthetic traits before bud break, were evaluated during the fourth growing season. No interaction between sites and seed sources was observed for any traits, suggesting similar plasticity between seed sources. There was no change in the rank of seed sources and sites between years for height growth. Moreover, a significant positive correlation was observed between the height from the nursery and that after 4 years in the plantation. Southern seed sources showed the best height growth, while optimum growth was observed at the central site. Juvenile height growth seems to be a good indicator of the juvenile carbon sequestration and could serve as a selection criterion for the best genetics sources for carbon sequestration. Vector analysis showed no nitrogen deficiency 4 years after planting. Neither seed sources nor planting sites had a
One-year-old seedlings of Pinus koraiensis, Pinus sylvestriformis, Phellodendron amurense were grown in open-top chambers (OTCs) with 700 and 500 mmol/mol CO2 concentrations, control chamber and on open site (ambient CO2, about 350 mmol/mol CO2) respectively at the Open Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences, and the growth course responses of three species to elevated CO2 and temperature during one growing season was studied from May to Oct. 1999. The results showed that increase in CO2 concentration enhanced the growth of seedlings and the effect of 700 mmol/mol CO2 was more remarkable than 500 mmol/mol CO2 on seedling growth. Under the condition of doubly elevated CO2 concentration, the biomass increased by 38% in average for coniferous seedlings and 60% for broad-leaved seedlings. With continuous treatment of high CO2 concentration, the monthly-accumulated biomass of shade-tolerant Pinus koraiensis seedlings was bigger in July than in August and September, while those of Pinus sylvestriformis and Phellodendron amurense seedlings showed an increase in July and August, or did not decrese until September. During the hot August, high CO2 concentration enhanced the growth of Pinus koraiensis seedlings by increasing temperature, but it did not show dominance in other two species.
Full Text Available The effects of different salt sources (C Cl2, NaCl, and KCl and concentrations, as measured by electrical conductivity, (0, "control", 1, 3, 5, 7 and 9 dS m-1 on seed germination and seedling growth of “Ferro”, “Obez”, “RS 841” and “Strong Tosa F1” pumpkin varieties used as rootstock were investigated in this study. The results showed that germination rate, root length, shoot length, fresh root weight, dry root weight, fresh shoot weight and dry shoot weights tend to decrease when the electrical conductivity of the solution is higher than 5 dS m-1, independent of salt sources and in all of the varieties. Three days after seeding, a germination ratio of 5 % was obtained from RS 841 variety in all salt source and concentrations, while a germination ratio over 50 % was obtained in “Strong Tosa” variety for the same conditions except CaCl2 salt source. Nevertheless, seeds germinated in medium having high concentrations of CaCl2 had lower germination rate and poor seedling growth, compared to media having the same concentrations of NaCl and KCl. It was concluded that all of the varieties studied were more sensitive to the concentrations prepared using CaCl2 than that of the KCl, and NaCl.
Lamousé-Smith, Esi S; Tzeng, Alice; Starnbach, Michael N
The presence of a complex and diverse intestinal flora is functionally important for regulating intestinal mucosal immune responses. However, the extent to which a balanced intestinal flora regulates systemic immune responses is still being defined. In order to specifically examine whether the acquisition of a less complex flora influences responses to immunization in the pre-weaning stages of life, we utilize a model in which infant mice acquire an intestinal flora from their mothers that has been altered by broad-spectrum antibiotics. In this model, pregnant dams are treated with a cocktail of antibiotics that alters both the density and microbial diversity of the intestinal flora. After challenge with a subcutaneous immunization, the antibiotic altered flora infant mice have lower antigen specific antibody titers compared to control age-matched mice. In a second model, we examined germ free (GF) mice to analyze how the complete lack of flora influences the ability to mount normal antibody responses following subcutaneous immunization. GF mice do not respond well to immunization and introduction of a normal flora into GF mice restores the capacity of these mice to respond. These results indicate that a gastrointestinal flora reduced in density and complexity at critical time points during development adversely impacts immune responses to systemic antigens.
Full Text Available The present study was undertaken to assess the allelopathic effect of Echinochloa colona L. and Cyperus iria L. in relation to the germination and primary growth of Oryza sativa L. (rice and Glycine max L. (soyabean. Effects of dichloromethane (DCM and double distilled water soluble (DDW fractions of E. colona L. and C. iria L. root and aerial part extracts reduced germination and suppressed early seedling growth of rice and soyabean. With increase in extract concentration from 1 to 100 mg/mL, a gradual decrease in seed germination and seedling length occurred. The highest growth of G. max seedling was recorded in DDW fraction of E. colona aerial part extract at 1 mg/mL concentration with 94% germination and the lowest length was found in DCM fraction of C. iria root extract at 100 mg/mL concentration with 65% germination. In O. sativa, the highest length was noted at 1 mg/mL concentration in DDW fraction of E. colona aerial part extract with 82% germination and the lowest length was found in DCM fraction of C. iria and E. colona root extracts with germination 57% and 62%, respectively, at 100 mg/mL concentration. The results suggested that these weeds had good allelopathic potential which reduces germination and plant growth.
Full Text Available In this study the effect of crude oil (0 to 20% w/w, one of the main pollutants of current age, on physiological characteristics of Prosopis juliflora, Acacia victoria, Ziziphus spina-chrisi and Robinia pseudoacacia in seed and seedling stages based on a completely randomized design with 10 replications in each experimental unit has been studied. The results revealed that germination rate of Prosopis and Acacia was not affected by the pollutant, but the germination reduced in Ziziphus with more than 6 percent pollutant and 4% pollution led to full inhibition in Robinia. The ED50 based on radicle growth for Acacia, Prosopis, Ziziphus and Robinia was 6.9, 3.2, 3.6 and 2.7%, respectively. In seedling stage green leaf percentage, chlorophyll concentration, and efficiency of photosystem II decreased by increasing contamination. Increasing oil concentration stopped seedling growth of Robinia and reduced stem length in Acacia and Prosopis, but no significant difference was observed in the root length. The increase of oil pollution up to more than three percentages was associated with increased growth of shoot and root in Ziziphus. The difference in response pattern of different species to crude oil enables us to select species based on a variety of objects from bio monitoring to phytoremediation.
Kozáková, Hana; Schwarzer, Martin; Tučková, Ludmila; Šrůtková, Dagmar; Czarnowska, E.; Rosiak, I.; Hudcovic, Tomáš; Schabussova, I.; Hermanová, Petra; Zákostelská, Zuzana; Aleksandrzak-Piekarczyk, T.; Koryszewska-Baginska, A.; Tlaskalová-Hogenová, Helena; Cukrowska, B.
Roč. 13, č. 2 (2016), s. 251-262 ISSN 1672-7681 R&D Projects: GA ČR(CZ) GAP304/11/1252; GA ČR GA303/09/0449; GA MŠk 7AMB15AT025 Institutional support: RVO:61388971 Keywords : allergic sensitization * germ-free * intestinal barrier Subject RIV: EC - Immunology Impact factor: 5.897, year: 2016
Full Text Available Elevated blood cholesterol is an important risk factor associated with atherosclerosis and coronary heart disease. Several studies have reported a decrease in serum cholesterol during the consumption of large doses of fermented dairy products or lactobacillus strains. The proposed mechanism for this effect is the removal or assimilation of intestinal cholesterol by the bacteria, reducing cholesterol absorption. Although this effect was demonstrated in vitro, its relevance in vivo is still controversial. Furthermore, few studies have investigated the role of lactobacilli in atherogenesis. The aim of the present study was to determine the effect of Lactobacillus delbrueckii on cholesterol metabolism in germ-free mice and the possible hypocholesterolemic and antiatherogenic action of these bacteria using atherosclerosis-prone apolipoprotein E (apo E knock-out (KO mice. For this purpose, Swiss/NIH germ-free mice were monoassociated with L. delbrueckii and fed a hypercholesterolemic diet for four weeks. In addition, apo E KO mice were fed a normal chow diet and treated with L. delbrueckii for 6 weeks. There was a reduction in cholesterol excretion in germ-free mice, which was not associated with changes in blood or liver cholesterol concentration. In apo E KO mice, no effect of L. delbrueckii was detected in blood, liver or fecal cholesterol. The atherosclerotic lesion in the aorta was also similar in mice receiving or not these bacteria. In conclusion, these results suggest that, although L. delbrueckii treatment was able to reduce cholesterol excretion in germ-free mice, no hypocholesterolemic or antiatherogenic effect was observed in apo E KO mice.
VU, T. S.; Zhang, D.; Xiao, W.; Chi, C.; Xing, Y.; Fu, D.; Yuan, Z.
In line with the salt-alkalinized soils found in the northeast of China, the conditions were simulated to investigate the mechanisms associated with this combination of stresses on Melilotus officinalis. The effects of salinity (NaCl: 0-300mM) in combination with alkali (pH: 7.1-9.8) on the seed germination and seedlings of M. officinalis were investigated. The results showed that germination was not inhibited completely by the salt-alkali conditions tested. The recovery germinations were significant higher than the control or had no significant differences with the control under the conditions of NaCl less than 200mM and pH=9.0, suggesting that non-germinated seeds may have a strategy to get through and resist the stress during germination stage. For the seedling growth, M. officinalis was capable of surviving at high pH (pH=9.8) and the salinity (NaCl=200mM) (seedling survival rate: 84.77 ± 8.62 percentage). The characteristic feature for combined salt-alkali stresses is the reciprocal enhancement between salt and alkali stresses. The combined action of salinity and pH should be considered when evaluating the effects of salt-alkali stresses. Correlation and regression analyses showed that salinity was the dominant stress factor, while pH was a secondary factor. From the physiological and ecological parameters, we suggested that M. officinalis is a salt-alkali tolerant species which can be used in vegetative restoration of saline soils in the northeast of China. (author)
Asghar, Tehseen; Jamil, Yasir; Iqbal, Munawar; Zia-Ul-Haq; Abbas, Mazhar
Laser and magnetic field bio-stimulation attracted the keen interest of scientific community in view of their potential to enhance seed germination, seedling growth, physiological, biochemical and yield attributes of plants, cereal crops and vegetables. Present study was conducted to appraise the laser and magnetic field pre-sowing seed treatment effects on soybean sugar, protein, nitrogen, hydrogen peroxide (H 2 O 2 ) ascorbic acid (AsA), proline, phenolic and malondialdehyde (MDA) along with chlorophyll contents (Chl "a" "b" and total chlorophyll contents). Specific activities of enzymes such as protease (PRT), amylase (AMY), catalyst (CAT), superoxide dismutase (SOD) and peroxides (POD) were also assayed. The specific activity of enzymes (during germination and early growth), biochemical and chlorophyll contents were enhanced significantly under the effect of both laser and magnetic pre-sowing treatments. Magnetic field treatment effect was slightly higher than laser treatment except PRT, AMY and ascorbic acid contents. However, both treatments (laser and magnetic field) effects were significantly higher versus control (un-treated seeds). Results revealed that laser and magnetic field pre-sowing seed treatments have potential to enhance soybean biological moieties, chlorophyll contents and metabolically important enzymes (degrade stored food and scavenge reactive oxygen species). Future study should be focused on growth characteristics at later stages and yield attributes. Copyright Â© 2016 Elsevier B.V. All rights reserved.
Full Text Available Zebrafish, Denio rerio, could be an alternative to other classic animal models for human infectious diseases to examine the processes of microbial infections and host-pathogen interactions in vivo because of their small body dimension but large clutch size. We established germ-free zebrafish infection models of Listeria monocytogenes through different routes of infection: oral immersion and injection via yolk sac, brain ventricle and blood island. Immersion of zebrafish larva even with 1010CFU/mL L. monocytogenes EGDe strain in egg water was unable to cause mortality, but GFP-expressing bacteria in the gut lumen could be observed in frozen sections. Several selected maker genes of the innate immune system, including cyp1a, irg1l, il1b and mmp9, were significantly induced by oral immersion not only with strain EGDe, but also with strain M7 and L. innocua, though to a lesser degree (P < 0.01. Such induction appears to be transient with peak at 48 h post-infection, but returned to basal level at 72 h post-infection. Of the three injection routes, mortality after infection by yolk sac was 80% in early stage of infection. Few eggs could survive and hatch. Injection into zebrafish embryos via brain ventricle or blood island led to progressive lethal infection. L. mocytogenes EGDe showed steady replication in the fish embryos and was far more pathogenic than strain M7, which is consistent with findings in the murine model. We conclude that zebrafish could serve as susceptible and microscopically visible infection models for L. monocytogenes via different routes and could be applied to further studies on the interactions between bacterial virulence factors and host immune responses.
McVey Neufeld, K A; Perez-Burgos, A; Mao, Y K; Bienenstock, J; Kunze, W A
The microbiome is essential for normal myenteric intrinsic primary afferent neuron (IPAN) excitability. These neurons control gut motility and modulate gut-brain signaling by exciting extrinsic afferent fibers innervating the enteric nervous system via an IPAN to extrinsic fiber sensory synapse. We investigated effects of germ-free (GF) status and conventionalization on extrinsic sensory fiber discharge in the mesenteric nerve bundle and IPAN electrophysiology, and compared these findings with those from specific pathogen-free (SPF) mice. As we have previously shown that the IPAN calcium-dependent slow afterhyperpolarization (sAHP) is enhanced in GF mice, we also examined the expression of the calcium-binding protein calbindin in these neurons in these different animal groups. IPAN sAHP and mesenteric nerve multiunit discharge were recorded using ex vivo jejunal gut segments from SPF, GF, or conventionalized (CONV) mice. IPANs were excited by adding 5 μM TRAM-34 to the serosal superfusate. We probed for calbindin expression using immunohistochemical techniques. SPF mice had a 21% increase in mesenteric nerve multiunit firing rate and CONV mice a 41% increase when IPANs were excited by TRAM-34. For GF mice, this increase was barely detectable (2%). TRAM-34 changed sAHP area under the curve by -77 for SPF, +3 for GF, or -54% for CONV animals. Calbindin-immunopositive neurons per myenteric ganglion were 36% in SPF, 24% in GF, and 52% in CONV animals. The intact microbiome is essential for normal intrinsic and extrinsic nerve function and gut-brain signaling. © 2015 John Wiley & Sons Ltd.
Full Text Available BACKGROUND AND AIMS: Celiac disease (CD is a chronic inflammatory disorder of the small intestine that is induced by dietary wheat gluten proteins (gliadins in genetically predisposed individuals. The overgrowth of potentially pathogenic bacteria and infections has been suggested to contribute to CD pathogenesis. We aimed to study the effects of gliadin and various intestinal bacterial strains on mucosal barrier integrity, gliadin translocation, and cytokine production. METHODOLOGY/PRINCIPAL FINDINGS: Changes in gut mucosa were assessed in the intestinal loops of inbred Wistar-AVN rats that were reared under germ-free conditions in the presence of various intestinal bacteria (enterobacteria and bifidobacteria isolated from CD patients and healthy children, respectively and CD-triggering agents (gliadin and IFN-γ by histology, scanning electron microscopy, immunofluorescence, and a rat cytokine antibody array. Adhesion of the bacterial strains to the IEC-6 rat cell line was evaluated in vitro. Gliadin fragments alone or together with the proinflammatory cytokine interferon (IFN-γ significantly decreased the number of goblet cells in the small intestine; this effect was more pronounced in the presence of Escherichia coli CBL2 and Shigella CBD8. Shigella CBD8 and IFN-γ induced the highest mucin secretion and greatest impairment in tight junctions and, consequently, translocation of gliadin fragments into the lamina propria. Shigella CBD8 and E. coli CBL2 strongly adhered to IEC-6 epithelial cells. The number of goblet cells in small intestine increased by the simultaneous incubation of Bifidobacterium bifidum IATA-ES2 with gliadin, IFN-γ and enterobacteria. B. bifidum IATA-ES2 also enhanced the production of chemotactic factors and inhibitors of metalloproteinases, which can contribute to gut mucosal protection. CONCLUSIONS: Our results suggest that the composition of the intestinal microbiota affects the permeability of the intestinal mucosa
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 ...
Full Text Available O achachairu (Garcinia sp, fruta largamente produzida na Bolívia, vem sendo comercializado no Brasil há vários anos. O fruto é globoso-oblongo, de polpa branca, suculenta e textura mucilaginosa e de sabor doce-acidulado equilibrado (ºBrix 15 e pH 4,1. Devido ao crescente interesse em seu cultivo no Brasil, pesquisaram-se a germinação das sementes e o desenvolvimento das plântulas durante os primeiros 12 meses após sua emergência. As sementes, extraídas de frutos bem maduros, foram postas a germinar em duas situações: 1 ambiente controlado em estufa tipo B.O.D., sob as temperaturas de 25 e 30 ºC, fotoperíodo de 16 horas e irradiância de 32 µmol.m-1.s-1, e 2 ambiente de temperatura não-controlada: 3 B.O.D, cuja temperatura oscilava entre 20 e 30 ºC, e 4 sob temperatura ambiente de laboratório (25± 2 ºC. O melhor resultado foi obtido na temperatura constante de 30 ºC, com germinação de 92% e índice de velocidade de germinação (IVG de 0,255. Quando germinada em ambiente de laboratório, a germinação das sementes mostrou-se baixa (30%, com IVG de 0,015. O desenvolvimento das plântulas em casa de vegetação ocorreu de forma bastante lenta, principalmente nas primeiras semanas após a emergência. O primeiro par de folhas surgiu após três semanas da emergência das plântulas, quando essas mediam 8 cm em média. A partir do oitavo mês de desenvolvimento, as plântulas emitiram várias ramificações laterais a partir da porção mediana para a região apical.The achachairu (Garcinia sp, a fruit widely grown in Bolivia, has been commercialized in Brazil for many years. The fruit is globular-oblong shaped, with a white succulent pulp, mucilaginous texture and a well balanced sweet-acid flavor (ºBrix 15; pH 4.1. Due to the increasing interest in its cultivation in Brazil, this work was carried out aiming to study the seeds germination and seedling development throughout the first 12 months after seed emergence. The
Results of experiences of low intensity gamma-ray irradiation on apricot seedlings and comparison of the variability to the variability of a control population. The characteristics studied were: flowering, fructification, growth and vegetative spreading. Favourable and unfavourable results are observed (earlier ripening time, or low fruitfulness), meanwhile, for higher intensity irradiation, only unfavourable results are obtained [fr
Verhoeven, K.J.F.; Biere, A.; Nevo, E.; Van Damme, J.M.M.
Very young seedlings of wild barley Hordeum spontaneum have the ability to survive extended periods of severe drought. This desiccation tolerance is considered an adaptation to the rain-limited and unpredictable habitats that the species occupies. Genetic variation has been observed for this trait,
Warley Marcos Nascimento
Full Text Available Important factors affecting seed priming have not been extensively reported in muskmelon (Cucumis melo L. studies. The optimization of the seed priming technique becomes very important at the commercial scale. Little information has been reported on seedling development of muskmelon subsequent to seed priming. Seeds of muskmelon were primed in darkness at 25°C in different solutions and three osmotic potentials. Seeds were also primed with and without aeration during different periods. In relation to osmotic solutions, an osmotic potential around -1.30 MPa is most adequate for muskmelon priming. Salt solutions gave better germination rate but were deleterious for seed germination, especially at higher osmotic potentials. Aeration of the soaking salt solution gave faster germination at 17°C, and because of the early germination, these treatments probably presented a better seedling development. Deleterious effect on total seed germination was observed for long soaking periods with aeration. Fungal growth increased on seeds primed in aerated solutions. Seeds from priming treatments had a better germination rate and seedling development under 17 and 25°C.Importantes fatores afetando o condicionamento osmótico não têm sido extensivamente relatados em sementes de melão (Cucumis melo L.. A otimização do condicionamento osmótico é extremamente importante em uma escala comercial. Poucas informações têm sido relatadas quanto ao desenvolvimento de plântulas em resposta ao condicionamento osmótico de sementes de melão. Sementes de melão foram condicionadas a 25°C, na ausência de luz, em diferentes soluções osmóticas utilizando três potenciais osmóticos para cada solução. Em outro estudo, sementes foram condicionadas com ou sem aeração durante vários períodos. Indiferentemente das soluções osmóticas, o potencial osmótico em torno de - 1,30 MPa foi mais adequado para o condicionamento osmótico. Sementes condicionadas em
Full Text Available The effect of soil polluted by diesel oil on the germination of seeds and the growth of Schinus terebinthifolius Raddi seedlings was analyzed at different times after contamination of the soil. The experiments were conducted under greenhouse conditions, with four treatments and five repetitions. The four treatments included: soil contaminated 30 (T30, 90 (T90 or 180 (T180 days before planting as well as a non-polluted soil (T0 (control. Soil saturated to 50% of its maximum retention capacity (MRC was contaminated with diesel oil at a rate of 92.4 mL per kg. The germination rate and germination speed index (GSI were significantly affected only in T30. The development of the plants was affected significantly in all the treatments, with reductions of biomass and eophyll area. It could be concluded that diesel oil significantly affected the germination, GSI and seedling growth of S. terebinthifolius, but the toxic effect decreased over the time.
Thomas, C L; Graham, N S; Hayden, R; Meacham, M C; Neugebauer, K; Nightingale, M; Dupuy, L X; Hammond, J P; White, P J; Broadley, M R
Root traits can be selected for crop improvement. Techniques such as soil excavations can be used to screen root traits in the field, but are limited to genotypes that are well-adapted to field conditions. The aim of this study was to compare a low-cost, high-throughput root phenotyping (HTP) technique in a controlled environment with field performance, using oilseed rape (OSR;Brassica napus) varieties. Primary root length (PRL), lateral root length and lateral root density (LRD) were measured on 14-d-old seedlings of elite OSR varieties (n = 32) using a 'pouch and wick' HTP system (∼40 replicates). Six field experiments were conducted using the same varieties at two UK sites each year for 3 years. Plants were excavated at the 6- to 8-leaf stage for general vigour assessments of roots and shoots in all six experiments, and final seed yield was determined. Leaves were sampled for mineral composition from one of the field experiments. Seedling PRL in the HTP system correlated with seed yield in four out of six (r = 0·50, 0·50, 0·33, 0·49;P emergence in three out of five (r = 0·59, 0·22, 0·49;P emergence, general early vigour or yield in the field. Associations between PRL and field performance are generally related to early vigour. These root traits might therefore be of limited additional selection value, given that vigour can be measured easily on shoots/canopies. In contrast, LRD cannot be assessed easily in the field and, if LRD can improve nutrient uptake, then it may be possible to use HTP systems to screen this trait in both elite and more genetically diverse, non-field-adapted OSR. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company.
Marcelo Sales de Almeida
Full Text Available Com o objetivo de avaliar a influência de massa de sementes e profundidades de semeadura sobre o vigor e o desenvolvimento vegetativo de mudas de tamarindeiro (Tamarindus indica L., conduziu-se um experimento em viveiro telado, de malha 0,38 mm², no Setor de Fruticultura da Fazenda Experimental Água Limpa, município de Uberlândia (MG, no período de 26 de dezembro de 2006 a 04 de junho de 2007. O delineamento experimental foi o inteiramente casualizado, com os tratamentos distribuídos em esquema fatorial 2 x 3, com 5 repetições e 5 mudas por parcela, sendo os fatores: duas massas de sementes, leves e pesadas (65,60 g/100 sementes; 94,54 g/100 sementes, respectivamente, e três profundidades de semeadura (1; 2 e 3 cm. Avaliaram-se o número de folhas, diâmetro do caule, altura da muda, comprimento da raiz principal, massas secas da parte aérea e de raízes. Os resultados demonstraram que sementes de maior massa proporcionam melhor desenvolvimento inicial das mudas. E quanto à profundidade de semeadura, não houve diferença significativa entre todas as características avaliadas.The effect of seeds weight and different sowing depths on tamarind (Tamarindus indica L. seedling vigor and vegetative growth was evaluated in a trial done in a screened nursery, with 0.38 mm² opening, at the experimental farm Água Limpa, in a nursery with anti-aphid screens, in the county of Uberlândia. The farm is located at 18º55'33''S and 48º17'19''W, at 872 m altitude, Minas Gerais, from December 26 2006 to June 4 2007. The experimental design was randomized blocks, in a 2 x 3 factorial, with 5 repetitions and 5 plants per plot. The factors were two seeds weight, slight and weighty (65.60 g and 94.54 g respectively, defined according to the weight of 100 seeds and three sowing depths (1cm; 2cm or 3cm. The number of leaves, stem diameter, plant height, root length, fresh and dry weight of roots and above ground matter were evaluated. The results
Bae, Jichul; Benoit, Diane L; Watson, Alan K
In southern Québec, supplement roadside ground covers (i.e. Trifolium spp.) struggle to establish near edges of major roads and thus fail to assist turf recruitment. It creates empty niches vulnerable to weed establishment such as common ragweed (Ambrosia artemisiifolia). We hypothesized that heavy metal stresses may drive such species shifts along roadside edges. A growth chamber experiment was conducted to assess effects of metals (Zn, Pb, Ni, Cu, and Cd) on germination and seedling behaviors of roadside weed (A. artemisiifolia) and ground cover legumes (Coronilla varia, Lotus corniculatus, and Trifolium arvense). All metals inhibited T. arvense germination, but the effect was least on A. artemisiifolia. Low levels of Pb and Ni promoted germination initiation of A. artemisiifolia. Germination of L. corniculatus was not affected by Zn, Pb, and Ni, but inhibited by Cu and Cd. Germination of C. varia was decreased by Ni, Cu, and Cd and delayed by Zn and Pb. Metal additions hindered seedling growth of all test species, and the inhibitory effect on the belowground growth was greater than on the aboveground growth. Seedling mortality was lowest in A. artemisiifolia but highest in T. arvense when exposed to the metal treatments. L. corniculatus and C. varia seedlings survived when subjected to high levels of Zn, Pb, and Cd. In conclusion, the successful establishment of A. artemisiifolia along roadside edges can be associated with its greater tolerance of heavy metals. The findings also revealed that L. corniculatus is a potential candidate for supplement ground cover in metal-contaminated roadside edges in southern Québec, especially sites contaminated with Zn and Pb. Copyright © 2015 Elsevier Ltd. All rights reserved.
Iqbal, M.; Muhammad, D.; Haq, Z.U.; Jamil, Y.; Ahmad, M.R.
The seeds of garden pea ( Pisum sativum L. cv. climax) were exposed to full-wave rectified sumusoidal non-uniform magnetic fields of strength 60 mT, 120 mT and 180 mT for 5, 10 and 15 min prior to sowing. The magnetically treated seeds were sown according to the protocol of International Seed Testing Association (ISTA). Magnetically treated seed showed significant increase in germination. The emergence index, final emergence index and vigor index increased by 86.43%, 13.21% and 204.60%, respectively. It was found that exposure of 5 min for magnetic field strengths of 60 mT and 180 mT significantly enhanced the germination parameters of the pea and these treatments can be used practically to accelerate the germination in garden pea. (author)
Štěpánková, Renata; Tonar, Z.; Bártová, J.; Nedorost, L.; Rossmann, Pavel; Poledne, R.; Schwarzer, Martin; Tlaskalová-Hogenová, Helena
Roč. 17, č. 8 (2010), s. 796-804 ISSN 1340-3478 R&D Projects: GA MZd NS9775; GA ČR GA303/08/0367; GA ČR GA305/08/0535; GA AV ČR 1QS500200572; GA MŠk 2B06155 Institutional research plan: CEZ:AV0Z50200510 Keywords : Germ-free mice * Commensal bacteria * Atherogenesis Subject RIV: EC - Immunology Impact factor: 2.293, year: 2010
Liu, Ting-Wu; Wu, Fei-Hua; Wang, Wen-Hua; Chen, Juan; Li, Zhen-Ji; Dong, Xue-Jun; Patton, Janet; Pei, Zhen-Ming; Zheng, Hai-Lei
For several decades, acid rain has been an environmental problem in North America and Europe and is now so in China. The aim of that study was to determine the effects and potential interactions between simulated acid rain (SiAR) and calcium on seed germination of different tree species present in China. Seeds from six tree species were grown is a laboratory where they were spread with SiAR or water as control and where calcium was applied at three levels. Results showed that two species were highly tolerant to SiAR while the others were sensitive; the addition of calcium also had a rescue effect on sensitive seeds but no significant effect on the tolerant ones.
Sun Landi; Zhang Yingcong; Wu Dali; Liang Kai; Zhang Yanping; Jia Ruiling; Qin Qianqian; Cheng Xi; Qian Pingping; Li Wenjian; Hou Suiwen
Crops of Brassica napus L., Linum usitatissmum L., Allium f istulosum L. and Lens culinaris Medic. were irradiated by 80 MeV/u 12 C 6+ ion beams with doses of 30, 90 and 180 Gy. The germination rates and heights of seedlings of M 1 and M 2 generation of these four plants were studied. The results indicated that germination rates and average heights of the B. napus and L. usitatissmum were improved by appropriate dose treatment, while great suppression was found in the irradiated groups of the A. fistulosum. As far as the L. Culinaris was concerned, little differences was observed on M 1 germination rate, but the 90 Gy irradiation was favorable to growth of plant. The treatments with 30, 90 and 180 Gy were inferior to contrast one on M 2 germination rate of the four species. Seedlings of M 2 generation of the B. napus, L. sitatissmum and L. culinaris under 30 Gy grew better than the other groups, while the best performance of the A. fistulosum was shown by the control group. (authors)
van Berlo, C L; de Jonge, H R; van den Bogaard, A E; van Eijk, H M; Janssen, M A; Soeters, P B
In recent hypotheses concerning the pathogenesis of hepatic encephalopathy, gamma-aminobutyric acid (GABA) is claimed to be produced by the colonic flora, although enzymes necessary to generate GABA have been reported to be present in intestinal mucosa. In this study, using normal and germ-free Wistar rats, we determined GABA levels and amino-grams of arterial blood and of venous effluent from small and large bowel. The data indicate that large and small intestinal mucosa significantly contribute to GABA production. In the fasted state GABA concentrations are greater in the venous effluent of the small bowel than in the venous effluent of the large bowel. Feeding increases the arterioportal differences, and uptake in the small bowel is still significantly higher than in the large bowel. This process is not, or can only be to a minor degree, bacterially mediated, because GABA production in the gut both in the fed and fasted state is of similar magnitude in germ-free and normal animals. gamma-Aminobutyric acid release correlates significantly with glutamine uptake in the small bowel of fasted rats. Only a small fraction of the glutamine taken up is needed to account for GABA release, so that conclusions concerning which amino acids may serve as precursors of GABA cannot be drawn. Further studies are needed to delineate the metabolic pathways leading to GABA synthesis.
Methyl tert-butyl ether (MTBE) is a widespread contaminant in surface and ground water in the United States. Frequently irrigation is used to water fields to germinate planted seeds and sustain plant growth. A likely possibility exists that water used may have some MTBE. Our s...
Brevault, T.; Guibert, H.; Naudin, K.
The present study evaluated the pest constraints of an innovative crop management system in Cameroon involving conservation tillage and direct seeding mulch-based strategies. We hypothesized that the presence of mulch (i) would support a higher density of phytophagous arthropods particularly
Jørgensen, Lise N; K. Nielsen, Linda; Nielsen, Bent J
germination by approximately 100%, which led to an improved crop stand and yield increases in the range of 1.2–1.5 tonnes ha−1. Attacks of Fusarium head blight were relatively slight in the two trials and the content of deoxynivalenol was below the EU limits of 1250 ppb in the harvested grain. Even so, seed...
Full Text Available There is a lack of information on basic agronomic properties of Jatropha curcas L. (jatropha cultivation on the marginal lands in the semi-arids. Evaluation of agronomic performance of identified elite strains of J. curcas in marginal lands would be of paramount importance for addressing gap areas in their agronomic properties and subsequently for harnessing their optimum economic potentials. The present study undertook the task of analysing the growth performance of a high oil bearing elite strain of J. curcas–DARL-2 in degraded land in semi-arid zone of Deccan Plateau, India. While undertaking the assessment of growth performance of elite strain DARL-2, two other native (wild strains (namely AHN-1 and AHN-2 of J. curcas were also considered so that a comparative evaluation could be carried out. The role of gypsum was also investigated on J. curcas in the nursery stage as well its carry over effects on growth performance of transplanted trees in the field. Two types of substrates, gypsum-treated soil (GS and untreated soil (SL were used for growing seedlings of all the three jatropha strains. Seedlings (120-days-old of DARL-2 exhibited greater plant height, collar diameter and number of branches but root length was greater in the local strains. In the second year of field transplantation, DARL-2 strain exhibited significantly (p<0.05 greater plant height and number of branches/plant. No carry over effects of gypsum treatment were observed in field transplanted plants as none of the growth parameters significantly varied among the substrate types.
Song, Chieun; Kim, Taeyoon; Chung, Woo Sik; Lim, Chae Oh
Phytocystatins (PhyCYSs) are plant-specific proteinaceous inhibitors that are implicated in protein turnover and stress responses. Here, we characterized a PhyCYS from Arabidopsis thaliana , which was designated AtCYS5. RT-qPCR analysis showed that the expression of AtCYS5 in germinating seeds was induced by heat stress (HS) and exogenous abscisic acid (ABA) treatment. Analysis of the expression of the β -glucuronidase reporter gene under the control of the AtCYS5 promoter showed that AtCYS5 expression during seed germination was induced by HS and ABA. Constitutive overexpression of AtCYS5 driven by the cauliflower mosaic virus 35S promoter led to enhanced HS tolerance in transgenic Arabidopsis , which was characterized by higher fresh weight and root length compared to wild-type (WT) and knockout ( cys5 ) plants grown under HS conditions. The HS tolerance of At-CYS5 -overexpressing transgenic plants was associated with increased insensitivity to exogenous ABA during both seed germination and post-germination compared to WT and cys5 . Although no HS elements were identified in the 5'-flanking region of AtCYS5 , canonical ABA-responsive elements (ABREs) were detected. AtCYS5 was upregulated in ABA-treated protoplasts transiently co-expressing this gene and genes encoding bZIP ABRE-binding factors (ABFs and AREB3). In the absence of ABA, ABF1 and ABF3 directly bound to the ABREs in the AtCYS5 promoter, which activated the transcription of this gene in the presence of ABA. These results suggest that an ABA-dependent pathway plays a positive role in the HS-responsive expression of AtCYS5 during seed germination and post-germination growth.
Robert P. Karrfalt
The role of high quality seeds in producing target seedlings is reviewed. Basic seed handling and upgrading techniques are summarized. Current advances in seed science and technology as well as those on the horizon are discussed.
Radhakrishan, R.; Lee, I.J.
Weeds are major challenges in crop cultivation and cause yield loss. The bacteria based bio-herbicides are emerging against chemical herbicides. This study was aimed to explore the bio-herbicide effect of salt marsh tolerant Enterobacter sp. I-3 on various weed species. The efficacy of I-3 bacterial isolates against weed growth was compared with I-4-5 bacterial strain. The bacterial strains, I-3 and I-4-5 inhibited the seed germination of Cyperus microiria Maxim. Enterobacter sp. I-3 showed higher weed control activity than I-4-5. It was confirmed with growth reduction of C. microiria Maxim. The seed germination of Digitaria sanguinalis L. weed was accelerated during the interaction of I-4-5 and it was drastically declined by I-3 bacterial culture. However, Alopecurus aequalis Sobol. seeds treated with either I-3 or I-4-5 bacterial culture showed no significant germination inhibition. The results of this study suggested that salt marsh tolerant Enterobacter sp. I-3 can be applied as bacterial herbicides to control weeds in agricultural fields. (author)
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 ...
Full Text Available Cashew (Anacardium occidentale nut shell liquid (CNSL has been successfully used in trials as an Aedes aegypti larvicide, but little is known about its environmental effects. In this study, the potential effects of CNSL and a CNSL-based phyto-product formulation on the germination and growth of Lactuca sativa (lettuce, Lycopersicon esculentum (tomato and Senna obtusifolia (coffee senna were assessed. The pH of CNSL and the formulation were 6.4 and 6.8, respectively; the electrical conductivities were 2.89 μS cm-1 (CNSL and 2.21 μS cm-1 (formulation, respectively, and both contained anacardic acid (53.2% and degradation products. In bioassays for germination and growth, CNSL (25, 50, 100, 150, and 200 mg mL-1, the formulation (100 mg mL-1 and the control were used in a completely randomized design. The results demonstrated the chemical effects of CNSL, which negatively affected the germination and vigor of lettuce and tomato and the vigor of coffee senna; for growth, it negatively influenced both the root and aerial parts of lettuce and tomato, but only the roots of coffee senna. The formulation had negative effects on the vigor of coffee senna and the growth of tomato and lettuce seedlings (roots and aerial parts. The results indicate the phytotoxicity of CNSL and the formulation for the plant species tested.
Eaton, D.; Murphy, C.E.
This study is a follow-up of a similar study done by Loehle (1990). The objectives of the original study were to: (1) measure the toxicity of groundwater contaminated by the F-Area seepage basins where this water surfaces in a seepline along Fourmile Branch and (2) to evaluate the effectiveness of rainwater for washing contaminants from the soil. Results of seed germination tests show no significant difference between water extracted from one extraction of F-Area seepline soil, soil from a control area, the sixth consecutive extraction from F-Area soil, and a deionized water control. A root-growth assay on the same seeds shows a significant effect with the order of growth, first extraction of F-Area soil< control site< deionized water
Cristin E Kearns
Full Text Available In 1965, the Sugar Research Foundation (SRF secretly funded a review in the New England Journal of Medicine that discounted evidence linking sucrose consumption to blood lipid levels and hence coronary heart disease (CHD. SRF subsequently funded animal research to evaluate sucrose's CHD risks. The objective of this study was to examine the planning, funding, and internal evaluation of an SRF-funded research project titled "Project 259: Dietary Carbohydrate and Blood Lipids in Germ-Free Rats," led by Dr. W.F.R. Pover at the University of Birmingham, Birmingham, United Kingdom, between 1967 and 1971. A narrative case study method was used to assess SRF Project 259 from 1967 to 1971 based on sugar industry internal documents. Project 259 found a statistically significant decrease in serum triglycerides in germ-free rats fed a high sugar diet compared to conventional rats fed a basic PRM diet (a pelleted diet containing cereal meals, soybean meals, whitefish meal, and dried yeast, fortified with a balanced vitamin supplement and trace element mixture. The results suggested to SRF that gut microbiota have a causal role in carbohydrate-induced hypertriglyceridemia. A study comparing conventional rats fed a high-sugar diet to those fed a high-starch diet suggested that sucrose consumption might be associated with elevated levels of beta-glucuronidase, an enzyme previously associated with bladder cancer in humans. SRF terminated Project 259 without publishing the results. The sugar industry did not disclose evidence of harm from animal studies that would have (1 strengthened the case that the CHD risk of sucrose is greater than starch and (2 caused sucrose to be scrutinized as a potential carcinogen. The influence of the gut microbiota in the differential effects of sucrose and starch on blood lipids, as well as the influence of carbohydrate quality on beta-glucuronidase and cancer activity, deserve further scrutiny.
Kearns, Cristin E.; Apollonio, Dorie
In 1965, the Sugar Research Foundation (SRF) secretly funded a review in the New England Journal of Medicine that discounted evidence linking sucrose consumption to blood lipid levels and hence coronary heart disease (CHD). SRF subsequently funded animal research to evaluate sucrose’s CHD risks. The objective of this study was to examine the planning, funding, and internal evaluation of an SRF-funded research project titled “Project 259: Dietary Carbohydrate and Blood Lipids in Germ-Free Rats,” led by Dr. W.F.R. Pover at the University of Birmingham, Birmingham, United Kingdom, between 1967 and 1971. A narrative case study method was used to assess SRF Project 259 from 1967 to 1971 based on sugar industry internal documents. Project 259 found a statistically significant decrease in serum triglycerides in germ-free rats fed a high sugar diet compared to conventional rats fed a basic PRM diet (a pelleted diet containing cereal meals, soybean meals, whitefish meal, and dried yeast, fortified with a balanced vitamin supplement and trace element mixture). The results suggested to SRF that gut microbiota have a causal role in carbohydrate-induced hypertriglyceridemia. A study comparing conventional rats fed a high-sugar diet to those fed a high-starch diet suggested that sucrose consumption might be associated with elevated levels of beta-glucuronidase, an enzyme previously associated with bladder cancer in humans. SRF terminated Project 259 without publishing the results. The sugar industry did not disclose evidence of harm from animal studies that would have (1) strengthened the case that the CHD risk of sucrose is greater than starch and (2) caused sucrose to be scrutinized as a potential carcinogen. The influence of the gut microbiota in the differential effects of sucrose and starch on blood lipids, as well as the influence of carbohydrate quality on beta-glucuronidase and cancer activity, deserve further scrutiny. PMID:29161267
Kearns, Cristin E; Apollonio, Dorie; Glantz, Stanton A
In 1965, the Sugar Research Foundation (SRF) secretly funded a review in the New England Journal of Medicine that discounted evidence linking sucrose consumption to blood lipid levels and hence coronary heart disease (CHD). SRF subsequently funded animal research to evaluate sucrose's CHD risks. The objective of this study was to examine the planning, funding, and internal evaluation of an SRF-funded research project titled "Project 259: Dietary Carbohydrate and Blood Lipids in Germ-Free Rats," led by Dr. W.F.R. Pover at the University of Birmingham, Birmingham, United Kingdom, between 1967 and 1971. A narrative case study method was used to assess SRF Project 259 from 1967 to 1971 based on sugar industry internal documents. Project 259 found a statistically significant decrease in serum triglycerides in germ-free rats fed a high sugar diet compared to conventional rats fed a basic PRM diet (a pelleted diet containing cereal meals, soybean meals, whitefish meal, and dried yeast, fortified with a balanced vitamin supplement and trace element mixture). The results suggested to SRF that gut microbiota have a causal role in carbohydrate-induced hypertriglyceridemia. A study comparing conventional rats fed a high-sugar diet to those fed a high-starch diet suggested that sucrose consumption might be associated with elevated levels of beta-glucuronidase, an enzyme previously associated with bladder cancer in humans. SRF terminated Project 259 without publishing the results. The sugar industry did not disclose evidence of harm from animal studies that would have (1) strengthened the case that the CHD risk of sucrose is greater than starch and (2) caused sucrose to be scrutinized as a potential carcinogen. The influence of the gut microbiota in the differential effects of sucrose and starch on blood lipids, as well as the influence of carbohydrate quality on beta-glucuronidase and cancer activity, deserve further scrutiny.
Ran, Chao; Hu, Jun; Liu, Wenshu; Liu, Zhi; He, Suxu; Dan, Bui Chau Truc; Diem, Nguyen Ngoc; Ooi, Ei Lin; Zhou, Zhigang
Essential oils (EOs) are commonly used as animal feed additives. Information is lacking on the mechanisms driving the beneficial effects of EOs in animals, especially the role played by the intestinal microbiota of the host. The purpose of this study was to clarify the relative contribution of direct effects of EOs on the physiology and immune system of tilapia and indirect effects mediated by the intestinal microbiota by using a germ-free zebrafish model. Juvenile hybrid tilapia were fed a control diet or 1 of 4 treatment diets containing 60-800 mg Next Enhance 150 (NE) (an EO product containing equal levels of thymol and carvacrol)/kg for 6 wk. The key humoral and cellular innate immune parameters were evaluated after the feeding period. In another experiment, the gut microbiota of tilapia fed a control or an NE diet (200 mg/kg) for 2 wk were transferred to 3-d postfertilization (dpf) germ-free (GF) zebrafish, and the expression of genes involved in innate immunity and tight junctions was evaluated in zebrafish at 6 dpf. Lastly, NE was directly applied to 3-dpf GF zebrafish at 3 doses ranging from 0.2 to 20 mg/L, and the direct effect of NE on zebrafish was evaluated after 1 and 3 d. NE supplementation at 200 mg/kg enhanced phagocytosis activity of head kidney macrophages (×1.36) (P tilapia compared with the control (P tilapia through a combination of factors, i.e., primarily through a direct effect on host tissue (immune-stimulating) but also an indirect effect mediated by microbial changes (immune-relieving). © 2016 American Society for Nutrition.
Lluvia de semillas y emergencia de plántulas de Fagus grandifolia subsp. mexicana en La Mojonera, Hidalgo, México Seed rain and seedling emergence of Fagus grandifolia subsp. mexicana at La Mojonera, Hidalgo, Mexico
Full Text Available Fagus grandifolia subsp. mexicana es una especie restringida a pequeñas poblaciones y sujeta a fuerte presión antropogénica. Con el objetivo de obtener información relevante que permita proponer alternativas de conservación, se analizó la producción de semillas y la demografía de plántulas de primer año en la Mojonera, Hidalgo. Se estableció una parcela de observación de 4 800 m² dividida en cuadrantes de 10 X 10 m. Se utilizaron trampas de 0.5 m² para estimar la producción de semillas, así como subparcelas de 1 m² para registrar la emergencia y supervivencia de plántulas. La producción fue de 521 667 semillas ha-1, de las que sólo el 24.44% estaban llenas; el 46.01% vanas, y el 29.55% dañadas. La densidad de plántulas emergidas varió de 1 a 33 plántulas por m². El porcentaje de supervivencia de plántulas de primer año fue de 2.8% después de 10 meses de observación, siendo las de mayor supervivencia las que emergieron durante las primeras fechas. El 34.44% de las plántulas murieron por herbivoría, el 24.07% por damping-off y 23.65% por causa desconocida. La especie presenta el patrón general de supervivencia de especies arbóreas con alta mortalidad durante el primer año de vida.Fagus grandifolia subsp. mexicana is a species restricted to small populations under high anthropogenic pressure. With the aim to attain information to propose conservation strategies of this species, the seed rain and demography of current-year seedlings were analyzed at La Mojonera, Hidalgo, Mexico. A 4 800 m² plot divided into 10 X 10 m quadrants was established. The seed rain, seedling emergence, and survival were analyzed using seed traps of 0.5 m² and adjacent 1 m² sub-plots. The total seed rain was 521 667 seeds ha-1. A high proportion of seeds were unsound (46.01%, followed by damaged seeds (29.5% and only 24.44% were sound. Emerged seedlings fluctuated from 1 to 33 seedlings m². Alter 10 months, 2.8% of emerged seedlings were
Mame Sokhna Sarr
Full Text Available Multipurpose trees such as Senegalia senegal are widespread in arid and semi-arid lands that have natural or induced saline soils and poor soil fertility. Such environmental problems impact growth and have the potential to influence plant physiological adaptations. Identifying superior genotypes better adapted to these environmental stresses will be of great importance for tree selection for reclamation of degraded drylands. The main objective of this study was to examine the growth performance, and physiological and morphological adaptations to salinity, and fertility treatments of different Senegalia senegal families. We used five families (DB16, DB14, K4B19, K17B19, NB1 selected from 60 families of a Senegalia senegal progeny trial in Dahra, Senegal. Seedlings were grown under greenhouse conditions by watering all plants for three weeks and then stopping all watering for three more weeks. In a randomized complete block design, a two-level factorial combination was used for salinity (zero and 183.1 mM NaCl added and fertility (zero and 100 kg/ha N-P-K added treatments. A significant family × salt × fertilizer interaction was found for all biomass parameters (leaf dry matter, stem dry matter, root dry matter, and leaf area. The fertilizer application resulted in a significant increase of total biomass of all families, ranging from 63% to 237% for NB1 and K17B19, respectively. In contrast, salt only decreased total biomass of NB1 and K17B19 increased growth. Despite similar net photosynthetic rates before treatment started, fertilizer and salinity induced different effects between families. Prior to drought stress, fertilizer did not affect photosynthesis of DB16, while salt significantly decreased stomatal conductance of all families. DB16 and N1B1, despite significant differences of stomata size and density, significantly decreased transpiration, and thereby increased their intrinsic water use efficiency. Under drought, relative growth rate
BAKKER, R; LASONDER, E; BOS, NA
We previously investigated the primary and secondary responses and hyperimmunization to the T cell-dependent antigen 2,4-dinitrophenyl keyhole limpet hemocyanin (DNP-KLH) in antigen-free (AF), germ-free (GF) and conventional (CV) mice. Both the absolute and relative numbers of DNP-specific
Veerappan, Vijaykumar; Chen, Naichong; Reichert, Angelika I; Allen, Randy D
The novel mutant allele hsi2-4 was isolated in a genetic screen to identify Arabidopsis mutants with constitutively elevated expression of a glutathione S-transferase F8::luciferase (GSTF8::LUC) reporter gene in Arabidopsis. The hsi2-4 mutant harbors a point mutation that affects the plant homeodomain (PHD)-like domain in HIGH-LEVEL EXPRESSION OF SUGAR-INDUCIBLE GENE2 (HSI2)/VIVIPAROUS1/ABI3-LIKE1 (VAL1). In hsi2-4 seedlings, expression of this LUC transgene and certain endogenous seed-maturation genes is constitutively enhanced. The parental reporter line (WT LUC ) that was used for mutagenesis harbors two independent transgene loci, Kan R and Kan S . Both loci express luciferase whereas only the Kan R locus confers resistance to kanamycin. Here we show that both transgene loci harbor multiple tandem insertions at single sites. Luciferase expression from these sites is regulated by the HSI2 PHD-like domain, which is required for the deposition of repressive histone methylation marks (H3K27me3) at both Kan R and Kan S loci. Expression of LUC and Neomycin Phosphotransferase II transgenes is associated with dynamic changes in H3K27me3 levels, and the activation marks H3K4me3 and H3K36me3 but does not appear to involve repressive H3K9me2 marks, DNA methylation or histone deacetylation. However, hsi2-2 and hsi2-4 mutants are partially resistant to growth inhibition associated with exposure to the DNA methylation inhibitor 5-aza-2'-deoxycytidine. HSI2 is also required for the repression of a subset of regulatory and structural seed maturation genes in vegetative tissues and H3K27me3 marks associated with most of these genes are also HSI2-dependent. These data implicate HSI2 PHD-like domain in the regulation of gene expression involving histone modifications and DNA methylation-mediated epigenetic mechanisms.
Sandra Regina Pelegrinello Schuab
Full Text Available Objetivou-se, nesse estudo, comparar os diferentes testes empregados na avaliação do vigor das sementes de soja e verificar a sua relação com a emergência das plântulas em campo. Assim, o vigor das sementes de soja de dez cultivares foi avaliado por meio dos seguintes testes: emergência das plântulas em campo; germinação; emergência dasplântulas em leito de areia; velocidade de emergência em areia; envelhecimento acelerado; frio modificado; tetrazólio (1-3 e 1-5 e condutividade elétrica. Foi possível observar que os testes de envelhecimento acelerado, germinação, tetrazólio e condutividade elétrica foram os que melhor se correlacionaram com a emergência em campo. Além disso, a interpretação dos resultados obtidos entre os testes de laboratório e de emergência em campo não deve considerar apenas a análise de correlação.The objective of this work was to compare different tests used to evaluate soybean seed vigour and to verify their relationship with seedlings emergence in field. Thus, the soybean seed vigour of ten cultivars was evaluated by the following tests: seedling emergence in field, standard germination, seedlings emergence in sand seedbed, speed of emergence in sand seedbed, accelerated aging, modified cold test, tetrazolium (1-3 and 1-5 and electrical conductivity. The accelerating aging, standard germination, tetrazolium and electrical conductivity tests showed higher correlations with field emergence. The results obtained from laboratory tests and seedlings emergence in field should not consider only the correlation analysis.
Elineide B. Silveira
bioassays were performed. In the first, 93 strains were tested; in the second, 32, and, in the third, eight from cucumber plus 10 bacterial epiphytic strains from other crops were used. The cucumber seeds were bacterized by immersion in the bacterial suspension adjusted to A580 = 0.7, sown in polystyrene trays filled with organic substrate and analyzed ten days after sowing in relation to shoot (MSPA, root (MSR, and total (MST dry matter. In the third bioassay the epiphytes PEP52, PEP8, PEP82, PEP91, and C22 were selected because they significantly (P=0.05 elevated MSR and MST in relation to the control reaching higher values than 70 and 40%, respectively. After compatibility tests the five isolates applied separately and in mixtures efficiently increased the index of MSPA, MSR, and MST in cucumber seedlings, without differing among them. It is worth noticing that PEP81 (Bacillus amyloliquefaciens and PEP91 (Enterobacter cloacae increased 55.5 and 34.5% (MSPA, 42.9 and 37.2% (MSR, and 41.6 and 34.0% (MST, respectively. The production of indolacetic acid, hydrogen cyanide, phosphate solubilization and changes in foliar levels of N, P, K, Ca, and Mg were evaluated as putative mechanisms of action for theses isolates, but they showed negative results. Seed bacterization with B. amyloliquefaciens PEP81 and E. cloacae PEP91 could improve quality of cucumber seedlings.
Study of Seed Germination and Morphological Characteristics of Wild Oat(Avena ludoviciana and Mustard (Sinapis arvensis Seedling, Affected by Aqueous Extracts of Black Cumin (Bunium persicum L, Chickpea (Cicer arietinum L and Mixed of Extracts
Full Text Available Abstract In order to evaluate the effects of shoot aqueous extracts of chickpea, black cumin and their mixed aqueous extracts on seed germination and seedling morphological characteristics of wild oat and mustard as two common weed, an experiment was conducted with a factorial arrangement based on completely randomized design with three replications. The experimental treatments were aqueous extracts in five levels (0, 10, 20, 40 and 60 percentage, Weed species in two levels (wild oat and mustard and extract concentration in five levels (0, 10, 20. 40 and 60 percentage. Result indicated that the highest and the lowest percentage and seed germination rate, length of radicle and hypocotyle, dry weight of radicle and hypocotyle and radicle / hypocotyle ratio (R/H, were obtained in control treatment and 60% concentration, respectively. Aqueous extract of black cumin and mixed extracts had the highest and the lowest effect on percentage and seed germination rate, length of radicle and hypocotyle, dry weight of radicle and hypocotyle and radicle / hypocotyle ratio, respectively. Between two weed species, wild oat had the lowest percentage of seed germination and length of radicle compared with mustard. Mustard had the lowest seed germination rate, dry weight of radicle and hypocotyle and length of hypocotyle compare with wild oat. Generally, it was concluded that chickpea and black cumin aqueous extracts have highly inhibitory in terms of weed control that can be useful for sustainable agriculture. Keywords: Allelopathy, Black cumin, Chickpea, Extract, Mustard, Wild oat
Janete Motta da Silva Gonzaga
Full Text Available Pre-germination treatments such as scarification and the use of growth regulators can provide the dormancy breaking in seeds and enhance the emergence and development of seedlings. The aim of this study was to determine appropriate treatments to overcome seed dormancy and enhance the initial growth of seedlings of Spondias tuberosa. We used a randomized design in factorial 2 x 4, with the following factors: seeds scarified or not scarified and then soaked in water or aqueous solutions of gibberellin, cytokinin and ethylene, with 4 replicates and 15 seeds. There was no significant interaction between scarification treatments and use of growth regulators. Mechanical scarification and soaking seeds in solutions containing umbuzeiro growth regulators does not increase the percentage of seedling emergence, however soaking in a solution of Ethrel at 100 ppm provides higher speed of emergence and root development. Tratamentos pré-germinativos, como a escarificação e o uso de reguladores de crescimento, podem proporcionar a superação de dormência em sementes e incrementar a emergência e o desenvolvimento de plântulas. O objetivo da presente pesquisa foi determinar tratamentos adequados para a superação da dormência de sementes e potencialização do crescimento inicial de plântulas de umbuzeiro. Utilizou-se o delineamento inteiramente casualizado, em fatorial 2 x 4, sendo os fatores: sementes escarificadas ou não escarificadas e, posteriormente, imersas em água ou soluções aquosas de giberelina, citocinina ou etileno, com 4 repetições de 15 sementes. Não houve interação significativa entre os tratamentos escarificação e uso de reguladores de crescimento. A escarificação mecânica e a embebição de sementes de umbuzeiro em soluções contendo reguladores de crescimento não aumenta a percentagem de emergência de plântulas, entretanto a embebição em solução de Ethrel a 100 ppm proporciona maior velocidade de emergência e
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, ...
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.
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.
Full Text Available Studies were conducted to estimate parameters and relationships associated with sub-processes in soil seed banks of oilseed rape in Gorgan, Iran. After one month of burial, seed viability decreased to 39%, with a slope of 2.03% per day, and subsequently decreased with a lower slope of 0.01 until 365 days following burial in the soil. Germinability remained at its highest value in autumn and winter and decreased from spring to the last month of summer. Non-dormant seeds of volunteer oilseed rape did not germinate at temperatures lower than 3.8 ºC and a water potential of -1.4 MPa ºd. The hydrothermal values were 36.2 and 42.9 MPa ºd for sub- and supra-optimal temperatures, respectively. Quantification of seed emergence as influenced by burial depth was performed satisfactorily (R² = 0.98 and RMSE = 5.03. The parameters and relationships estimated here can be used for modelling soil seed bank dynamics or establishing a new model for the environment.Estudos foram realizados para estimar os parâmetros e as relações ligados a subprocessos em bancos de sementes de canola no solo, em Gorgan, Iran. Após um mês de enterrio, a viabilidade das sementes diminuiu para 39%, com inclinação de 2,03% ao dia; posteriormente, diminuiu com menor inclinação: de 0,01 até 365 dias após o enterrio no solo. A germinação manteve-se em seu maior valor no outono e inverno, reduzindo da primavera ao último mês do verão. Sementes de canola não dormentes não germinaram em temperaturas abaixo de 3,8 °C e potencial hídrico abaixo de -1,4 Mpaºd. Os valores hidrotermais foram de 36,2 e 42,9 Mpaºd para temperaturas sub e supraótima, respectivamente. A quantificação da emergência das sementes sob influência da profundidade de enterrio foi delineada de forma satisfatória (R²= 0,98 e RMSE = 5,03. Os parâmetros e as relações estimadas neste estudo podem ser utilizados em modelagens do banco de sementes do solo ou para estabelecer um novo modelo para
Morfologia do fruto, da semente e morfo-anatomia da plântula de Vitex megapotamica (Spreng. Moldenke (Lamiaceae Fruit and seed morphology and morpho-anatomy of seedlings of Vitex megapotamica (Spreng. Moldenke (Lamiaceae
Nelson Luiz Cosmo
Full Text Available Vitex megapotamica (tarumã é espécie arbórea, decídua, com ocorrência, no Brasil, desde Minas Gerais até o Rio Grande do Sul. Visando à caracterização morfológica do fruto, da semente e morfo-anatômica da plântula, frutos desta espécie foram coletados e as sementes postas para germinar em laboratório. As plântulas foram coletadas desde a protrusão da raiz até o desenvolvimento do primeiro par de eofilo. Foram realizadas medições e pesagem de frutos, e contagem do número de sementes por frutos. As características morfológicas do fruto e da semente são aqui descritas e ilustradas, assim como a morfo-anatomia da plântula. O fruto é drupóide, nuculânio, tetralocular, contendo apenas uma ou duas sementes com fina camada de endosperma e embrião axial, foliáceo. O diásporo (pirênio é constituído pelo endocarpo mais a semente. O endocarpo lenhoso parece exercer restrição sobre a germinação das sementes desta espécie. A plântula é epigea, fanerocotiledonar, com paracotilédones elípticos, com margem inteira, e eofilos opostos, simples, elípticos, com margem serreada, apresentando tricomas tectores. Tanto o paracotilédone quanto o eofilo apresentam mesofilo heterogêneo, dorsiventral, feixe colateral em forma de arco e estômatos anomocíticos. A raiz é poliarca, com córtex parênquimático; o hipocótilo possui tricomas glandulares e não-glandulares, colo distinto, e com cerca de 20 dias encontra-se em início de crescimento secundário. Diversas das características da plântula de Vitex megapotamica estão relacionadas à sua condição de espécie heliófila.Vitex Megapotamica (tarumã is a deciduous tree occurring in Brazil from Minas Gerais to Rio Grande do Sul States. In order to characterize fruit and seed morphology and morpho-anatomy of seedlings, fruits of this species were collected and seeds were germinated in the laboratory. Seedlings were collected from root protrusion to development of the
Jourová, L; Anzenbacher, P; Lišková, B; Matušková, Z; Hermanová, P; Hudcovic, T; Kozáková, H; Hrnčířová, L; Anzenbacherová, E
Gut microbiota provides a wide range of beneficial function for the host and has an immense effect on the host's health state. It has also been shown that gut microbiome is often involved in the biotransformation of xenobiotics; however, the molecular mechanisms of the interaction between the gut bacteria and the metabolism of drugs by the host are still unclear. To investigate the effect of microbial colonization on messenger RNA (mRNA) expression of liver cytochromes P450 (CYPs), the main drug-metabolizing enzymes, we used germ-free (GF) mice, lacking the intestinal flora and mice monocolonized by non-pathogenic bacteria Lactobacillus plantarum NIZO2877 or probiotic bacteria Escherichia coli Nissle 1917 compared to specific pathogen-free (SPF) mice. Our results show that the mRNA expression of Cyp1a2 and Cyp2e1 was significantly increased, while the expression of Cyp3a11 mRNA was decreased under GF conditions compared to the SPF mice. The both bacteria L. plantarum NIZO2877 and E. coli Nissle 1917 given to the GF mice decreased the level of Cyp1a2 mRNA and normalized it to the control level. On the other hand, the colonization by these bacteria had no effect on the expression of Cyp3a11 mRNA in the liver of the GF mice (which remained decreased). Surprisingly, monocolonization with chosen bacterial strains has shown a different effect on the expression of Cyp2e1 mRNA in GF mice. Increased level of Cyp2e1 expression observed in the GF mice was found also in mice colonized by L. plantarum NIZO2877 ; however, the colonization with probiotic E. coli Nissle 1917 caused a decrease in Cyp2e1 expression and partially restored the SPF mice conditions.
Morfologia de frutos, sementes e plântulas de castanheira (Terminalia catappa L. - COMBRETACEAE Morphology of the fruit, the seed and the seedlings of chestnut tree (Terminalia catappa L. - COMBRETACEAE
Silvia de Azevedo Ivani
Full Text Available O trabalho foi realizado com o objetivo de descrever morfologicamente os frutos, sementes e plântulas de castanheira. Foi feita a biometria dos frutos e das sementes e sua caracterização quanto à forma, por meio de mensurações com paquímetro e observações realizadas em estereomicroscópio com câmara clara. Os frutos de castanheira são carnosos, indeiscentes, do tipo nucóide, glabros, de coloração verde a vinácea, projeção das nervuras carpelares externamente evidentes, com epicarpo delgado, mesocarpo carnoso e esponjoso de coloração vinácea, com feixes vasculares conspícuos em corte transversal. Geralmente, cada fruto contém apenas uma semente. As sementes são exalbuminosas, de formas alongadas e cilíndricas, recobertas por endocarpo rígido de coloração marrom; possuem cerca de 2,5cm, 0,7cm e 0,7cm, de comprimento, largura e espessura, respectivamente. A germinação das sementes de castanheira é epígea, e a plantula é fanerocotiledonar.The work was carried out with the objective of describing morphologically the fruits, seeds and seedlings of chestnut tree. It was made the biometry of the fruits and seeds with a digital pachymeter and its characterization in relation to the shape, in stereomicroscope with clear chamber. It can be evidenced that the chestnut tree fruits are fleshly, indehiscent, nucoid, glabrous, from green to purple coloration, with evident projection of the carpel ribbings, with a fleshly and spongy epicarp and mesocarp, of purple color, with conspicuous vascular bundle in transversal cut. Generally, it has a seed per fruit. The seeds are unalbuminous, of prolongated and cylindrical shape and recovered with a rigid endocarp of brown coloration. The seeds possess about 2,5; 0,7 and 0,7 cm, of length, width and thickness, respectively. The germination of the seeds of chestnut tree is epigeal and the seedling is fanerocotyledonary.
Elisa del Carmen Martínez Ochoa
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.
Germinação de sementes e desenvolvimento de plântulas de moringa (Moringa oleifera Lam. em função do peso da semente e do tipo de substrato Germination of seeds and seedling development of drumstick as a function of seed weight and substrate type
Antonio Marcos E. Bezerra
Full Text Available Moringa oleifera Lam. é uma espécie arbórea originária do noroeste indiano, cultivada graças ao seu valor alimentar, medicinal, industrial e no tratamento de água para o consumo humano. Os efeitos do peso de sementes e do substrato na germinação e desenvolvimento das plântulas foram determinados, sob condições de casa de vegetação (sombrite 50% com nebulização intermitente em Fortaleza (CE, de 29/11 a 14/12/02. Os tratamentos constaram de arranjo fatorial 3x3 referente a três categorias de semente: pesadas (272,41 g/1000 sementes, médias (218,88 g/1000 sementes e leves (177,07 g/1000 sementes; e três substratos: vermiculita; Plantmax® e uma mistura à base de solo esterilizado (S, húmus de minhoca (H e pó de coco lavado (PC, na proporção de 2:1:1, dispostos em delineamento inteiramente casualizado com quatro repetições (24 sementes/repetição. Efetuou-se a semeadura das três classes de pesos de sementes em bandejas de isopor de 72 células contendo os substratos, avaliando-se a percentagem, velocidade e tempo médio de germinação, altura da plântula, massa seca da parte aérea e massa seca total. As sementes pesadas e médias apresentaram maior percentagem e velocidade de germinação do que as leves; as sementes pesadas proporcionaram plântulas mais vigorosas; no substrato Plantmax® e na mistura (S+H+PC a percentagem e a velocidade de germinação foi superior à vermiculita; e as plântulas desenvolveram-se melhor no substrato Plantmax®.To compensate the shortage of information on the influence of seed weight and substrate over the germination and seedling development of Moringa oleifera an experiment was conducted under greenhouse conditions (50% of natural light with intermittent nebulization in Fortaleza, Ceará State, Brazil. The treatments consisted of a 3x3 factorial arrangement [three seed weights: heavy (272.41 g/1000 seeds; medium (218.88 g/1000 seeds and light (177.07 g/1000 seeds and three substrates
Full Text Available the objectives of an agricultural enterprise. The objectives of this study were to determine the effects of gut passage (goats, cattle), dung (nutrients), fire, grass competition and trampling on establishment of A. nilotica and D. cinerea seedlings. Germination...
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...
Patrícia Marluci da Conceição
Full Text Available O comprimento da raiz primária das plântulas é usado como teste de vigor de sementes de poáceas, no entanto, além da raiz primária, existe um número variável de raízes seminais, as quais também poderiam ser usadas. Com este trabalho, objetivou-se a avaliação das raízes seminais de plântulas de milho como indicativo do vigor das sementes colhidas em diferentes épocas e submetidas a diferentes métodos de debulha. Para obter lotes de diferentes qualidades, as sementes da variedade de milho UFV-M100 Nativo foram colhidas em diferentes épocas (experimento 1 e submetidas a diferentes métodos de debulha (experimento 2. No experimento 1, as sementes foram colhidas em quatro épocas: quando atingiram o teor de água de 25% e 10, 20 e 30 dias depois da primeira colheita, em delineamento inteiramente casualizado, com quatro repetições. No experimento 2, as sementes foram colhidas com teor de água de 25% e submetidas à debulha manual, em debulhador estacionário manual e em debulhador estacionário, no delineamento inteiramente casualizado, com cinco repetições. No experimento 1, a massa seca das raízes seminais das plântulas diminuiu com o atraso da colheita e correlacionaram-se positivamente com o teste de emergência em leito de areia. No experimento 2, os métodos de debulha não influenciaram as características de raiz e não houve correlação entre elas e a emergência em leito de areia. A massa seca das raízes seminais pode diferenciar o vigor de lotes colhidos em diferentes épocas, mas nenhuma característica de raiz foi eficiente para diferenciar lotes de sementes com variações no dano mecânico.Length of primary root of seedlings is used as seed vigor test of Poaceae. However, besides primary root, there is a variable number of seminal roots, which could have been used. The objective of this work was to evaluate seminal root of corn seedlings as indicative of seed vigor of corn seeds harvested in different seasons
Germinación asimbiótica de semillas y desarrollo in vitro de plántulas de Cattleya mendelii Dombrain (Orchidaceae Asymbiotic seed germination and in vitro seedling development of Cattleya mendelii Dombrain (Orchidaceae
Seir Antonio Salazar-Mercado
Full Text Available Cattleya mendelii es una orquídea endémica de Colombia de gran valor ornamental que se encuentra en peligro de extinción a causa de la recolección masiva y a la destrucción de sus hábitats naturales por la acción antrópica. El cultivo in vitro es una alternativa para la conservación de esta especie o su comercialización. En esta investigación se evaluaron la germinación asimbiótica y el desarrollo de plántulas de las semillas de orquídeas de la especie C. mendelii, en diferentes medios de cultivos in vitro. Inicialmente se recolectaron cápsulas maduras; posteriormente, se determinó la viabilidad de las semillas con la prueba de Tetrazolio. En forma paralela, las semillas se desinfectaron y sembraron con el método de jeringuilla para evaluar el efecto de cinco medios de cultivo en el desarrollo de C. mendelii después de dieciséis semanas de cultivo. Se encontró que la viabilidad de las semillas fue del 93%. El mejor porcentaje de germinación se halló en el medio de cultivo Murashige-Skoog más agua de coco (MS + AC con diferencias significativas (P Cattleya mendelii is an endemic orchid species from Colombia, which has a great ornamental value which is in danger of extinction due to massive collection and their natural habitat's destruction by human activities. In vitro culture is an alternative to preserve this species and/or carry out its marketing. In this study the asymbiotic germination and seedling development of seeds of C. mendelii, in several in vitro culture media were evaluated. Mature capsules were collected. Seed viability with tetrazolium test was done; seeds were disinfected at the same time and planted by the syringe method to evaluate the effect of five growth culture media on the development of C. mendelii after 16 weeks of cultivation. It was found that seed viability was 93%, the highest percentage of germination was found in the culture medium Murashige-Skoog plus coconut water (MS+AC with significant
Taghi Bararpour; Nicholas E. Korres
Two of the most troublesome weeds in soybean, cotton, and corn in cropping systems of mid-south United States (US) are Senna obtusifolia and Xanthium strumarium. Understanding their population dynamics, particularly weed seedling emergence patterns, is important for the timely implementation and the success of weed management strategies. Identifying the sources of variation of emergence patterns could greatly improve our ability to predict emergence timing. A three-years field study was condu...
Lucinete Lima da Silva
development of açaí palm seedlings. The experimental design was completely randomized with five treatments, five replications with 50 seeds per plot. The treatments corresponded to the use of four methods for breaking seed dormancy. In the control treatment (T1, the seeds were not scarified; (T2 thermal scarification at 80ºC from two hours; (T3 thermal scarification in water at the temperature of 100ºC for two hours; (T4 the seeds were submitted to mechanical scarification in aluminum can previously pierced with circular movements for four minutes for 250-seed samples, (T5 the seeds wee submersed in 20 L of water containing 500 g of caustic soda for two hours. The number of emerged seedlings (NPE, %, the length of the seedlings’ shoot (CPA, cm, the leaf length (CF, cm, the root length (CR, cm and dry matter (DM, g were evaluated. The previous cooling of açaí fruits is not indicated because it reduces the percentage of seed emergence and initial seedling development. Higher emergence of percentage and initial seedling development of açaí are obtained with mechanical scarification of the seeds.
Li, S. S.; Yu, L.; Lin, W. G.; Pingi, T. F.
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)
Estudos morfoanatômicos da semente e da plântula de espécies de Anileiras (Indigofera L., Leguminosae Morpho-anatomical studies of seeds and seedlings of wild indigo, "anileira", Indigofera- Leguminosae
Juliana Villela Paulino
Full Text Available O nome popular "anileira" designa Indigofera anil L., I. suffruticosa Mill. e I. truxillensis Kunth, muito semelhantes quanto à morfologia externa. Este trabalho teve por objetivo avaliar se caracteres da semente e plântula apresentavam valor diagnóstico para este grupo, já que tais caracteres têm sido muito utilizados na Taxonomia de Leguminosae. A superfície e morfoanatomia de sementes e cotilédones foram estudadas por microscopias eletrônica de varredura e de luz, e as etapas do desenvolvimento das plântulas descritas. Embora as plântulas sejam semelhantes, caracteres de sementes (tamanho, forma, ornamentação da superfície, forma do hilo e tamanho do embrião e cotilédones (forma, organização do parênquima lacunoso na nervura central e distribuição de metabólitos nos tecidos apresentaram valor diagnóstico para as espécies. I. anil distingue-se de I. suffruticosa por suas sementes maiores e cotilédones com borda acuminada. I. truxillensis caracteriza-se por apresentar sementes cilíndricas e cotilédones reniformes contendo gotas de óleo e alcalóides. Nossos dados, a morfologia externa dos frutos (curvos em I. anil e I. suffruticosa, e retos em I. truxillensis e, ainda, a anatomia foliar (células parenquimáticas grandes e fenólicas no floema de I. suffruticosa e sua ausência em I. anil sugerem que I. anil, I. suffruticosa e I. truxillensis não devem ser sinonimizadas.The common name "wild indigo" specifies Indigofera anil L., I. suffruticosa Mill. (legitimate name and I. truxillensis Kunth (legitimate name that are very similar due to their external morphology. This work analyzed diagnostic characteristics of seeds and seedlings of these species since such features are widely used in taxonomic approaches within Leguminosae. We studied surface features and morpho-anatomy of seeds and cotyledons with scanning electronic microscopy and light microscopy, and described seedling phases. Although seedlings are similar
Márcia de Nazaré Oliveira Ribeiro
Full Text Available Annona crassiflora Mart known as 'araticum', 'marolo' or 'field araticum' is a typical fruit from the Cerrado biome of Brazil with socio-economic and medicinal importance. Normally, Annona crassiflora is propagated through seeds. However, due to a deep dormancy that the seeds display at dispersion and the difficulty to obtain uniform plants in a short time period, micropropagation may be a feasible alternative. Concentrations of gibberellic acid (GA3 and naphthalene-acetic acid (NAA and their interactive effects on in vitro seed germination and seedling development of Annona crassiflora were studied. Mature fruits of Annona crassiflora were depulped and the seeds washed in clear water and dried at room temperature. Seed coat was removed and the seeds were placed on Murashige & Skoog (MS medium supplemented with gibberellic acid (GA3 and naphthalene-acetic acid (NAA, 30 g L-1 sucrose and 6 g L-1 agar-agar. Seeds were kept under these conditions for 30 days. After this period, seedlings were kept for another 90 days on Wood Plant Medium (WPM with 20 g L-1 sucrose and 5 g L-1 agar-agar supplemented with the same GA3 and NAA concentrations. Cultures were incubated under controlled conditions at 25 ± 2°C temperature, 16: 8 (light: dark photoperiod of 32 µmol m-2 s-1 irradiance provided by cool white fluorescent tubes (Philips. Use of WPM medium supplemented with 25-32 mg L-1 GA3 or MS with 26-30 mg L-1 GA3 and 2 mg L-1 NAA promoted rooting and plant growth.O araticum ou marolo (Annona crassiflora Mart. é uma fruta típica de Cerrado com grande importância sócio-econômico e medicinal. Sua propagação pode ser feita através de sementes, porém devido à dormência das sementes e dificuldade de se obterem plantas uniformes e em curto espaço de tempo, a micropropagação poderá ser uma alternativa. Estudaram-se os efeitos do GA3 associado ao ANA sobre a germinação de sementes e desenvolvimento in vitro de marolo. Frutos maduros foram
Restovic, Franko; Espinoza-Corral, Roberto; Gómez, Isabel; Vicente-Carbajosa, Jesús; Jordana, Xavier
Complex II (succinate dehydrogenase) is an essential mitochondrial enzyme involved in both the tricarboxylic acid cycle and the respiratory chain. In Arabidopsis thaliana , its iron-sulfur subunit (SDH2) is encoded by three genes, one of them ( SDH2.3 ) being specifically expressed during seed maturation in the embryo. Here we show that seed SDH2.3 expression is regulated by abscisic acid (ABA) and we define the promoter region (-114 to +49) possessing all the cis -elements necessary and sufficient for high expression in seeds. This region includes between -114 and -32 three ABRE (ABA-responsive) elements and one RY-enhancer like element, and we demonstrate that these elements, although necessary, are not sufficient for seed expression, our results supporting a role for the region encoding the 5' untranslated region (+1 to +49). The SDH2.3 promoter is activated in leaf protoplasts by heterodimers between the basic leucine zipper transcription factors bZIP53 (group S1) and bZIP10 (group C) acting through the ABRE elements, and by the B3 domain transcription factor ABA insensitive 3 (ABI3). The in vivo role of bZIP53 is further supported by decreased SDH2.3 expression in a knockdown bzip53 mutant. By using the protein synthesis inhibitor cycloheximide and sdh2 mutants we have been able to conclusively show that complex II is already present in mature embryos before imbibition, and contains mainly SDH2.3 as iron-sulfur subunit. This complex plays a role during seed germination sensu-stricto since we have previously shown that seeds lacking SDH2.3 show retarded germination and now we demonstrate that low concentrations of thenoyltrifluoroacetone, a complex II inhibitor, also delay germination. Furthermore, complex II inhibitors completely block hypocotyl elongation in the dark and seedling establishment in the light, highlighting an essential role of complex II in the acquisition of photosynthetic competence and the transition from heterotrophy to autotrophy.
Mar 13, 2013 ... Effects of hydropriming on seed germination and seedling ... through stem cuttings. .... and shoot length, and seedling fresh and dry weights were .... division in all the cells of germinating seeds. .... electric field treatments.
Karungi, J.; Obua, T.; Kyamanywa, S.
The focus of this study was on nursery and field management of seed and insect vectors of viruses on hot pepper. Seedlings raised from hypochlorite-treated seeds under a net tunnel nursery were compared with seedlings raised from untreated seeds in an open nursery. The two groups of seedlings were...
Full Text Available Ruta graveolens L., também conhecida com arruda, é planta originária do sul da Europa, cultivada no Brasil e em outros países como planta medicinal, muito utilizada em rituais religiosos. Tendo em vista que a germinação constitui um fator primordial para que a semente possa gerar uma planta vigorosa e com alto potencial produtivo, o presente trabalho teve como objetivo avaliar a resposta germinativa de sementes para arruda sob condições de temperatura, luminosidade, estresse hídrico e salino e emergência de plântulas em diferentes profundidades de semeadura. Sementes de Ruta graveolens são indiferentes à luz, germinando melhor em temperatura constante de 25ºC ou alterna (20-30ºC. Os potenciais osmóticos induzidos por manitol a partir de -0,4MPa e por NaCl a partir de -0,8MPa influenciam negativamente o processo germinativo. Maiores percentuais de plântulas são obtidas quando a espécie é semeada na superfície do substrato.Ruta graveolens L., also known as rue, is from the south of Europe, cultivated in Brazil and other countries as a medicinal plant greatly used in religious rituals. Since germination is essential for the seed to generate a vigorous plant of high productive potential, this work aimed to evaluate the germinative response of rue seeds under different temperatures, luminosity conditions, and water and salt stress, besides seedling emergence at different sowing depths. Ruta graveolens L. seeds are indifferent to light, better germinating at constant temperature of 25ºC or alternated temperature (20-30ºC. The osmotic potentials induced by mannitol from -0.4MPa and by NaCl from -0.8MPa negatively influenced the germination process. Higher seedling percentages are obtained when the species is sown on the substratum surface.
Germinação de sementes e formação de mudas de Caesalpinia echinata Lam. (Pau - Brasil: efeito de sombreamento Seed germination and seedling growth of Caesalpinia echinata Lam. (Brazilwood: shading effect
Francismar Francisco Alves Aguiar
Full Text Available Caesalpinia echinata Lam. (pau-brasil é a árvore nacional do Brasil, possui grande potencial ornamental, estando atualmente em perigo de extinção devido à exploração extrativista. O objetivo deste trabalho foi avaliar a germinação das sementes de C. echinata e o crescimento de mudas sob condições de sombreamento. Os experimentos foram conduzidos na Seção de Ornamentais do IBt/SMA, São Paulo, SP. As sementes foram coletadas de frutos maduros, de árvores-matriz no arboreto experimental de C. echinata em Mogi-Guaçu, SP. Os testes de germinação foram realizados nos anos de 1999, 2000 e 2003, com quatro repetições de 25 sementes cada, sendo avaliadas a porcentagem de germinação e o índice de velocidade de emergência (IVE, submetidas a cinco níveis de sombreamento (0, 20, 40, 60 e 80%. Mudas de C. echinata com nove meses de idade foram submetidas aos mesmos tratamentos de sombreamento das sementes, sendo as variáveis analisadas altura da planta, diâmetro do colo e número de folhas. O delineamento estatístico utilizado foi o inteiramente casualizado, com quatro repetições e 24 plantas por parcela, totalizando 96 mudas por tratamento. Os resultados indicaram que a germinação e o IVE não sofreram influência dos níveis de sombreamento testados. O diâmetro do coleto das mudas a pleno sol, a 20 e 40% de sombreamento, não diferiram significativamente entre si, mas dos tratamentos de 60 e 80%.Caesalpinia echinata Lam. (Brazilwood, Brazil's national tree, has ornamental potential, and due to years of exploitation this species has been reduced on the verge of extinction. This study was aimed to evaluate seed germination and seedling growth of brazil wood under shading conditions. The experiments were conducted at the IBt/SMA Ornamental Department, São Paulo-SP. Seeds were harvested from ripe fruits, from trees of the experimental arboretum of brazilwood at Mogí-Guaçu-SP. The germination tests were carried out in 1999
Douglass F. Jacobs
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...
Boccaccini, A.; Lorrai, R.; Ruta, V.; Frey, A.; Mercey-Boutet, S.; Marion-Poll, F.; Tarkowská, Danuše; Strnad, Miroslav; Costantino, P.; Vittorioso, P.
Roč. 16, SEP 9 (2016), s. 198 ISSN 1471-2229 R&D Projects: GA MŠk LK21306; GA MŠk(CZ) LO1204; GA ČR GA14-34792S Institutional support: RVO:61389030 Keywords : DAG1 * Seed development * Chromatin remodelling Subject RIV: EF - Botanics Impact factor: 3.964, year: 2016
Full Text Available The aim of the present study was to elucidate impact of the aqueous extracts from leaves of Morus alba L. on germination, growth and photosynthetic activity of Cucumis sativus L. and Sinapis alba L. Plants were grown for 21 days at the temperature 25°C (day and 18°C (night, within 12/12 hours photoperiod, light intensity 150 μmol·m-2·s-1 and relative humidity 60-70% (day/night. Our experiments proved that allelopathic compounds in aqueous extracts of the leaves M. alba at high concentrations, reduce power and energy of germination. Biometric analysis of seedlings and adult plants grown showed that allelopathic substances have stimulating or inhibiting function depending on the stage of treatment. Moreover, they cause changes in chlorophyll contents and activity of photosystem II (PS II.
Substrate for tests of seedlings emergency and seed vigor of Erythrina velutina Willd., Fabaceae/ Substratos para testes de emergência de plântulas e vigor de sementes de Erythrina velutina Willd., Fabaceae
Edson de Almeida Cardoso
Full Text Available This research work had as objective to evaluate the effect of different substrates on emergence and seedlings development of Erythrina velutina Willd. The experiment was carried out at the greenhouse of the Laboratory of Vegetable Ecology in the Center of Agrarian Sciences - Federal University of Paraíba. The substrates evaluated were washed sand; washed sand + vermiculite in the proportions of 1:1, 3:1 and 1:3; vegetable earth, vegetable earth + washed sand in the proportions of 1:1, 3:1 and 1:3, vegetable earth + vermiculite in the proportions of 1:1, 3:1 and 1:3, vermiculite, bioclone®, bioplant® and plugmix®. The experimental design was completely randomized with fifteen treatments (substrates and four replications of 25 seeds. The effect was evaluated through percent of emergence, first count, emergence velocity index, medium time and relative frequency of emergency, length and dry mass of the root and it leaves aerial of the seedling. The substrates sand and vermiculite had the best results and are recommended for conduction of tests of emergency of mulungu seedlings.Com o objetivo de avaliar a influência de diferentes substratos na emergência e desenvolvimento de plântulas de Erythrina velutina Willd. foi conduzido um experimento em casa de vegetação pertencente ao Laboratório de Ecologia Vegetal do Centro de Ciências Agrárias da Universidade Federal da Paraíba. Foram comparados os substratos areia lavada; areia lavada + vermiculita na proporção de 1:1, 3:1 e 1:3; terra vegetal, terra vegetal + areia lavada na proporção de 1:1, 3:1 e 1:3, terra vegetal + vermiculita na proporção de 1:1, 3:1 e 1:3, vermiculita, bioclone®, bioplant® e plugmix®. O delineamento utilizado foi o inteiramente casualizado com 15 tratamentos (substratos e quatro repetições de 25 sementes. Foram avaliados os seguintes parâmetros: porcentagem de emergência, primeira contagem, índice de velocidade, tempo médio e frequência relativa de
Barnett, J. P. [Southern Forest Experiment Station, New Orleans, LA (United States); Krugman, S. L.
Loblolly pine (Pinus faeda L.) seeds were exposed to an electromagnetic radiation treatment (Energy Transfer Process@, marketed by the Energy Transfer Corporation), and the effects of the treatments on seed germination, seedling development, disease resistance, and field performance of seedlings were evaluated. None of the evaluated variables showed any improvement over untreated controls.
Full Text Available Foram plantadas separadamente, para comparação, amostras de sementes oriundas da ponta, do centro e da base de frutos de cacaueiro. Não foram notadas diferenças, quer na germinação das sementes, quer no desenvolvimento das mudas, em duas variedades estudadas.Seed samples from the top, center, and bottom of the cocoa fruit (Theobroma leiocarpa Bern. were planted separately for comparison. No difference in germination of the seeds or growth of the seedlings for the three types of samples was noticed.
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
Alexandre Bosco de Oliveira
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
Clause, J.; Forey, E.; Eisenhauer, N.; Seal, C.E.; Soudey, A.; Colville, L.; Barot, Sébastien
Aims : The passage of seeds through the earthworm gut potentially damages seeds, altering seed and seedling performances depending on seed traits. This work was conducted to study to what extent chemical and morphological seed traits determine the seed attractiveness for earthworms. Methods : We tested seed selection via the ingestion and digestion of 23 grassland plant species spanning a range of 14 morphological and chemical traits by two common earthworm species: the anecic Lumbricus te...
Dhamayanthi, K.P.M.; Reddy, V.R.K.
Seeds of chilli variety CO-2 (Coimbatore-2) were irradiated with gamma rays ranging from 10 kR to 35 kR at an interval of 5 kR and the effect on seed germination, seedling survival, percent lethality and seedling injury were studied. Lower doses were stimulative, while higher doses had inhibitory effect on seed germination and seedling survival. The highest percentage of seed germination (37.5) and seedling survival (31.3) was recorded at 10 kR as compared to 28 percent of germination and 3.3 percent seedling survival in control. Percent lethality (9.6%) and seedling injury (6.5%) were comparatively low than the lethality percentage and seedling injury of the higher dose treatments. In chemical mutagen treatments, the maximum seed germination (54.5%) and seedling survival (51.2%), seedling lethality (0.97%) and seedling injury (1.37%) were obtained in the treated seeds of EMS at 0.5% concentration followed by 39.5% seed germination and 30.0% seedling survival, seedling lethality (3.8%) and seedling injury (3.06%) of MMS. The stimulative effect of seed germination is more in chemical mutagens than the physical mutagen. There was a proportionate decrease in germination percentage and seedling survival with an increase in dose/concentration of both the chemicals. (author)
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.
Khan, M.B.; Gurchani, M.A.; Hussain, M.
Seed priming has proven beneficial in many important agricultural crops. The present study was conducted to explore the role (if any) of hormonal and vitamin seed priming to improve the germination, seedling emergence, early seedling establishment, electrolyte leakage and nutrients uptake in wheat seedlings. The wheat seeds were soaked for 48 hours in aerated solution of salicylic acid, ascorbic acid, kinetin and GA3 with 20 ppm concentration of each solution, whereas untreated seeds were taken as control. Seed priming with ascorbic acid resulted in maximum final germination and emergence percentage (FGP and FEP), radical and plumule length, root and shoot length, number of secondary roots, root shoot ratio, root dry weight, shoot dry weight and seedling dry weight compared to control (untreated seeds). Minimum mean germination and emergence time (MGT and MET) was recorded in seeds primed with kinetin and GA3. While in case of biochemical attributes, seedling potassium contents were decreased by hormonal seed priming while total soluble sugars were increased by salicylic acid and ascorbic acid seed priming. Hormonal seed priming had non-significant effect on phosphorus seedling contents. Untreated (Control) seeds showed maximum electrical conductivity at 0.5, 1, 2, 6, 12 and 24 h after inbibition than primed seeds against the minimum electrical conductivity that was recorded in seeds primed with salicylic acid and ascorbic acid. In conclusion, the wheat seeds primed with 20 ppm solution of ascorbic acid may be used for wheat seed invigoration. (author)
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.
Harold J. Derr; William F. Mann
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...
José Magno Q Luz
, with four replications of 20 seeds per plot. The use of the substrates vermiculite and rolled paper at 25ºC increased the percentage of normal seedlings and germinated seeds. The seeds germination was slower when they were placed on filter paper, and it was more asynchronous in this substrate. Additionally, the alternating temperature 20-30ºC delayed the beginning of the germination of Dorstenia cayapia seeds.
Achmad Nasroh, K.
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
Ronan Carlos Colombo
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.
Biometria de frutos e sementes e emergência de plântulas de duas espécies frutíferas do gênero Campomanesia Biometrics of fruits and seeds and seedling emergence of two species fruit of the Campomanesia genus
Michele Camargo de Oliveira
and C. pubescens, and the process of emergence of seedlings, for comparisons between species. In November 2007, 50 fruits of each species were measured of the transversal length (mm and longitudinal (mm of the fruits and seeds, fresh weight of fruits (g, number of locules per fruit and number of loci seeds. For the emergence testing, two independent experiments, one for each species, were installed in a completely randomized design with six methods of fruit processing for removal, drying or washing the mucilage, and four replicates with 40 seeds per plot. With the fruits of greater volume, with accumulation of fresh and wider biometrics in relation to C. pubescens, C. adamantium has a potential for selection of promising materials for breeding purposes. Drying in the shade for 24 hours with seed mucilage reduces the percentage of emergence and normal seedlings of C. adamantium, besides the seedlings emergence rate, although this method is indifferent to seedlings of C. pubescens. Under the same experimental conditions, seedlings of C. pubescens have a higher capacity emergence and normal seedlings as well as higher daily frequencies of seedlings emerged and reducing the time of emergence in relation to the seedlings of C. adamantium.
Full Text Available The study was conducted to evaluate the potential of different strains of plant growth-promoting rhizobacteria (PGPR to reduce the effects of salinity stress on the medicinal hopbush plant. The bacterium factor was applied at five levels (non-inoculated, inoculated by Pseudomonas putida, Azospirillum lipoferum + Pseudomonas putida, Azotobacter chroococcum + Pseudomonas putida, and Azospirillum lipoferum + Azotobacter chroococcum + Pseudomonas putida, and the salinity stress at six levels: 0, 5, 10, 15, 20, and 50 dS m-1. The results revealed that Pseudomonas putida showed maximal germination percentage and rate at 20 dS m-1 (18.33% and 0.35 seed per day, respectively. The strongest effect among the treatments was obtained with the treatment combining the given 3 bacteria at 15 dS m-1 salinity stress. This treatment increased the root fresh and dry weights by 31% and 87.5%, respectively (compared to the control. Our results indicate that these bacteria applied on hopbush affected positively both its germination and root growth. The plant compatibility with the three bacteria was found good, and the treatments combining Pseudomonas putida with the other one or two bacteria discussed in this study can be applied in nurseries in order to restore and extend the area of hopbush forests and akin dry stands.
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.
Dec 5, 2011 ... the relationship between speed of germination and seed vigor, salt stress decreased seed vigor of rice cultivars LD a superior ... Key words: Salinity, seed germination, seedling property, seed vigor. INTRODUCTION ... The salt solutions were prepared based on the methods by. (Rhoades et al., 1992) with ...
Jabeen, Nusrat; Ahmad, Rafiq
Salt tolerance is a complex trait which involves the coordinated action of many genes that perform a variety of functions, such as ion sequestration, metabolic adjustment, osmotic adjustment and antioxidative defence. In this article, the growth and the generation and scavenging of reactive oxygen species (ROS) under normal (ECiw [Electrical conductivity of irrigation water] = 0.5 dS m(-1)) and salt stress conditions (ECiw = 3.4, 6.1, 8.6 and 10.8 dS m(-1) ) in relation to the priming of seeds of the two important oil yielding crops, i.e. safflower and sunflower, with different concentrations of chitosan [0% (control), 0.25%, 0.50%, 0.75%] is discussed. Induced salinity stress significantly decreased germination percentage, germination rate, length and weight of root and shoot, and protein content. Proline content, malondialdehyde content (MDA), catalase (CAT) and peroxidase (POX) activity increased at 10.8 dS m(-1). Under control conditions there were no significant differences in germination percentage among different concentrations of chitosan, whereas CAT and POX activity were increased by low concentrations of chitosan. With increasing salt stress, low concentrations of chitosan increased germination percentage but decreased MDA and proline contents and CAT and POX activity. Generation of ROS seems to be unavoidable under normal conditions and the activity of antioxidant enzymes in plants varies in terms of ROS generation under salt stress. However, the data indicate that plants subjected to salt stress-induced oxidative stress and the low concentrations of chitosan exhibited positive effects on salt stress alleviation through the reduction of enzyme activity in both crops. © 2012 Society of Chemical Industry.
Faba Bean: Transcriptome Analysis from Etiolated Seedling and Developing Seed Coat of Key Cultivars for Synthesis of Proanthocyanidins, Phytate, Raffinose Family Oligosaccharides, Vicine, and Convicine
Full Text Available Faba bean ( L. has been little examined from a genetic or genomic perspective despite its status as an established food and forage crop with some key pharmaceutical factors such as vicine and convicine (VC, which provoke severe haemolysis in genetically susceptible humans. We developed next-generation sequencing libraries to maximize information to elucidate the VC pathway or relevant markers as well as other genes of interest for the species. One selected cultivar, A01155, lacks synthesis of the favism-provoking factors, VC, and is low in tannin, while two cultivars, SSNS-1 and CDC Fatima, are wild-type for these factors. Tissues (5- to 6-d-old root and etiolated shoot and developing seed coat were selected to maximize the utility and breadth of the gene expression profile. Approximately 1.2 × 10 expressed transcripts were sequenced and assembled into contigs. The synthetic pathways for phosphatidylinositol or phytate, the raffinose family oligosaccharides, and proanthocyanidin were examined and found to contain nearly a full complement of the synthetic genes for these pathways. A severe deficiency in anthocyanidin reductase expression was found in the low-tannin cultivar A01155. Approximately 5300 variants, including 234 variants specific to one of the three cultivars, were identified. Differences in expression and variants potentially related to VC synthesis were analyzed using strategies exploiting differences in expression between cultivars and tissues. These sequences should be of high utility for marker-assisted selection for the key traits vicine, convicine, and proanthocyanidin, and should contribute to the scant genetic maps available for this species.
Nakashima, Kazuo; Fujita, Yasunari; Katsura, Koji; Maruyama, Kyonoshin; Narusaka, Yoshihiro; Seki, Motoaki; Shinozaki, Kazuo; Yamaguchi-Shinozaki, Kazuko
ABA-responsive elements (ABREs) are cis-acting elements and basic leucine zipper (bZIP)-type ABRE-binding proteins (AREBs) are transcriptional activators that function in the expression of RD29B in vegetative tissue of Arabidopsis in response to abscisic acid (ABA) treatment. Dehydration-responsive elements (DREs) function as coupling elements of ABRE in the expression of RD29A in response to ABA. Expression analysis using abi3 and abi5 mutants showed that ABI3 and ABI5 play important roles in the expression of RD29B in seeds. Base-substitution analysis showed that two ABREs function strongly and one ABRE coupled with DRE functions weakly in the expression of RD29A in embryos. In a transient transactivation experiment, ABI3, ABI5 and AREB1 activated transcription of a GUS reporter gene driven by the RD29B promoter strongly but these proteins activated the transcription driven by the RD29A promoter weakly. In 35S::ABI3 Arabidopsis plants, the expression of RD29B was up-regulated strongly, but that of RD29A was up-regulated weakly. These results indicate that the expression of RD29B having ABREs in the promoter is up-regulated strongly by ABI3, whereas that of RD29A having one ABRE coupled with DREs in the promoter is up-regulated weakly by ABI3. We compared the expression of 7000 Arabidopsis genes in response to ABA treatment during germination and in the vegetative growth stage, and that in 35S::ABI3 plants using a full-length cDNA microarray. The expression of ABI3- and/or ABA-responsive genes and cis-elements in the promoters are discussed.
Erin K Kuprewicz
Full Text Available Scatter hoarding of seeds by animals contributes significantly to forest-level processes, including plant recruitment and forest community composition. However, the potential positive and negative effects of caching on seed survival, germination success, and seedling survival have rarely been assessed through experimental studies. Here, I tested the hypothesis that seed burial mimicking caches made by scatter hoarding Central American agoutis (Dasyprocta punctate enhances seed survival, germination, and growth by protecting seeds from seed predators and providing favorable microhabitats for germination. In a series of experiments, I used simulated agouti seed caches to assess how hoarding affects seed predation by ground-dwelling invertebrates and vertebrates for four plant species. I tracked germination and seedling growth of intact and beetle-infested seeds and, using exclosures, monitored the effects of mammals on seedling survival through time. All experiments were conducted over three years in a lowland wet forest in Costa Rica. The majority of hoarded palm seeds escaped predation by both invertebrates and vertebrates while exposed seeds suffered high levels of infestation and removal. Hoarding had no effect on infestation rates of D. panamensis, but burial negatively affected germination success by preventing endocarp dehiscence. Non-infested palm seeds had higher germination success and produced larger seedlings than infested seeds. Seedlings of A. alatum and I. deltoidea suffered high mortality by seed-eating mammals. Hoarding protected most seeds from predators and enhanced germination success (except for D. panamensis and seedling growth, although mammals killed many seedlings of two plant species; all seedling deaths were due to seed removal from the plant base. Using experimental caches, this study shows that scatter hoarding is beneficial to most seeds and may positively affect plant propagation in tropical forests, although
Hilf, Mark E
Huanglongbing is an economically damaging disease of citrus associated with infection by 'Candidatus Liberibacter asiaticus'. Transmission of the organism via infection of seeds has not been demonstrated but is a concern since some citrus varieties, particularly those used as rootstocks in commercial plantings are propagated from seed. We compared the incidence of detection of 'Ca. Liberibacter asiaticus' DNA in individual fruit peduncles, seed coats, seeds, and in germinated seedlings from 'Sanguenelli' sweet orange and 'Conners' grapefruit fruits sampled from infected trees. Using real-time quantitative PCR (qPCR) we detected pathogen DNA in nucleic acid extracts of 36 and 100% of peduncles from 'Sanguenelli' and from 'Conners' fruits, respectively. We also detected pathogen DNA in extracts of 37 and 98% of seed coats and in 1.6 and 4% of extracts from the corresponding seeds of 'Sanguenelli' and 'Conners', respectively. Small amounts of pathogen DNA were detected in 10% of 'Sanguenelli' seedlings grown in the greenhouse, but in none of 204 extracts from 'Conners' seedlings. Pathogen DNA was detected in 4.9% and in 89% of seed coats peeled from seeds of 'Sanguenelli' and 'Conners' which were germinated on agar, and in 5% of 'Sanguenelli' but in none of 164 'Conners' seedlings which grew from these seeds on agar. No pathogen DNA was detected in 'Ridge Pineapple' tissue at 3 months post-grafting onto 'Sanguenelli' seedlings, even when pathogen DNA had been detected initially in the 'Sanguenelli' seedling. Though the apparent colonization of 'Conners' seeds was more extensive and nearly uniform compared with 'Sanguenelli' seeds, no pathogen DNA was detected in 'Conners' seedlings grown from these seeds. For either variety, no association was established between the presence of pathogen DNA in fruit peduncles and seed coats and in seedlings.
ity, reflects potential seed germination, seedling growth, seed ... Keywords. recombinant inbred line population; seed vigour; quantitative trait locus analysis; cold tolerance. ..... nent youth fund of Henan province, Corn Industry Technology Sys-.
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.
Full Text Available Polyembryonic seeds are characterized by the development of over one embryo in the same seed, which can be zygotic and nucellar. The objective of this work was to identify the genetic origin, whether zygotic or nucellar, of seedlings of polyembryonic seeds of 'Ubá' mango tree using ISSR markers, and relating them with the vigor of the seedlings. Thus, mangos were harvested in Visconde do Rio Branco (accession 102 and Ubá (accessions 112, 138, 152 and 159, whose seeds were germinated in plastic trays filled with washed sand. Fifty days after sowing, seedlings from five seeds of each one of the accessions 102, 112, 138, 159 and from 10 seeds of the accession 152, were analyzed. These sseedlings were characterized and evaluated for plant height, stem circumference and mass of fresh aerial part and the most vigorous seedling was the one displaying at least two of these traits higher than the other seedlings from seed. Leaves were collected for genomic DNA extraction, which was amplified using seven ISSR primers previously selected based on the amplification profile and considering the number and resolution of fragments. Zygotic seedlings were found in 18 seeds, which were the most vigorous in six seeds. The results evidenced the existence of genetic variability in orchards using seedlings grown from seeds, because the farmer usually uses the most vigorous ones, assuming that this is of nucellar origin. These results also indicate that the most vigorous seedling are not always nucellar, inasmuch as of 20% of the total seeds evaluated, the zygotic seedling was the most vigorous.
Full Text Available Seedling emergence of an array of Campomanesia adamantium (Cambess. O. Berg, under different conditions. Campomanesia adamantium are shrubs with berries that are yellow when ripe, with sweet, aromatic and juicy pulp. The fruits are very appreciated by the Midwestern Brazilian population because, beyond the economic potential, gabirobeiras have important ecological and medicinal applications. The few reports concerning methods of C. adamantium propagation demonstrate varied responses of the germination process, and variation sometimes occurs for seeds planted under similar conditions. The objective of this study was to evaluate the inluence of different substrates and seed pulp extraction methods on seedling emergence of C. adamantium. Seeds were collected from a single individual. The experiment tested four methods of seed pulp extraction: a Control: seeds sown with pulp, b seeds whose pulp was mechanically removed by friction using fine sawdust, c seeds whose pulp was removed by washing in running water; d seeds with pulp soaked for 24 h. Four different substrates per pulp extraction type were then used for planting: 1 Vermiculite; 2 Plantmax ®; 3 Tri-Mix ®, 4 washed medium-grain sand. Sand was the substrate that produced the best result for seedling emergence, however there were no significant differences in seedling emergence between seed processing methods. The presence of seed pulp did not impact percent seedling emergence, nor did it affect average time or speed of seedling emergence.
Jul 31, 2016 ... Parameters related to seed germination and seedlings vigour was evaluated. Results indicated that substrate do not affect seed germination and plant vigour. However ..... Annual plant reviews California, USA, pp. 50-. 6.7.
Nov 16, 2016 ... investigate the effects of different priming techniques on seed germination and early seedling growth. The seeds ... methods in which the environment must be controlled for prolonged ..... Guanabara Koogan, Rio de Janeiro ...
Seed germination and seedling vigour of italian ryegrass, cocksfoot and timothy following harvest and storage Germinação de sementes e o vigor de plantas jovens de azevem italiano, dactilis e timóteo após a colheita e o armazenamento
Full Text Available During post-harvest maturation, different species vary in the length of dormancy breaking or germination increases. Seed dormancy and slow seedling development often limit establishment of forage grass stands. Seed germination and seedling vigour of Italian ryegrass (Lolium italicum A. Braun, Synonym Lolium multiflorum L., cocksfoot (Dactylis glomerata L. and timothy (Phleum pretense L. were observed after harvest and storage. After harvest in June, seeds were stored under standard storage conditions and sampled every 30 days after harvest (DAH, up to 270 DAH, and then every 60 days up to 990 DAH. At each date, seeds were tested for final germination percentage and for seedling vigour traits. Timothy seeds had a maximum germination (88% and the best seedlings vigour at 90 DAH, which implies that early autumn (September-October is the best sowing period for freshly harvested seeds of timothy. Timothy seed germination was poor from 270 DAH (73%. The best germination and vigour of Italian ryegrass and cocksfoot seedlings were between 270 and 330 DAH, which equates to spring sowing time (March-April in the succeeding year. Cocksfoot and Italian ryegrass seeds maintained satisfactory germination levels up to 630 DAH (81% and 810 DAH (81%, respectively. The data can serve for the determination of a proper storage duration management between harvest and sowing of the tested species under ambient conditions of south-eastern Europe.Durante o armazenamento, diferentes espécies comportam-se diferentemente quanto à dormência e crescimento de plântulas. A dormência o desenvolvimento lento das plântulas limitam a época do plantio das gramíneas forrageiras plurianuais. A germinação de sementes e o crescimento das plântulas de azevem italiano (Lolium italicum A. Braun sin. Lolium multiflorum L., Dactilis (Dactilis glomerata L. e de timoteo (Phleum pratense L. foi pesquisada durante a maturação pós-colheita e a silagem. Após a colheita, em junho
The following aspects of the marmeleiro, cydonia oblonga Mill., were, researched: media nad periods to supply the seed chilling requirement in moist cold storage (5-10 0 c); quince seeds viability prepared by several extraction processes; seed germination and seedling development; cytogenetic aspects; seeds viability influenced by storage conditions and periods of time for storage; preliminary determination of seed radiosensitivity; concentrations of some macro and micronutrients in quince seedlings obtained from irradiated seeds, and radiosensitivity and interphasic nuclear volumes. (MAC) [pt
Salahbiah Abdul Majid; Zaiton Ahmad; Mohd Rafaie Abdul Salam; Nurhayati Irwan; Affrida Abu Hassan; Rusli Ibrahim
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)
Alvarenga,Renata Oliveira; Marcos-Filho,Julio; Timóteo,Tathiana Silva
The assessment of physiological potential is essential in seed quality control programs. This study compared the sensitivity of different procedures for evaluating super sweet corn seed vigor, focusing on the primary root protrusion test. Six seed lots, each of the SWB 551 and SWB 585 hybrids, were used. Seed physiological potential was evaluated by germination and vigor tests (speed of germination, traditional and saturated salt accelerated aging, cold test, seedling length, seedling emergen...
Diane L. Haase
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...
Nancy L. Shaw; Emerenciana G. Hurd; Marshall R. Haferkamp
Rangeland seedings of spiny hopsage (Gruyia spinosa [Hook.] Moq.) may be made with either bracted utricles or seeds. Problems have resulted from inconsistent use of terminology describing these 2 structures and the fact their germination and seedling emergence is not the same with similar environmental conditions and seeding techniques. We examined...
The effects of factorial combinations of four storage duration (in days after seed extraction) and surface sterilization with three dilution levels of sodium hypochlorite on seedling emergence and seedling quality of African breadfruit were studied. Storage duration significantly influenced days to seedling emergence, ...
Silvana de Paula Quintão Scalon
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.
Full Text Available Seed germination is first critical and the most sensitive stage in the life cycle of plants compromise the seedlings establishment. Salt and drought tolerance testing in initial stages of plant development is of vital importance, because the seed with more rapid germination under salt or water deficit conditions may be expected to achieve a rapid seedling establishment, resulting in higher yields. The aim of this study was to determine whether the pea seed germination and seedling growth were inhibited by the salt toxicity and osmotic effect during the seedling development, and also identification of the sensitive seedling growth parameters in response to those stresses. Based on the obtained results, pea has been presented to be more tolerant to salt than water stress during germination and early embryo growth. Investigated cultivars showed greater susceptibility to both abiotic stresses when it comes growth parameters compared to seed germination. [Projekat Ministarstva nauke Republike Srbije, br. TR-31024 i br. TR-31022
The life stage from seed dispersal to seedling emergence is often critical in determining the regeneration success of plants. During this period seeds must survive an array of seed predators and pathogens and germinate under conditions favorable for seedling establishment. To maximise recruitment s...
Iraídes Fernandes Carneiro
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
The effects of commercial storage of cabbage seeds on the germination of seeds and the emergence and growth of seedlings have been studied. Progressive ageing of seeds caused loss of seed vigour which resulted in poor emergence and growth of seedlings and the formation of abnormal
Full Text Available Altogether 300 seed samples were collected during 9 years in 8 regions of Poland and the fungi Were isolated and their pathogenicity to carrot seedlings was examined. Alternaria rudicina provcd to be the most important pathogen although. A. alternata was more common. The other important pathogens were Fusarium spp., Phoma spp. and Botrytis cinerea. The infection of carrot seeds by A. radicina should be used as an important criterium in seed quality evaluation.
Yuniarti, Naning; Megawati, Megawati; Leksono, Budi
Improper seed handling of Eucalyptus pellita will reduce seed quality, so as to improve the viability of the seed proper handling techniques are needed. To investigate the seed germination potency as a result of seed handling germination seed tests are needed. The purpose of this study was to examine the effect of germination method and paper substrate on the viability of E. pellita seeds. Seeds used in this study were from seedling seed orchard in South Sumatra, South Kalimantan, and Riau. ...
Relationships between Prosopis flexuosa (Fabaceae and cattle in the Monte desert: Seeds, seedlings and saplings on cattle-use site classes Interacciones entre Prosopis flexuosa (Fabaceae y el ganado en el desierto de Monte: Semillas, plántulas y renovales en los sitios de uso del ganado
CLAUDIA M CAMPOS
Full Text Available The fate of Prosopis flexuosa seeds dispersed by cattle is dependant on the spatial pattern of dung deposition and foraging movements. We hypothesised that cattle-use site classes explain the response variables related to seed input and fate of seeds, seedlings and saplings (small plants more than one year old. We defined sites with heavy cattle traffic ("trails" and "periphery of trails", sites used for resting and foraging ("under Prosopis", and sites where isolated individuals only walk ("under shrubs" and "bare soil". Considering the established cattle-use site classes, our specific goals were to quantify and compare: (1 seeds transported in cattle dung; (2 seedlings 10 months after dung deposition; (3 established saplings; and (4 germinated and remaining seeds, and seedling survival in dung immediately after dung deposition. In a grazed field at Ñacuñán (Mendoza, Argentina we worked in four similar areas, each consisting of 25-ha plots 2 km apart. Space use by cattle caused differential seed input: "under Prosopis" and in the "periphery of trails" animals deposited the largest amounts of dung and seeds. Ten months after dung deposition, the highest number of seedlings occurred on "trails", "under Prosopis" and in the "periphery of trails". In the long term, the highest number of established saplings occurred only in the "periphery of trails". The number of seeds germinated immediately after fruit production and dung deposition was very low. Survival of seedlings sprouting from dung-germinated seeds did not exceed one week. On "trails" and in the "periphery of trails" the persistence of seeds in dung was low because of dung disintegration by the action of cattle trampling. The seeds that did not remain in dung were probably the source of seeds that will germinate in the next wet season (i.e. 10 months after dung deposition. With different effects depending on cattle site activity and on the stage of the P. flexuosa plant (seed, seedling
Relationships between fruits and seeds sizes; seed germination and early seedling growth of seedlings of 25 plant species were studied at the University of Agriculture, Umudike, Nigeria. The destruction of Nigeria rainforest without an assured method of naturally regenerating it, has contributed to some edible plant species ...
Nov 16, 2009 ... treated seeds grown under drought stress was markedly lower than the ... which persists in the seedlings to alleviate the oxidative damage, leading to .... shoots of the wheat seedlings (25 plants per treatment) were har-.
Estresse salino na germinação de sementes e desenvolvimento de plântulas de niger (Guizotia abyssinica (L.f. Cass. Salt stress on seeds germination and seedlings development of niger (Guizotia abyssinica (L.f. Cass.
Carla Regina Baptista Gordin
Full Text Available O processo de salinização dos solos e das águas subterrâneas e superficiais é um dos mais importantes problemas de degradação ambiental. O niger é uma herbácea anual com potencial para a produção de biodiesel, cujo comportamento em condições salinas ainda é desconhecido. Dessa forma, objetivou-se avaliar a germinação de sementes e crescimento de plântulas de niger submetidos a diferentes sais e concentrações. Os tratamentos utilizados corresponderam a três sais: cloreto de potássio (KCl, cloreto de cálcio (CaCl2 e cloreto de sódio (NaCl, associados a quatro potenciais osmóticos (-0,3; -0,6; -0,9 e -1,2 MPa. As sementes de niger semeadas diretamente sobre substrato umedecido com água destilada constituíram o controle. O efeito da salinidade na germinação das sementes foi avaliado pela porcentagem, tempo médio e índice de velocidade. As plântulas foram analisadas quanto ao comprimento da parte aérea e raiz e massas fresca e seca de plântulas inteiras. O delineamento estatístico adotado foi o inteiramente casualizado, constituindo-se de um fatorial 3x5 (sais x potenciais osmóticos com quatro repetições de 50 sementes cada. As sementes de niger são sensíveis a salinidade. A exposição ao NaCl, KCl e CaCl2 a partir do potencial osmótico de -0,3 MPa reduz o poder germinativo e o crescimento de plântulas. Os sais inibem a germinação de sementes do niger no potencial de -1,2 MPa.The soil, and subterranean and superficial water saltiness process is one of the most important environment degradation problems. Niger is an annual herbaceous with biodiesel production potential, which seeds behavior is unknown in saline conditions. In this way, this work aimed to evaluate the niger seeds germination and initial seedlings growth submitted to different salt solutions. The treatments used constituted of three types of salts: NaCl, KCl and CaCl2 at four osmotic potentials (-0.3; -0.6; -0.9 e -1.2 MPa. The niger seeds
Rasmussen, Hanne N; Dixon, Kingsley W; Jersáková, Jana; Těšitelová, Tamara
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
Salni Salni; Poedji Loekitowati Hariani; Hanifa Marisa Hanifa
This research studies the influence of the type of rubber seed that is superior and local, altitude plant in South Sumatra province to the characteristic of seed, oil and biodiesel (methyl ester). Rubber plants planted from local rubber seed by seeds seedlings and superior rubber seed by selected clones. In the study, rubber plants planted at a different altitude, namely in Banyuasin district (18 m above sea level), Prabumulih District (176 m above sea level) and Lahat District (627 m above s...
Salni, Salni; Hariani, Poedji Loekitowati; Hanifa, Hanifa Marisa
This research studies the influence of the type of rubber seed that is superior and local, altitude plant in South Sumatra province to the characteristic of seed, oil and biodiesel (methyl ester). Rubber plants planted from local rubber seed by seeds seedlings and superior rubber seed by selected clones. In the study, rubber plants planted at a different altitude, namely in Banyuasin district (18 m above sea level), Prabumulih District (176 m above sea level) and Lahat District (627 m above s...
Graae, Bente J; Ejrnæs, Rasmus; Lang, Simone I
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...
Influência do substrato, tamanho de sementes e maturação de frutos na formação de mudas de pitangueira Influence of the substrate, seed size and fruit maturation in the formation of cherry tree seedlings
Luis Eduardo Corrêa Antunes
design, using four replicates with 12 seeds each (Experiment 1 and three replicates of 18 seeds each (Experiment 2. The treatments of experiment 1 were the seed size (medium and small and substrate (Plantimax®, vermiculite, coconut fiber. In the second experiment the treatments were the selections of Surinam cherry (67 and 172 and fruit ripening (partially and fully mature. The parameters were evaluated: emergency percentage, shoot length and the longest root (cm, number of leaves per plant, dry mass of root and shoot (g, brocade seeds, dormant and not emerged. The seeds of medium size were higher than little seeds in all variables. The substrate Plantimax® provided greater total dry matter than the coconut fiber, but no difference from the vermiculite. The selection 172 had a higher percentage of emergency and lower dormancy than 67. Seeds from fully ripe fruits showed higher dormancy and fewer leaves than partially ripe fruit seeds. It is concluded that the use of medium size seed and the substrate Plantimax® improve seedling development of Surinam cherry. The degree of ripeness of the fruit affects the process of seeds dormancy and initial seedling of Surinam cherry.
A study was conducted to determine suitable sources of teak (Tectona grandis) seeds and methods of treating the seeds to promote higher rate of germination, with the objective to supply large quantities of seedlings for developing commercial teak plantations in Ghana. The field work involved seed collection, seed pericarp ...
The initial size of conifer seedlings is closely related to seed size (Hadders 1963), and seed size is a maternal characteristic that is highly subject to environmental modification (Mergen et al. 1964; Righter 1945). The effect of seed weight must be accounted for in critical studies of seedlings which attempt to attribute differences in growth to specific genetic or...
Abstract. To explore the effect of space flight factors on the early development of alfalfa seedling, dry seeds were placed onboard a satellite for a 15-day flight. After retrieval, the ultra structure of seed coat and the chemical content of seed were tested, followed by tests for germinate ability, seedling growth, and mitotic and ...
H Tavakoli Kakhki
Full Text Available Abstract Germination and beneficial seedling establishment is affected by different seed vigor indices. In order to study the effect of seed size on seed vigor indices of wheat, a factorial experiment with two factors was conducted in a completely randomized design with four replications at the Agricultural Natural Resources Research Center Lab of Khorasan Razavi. The first factor was thirteen genotypes of wheat in three types of growth, containing winter, facultative and spring and the second factor was seed size in four levels including 3, 2.5, 2 and 1.5 millimeter. Germination percentage, germination rate, shoots and root length, seedling growth rate and shoot:root length ratio characteristics were investigated. Analysis of variance showed that the effect of wheat cultivars and seed size on traits was significant (p≤ 0.01 but interaction effect of seed size and wheat cultivar was significant (p≤ 0.01 only for shoot and root length, seedling growth rate and shoot:root length ratio. The highest and lowest seedling growth rate was (15.85 and 8.23 mg dry weight/germinal seedling that they were related to 3 and 1.5mm seed size, respectively. According to these observations the most and least percentage and germination rate was related to these seed size treatments. Correlation coefficient of seed size and seedling growth rate was highly significant (r=0.85 p≤ 0.01. Stepwise regression method indicated that the seed size (x1 and shoot length (x2 as independent variables could be described (r2=0.84 seedling growth rate as a dependent variable in y= -5.000955+(5.128078x1+(0.78494x2 equation. Keywords: Seedling growth rate, Germination rate, Correlation, Regression
Seedling length test in the evaluation of the physiological quality of Erythrina velutina Willd seeds / Teste de comprimento de plântula na avaliação da qualidade fisiológica de sementes de Erythrina velutina Willd
Cosmo Rufino de Lima
Full Text Available Amongst the vigor tests, the test of length of seedlings has potential to give complementary informations to the germination test and makes possible to estimate the potential of emergence of seedlings in the field. The aim of this research work was to inquire the possibility of use of the length of seedlings test as a method of vigor to classify lots of seeds of Erythrina velutina. The physiological quality of five lots of E. velutina was evaluated by tests of viability and vigor, developed in laboratory and field. The length of the root of seedlings of E. velutina was more sensible to differentiate lots than the traditional methods. The length of seedlins, or its parts, distinguished the five lots from seeds only when its average results were divided by the number of seeds in test, showing to be the most efficient form to classify lots of high quality and with subtle differences of vigor.Dentre os testes de vigor, o teste de comprimento de plântulas tem potencial para fornecer informações complementares às obtidas no teste de germinação e que possibilitem estimar o potencial de emergência de plântulas em campo. Deste modo, objetivou-se averiguar a possibilidade de utilização do teste de comprimento de plântulas como um método de vigor para classificar lotes de sementes de Erythrina velutina. A qualidade fisiológica de cinco lotes de E. velutina foi avaliada por testes de viabilidade e vigor, desenvolvidos em laboratório e campo. O comprimento da raiz das plântulas de E. velutina foi mais sensível para diferenciar lotes do que os métodos tradicionais. O comprimento de plântulas, ou de suas partes, distinguiu os cinco lotes de sementes somente quando seus resultados médios foram divididos pelo número de sementes em teste, mostrando ser a forma mais eficaz para classificar lotes de alta qualidade e com diferenças sutis de vigor.
Correlação entre testes para avaliação da qualidade de sementes de girassol e emergência das plântulas em campo Correlation between sunflower seeds quality evaluation tests and seedling emergence in field
Madelon Rodrigues Sá Braz
Full Text Available A capacidade do teste de germinação para estimar o potencial de emergência de plântulas no campo diminui à medida que as condições do ambiente são desfavoráveis. No entanto, diferentes testes de vigor têm sido utilizados para identificar os lotes de sementes que apresentam melhor desempenho nessas situações. O objetivo do trabalho foi correlacionar os resultados dos testes conduzidos no laboratório com a emergência das plântulas de girassol em campo. Para isso, cinco lotes de sementes de girassol da cultivar 'Embrapa 122 V2000' foram submetidos aos testes de germinação e vigor (primeira contagem, classificação de plântulas, teste de frio, condutividade elétrica, emergência de plântulas em areia e em campo, índice de velocidade de emergência, envelhecimento acelerado e deterioração controlada. Em condições adversas, a emergência das plântulas de girassol em campo apresentou maior correlação com o vigor, avaliado pelos testes de envelhecimento acelerado, de deterioração controlada e de condutividade elétrica.The germination capacity test to estimate the potential of seedlings emergence in the field decreases when the environmental conditions are unfavorable. However, different vigour tests have been used to identify the seed lots that have better perform in these situations. The objective of this research was to correlate the results of tests conducted in the laboratory with the emergence of sunflower seedlings in the field. For this, five lots of seeds sunflower cultivar 'Embrapa 122 V2000' were submitted to the germination and vigour tests (first count, classification of seedlings, cold test, electrical conductivity, seedling emergence in sand and in the field, emergence speed index, accelerated aging and controlled deterioration. Under adverse conditions, the seed vigour evaluated by accelerated aging, controlled deterioration and electrical conductivity presented higher correlation with sunflower plant
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
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
Full Text Available Over 10% ofseeds harvested in 1991 and 1992 (50 samples, 400 seeds in each sample proved to be infested with various fungi. Fusarium spp. and Botrytis cinerea were the most common pathogens isolated. Fusarium avenaceum was the most common and highIy pathogenic species. Fusarium semitectum and F. tricinctum were highly pathogenic to lupin seedlings but they were the least common Fusarium isolated from seeds. Similarily, Sclerotinia sclerotiorum was isolated only from 0,2% seeds tested but this fungus was highly pathogenic to lupin seedlings. Some other fungi know as lupin pathogens (F. oxysporum, Stemphylium botryosum, Pleiochaeta setosa and Phomopsis leptostromiformis were also noted in tested seeds.
Nancy L. Shaw; Marshall R. Haferkamp; Emerenciana G. Hurd
Reestablishment of spiny hopsrge (Grayia spinosa [Hook.] Moq.) in the shrub steppe requires development of appropriate seeding technology. We examined the effect of planting date and seedbed environment on germination and seedling establishment of 2 seed sources at 2 southwestern Idaho sites. Seedbeds were prepared by rototilling. In 1987-88, seeds...
Cao, Dechang; Baskin, Carol C.; Baskin, Jerry M.; Yang, Fan; Huang, Zhenying
Background and Aims Differences in dormancy and germination requirements have been documented in heteromorphic seeds of many species, but it is unknown how this difference contributes to maintenance and regeneration of populations. The primary aim of this study was to compare the seed bank dynamics, including dormancy cycling, of the two seed morphs (black and brown) of the cold desert halophyte Suaeda corniculata and, if differences were found, to determine their influence on regeneration of the species. Method Seeds of the two seed morphs were buried, exhumed and tested monthly for 24 months over a range of temperatures and salinities, and germination recovery and viability were determined after exposure to salinity and water stress. Seedling emergence and dynamics of the soil seed bank were also investigated for the two morphs. Key Results Black seeds had an annual dormancy/non-dormancy cycle, while brown seeds, which were non-dormant at maturity, remained non-dormant. Black seeds also exhibited an annual cycle in sensitivity of germination to salinity. Seedlings derived from black seeds emerged in July and August and those from brown seeds in May. Seedlings were recruited from 2·6 % of the black seeds and from 2·8 % of the brown seeds in the soil, and only 0·5 % and 0·4 % of the total number of black and brown seeds in the soil, respectively, gave rise to seedlings that survived to produce seeds. Salinity and water stress induced dormancy in black seeds and decreased viability of brown seeds. Brown seeds formed only a transient soil seed bank and black seeds a persistent seed bank. Conclusions The presence of a dormancy cycle in black but not in brown seeds of S. corniculata and differences in germination requirements of the two morphs cause them to differ in their germination dynamics. The study contributes to our limited knowledge of dormancy cycling and seed bank formation in species producing heteromorphic seeds. PMID:22975287
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...
José Luís de Marchi
Full Text Available ABSTRACT Seed vigor has traditionally been evaluated by physiological, biochemical and stress tolerance tests. More recently, with the use of computerized image analysis, objective information has become accessible in a relatively short period of time, with less human interference. The aim of this study was to verify the efficiency of computerized seedling image analysis by Seed Vigor Imaging System (SVIS® to detect differences in vigor between carrot (Daucus carota L. seed lots as compared to those provided by traditional vigor tests. Seeds from seven lots from the Brasilia cultivar were subjected to a germination test, first count of germination, speed of germination, accelerated aging with saline solution and seedling emergence; furthermore, a vigor index, growth index and uniformity index were determined by the Seed Vigor Imaging System (SVIS® during four evaluation periods. The results obtained by the computerized seedling analysis (vigor index and growth index show that SVIS® is efficient in assessing carrot seed vigor.
Camila Santos Barros de Morais
Full Text Available The aim of this study was to evaluate the effect of seeds osmotic conditioning in seedlings emergence and plants performance of sunflower. Three lots of seeds sunflower (Catissol, was submited to osmotic conditioning with polyethylene glycol solution, –2,0 MPa in aerated system, under 15 ºC for 8 hour and then was evaluated for germination tests and vigour. Under filed conditions was conducted emergency evaluations of seedling, plants development as well as the productivity and seeds quality, and the accumulation of nutrients in the seeds. The osmotic conditioning improve the survival of seedling, the dry matter mass to aerial part of plants from 60 days after sowing and oil content, in lots with low seeds physiological quality. The osmotic conditioning not increase the seeds yield but promotes the vigour of seeds produced, regardless of the lot used for sowing seeds.
Seed characteristics are important for seed dispersal, seedling growth, and seedling survival, but there is little information on seed characteristics for several taxa of the tribe Cynareae (Family: Asteraceae). We determined seed characteristics and their variation from natural populations of twen...
Maasoumeh Asadi Aghbolaghi
Full Text Available The objective of this research was to evaluate the effect of seed priming with osmo and hormone priming on growth and seed reserve utilization of millet seeds under drought stress. Treatments were combinations of 4 levels of drought stress (0, -4, -8 and -12 bar and 3 levels of seed priming and control with 3 replications. Results showed that with increase in drought stress, germination components such as germination percentage, germination index, mean time to germination, normal seedling percentage, seedling length, seedling dry weight, weight of utilized (mobilized seed and seed reserve utilization efficiency decreased, but seed priming showed lower reduction. The highest germination characteristics and seed reserve utilization was obtained by priming in control conditions. It is concluded that priming results in improvement in germination components of millet in drought stress conditions.
Full Text Available The objective of this study was to study the seed quality aspects of wheat (Triticum aestivum L. and the extent of weed seed contamination present in wheat seeds produced in different regions of Iran. Four districts (cities, each including 12 fields (six certified seed fields and six farm-saved seed fields, were selected in each regions (provinces. One kilogram of the wheat seed sample was collected from each field for analysis in the laboratory. Wheat seeding was commonly done by farm-saved seed sourced from within the farm due to the high costs of certified seeds purchased from outside sources, followed by the low seed quality. The use of a farm-saved seed resulted in a higher germination rate and a lower mean time to germination compared with another system. The more positive temperatures experienced by mother plants could decrease the number of normal seedling and seedling length vigor index. Generally there was virtually no difference about physiological quality between certified seed and farm-saved seed sector that is related to lower quality of certified seed. The certified produced seeds had the lower number of weed seed, species and genus before and after cleaning. The highest seed purity and 1000 seed weight was obtained from the certified seed production system. The need for cleaning the farm-saved seed samples before sowing is one of the important findings of this survey.
Dana Madsen Schulze; John L. Walker; Timothy P. Spira
Macbridea alba (Lamiaceae) is a Federally threatened plant endemic to Florida. Seedlings are rarely observed in natural populations, but seed production has been documented. We assessed the germinability of dry-stored seeds and of experimentally buried seeds, and sampled soil to detect a persistent seed bank.More than 20% of recorded seeds...
Yildirim, E.; Karlidag, H.
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)
Full Text Available The acid phosphatase and hemagglutinating activities of four species of Cucurbitaceae were determined during seeds germination and seedlings development. In all cases traces of enzyme and hemagglutinating activities were found in dry and imbibided seeds. In developing seedlings of Cucumis sativus the activities increased to maximum on the 3rd day while in other species on the 6th day of germination and than fell down. Dot blot and Western blot techniques have shown that in seeds and seedlings of all investigated species present were proteins which cross-reacted with antibodies raised against lectins: CLBa and Con A. It has been shown that proteins from seeds and seedlings of Cucurbita maxima var. bambino, Cucurbita pepo var. giromontia and Cucumis sativus had more pronounced antigenical similarity to lectin CLBa (from Cucurbitaceae than Con A, while proteins from cotyledons of Cucurbita pepo var. patissonina reacted better with antibodies raised against Con A (the lectin from Papilionaceae than with CLBa.
Vissoh, Pierre V.; Tossou, Rigobert C.; Akpo, Essegbemon; Kossou, Dansou; Jiggins, Janice
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
S. A. Lay; M. A. Remaley; S. E. Schlarbaum; P. P. Kormanik; T. Tibbs; R. A. Cox; T. LaFarge; A. M. Saxton
Artificial regeneration of northern red oak (Quercus rubra L.) has had variable success over time. Current nursery practices generally involve the growth of seedlings to a standardized height and form with little regard to seed source, seedling quality, or subsequent field performance. Additionally, there is not an accepted culling criteria for...
Potencial alelopático de Tropaeolum majus L. na germinação e crescimento inicial de plântulas de picão-preto Allelophaty potential of Tropaeolum majus L on picão-preto seeds germination and initial seedling growth
Anelise Samara Nazari Formagio
Full Text Available Objetivou-se com este estudo avaliar o potencial alelopático de extratos metanólicos de folhas, flores e raízes de capuchinha (Tropaeolum majus L. sobre a germinação de sementes e o crescimento inicial de plântulas de picão-preto. O extrato metanólico com melhor potencial de inibição foi submetido a particionamento, resultando nas frações hexânica, clorofórmica, acetato de etila e hidrometanólica e posterior caracterização pelo espectro de absorção na região do infravermelho (IV. O efeito alelopático foi avaliado sobre as sementes de picão-preto, as quais foram distribuídas sobre papel germitest umedecido com 2mL dos extratos e mantidas em germinador do tipo B.O.D. regulado a temperatura de 25°C e luz branca constante, sendo que as sementes imersas diretamente em água constituíram o tratamento controle. A avaliação da qualidade da semente foi realizada pelos testes de germinação e vigor (primeira contagem e comprimento de raiz primária e de hipocótilo das plântulas, em delineamento inteiramente ao acaso. O potencial alelopático das folhas de capuchinha foi maior em relação às demais partes da planta sobre a germinação das sementes, comprimento de hipocótilo e de raiz das plântulas de picão-preto. Estes efeitos podem estar associados à presença de grupos químicos polares, pois à medida que se aumentou a polaridade dos solventes detectou-se maior efeito inibitório sobre a germinação e o crescimento inicial de plântulas de picão-preto.This research aimed to evaluate the metanolic extracts allelopathic potential from leaves, flowers and roots of capuchinha (Tropaeolum majus L. on picão-preto seeds germination and initial seedling growth. The best inhibitor metanolic extract was fractioned, in hexanic, cloroformic, etil acetate and hidrometanolic fractions and it was characterized through absorption spectrum using mid-infrared. To evaluate the allelopathic effect of metanolic extracts and the
Caglar, S; Akgun, A
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.
The association of yogurt starters with Lactobacillus casei DN 114.001 in fermented milk alters the composition and metabolism of intestinal microflora in germ-free rats and in human flora-associated rats.
Djouzi, Z; Andrieux, C; Degivry, M C; Bouley, C; Szylit, O
The aim of this study was to compare the effects of milk and of various fermented milks on the composition and metabolic activities of the intestinal microflora. Groups of eight rats were fed for 6 wk a diet containing 30% nonfermented milk (M), yogurt (Y), milk fermented with Lactobacillus casei (LcFM) or milk fermented with the association of L. casei DN 114.001 and yogurt starters (LcYFM). In the first study, the survival of the lactic acid bacteria from the fermented milks was assessed by bacterial enumeration in feces of germ-free rats (GF rats) fed milk or fermented milks. The metabolic activities of the lactic acid bacteria were studied in these rats by the measurement of glycolytic activities and products of bacterial fermentation, i.e., acetate and lactate (isoforms L and D). In a second study, the effects of fermented milks on the composition and metabolism [gas, glycolytic activities, short-chain fatty acids (SCFA), alcohol and ammonia] of human flora were studied using human flora-associated rats (HF rats). In GF rats, the survival of L. casei in the feces did not differ between those fed the LcFM and LcYFM diets. L. bulgaricus was detected in the feces of the rats fed Y, whereas Streptoccus thermophilus was found in the feces of the LcYFM group. In HF rats, fecal concentration of Bifidobacteria was greater in the LcFM group than in the others. beta-Glucuronidase (EC 22.214.171.124) activity was lower in rats fed LcFM and Y than in those fed M and LcYFM, whereas beta-galactosidase (126.96.36.199), alpha-glucosidase (EC 3.2.1 20) and beta-glucosidase (EC 188.8.131.52) activities were higher in the LcYFM group compared with the others. Methane excretion was higher in rats fed Y than in other groups. Cecal SCFA concentrations did not differ in LcFM, Y and M groups, but total SCFA, acetate, propionate and butyrate were significantly greater in the LcYFM group. These results suggest that milk fermented with the combination of L. casei and yogurt starters leads to specific
Tyagi, K.; Park, M.R.; Lee, H.J.; Lee, C.A.; Rehman, S.; Steffenson, B.; Lee, K.J.; Yun, S.J.
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)
Gray John C
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.
Fernanda Aparecida Rodrigues Guimarães
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.
Far red treatment of aged achenes of lettuce (Lactuca sativa L.) during 4 days after inhibition usually reduced the percentage of seedlings with developmental abnormities. This effect was retained also in redried seeds. The field test yielded a greater number of plants emerging from treated than from control seeds. The results are similar to seed invigoration by other factors inhibiting an immediate germination of imbibed seeds
Biorregulador e pré-condicionamento osmótico na germinação de sementes e no crescimento inicial da muda de carobinha (Jacaranda decurrens subsp. symmetrifoliolata Farias & Proença - Bignoniaceae Bioregulator and priming on seed germination and initial growth of "carobinha" (Jacaranda decurrens subsp. symmetrifoliolata Farias & Proença - Bignoniaceae seedlings
ão interferiram na vitalidade e no vigor das sementes osmocondicionadas por até 12 horas. Não houve diferença entre as temperaturas de 10 e 20ºC para germinabilidade (60 % e IVG, porém a temperatura de 10ºC originou plântulas com maior massa fresca (95,7 mg e comprimento médio de raiz (3,2 cm e de parte aérea (2,6 cm. O osmocondicionamento por 24 horas causou redução na qualidade das sementes e vigor das plântulas.The aim of this work was to evaluate the effect of pregerminative treatments on the emergence and initial growth of Jacaranda decurrens subsp. symmetrifoliolata Farias & Proença seedlings. Two experiments were carried out. In the first experiment, seeds were separated into light and dark seeds and were subjected to the following pregerminative treatments: 1 KNO3 (20000 mg L-1; 2 Gibberellic acid (GA3 50 mg L-1, 3 GA3 100 mg L-1 4 GA3 200 mg L-1; 5 Stimulate 5 mL 0.5 kg-1 seeds; 6 Stimulate 10 mL 0.5 kg-1 seeds; 7 Water 24h; and 8 Control. The sowing was performed on polystyrene trays filled with land + commercial substrate. The five best treatments were selected to evaluate seedling growth. Plants aged 120 days from treatments 3, 4, 5, 6 and 8 were transplanted to plastic bags (3kg filled with land + sand + poultry manure (1:1:1 - v:v, kept under 50% shading and evaluated at 70, 130, 170 and 210 days after transplanting. In general, light seeds had higher germinability and germination speed index (GSI than the dark ones. However, the plants obtained from these seeds had lower growth than plants from dark seeds. In the second experiment, seeds were primed in the solutions: 1 PEG 6000 (-1.0 MPa; 2 PEG 6000 (-1.0 MPa + KNO3 (20000 mg L-1 (-1.0 MPa; 3 KNO3 (20000 mg L-1 (-1.0 MPa; 4 Water; and 5 Deionized water, and incubated in a BOD chamber at 10 and 20ºC for 0 (control, 6, 12 and 24h. Then, seeds were dried at room temperature until reaching the matter presented before priming and incubated in a BOD chamber at 20-30ºC with 8h dark - 12h light. The
Dall'Orto, F.A.C.; Ojima, M.; Hiroce, R.; Igue, T.; Ferraz, E.S.B.; Nascimento Filho, V.F. do; Menten, J.O.M.; Tulmann Neto, A.; Ando, A.
The investigation with quince seeds (Cydonia oblonga Mill.) radiosensitivity and the mineral composition of the plants obtained for mutation breeding are related. The concentration of some macro and micronutrients in quince seedlings obtained from irradiated seeds are studied. (M.A.C.) [pt
Adriana Luiza Wain-Tassi
Full Text Available Adequate procedures to evaluate seed vigor are important. Regarding the electrical conductivity test (EC, the interference in the test results caused by seed-borne pathogens has not been clarified. This research was carried out to study the influence of Phomopsis sojae (Leh. and Colletotrichum dematium (Pers. ex Fr. Grove var. truncata (Schw. Arx. fungi on EC results. Soybean seeds (Glycine max L. were inoculated with those fungi using potato, agar and dextrose (PDA medium with manitol (-1.0 MPa and incubated for 20 h at 25 °C. The colony diameter, index of mycelial growth, seed water content, occurrence of seed-borne pathogens, physiological potential of the seeds, measured by germination and vigor tests (seed germination index, cold test, accelerated aging and electrical conductivity, and seedling field emergence were determined. The contents of K+, Ca2+, and Mg2+ in the seed and in the soaking solution were also determined. A complete 2 × 4 factorial design with two seed sizes (5.5 and 6.5 mm and four treatments (control, seeds incubated without fungi, seeds incubated with Phomopsis and seeds incubated with Colletotrichum were used with eight (5.5 mm large seeds and six (6.5 mm large seeds replications. All seeds submitted to PDA medium had their germination reduced in comparison to the control seeds. This reduction was also observed when seed vigor and leached ions were considered. The presence of Phomopsis sojae fungus in soybean seed samples submitted to the EC test may be the cause of misleading results.
DeFalco, Lesley A.; Esque, Todd C.; Nicklas, Melissa B.; Kane, Jeffrey M.
Revegetation of degraded arid lands often involves supplementing impoverished seed banks and improving the seedbed, yet these approaches frequently fail. To understand these failures, we tracked the fates of seeds for six shrub species that were broadcast across two contrasting surface disturbances common to the Mojave Desert—sites compacted by concentrated vehicle use and trenched sites where topsoil and subsurface soils were mixed. We evaluated seedbed treatments that enhance soil-seed contact (tackifier) and create surface roughness while reducing soil bulk density (harrowing). We also explored whether seed harvesting by granivores and seedling suppression by non-native annuals influence the success of broadcast seeding in revegetating degraded shrublands. Ten weeks after treatments, seeds readily moved off of experimental plots in untreated compacted sites, but seed movements were reduced 32% by tackifier and 55% through harrowing. Harrowing promoted seedling emergence in compacted sites, particularly for the early-colonizing species Encelia farinosa, but tackifier was largely ineffective. The inherent surface roughness of trenched sites retained three times the number of seeds than compacted sites, but soil mixing during trench development likely altered the suitability of the seedbed thus resulting in poor seedling emergence. Non-native annuals had little influence on seed fates during our study. In contrast, the prevalence of harvester ants increased seed removal on compacted sites, whereas rodent activity influenced removal on trenched sites. Future success of broadcast seeding in arid lands depends on evaluating disturbance characteristics prior to seeding and selecting appropriate species and seasons for application.
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.
Costa,Denis Santiago da; Bonassa,Nathalie; Novembre,Ana Dionisia da Luz Coelho
Priming is a technique applicable to seeds of various plant species; however, for soybean seed there is little available information correlating such technique to the storage fungi. The objective of this study was to assess hydropriming on soybeans seeds and correlate this technique to occurrence of such fungi. For this, soon after acquisition the soybean seeds, cv. M-SOY 7908 RR, were characterized by: moisture content, mechanical damage, viability (seed germination and seedling emergence) a...
Nov 13, 2013 ... As a result, fresh and dry weights of shoot and root were improved. Seed priming alleviated the inhibitory effect of salt stress on germination and seedling growth of maize under salt stress. ... Salinization is more spreading in irrigated lands because of inappropriate management of irrigation and drainage.
Michael P. Walsh; Jerry Van Sambeek; Mark Coggeshall; David. Gwaze
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...
Yulan Xu; Nianhui Cai; Bin He; Ruili Zhang; Wei Zhao; Jianfeng Mao; Anan Duan; Yue Li; Keith Woeste
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...
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 ...
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 ...
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 ...
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.
Seeds of watermelon [Citrullus lanatus (Thunb.) Matsum and Nakai, cv. Crimson Sweet] were used to investigate the effects of different priming techniques on seed germination and early seedling growth. The seeds were soaked in solutions of 0.2% gibberellin (50 mg L–1 gibberellic acid), 0.2% cytokinin (90 mg L–1 kinetin) ...
Raz, V.; Bergervoet, J.H.W.; Koornneef, M.
The continuous growth of the plant embryo is interrupted during the seed maturation processes which results in a dormant seed. The embryo continues development after germination when it grows into a seedling. The embryo growth phase starts after morphogenesis and ends when the embryo fills the seed
Reproduction is a critical time in plant life history. Therefore, genes affecting seed dormancy and germination are among those under strongest selection in natural plant populations. Germination terminates seed dispersal and thus influences the location and timing of plant growth. After seed shedding, germination can be prevented by a property known as seed dormancy. In practise, seeds are rarely either dormant or non-dormant, but seeds whose dormancy-inducing pathways are activated to higher levels will germinate in an ever-narrower range of environments. Thus, measurements of dormancy must always be accompanied by analysis of environmental contexts in which phenotypes or behaviours are described. At its simplest, dormancy can be imposed by the formation of a simple physical barrier around the seed through which gas exchange and the passage of water are prevented. Seeds featuring this so-called 'physical dormancy' often require either scarification or passage through an animal gut (replete with its associated digestive enzymes) to disrupt the barrier and permit germination. In other types of seeds with 'morphological dormancy' the embryo remains under-developed at maturity and a dormant phase exists as the embryo continues its growth post-shedding, eventually breaking through the surrounding tissues. By far, the majority of seeds exhibit 'physiological dormancy' - a quiescence program initiated by either the embryo or the surrounding endosperm tissues. Physiological dormancy uses germination-inhibiting hormones to prevent germination in the absence of the specific environmental triggers that promote germination. During and after germination, early seedling growth is supported by catabolism of stored reserves of protein, oil or starch accumulated during seed maturation. These reserves support cell expansion, chloroplast development and root growth until photoauxotrophic growth can be resumed. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.
Xu, Jin; Zhang, Ying; Cui, Guang-Lin; She, Yue-Hui; Li, Long-Yun
In order to improve reproductive efficiency and quality standard, the influence factors of seed germination and seeding growth of Lonicera macranthoides werew studied. The fruit and seed morphological characteristics of L. macranthoides were observed, the seed water absorbing capacity was determined, and different wet sand stratification time, temperature and germination bed treatment were set up. The effects of the parameters on seed germination and seedling growth were analysed. There was no obstacles of water absorption on L. macranthoides seed, quantity for 22 h water absorption was close to saturation. In the first 80 d, with the increase of the stratification time, seed initial germination time was shortened, germination rate and germination potential was improved. Stratification for 100 d, germination rate decreased. At 15 ℃, seed germination and seedling growth indicators were the best. The seedling cotyledon width in light was significantly higher than that in dark. Seeds on the top of paper and top of sand germination rate, germination potential, and germination index was significantly higher than that of other germination bed and mildew rate is low. The optimal conditions of seeds germination test was stratified in 4 ℃ wet sand for 80 d, 15 ℃ illuminate culture on the top of paper or top of sand. The first seeding counting time was the 4th day after beginning the test, the final time was the 23th day. The germination potential statistical time was the 13th day after beginning the test. Copyright© by the Chinese Pharmaceutical Association.
Tingstad, Lise; Olsen, Siri Lie; Klanderud, Kari; Vandvik, Vigdis; Ohlson, Mikael
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.
Li Xiufen; Wu Fulan; Zhang Deshun; Meng Zhennong; Cao Jiyun
The seeds of Hibiscus syria cus were irradiated by 60 Co γ-rays at dose rate of 50 ∼ 500Gy/h for 0.5 and 1h, the seed germination rate and the seedling growth characters were surveyed. The results indicated that the seed germination was promoted when the absorbed dose was below 200Gy, and the seedling survival rate was increased when the dose was below 100Gy. The germination was inhibited, leaves and secondary roots were difficult to form, and the seedlings blasting occurred when the dose was over 200Gy. The dose rate affects the irradiation results. Absorbed dosed of 50 ∼ 100Gy were suggested for increasing seedling growth rate and 100 ∼ 200Gy were recommend for mutagenesis. (authors)
Cíntia L. M. de Souza
Full Text Available ABSTRACT Physalis peruviana belongs to Solanaceae family and has a high nutritional and nutraceutical potential. The production is intended for fruit consumption and the propagation is mainly by seeds. This study aimed to evaluate the influence of priming on the kinetics of germination of P. peruviana seeds stored at different temperatures. The seeds were stored at 5 and 25 °C in a chamber saturated with zinc chloride solution and in liquid nitrogen (-196 °C. Every 4 months, the seeds were removed from storage for evaluation of germination and moisture content in the laboratory and emergence and development of seedlings in greenhouse. During the last evaluation at 16 months, the seeds under the same conditions were subjected to salt stress. The moisture content varied during the storage period, but was always higher for seeds kept at -196 ºC. These seeds kept high germination percentage in water until 16 months, regardless of the tested temperature; however, in salt solution the germination percentage was significantly reduced.
The experiments were carried out to evaluate the comparative study for salt stress among seed, root stock and direct regenerated violet (Viola odorata L.) seedlings. Violet seedlings propagated through tissue culture (direct regeneration) had significantly higher salicylic acid (SA) concentrations from seed and rootstock ...
Hautier, Yann; Saner, Philippe; Philipson, Christopher; Bagchi, Robert; Ong, Robert C; Hector, Andy
The Janzen-Connell hypothesis proposes that seed and seedling enemies play a major role in maintaining high levels of tree diversity in tropical forests. However, human disturbance may alter guilds of seed predators including their body size distribution. These changes have the potential to affect seedling survival in logged forest and may alter forest composition and diversity. We manipulated seed density in plots beneath con- and heterospecific adult trees within a logged forest and excluded vertebrate predators of different body sizes using cages. We show that small and large-bodied predators differed in their effect on con- and heterospecific seedling mortality. In combination small and large-bodied predators dramatically decreased both con- and heterospecific seedling survival. In contrast, when larger-bodied predators were excluded small-bodied predators reduced conspecific seed survival leaving seeds coming from the distant tree of a different species. Our results suggest that seed survival is affected differently by vertebrate predators according to their body size. Therefore, changes in the body size structure of the seed predator community in logged forests may change patterns of seed mortality and potentially affect recruitment and community composition.
JanaLynn Franke; Brad Geary; Susan E. Meyer
The genus Fusarium has a wide host range and causes many different forms of plant disease. These include seed rot and seedling blight diseases of cultivated plants. The diseases caused by Fusarium on wild plants are less well-known. In this study, we examined disease development caused by Fusarium sp. n on nondormant seeds of the important rangeland weed Bromus...
Eficiência de Inseticidas no Controle de Pragas em Sementes e Mudas de Pau-rosa (Aniba rosaeodora Ducke, em Viveiros, Manaus, Amazonas Inseticides efficiency on pest control of rosewood (Aniba rosaeodora Ducke seeds and seedling in greenhouse, Manaus, Amazonas
José Wellington Morais
Full Text Available O pau-rosa (Aniba rosaeodora é conhecido pela presença do álcool linalol, que fornece um odor forte e perfumado em todas as partes da planta. A sua exploração na Amazônia ao longo dos últimos anos, para utilização do linalol como fixador de perfumes, coloca o pau-rosa em risco de extinção, a sua frutificação irregular aumenta a dificuldade em se obter sementes para a produção de mudas e, além disso, parte de sua produção é perdida face ao ataque de pragas nas sementes. Em razão desses fatores o presente estudo teve como objetivo realizar a aplicação de inseticidas nas sementes e mudas em viveiro a fim de evitar ou minimizar o ataque de pragas, aumentando, assim, a produção de mudas. Utilizou-se um total de 300 sementes, distribuídas em 2 tratamentos e 1 testemunha. Cada tratamento (n = 100 foi constituído por 4 repetições (bandejas com 25 sementes. O inseticida utilizado nos tratamentos foi acetamiprid e fipronil nas concentrações de 0,09 mg/planta e 0,18 mg/planta, respectivamente, para o tratamento 1 (T1 e o tratamento 2 (T2, distribuídos na forma de sachês. O T1 recebeu a aplicação de 1 sachê e o T2 a aplicação de dois sachês, enterrados com areia lavada nas sementeiras. Para avaliar os resultados foi feita uma análise de Variância (ANOVA, usando o programa Systat 9 e as médias comparadas pelo teste de Tukey em nível de 5%. As taxas de germinação foram: testemunha com 62%; T1 com 73% e T2 com 79%. Houve ataque de insetos em sementes apenas na testemunha com 23% do total (n = 100 e os resultados foram estatisticamente significativos (F = 31,263; p The rosewood tree (Aniba rosaeodora Ducke is known for its linalool which provides a strong, fragrant smell in all parts of the plant. Due to its exploitation in the Amazon for its linalool in the use of perfumes, the rosewood is in danger of extinction. Its irregular fruiting increases the difficulty in obtaining seeds for producing seedlings and, in
Bharti, Niharika; Tripathi, Smita; Bhatla, Satish Chander
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
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
Frank J. Baron; Gilbert H. Schubert
Ponderosa pine planting stock (1-0 and 2-0) grown from five different seed collection zones in the California pine region differed noticeably in size. On the west side of the Sierra Nevada, seeds from zones above 4,000 feet yielded smaller seedlings than those from lower zones, but larger seedlings than those from east-side sources. Average dimensions (seedling weight...
Germinação de sementes e crescimento de plântulas de brassica chinensis L. var. parachinensis (bailey sinskaja (couve-da-malásia Seed germination and seedling growth of brassica chinensis L. var. parachinensis (bailey sinskaja (flowering white cabbage
Wanessa Resende Ferreira
Full Text Available Brassica chinensis var. parachinensis, introduzida no Brasil em 1992, apresenta alto teor de vitamina A e ciclo curto. As sementes foram submetidas a 24 tratamentos em laboratório e 12 em campo, com o objetivo de avaliar o padrão de germinação e o crescimento das plântulas. Em laboratório, as sementes foram indiferentes à luz e mostraram baixa sensibilidade à ação escarificante do hipoclorito de sódio. Ácido giberélico, KNO3, escarificação e estratificação não modificaram sua germinabilidade (96-100% nem o tempo médio de germinação (1-1,28 dias em relação ao controle. Em condições de campo os maiores valores de emergência (89,2-96,4% e os maiores índices de velocidade de emergência (14,2-17,4 ocorreram em solo com adubação mineral, entre 0,5 e 1,5 cm de profundidade. Os menores tempos médios de emergência foram registrados entre 0,5 e 1,5 cm de profundidade (2,90-3,97 dias, com os três adubos testados (mineral, esterco de gado e de galinha. As plântulas se mostraram sensíveis ao hipoclorito de sódio, com redução significativa do hipocótilo e da raiz primária. A estratificação das sementes por 24 horas estimulou o crescimento da raiz primária, o que beneficia o estabelecimento da plântula no solo.Brassica chinensis var. parachinensis was introduced in Brazil in 1992. This variety presents a high content of vitamin A and a short life cycle. Seeds were submitted to 24 treatments in laboratory conditions and 12 treatments in field conditions with the objective of evaluating the germination pattern and seedling growth. In laboratory conditions, seed germination was light independent and the germinability was reduced in 12% by the action of sodium hypochlorite scarification. Gibberellic acid, KNO3, mechanical scarification and stratification did not modify the germinability of the seeds (96-100% neither the average time of germination (1-1.28 days in relation to the control treatment. In field conditions the
Li, X.; Cai, J.; Liu, Fulai
Low temperature seriously depresses seed germination and seedling growth in winter wheat (Triticum aestivum L.). In this study, wheat plants were sprayed with abscisic acid (ABA) and fluridone (inhibitor of ABA biosynthesis) at 19 days after anthesis (DAA) and repeated at 26 DAA. The seeds of those...
ter Heerdt, Gerard N. J.; Veen, Ciska G.F.; van der Putten, Wim H.; Bakker, Jan P.
Restoration of riparian plant communities on bare soil requires germination of seeds and establishment of seedlings. However, species that are present in the soil seed bank do not always establish in the vegetation. Temperature, moisture conditions and soil type could play a major role in the
Heerdt, ter Gerard N.J.; Veen, Ciska G.F.; Putten, van der Wim H.; Bakker, Jan P.
Restoration of riparian plant communities on bare soil requires germination of seeds and establishment of seedlings. However, species that are present in the soil seed bank do not always establish in the vegetation. Temperature, moisture conditions and soil type could play a major role in the
Ter Heerdt, Gerard N.J.; Veen, G.F.; Van der Putten, Wim H.; Bakker, Jan P.
Abstract Restoration of riparian plant communities on bare soil requires germination of seeds and establishment of seedlings. However, species that are present in the soil seed bank do not always establish in the vegetation. Temperature, moisture conditions and soil type could play a major role in
It is needed to minimize the economic loss by sorting infected seeds from healthy seeds before seeding. However, current methods of detecting infection seeds such as seedling grow-out, enzyme-linked immunosorbent assay (ELISA), polymerase chain reaction (PCR), and real-time polymerase chain reaction...
Early growth performances of various seed sources of black (Prunus serotina Erhr.) and wild cherry ( Prunus avium L.) seedlings on low and high elevation sites in the western Black Sea Region of Turkey.
Earl R. Sluder
Seedling establishment rates varied from 0 to 50 percent in a direct seeding study with scarlet oak (Quercus coccinea Muenchh.) on the Bent Creek Experimental Forest near Asheville, North Carolina. Acorns planted 2 inches deep in the spring with screen protection produced the most seedlings; those surface sown without screens in the spring or fall...
Philip M. McDonald
After ponderosa pine seed trees were removed on the Challenge Experimental Forest, California, seedling stocking fell by 3.8 percent or about 212 seedlings per acre. This loss is slightly less than that incurred from natural mortality, and one that did not reduce regeneration levels below the minimum standard.
Gaxiola, Aurora; Burrows, Larry E; Coomes, David A
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.
Alan Mario Zuffo
Full Text Available The objective of this work to evaluate the influence of the position of baru seeds, the emergence and early seedling development. The test was conducted in a greenhouse experiment in randomized blocks, with five treatments (seeding position, with four replications, positions were: A - Hilo up, B - hilo down C - hilum and raphe aside, D - horizontal raphe up, E - horizontal raphe down. It was observed that the seeds deposited at the position B (heel down provided better emergence and seedling development. We evaluated the emergence, speed of emergence index, plant height, stem diameter, root length, dry mass of air, root dry weight, relative AP/DC, FSPA/FSR and Dickson quality index. The emergence and early seedling development baru were influenced by sowing position. The seeds deposited with the hilum down provided better results.
Micheli Angelica Horbach
Full Text Available ABSTRACT Seed deterioration is a natural and irreversible process. Nevertheless, seed priming with water and antioxidants can minimize oxidative damage in oilseeds, resulting in attenuation of seed deterioration. The objective of this assay was to evaluate seed priming on respiratory activity of Jatropha curcas submitted to accelerated aging. Seeds from two provenances (Janauba and Pedro J. Caballero were submitted to three priming treatments (control, immersion in deionized water, and with 750 µmol L-1 of ascorbic acid and treated for accelerated aging at 41 °C for 72 h. The results showed that the priming of J. curcas seeds promoted tolerance to accelerated aging. Primed seeds, with ascorbic acid from Janauba and deionized water from Pedro J. Caballero, resulted in a higher percentage of normal seedlings, and increased germination speed index and seed respiration. The decline of physiological quality of J. curcas seeds after accelerated aging is directly associated with a reduction in respiratory activity that is related to seed moisture content.
Teixeira da Silva, Jaime A; Tsavkelova, Elena A; Ng, Tzi Bun; Parthibhan, S; Dobránszki, Judit; Cardoso, Jean Carlos; Rao, M V; Zeng, Songjun
The ability to germinate orchids from seeds in vitro presents a useful and viable method for the propagation of valuable germplasm, maintaining the genetic heterogeneity inherent in seeds. Given the ornamental and medicinal importance of many species within the genus Dendrobium, this review explores in vitro techniques for their asymbiotic seed germination. The influence of abiotic factors (such as temperature and light), methods of sterilization, composition of basal media, and supplementation with organic additives and plant growth regulators are discussed in context to achieve successful seed germination, protocorm formation, and further seedling growth and development. This review provides both a basis for the selection of optimal conditions, and a platform for the discovery of better ones, that would allow the development of new protocols and the exploration of new hypotheses for germination and conservation of Dendrobium seeds and seedlings.
Keila Regina Hossa
Full Text Available The foremost factor necessary for plant growers cultivating large acreages of Stevia rebaudiana (Bert Bertoni is the production of qualitative bedding plants. The objective of this study was to evaluate the influence of osmotic-priming on the uniformity of seed germination. First, we evaluated the percentage of normal seedlings from two seed samples harvested in 2011 and 2012. The seeds harvested in 2012 produced 71.4% normal seedlings and thus they were used in the next experiments. The seeds were subjected to osmotic stress using five concentrations of polyethylene glycol (PEG-6000 at -0.2, -0.4, -0.6, -0.8, and -1.0 MPa in contrast with distilled water. Based on these first results, only -0.8 and -1.0 MPa were evaluated in the third experiment. The seeds were immersed in both concentrations of polyethylene glycol (PEG-6000 for imbibing at 20ºC for four, five, six, and seven days. Thereafter, we evaluated the time to the first normal seedling (Ti, time to the last normal seedling (Tf, percentage normal seedlings at the initial time (Pi and percentage of normal seedlings at the end of every treatment (Pf. Osmotic priming increased the percentage of normal seedlings of the Stevia rebaudiana and reduced the time to the first and last germination events.
Denise de Castro Lima
Full Text Available The sunflower is among the top five crops in the world for the production of edible vegetable oil. The species displays rustic behavior, with an excellent edaphic and climatic adaptability index, being able to be cultivated throughout Brazil. Seed quality is the key to increasing production and productivity in the sunflower. The objective of this work was to monitor the viability of sunflower seeds with a view to their conservation when stored in different environments and packaging. The seeds were packed in paper bags, multilayered paper, black polyethylene and PET bottles; and stored for a period of twelve months in the following environments: dry cold room (10 ºC and 55% RH, the ambient conditions of Fortaleza, Ceará, Brazil (30-32 ºC and 75% RH, refrigerator (4 ºC and 38-43% RH and freezer (-20 ºC. Every three months, the water content of the seeds was determined and germination, accelerated ageing, speed of emergence index, and seedling dry weight were evaluated. The experimental design was completely randomized, in a scheme of split-lots, with four replications. It can be concluded that the natural environment is not suitable for the storage of sunflower seeds. Sunflower seeds remain viable for 12 months when stored in a dry cold room, refrigerator or freezer, irrespective of the type of packaging used.
Germinação de sementes e sobrevivência de plântulas de Himatanthus sucuuba (Spruce Wood. em resposta ao alagamento, nas várzeas da Amazônia Central Seed germination and seedling survival of Himatanthus sucuuba(Spruce Wood., in response to flooding in the varzeas of the Central Amazon
Cristiane da Silva Ferreira
Amazonia. The present work was carried out in order to analyze the adaptive strategies of the species to cope with the long periods of flooding common in the várzea. Seeds were accompanied from germination until the seedling stage, in experimental conditions simulating natural field conditions (terrestrial phase and flooding period. Germination was tested in two substrates: sand + sawdust (only irrigated, and in water (submergence. The seedlings produced were then subjected, for 120 days, to three treatments: control (daily irrigation, partial submersion (root system and total submersion (whole seedling. Alterations in the morphology of seedlings and in root anatomy were examined, together with the activity of the enzyme alcohol dehydrogenase (ADH 0, 15, 30, 60, 90, and 120 days after the start of the treatments. Irrespective of the flooding regime, germination rates and seedling formation were high, both above 80%. Under partial submersion, hypertrophic lenticels, adventitious roots and aerenchyma were formed in the roots while ADH activity remained high until the 60th day of flooding, declining afterwards. Seedlings under total submersion lost all leaves, did not form adventitious roots or lenticels, but developed aerenchyma. These seedlings showed the highest values of ADH, which remained high until the end of the experiment, indicating the diversion of the aerobic metabolism to the production of ethanol as the main pathway to maintain the energetic balance. Although some totally submersed seedlings died, 70% of them survived the 120 days of flooding. Seedlings of H. sucuuba modulate morpho-physiologically the tolerance to flooding according to the time of exposure to the stress and the height of the water column.
Nolasco, H.; Vega-Villasante, F.; Diaz-Rondero, A.
Germination of Stenocereus thurberi seeds was evaluated under different conditions of solar irradiation and humidity. Seed germination increased under higher humidity and low solar irradiation which provided cooler temperatures and higher water availability. Seedlings were also greener and more turgid under these conditions. Increased solar irradiation reduced seed germination and decreased seedling size and water content. The results of this study support the importance of natural shelter systems in the arid zones in providing better conditions for S. thurberi seeds germination and seedling establishment, particularly in the desert of Baja California. (author)
MARCOS ALTOMANI NEVES DIAS
Full Text Available This study aimed to associate two concepts of seed vigor testing, the aging and seedling growth using image analysis, providing a feasible and time-saving way to evaluate maize seed vigor in large scale. For this purpose, five seed lots with different vigor levels from two single hybrids were used. The seeds were characterized by moisture content, germination, seedling emergence, seedling emergence speed index, accelerated aging and cold tests. The treatments were composed by varying the accelerated aging periods (0, 24, 48, 72 and 96h and seedling growth periods (48 and 72h, before submitting the seedlings to image analysis for seedling root length measurement. Considering the results obtained, the adaptation of accelerated aging test by reducing the aging duration from 96h to 48h, and the replacement of the germination test by seedling root length measurement using image analysis could be considered a potential tool for maize seed vigor assessment. The treatments composed of 48h of seed aging followed by seedlings root length measurements using image analysis provided reliable data, compared to traditional vigor tests and it could be considered an efficient and timesaving approach, associating two different concepts of seed vigor analysis.
Emergência de plântulas de Astrocaryum aculeatum G. May. em função da temperatura e do período de embebição das sementes Emergence of Astrocaryum aculeatum seedlings according temperature and soaking period of seeds
Full Text Available O presente trabalho teve por objetivo avaliar a emergência de plântulas de Astrocaryum aculeatum a partir de sementes submetidas a diferentes temperaturas e períodos de embebição. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 4 (temperaturas de embebição em água: 25ºC, 30ºC, 35ºC e 40ºC X 3 (períodos de embebição: 2, 4 e 6 dias, com testemunha (sem embebição e com quatro repetições. As semeaduras foram realizadas em viveiro. A emergência e o índice de velocidade de emergência só diferiram entre a testemunha e os tratamentos aplicados, independentes do período e da temperatura, com resultados favoráveis para a embebição das sementes. O tempo médio de emergência apresentou efeito de interação significativo, destacando-se a utilização da temperatura de embebição de 40ºC, associada ao período de 4 dias, que proporcionou um menor tempo médio (163 dias. O tempo inicial de emergência foi menor na temperatura de 35ºC (80 dias, enquanto o tempo final de emergência não apresentou diferença entre as médias. Sementes embebidas por 2 dias apresentaram 50% de sementes mortas ao final do experimento, enquanto as embebidas por 4 dias, apenas 38%. A emergência de plântulas de A. aculeatum foi favorecida pela embebição, independente da temperatura e do período utilizados.This study evaluated the seedling emergence of Astrocaryum aculetum seeds soaked in water for different periods at different temperatures. The experimental design was entirely randomized, in factorial 4 (temperatures of soaking in water: 25ºC, 30ºC, 35ºC e 40ºC X 3 (period of soaking: 2, 4 and 6 days, additional treatment (control, without soaking, with four replications. Before (control and after the soaking periods in different temperatures, the seeds were planted in nursery. The emergence and its velocity differed only in the comparison of the control with the applied treatments, with favorable results of all
Zhao, Xueguan; Gao, Yuanyuan; Wang, Xiu; Li, Cuiling; Wang, Songlin; Feng, Qinghun
Seed size, interior abnormal and damage of the tomato seeds will affect the germination. The purpose of this paper was to study the relationship between the internal morphology, seed size and seed germination of tomato. The preprocessing algorithm of X-ray image of tomato seeds was studied, and the internal structure characteristics of tomato seeds were extracted by image processing algorithm. By developing the image processing software, the cavity area between embryo and endosperm and the whole seed zone were determined. According to the difference of area of embryo and endosperm and Internal structural condition, seeds were divided into six categories, Respectively for three kinds of tomato seed germination test, the relationship between seed vigor and seed size , internal free cavity was explored through germination experiment. Through seedling evaluation test found that X-ray image analysis provide a perfect view of the inside part of the seed and seed morphology research methods. The larger the area of the endosperm and the embryo, the greater the probability of healthy seedlings sprout from the same size seeds. Mechanical damage adversely effects on seed germination, deterioration of tissue prone to produce week seedlings and abnormal seedlings.
El-Saidy, Aml E A; El-Hai, K M Abd
This study focuses on finding compounds that are safe to humans and environment, such as propionic and acetic acids that may provide an alternative control of seed-borne pathogens and decrease seed deterioration during storage. The objectives of this study were to reduce sunflower seed deterioration and improve the viability of sunflower seed using environmentally safe organic acids. Propionic and acetic acids were applied on sunflower seed at different concentrations under laboratory conditions during different storage periods. After 6 months storage period, the viability of sunflower seed as well as morphological and physiological characteristics of seedlings were evaluated under greenhouse conditions. Laboratory experiment was conducted in a factorial completely randomized design and randomized complete block design for greenhouse experiment. Propionic and acetic acids at different concentrations showed inhibitory effects on the presence of different fungal genera in all storage periods. Propionic acid was most effective followed by acetic acid. Increasing storage periods from 0-6 months significantly decreased germination percentage, germination energy, seedling characters, survived healthy seedlings and seed oil and protein percentages but dead and rotted seeds, as well as rotted seedlings were increased. Treating sunflower seeds with propionic acid (100%) improved germination criteria, seedling characters and seed chemical characters as well as survival seedlings and minimized the dead seeds, rotted seeds and rotted seedlings as compared with the control under all storage periods. Under greenhouse conditions, the maximum growth parameter and physiological characters (chlorophylls a, b, carotenoids and total phenols) were recorded from seed treated with 100% propionic acid after 6 months of storage. It may be concluded that propionic and acetic acids vapors can have considerable fungicidal activity against sunflower pathogens and improve seed viability
Full Text Available Promoting the seed regeneration potential of secondary forests undergoing gap disturbances is an important approach for achieving forest restoration and sustainable management. Seedling recruitment from seed banks strongly determines the seed regeneration potential, but the process is poorly understood in the gaps of secondary forests. The objectives of the present study were to evaluate the effects of gap size, seed availability, and environmental conditions on the seed regeneration potential in temperate secondary forests. It was found that gap formation could favor the invasion of more varieties of species in seed banks, but it also could speed up the turnover rate of seed banks leading to lower seed densities. Seeds of the dominant species, Fraxinus rhynchophylla, were transient in soil and there was a minor and discontinuous contribution of the seed bank to its seedling emergence. For Quercus mongolica, emerging seedling number was positively correlated with seed density in gaps (R = 0.32, P<0.01, especially in medium and small gaps (<500 m(2. Furthermore, under canopies, there was a positive correlation between seedling number and seed density of Acer mono (R = 0.43, P<0.01. Gap formation could promote seedling emergence of two gap-dependent species (i.e., Q. mongolica and A. mono, but the contribution of seed banks to seedlings was below 10% after gap creation. Soil moisture and temperature were the restrictive factors controlling the seedling emergence from seeds in gaps and under canopies, respectively. Thus, the regeneration potential from seed banks is limited after gap formation.
Yan, Qiao-Ling; Zhu, Jiao-Jun; Yu, Li-Zhong
Promoting the seed regeneration potential of secondary forests undergoing gap disturbances is an important approach for achieving forest restoration and sustainable management. Seedling recruitment from seed banks strongly determines the seed regeneration potential, but the process is poorly understood in the gaps of secondary forests. The objectives of the present study were to evaluate the effects of gap size, seed availability, and environmental conditions on the seed regeneration potential in temperate secondary forests. It was found that gap formation could favor the invasion of more varieties of species in seed banks, but it also could speed up the turnover rate of seed banks leading to lower seed densities. Seeds of the dominant species, Fraxinus rhynchophylla, were transient in soil and there was a minor and discontinuous contribution of the seed bank to its seedling emergence. For Quercus mongolica, emerging seedling number was positively correlated with seed density in gaps (R = 0.32, P<0.01), especially in medium and small gaps (<500 m2). Furthermore, under canopies, there was a positive correlation between seedling number and seed density of Acer mono (R = 0.43, P<0.01). Gap formation could promote seedling emergence of two gap-dependent species (i.e., Q. mongolica and A. mono), but the contribution of seed banks to seedlings was below 10% after gap creation. Soil moisture and temperature were the restrictive factors controlling the seedling emergence from seeds in gaps and under canopies, respectively. Thus, the regeneration potential from seed banks is limited after gap formation. PMID:22745771
Grinikh, L.I.; Shevchenko, V.V.
Seeds of Crepis tectorum natural populations 1 and 3 subjected to chronic irradiation in 1986 during 4 months in 30-kilometers zone of Chernobyl were stored for 6 years in a laboratory. In analysis of chromosome aberrations in the first tetraploid cells was made as it was done in 1987 just after finishing of a dromant period of seeds. By extrapolation from the data obtained by studing cells of the second colchicine mitosis to the cells of the previous mitosis from which they derived it was shown that the frequency of chromaid type aberrations in the early dividing cells after 6 year storage remained at the level which was observed just after finishing of a dormant period
Statton, John; Montoya, Leonardo R; Orth, Robert J; Dixon, Kingsley W; Kendrick, Gary A
Identifying early life-stage transitions limiting seagrass recruitment could improve our ability to target demographic processes most responsive to management. Here we determine the magnitude of life-stage transitions along gradients in physical disturbance limiting seedling establishment for the marine angiosperm, Posidonia australis. Transition matrix models and sensitivity analyses were used to identify which transitions were critical for successful seedling establishment during the first year of seed recruitment and projection models were used to predict the most appropriate environments and seeding densities. Total survival probability of seedlings was low (0.001), however, transition probabilities between life-stages differed across the environmental gradients; seedling recruitment was affected by grazing and bioturbation prevailing during the first life-stage transition (1 month), and 4-6 months later during the third life-stage transition when establishing seedlings are physically removed by winter storms. Models projecting population growth from different starting seed densities showed that seeds could replace other more labour intensive and costly methods, such as transplanting adult shoots, if disturbances are moderated sufficiently and if large numbers of seed can be collected in sufficient quantity and delivered to restoration sites efficiently. These outcomes suggest that by improving management of early demographic processes, we could increase recruitment in restoration programs.
Thobunluepop, P; Pawelzik, E; Vearasilp, S
This study aimed to evaluate the perspective changes of several physiological performances of rice seeds cv. KDML 105 which were coated with various seed coating substances [chemical fungicide, captan (CA) and biological coating polymers; chitosan-lignosulphonate polymer (CL) and eugenol incorporated into chitosan-lignosulphonate polymer (E + CL)] during storage (12 months). CA significantly increased seed moisture content and seed water activity through out the storage period. The qualities and viability of the seeds were seriously declined by this treatment. Moreover, CA inhibited the shoot and root development, seedling dry weight accumulation, delayed the seed germination and seedling growth rate. CA treated seeds were susceptible to stress conditions that declined the seed germination potential under cold, high moisture and temperature stress conditions. Nevertheless, CL and E + CL coating polymer could maintain seed storability, which significantly improved seed germination and seedling performances. These improvements were attributed to maintain the nutritive reserve and dehydrogenase activity in seeds. Moreover, the biological seed treatment stimulated the embryo growth and so speeding up the seedling emergence when compared untreated seeds.
Winkler, Manuela; Hülber, Karl; Hietz, Peter
Seeds of epiphytes must land on branches with suitable substrates and microclimates to germinate and for the resulting seedlings to survive. It is important to understand the fate of seeds and seedlings in order to model populations, but this is often neglected when only established plants are included in analyses. The seeds of five bromeliad species were exposed to different canopy positions in a Mexican montane forest, and germination and early seedling survival were recorded. Additionally, the survival of naturally dispersed seedlings was monitored in a census over 2.5 years. Survival analysis, a procedure rarely used in plant ecology, was used to study the influence of branch characteristics and light on germination and seedling survival in natural and experimental populations. Experimental germination percentages ranged from 7.2 % in Tillandsia deppeana to 33.7 % in T. juncea, but the seeds of T. multicaulis largely failed to germinate. Twenty months after exposure between 3.5 and 9.4 % of the seedlings were still alive. There was no evidence that canopy position affected the probability of germination, but time to germination was shorter in less exposed canopy positions indicating that higher humidity accelerates germination. More experimental seedlings survived when canopy openness was high, whereas survival in census-seedlings was influenced by moss cover. While mortality decreased steadily with age in juveniles of the atmospheric Tillandsia, in the more mesomorphic Catopsis sessiliflora mortality increased dramatically in the dry season. Seedling mortality, rather than the failure to germinate, accounts for the differential distribution of epiphytes within the canopy studied. With few safe sites to germinate and high seedling mortality, changes of local climate may affect epiphyte populations primarily through their seedling stage.
Chun, S C; Schneider, R W
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
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
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
João Ricardo Avelino Leão
Full Text Available This paper aimed to define the ideal type of agroforestry substrate and the adequate depth of sweet angelim sowing, providing information on the development of seedlings, as well as on low-cost substrates which are easy to be obtained. An experiment in a greenhouse was carried out, in a completely randomized design with treatments distributed in a factorial scheme (5x3, with the factors agroforestry substrates and depths being replicated seven times with a seed in each container. The following parameters were analyzed: germination percentage, germination speed index, total dry weight, number of leaves, seedlings height and coll diameter, and Dickson’s seedling quality index. The results showed that the most suitable substrate for germination and development of this native species was that containing Brazil nut shell, peanut hull, or açai seed, and the ideal depth for sowing and managing seedlings was on the surface.
Yildiz, Mustafa; Er, Celâl
The aim of this study was to determine the effect of concentration (40, 60, and 80%) and temperature (0, 10, 20, and 30°C) of sodium hypochlorite (NaOCl) solutions on seed germination, in vitro viability and growth of flax seedlings and regeneration capacity of hypocotyl explants. Results showed that seed germination, seedling growth and shoot regeneration were negatively affected by increasing concentration and temperature of disinfectant. The best results in seedling growth and shoot regeneration were obtained when 40% disinfectant concentration at 10°C was used.
Guan, Yajing; Wang, Jianchen; Tian, Yixin; Hu, Weimin; Zhu, Liwei; Zhu, Shuijin; Hu, Jin
Seed security is of prime importance for agriculture. To protect true seeds from being faked, more secure dual anti-counterfeiting technologies for tobacco (Nicotiana tabacum L.) pelleted seed were developed in this paper. Fluorescein (FR), rhodamine B (RB), and magnetic powder (MP) were used as anti-counterfeiting labels. According to their different properties and the special seed pelleting process, four dual-labeling treatments were conducted for two tobacco varieties, MS Yunyan85 (MSYY85) and Honghua Dajinyuan (HHDJY). Then the seed germination and seedling growth status were investigated, and the fluorescence in cracked pellets and developing seedlings was observed under different excitation lights. The results showed that FR, RB, and MP had no negative effects on the germination, seedling growth, and MDA content of the pelleted seeds, and even some treatments significantly enhanced seedling dry weight, vigor index, and shoot height in MS YY85, and increased SOD activity and chlorophyll content in HHDJY as compared to the control. In addition, the cotyledon tip of seedlings treated with FR and MP together represented bright green fluorescence under illumination of blue light (478 nm). And the seedling cotyledon vein treated with RB and MP together showed red fluorescence under green light (546 nm). All seeds pelleted with magnetic powder of proper concentration could be attracted by a magnet. Thus, it indicated that those new dual-labeling methods that fluorescent compound and magnetic powder simultaneously applied in the same seed pellets definitely improved anti-counterfeiting technology and enhanced the seed security. This technology will ensure that high quality seed will be used in the crop production.
Full Text Available Seed security is of prime importance for agriculture. To protect true seeds from being faked, more secure dual anti-counterfeiting technologies for tobacco (Nicotiana tabacum L. pelleted seed were developed in this paper. Fluorescein (FR, rhodamine B (RB, and magnetic powder (MP were used as anti-counterfeiting labels. According to their different properties and the special seed pelleting process, four dual-labeling treatments were conducted for two tobacco varieties, MS Yunyan85 (MSYY85 and Honghua Dajinyuan (HHDJY. Then the seed germination and seedling growth status were investigated, and the fluorescence in cracked pellets and developing seedlings was observed under different excitation lights. The results showed that FR, RB, and MP had no negative effects on the germination, seedling growth, and MDA content of the pelleted seeds, and even some treatments significantly enhanced seedling dry weight, vigor index, and shoot height in MS YY85, and increased SOD activity and chlorophyll content in HHDJY as compared to the control. In addition, the cotyledon tip of seedlings treated with FR and MP together represented bright green fluorescence under illumination of blue light (478 nm. And the seedling cotyledon vein treated with RB and MP together showed red fluorescence under green light (546 nm. All seeds pelleted with magnetic powder of proper concentration could be attracted by a magnet. Thus, it indicated that those new dual-labeling methods that fluorescent compound and magnetic powder simultaneously applied in the same seed pellets definitely improved anti-counterfeiting technology and enhanced the seed security. This technology will ensure that high quality seed will be used in the crop production.
Andreya Kalyana de Oliveira
Full Text Available The melon crop is of great socioeconomic importance in Brazil and some species from the Caatinga biome show allelopathic effects on other species. The aim of this study was to assess leaf and seed extracts of cumaru (Amburana cearensis (Allemao A.C. Sm., the jujube tree (Zizyphus joazeiro Mart., Jucá (Caesalpinia ferrea Mart. Ex. Tul. Var. Ferrea and mulungu (Erythrina velutina Willd. on the emergence of melon seeds (Cucumis melo L.. Leaves and seeds were used to produce extracts for each species at concentrations of a 1%, b 0.5% c 0.25%, d 0.125% and e 0% (control. The experiment was conducted with each extract type and its respective concentrations in a completely randomized design, with four replicates, each of 20 seeds. The percentage emergence and rate index, percentage of abnormal seedlings, seedling dry matter and seedling shoot and root length were assessed. Seed extracts of A. cearensis prevented melon germination, whereas the other extracts had no effect on this variable. Leaf extracts of A. cearensis and leaf and seed extracts of Z. joazeiro, C. ferrea and E. velutina resulted in abnormal melon seedlings. The percentage of abnormal melon seedlings exceeded 30% when treated with C. ferrea seed extract at the highest concentration. Most extracts did not affect seedling dry matter, but E. velutina leaf and seed extract increased the dry matter accumulation of melon seedlings and Z. joazeiro seed extract decreased dry matter accumulation at a concentration of 0.25%. The highest concentrations of mulungu and jucá leaf extracts promoted the shoot growth of melon seedlings. The extract from E. velutina seeds negatively affected root length compared to the control, similar to the effect of C. ferrea and E. velutina leaf extracts at the highest concentrations. Extracts of different organs of Caatinga plants can affect the emergence and characteristics related to seedling growth, depending on the concentration. Most extracts did not affect
Mondal, Subinoy; Kumar, Mousumi; Haque, Smaranya; Kundu, Debajyoti
The present study evaluated the effects of glyphosate on Pisum sativum germination as well as its effect on the physiology and biochemistry of germinated seedlings. Different physico-chemical biomarkers, viz., chlorophyll, root and shoot length, total protein and soluble sugar, along with sodium and potassium concentration, were investigated in germinated seedlings at different glyphosate concentrations. This study reports the influence of different concentrations of glyphosate on pea seeds a...
Full Text Available This work studied the behavior of G. americana L. (Rubiaceae seeds in an induced soil seed bank. This study was conducted in Lavras-MG in a seasonal semideciduous forest of the Federal University of Lavras. Seeds collected in the area were cleaned and analyzed (water content, viability and desiccation tolerance. Soil banks were installed in two distinct areas (top of hill and riparian forest located in the understory of the forest. Seeds were placed in nylon nets and covered with a thin litter layer that was previously removed for this purpose. Monthly assessment of germination, seedling emergence, seed and soil water content, and the characterization of the initial seedling growth was performed. It was observed that G. americana seeds forms a transitory seed bank, with maintenance of its viability until the fourth month after disposal in natural environment. In general, the seed bank located in the riparian forest area showed the best potential for seedling establishment in a natural environment, which supports the ecological behavior of this species.
José E. S. B. da Silva
Full Text Available ABSTRACTThe limited access and the scarcity of good quality water for agriculture are some of the major problems faced in agricultural areas, particularly in arid and semiarid regions. The aim of this study was to evaluate the quality of watermelon seedlings (cv. Crimson Sweet, irrigated with different concentrations of biosaline water of fish culture. The experimental design was completely randomized with five treatments, corresponding to biosaline water at different concentrations (0, 33, 50, 67 and 100%, and four replicates of 108 seedlings. Watermelon seeds were sown in plastic trays filled with commercial substrate and irrigated with different solutions of biosaline water. Seedlings were harvested for biometric analysis at 14, 21 and 28 days after sowing. The use of biosaline water did not affect emergence and establishment of seedlings until 14 days after sowing, the period recommended for transplantation. However, the use of biosaline water affected the development of seedlings with longer exposure time.
Utoyo, Bambang; Yolandika, Clara
This research aimed to analyse (1) decission making process of certified and uncertified palm oil seedlings and (2) factors that influence farmer decision to select certified and uncertified palm oil seedlings. This research was conducted in some districts in Lampung, such as Mesuji, Central Lampung, Tulang Bawang, North Lampung, Way Kanan and South Lampung. The respondents consisted of 30 farmers using certified seeds and 30 farmers using uncertified seeds. The study was conducted from January to May 2017. In addition, factors that influence farmer decision was analysed by logistic regression model. The results showed that decision making on the use of certified or uncertified palm seeds by farmers through the stages: introduction of problems or needs, searching of information, alternative evaluation, purchasing decisions, and post-purchase behaviour. Factors that significantly influence farmer's decision to use certified seeds were land area, seeds price, external influenced, and farmers’ perception.
Kruidhof, H.M.; Gallandt, E.R.; Haramoto, E.R.; Bastiaans, L.
Laboratory bioassays have shown that large-seeded species better tolerate cover crop residue–mediated stress than small-seeded species. This provides the potential for selective suppression of small-seeded weeds in large-seeded crops. We conducted two field experiments in which seedling emergence of
Tirtha Ayu Paramitha
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.
Efeito da temperatura de armazenamento e de fitoreguladores na germinação de sementes de maracujá doce e desenvolvimento inicial de mudas = Effect of storage temperature and phytoregulators on germination of sweet passion fruit seeds and seedling development
Marco Eustáquio de Sá
Full Text Available A germinação de sementes de maracujazeiro doce apresenta problemas e estudos que possam elucidar o processo e verificar sua viabilidade são importantes para que os produtores de mudas possam melhorar seu rendimento e obter maiores lucros. O objetivo do trabalho foi verificar o efeito da temperatura de armazenamento das sementes, e embebição em fitoreguladores e KNO3 na germinação e desenvolvimento inicial de mudas de maracujá doce. O experimento foi instalado na Casa de Vegetação, da Faculdade de Engenharia de Ilha Solteira/Unesp, Estado de São Paulo, em delineamento inteiramente casualizado, numesquema fatorial 2 X 5, sendo 2 temperaturas de armazenamento das sementes (ambiente e geladeira e 5 tratamentos de embebição (sem embebição, água destilada, giberelina 250 ppm, citocinina 250 ppm e KNO3 0,1%, com 4 repetições. As sementes foram armazenadas por 20dias, seguidas de embebição por 24 horas. As avaliações foram feitas até os 62 dias após a semeadura, determinando-se porcentagem de germinação, o índice velocidade de germinação e parâmetros do desenvolvimento inicial das mudas. A baixa temperatura teve efeito positivo na germinação. A giberelina influenciou positivamente o desenvolvimento inicial das mudas, constatando-se que o seu efeito pode ser perfeitamente substituído pela baixa temperatura dearmazenamento das sementes.The germination of sweet passion fruit seeds has problems. Studies that explain and verify its viability are important for seedproducers to improve their income and profit. The aim of this work was to verify the effect of storage temperature and imbibition in phytoregulators and KNO2 on germination and seedling development of passion fruit. The experiment was carried out at Casa de Vegetação from Faculdade de Engenharia de Ilha Solteira/Unesp, São Paulo State, using a completely randomized design in a 2 (storage temperature of seeds (room temperature and refrigerator x 5 (imbibition
Full Text Available In order to estimate the best germination conditions of Encyclia aff. oncidioides seeds, five different media (Fast, Knudson C modified by Vajrabhaya, Murashige and Skoog, PB2 and modified Vacin and Went with different concentrations of plant growth regulators such as benzyladenine (BA, naphthaleneacetic acid (NAA and gibberellic acid (GA3 were tested. No beneficial effect was observed when BA and NAA were applied to the germination medium and GA3 inhibited germination. The effect of light, activated charcoal, coconut water and casein hydrolysate on seed germination was also studied. The growth rate of seedlings on three different media supplemented with activated charcoal and plant growth regulators was checked. The applied plant growth regulators had no beneficial effect on the further growth of seedlings. Fast and PB2 media with 0.2% activated charcoal proved to be the best for E. aff. oncidioides seed germination, seedling development and plantlet propagation.
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 ...
Garcinia kola seeds to six different hormonal pre-germination treatments. This consisted of ... Thus, seed dormancy in this case is not a coat- imposed .... development of the cultivation of the species. The cause .... Hormonal regulation of seed ...
Florina Maria Copaciu
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.
Full Text Available Tlie experiment was conducted in the glasshouse of UPM from March 2003 to June 2004 to determine the soil seedbank in the ricefields ot'Muda rice granary area in Peninsular Malaysia. Six soil cores of 5 cm in diameter and 10 cm depth were sampled from each of 24 fields. All samples from each individual field were bulked and placed in plastic trays of 38 x 25 x 10 cm. Soil was moistened as required and emergence of weed seedlings were recorded over period of one year. After one year, remaining seeds were separated, removed and identified. The total seed bank was estimated at 1136.48 million/ha of whic h 62.35% (708.60 million seedlings ha"1 germinated within 12 months and 37.65% (427.88 million seeds ha"1 remained ungerminated. Total of 20 taxa were recognized. Based on importance value (I.V. the five most dominant species in terms of emerged seedling were Fimbristylis miliacea, Leplochloa chinensis, LitJwigia hyssopifolia, Cyperus difformii and C. iria. Of the remaining seeds the five dominant species with decreasing trend in ranking were F. miliacea, Scirpus lateriflonis, Monochoria vagina/is, L. hyssopifolia and L. chinensis. Ranking of total seed reserves (seedlings+ remaining seeds were similar to emerged seedling indi cating that emerged seedlings reflect the actual weed flora in the Muda area. Among the dominant species F. miliacea accounted for 58.07% of emerged seedlings, 79.31% of remaining seeds and 66.07% of total seed bank. Total seedling emergence of all species was higher in the first observation in April 2003 and cumulative seedling emergence showed no clear peaks.
Rafal Zwolak; Kerry Foresman; Elizabeth Crone; Dean Pearson; Yvette Ortega
Wildlife, even miniscule mice, can play an important role in forest regeneration and composition by consuming seeds, seedlings, and saplings. Mice can, through sheer numbers, consume a tremendous number of seeds. We wanted to learn if deer mice could affect how ponderosa pine forests regenerate after fire.
In order to evaluate the performance of sprout cutting for seed potato production against virus infection, a study was conducted at Bangladesh Agricultural Development Corporation (BADC) Foundation Seed Potato Production Farm, Domar, Nilphamary, Bangladesh in 2005 - 2006. Sprout cut seedlings were grown under ...
Sep 6, 2010 ... In order to evaluate the performance of sprout cutting for seed potato production against virus infection, a study was conducted at Bangladesh Agricultural Development Corporation (BADC). Foundation Seed Potato Production Farm, Domar, Nilphamary, Bangladesh in 2005 - 2006. Sprout cut seedlings ...
Li, Xiangnan; Jiang, Haidong; Liu, Fulai
Chilling depresses seed germination and seedling establishment, and is one major constraint to grain yield formation in late sown winter wheat. Seeds of winter wheat (Triticum aestivum L.) were separately pre-soaked with sodium nitroprusside (SNP, as nitric oxide donor) and Gibberellic acid (GA3...... by exogenous NO and GA3 as a result of improved seed germination and maintenance of better reactive oxygen species homeostasis in seedling growing under chilling temperatures. It is indicated that exogenous NO was more effective than GA3 in alleviating chilling stress during seed germination and seedling...
Marcos Altomani Neves Dias
Full Text Available Seed vigor is a major attribute in the determination of whether a seed lot can be commercialized. Different physiological tests are used to assess seed vigor and are generally based on different concepts, which could lead to variable interpretations, particularly when comparing lots presenting different vigor levels. This study was conducted to compare the different approaches used to evaluate bell pepper seed vigor and verify the applicability of the Seed Vigor Imaging System (SVIS for this purpose. The experiment was performed using four seed lots of bell pepper hybrids in two periods, and the evaluations involved germination, seedling emergence, seedling emergence speed index, saturated salt accelerated aging and image analysis. The use of seedling imaging analysis by SVISis a new approach for bell pepper seed vigor evaluation. Both the software and traditional tests provided sufficient information for seed vigor analysis, enabling the segregation of the analyzed seed lots. Thus, the new method fulfills the requirement for an efficient, rapid, cost-effective and standardized method that allows comparisons among laboratories and avoids human influence on the interpretation of the results. SVIS can be considered a feasible option to be included in quality assurance programs of the bell pepper seed industry.
Gyrbev, B.; Velikov, S.
A series of experiments was carried out in the Struma river valley with tobacco seedlings in the period 1984-1987. The seeds were gamma irradiated with 1000 R and 2000 R and sowed after 2-3 days with and without fertilizers. The results from phenological observations and biometrical measurements of the seedlings showed no positive radiation effect on the sprouting and phenophase transition. No significant changes between irradiated plants and controls were detected in the total weight of the seedlings, the number, height, length and width of the leaves, the yield and quality of tobacco. In conclusion the authors do not recommend gamma irradiation of tobacco seeds as a plant growth stimulation agent. 3 tabs
James Barnett; Sue Varela
Slash pine is a desirable species. It serves many purposes and is well adapted to poorly drained flatwoods and seasonally flooded areas along the lower Coastal Plain of the Southeastern US. The use of high-quality seeds has been shown to produce uniform seedlings for outplanting, which is key to silvicultural success along the Coastal Plain and elsewhere. We present...
J. W. Tomala-Bednarek
Full Text Available It was established that the mycelium of Ustilago perennans does not grow into the pericarp and seed coat of Arrhenatherum elatius caryopses. The main source of seedling infection at this year .seeds sowing were mycelium and gemmes present in hull tissues whereas ait last-year seeds sowing-the spores wintering on the hull and caryopsis surfaces, as they proved to be more survived. The ability of the fungus to seedling infection was decreasing gradually with the seed ageing.
Crislaine Aparecida Gomes Pinto
Full Text Available The Seed Analysis System (SAS is used in the image analysis of seeds and seedlings, and has the potential for use in the control of seed quality. The aim of this research was to adapt the methodology of image analysis of maize seedlings by SAS, and to verify the potential use of this equipment in the evaluation of the physiological potential of maize seeds. Nine batches of two maize hybrids were characterised by means of the following tests and determinations: germination, first count, accelerated ageing, cold test, seedling emergence at 25 and 30ºC, and speed of emergence index. The image analysis experiment was carried out in a factorial scheme of 9 batches x 4 methods of analysis of the seedling images (with and without the use of NWF as substrate, and with and without manual correction of the images. Images of the seedlings were evaluated using the average lengths of the coleoptile, roots and seedlings; and by the automatic and manual indices of vigour, uniformity and growth produced by the SAS. Use of blue NWF afffects the initial development of maize seedlings. The physiological potential of maize seeds can be evaluated in seedlings which are seeded on white paper towels at a temperature of 25 °C and evaluated on the third day. Image analysis should be carried out with the SAS software using automatic calibration and with no correction of the seedling images. Use of SAS equipment for the analysis of seedling images is a potential tool in evaluating the physiological quality of maize seeds.
Full Text Available The effect of seed moisture content at harvest on the most important parameters of dry pea was examined. The seed moisture content, germination energy, germination, proportion of abnormal seedlings and 1000-seed weight were analyzed in three dry pea cultivars (Jezero, Javor and NS-Junior and at eight harvest stages. At the first harvest stage, seed moisture content was 20.44%, while at the eighth stage it was 11.26%. The best seed quality, with germination energy of 81.70% and germination of 90.11%, was at the sixth harvest time when seed moisture content was 12.92%. The poorest seed quality one was at the first harvest stage, with germination energy of 68.55% and germination of 78.56%. Cultivar Jezero, with shorter growing season, determinant stem growth and uniform maturity, had the highest germination energy (82.00%, germination (92.21% and percent of abnormal seedlings (1.96%. Cultivar NS Junior, with the longest growing season, indeterminant stem growth and non-uniform maturity, had the lowest germination energy (70.39% and germination (76.54%, and the highest percent of abnormal seedlings (3.58%.
Dante Castellanos-Acuña; Kenneth W. Vance-Borland; J. Bradley St. Clair; Andreas Hamann; Javier López-Upton; Erika Gómez-Pineda; Juan Manuel Ortega-Rodríguez; Cuauhtémoc Sáenz-Romero
Seed zones for forest tree species are a widely used tool in reforestation programs to ensure that seedlings are well adapted to their planting environments. Here, we propose a climate-based seed zone system for Mexico to address observed and projected climate change. The proposed seed zone classification is based on bands of climate variables often related to genetic...
Maria Luiza de Souza Medeiros
Full Text Available This study aimed to adapt and test the efficiency of electrical conductivity methodology test in quality evaluation of Moringa oleifera Lam seeds. For physiological characterization four seed sets were evaluated by tests of germination, seedlings emergency, speed of emergency index, emergency first count, seedlings length and dry mass and cold test. The electrical conductivity test was carried out at 25 °C for 4, 8, 12, 16 and 24 h of immersion in 75 or 125 mL of distilled water using 25 or 50 seeds. A completely randomized design was used. The best results were obtained when using 50 seeds immersed in 75 mL or 125 mL of distilled water for 4 h. The electrical conductivity test adapted to moringa seeds was efficient in ranking sets of different vigor levels. The test may be efficiently used for physiological quality evaluation of moringa seeds.
Jiayun, Tong; Rui, He; Xiaoli, Zhang; Ruoting, Zhan; Weiwen, Chen [Key Laboratory of Chinese Medicinal Resource from Lingnan (Guangzhou University of Chinese Medicine), Ministry of Education, Guangzhou 510006 (China); Yang Size, E-mail: firstname.lastname@example.org [Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)
The objective of this paper is to demonstrate whether air plasma can change the seed germination characteristics, seedling emergence, as well as biochemical reactivity, in Andrographis paniculata (A. paniculata) seedlings by modifying the seed coat and finding a beneficial treatment dose. Eight treatment doses and one control were used to conduct electrical conductivity determination, a germination test, a seedling emergence test and a biochemical assay. The results showed that after being treated with air plasma excited at 5950 V for 10 s, the permeability of the seeds was improved significantly, resulting in the acceleration of seed germination and seedling emergence. In the meantime, the catalase activity and catalase isoenzyme expression were also improved, while the malondialdehyde content in the seedlings was decreased (which means greater counteraction with environmental stress). After being treated with 4250 V for 10 s and 5950 V for 20 s, the seed germination was enhanced, but without an obvious change in seedling emergence. However, after treatment with 3400 V for 20 s and 5100 V for 10 s, the permeability of the seeds was decreased, resulting in a delay in seedling emergence. These results indicate that air plasma can change the physiological and biochemical characteristics of Andrographis paniculata seeds by modifying the seed coat, combined with the effects of the active plasma species, and that different treating doses have different effects.
Tong Jiayun; He Rui; Zhang Xiaoli; Zhan Ruoting; Chen Weiwen; Yang Size
The objective of this paper is to demonstrate whether air plasma can change the seed germination characteristics, seedling emergence, as well as biochemical reactivity, in Andrographis paniculata (A. paniculata) seedlings by modifying the seed coat and finding a beneficial treatment dose. Eight treatment doses and one control were used to conduct electrical conductivity determination, a germination test, a seedling emergence test and a biochemical assay. The results showed that after being treated with air plasma excited at 5950 V for 10 s, the permeability of the seeds was improved significantly, resulting in the acceleration of seed germination and seedling emergence. In the meantime, the catalase activity and catalase isoenzyme expression were also improved, while the malondialdehyde content in the seedlings was decreased (which means greater counteraction with environmental stress). After being treated with 4250 V for 10 s and 5950 V for 20 s, the seed germination was enhanced, but without an obvious change in seedling emergence. However, after treatment with 3400 V for 20 s and 5100 V for 10 s, the permeability of the seeds was decreased, resulting in a delay in seedling emergence. These results indicate that air plasma can change the physiological and biochemical characteristics of Andrographis paniculata seeds by modifying the seed coat, combined with the effects of the active plasma species, and that different treating doses have different effects
Cao, Hui-ying; Wang, Ding-bo; Shi, Jian-guo; Zhu, Kun-lun; Dong, Shu-ting; Liu, Peng; Zhao, Bin; Zhang, Ji-wang
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.
Edilma Pereira Gonçalves
Full Text Available Ormosia arborea is a tree species planted in urban areas and used to restore degraded areas. Its seeds are dormant and propagation is difficult. This study compares different dormancy breaking methods and physiological seed quality and seedling production. The seeds were germinated in sand in the laboratory of the Universidade Estadual de Santa Cruz, Ilhéus, Bahia, Brazil. The following dormancy breaking treatments were applied: control (intact seeds, 100°C water immersion; boiling water immersion followed by 24 hours of soaking; scarification with number 100 and number 50 sandpaper opposite from root emergence; sulfuric acid immersion for 1 hour, 50, 45, and 30 minutes. Seed immersion in 100°C and boiling water did not break the dormancy. The study species showed a greater vigor of seedling when its seeds were submitted to treatments associated with tegument rupturing by sandpaper or sulfuric acid. On the other hand, seed scarification with sulfuric acid for 1 hour, 50, 45, and 30 minutes or sandpaper favored seed germination and vigor.
Ru, Sushan; Hardner, Craig; Carter, Patrick A; Evans, Kate; Main, Dorrie; Peace, Cameron
Seedling selection identifies superior seedlings as candidate cultivars based on predicted genetic potential for traits of interest. Traditionally, genetic potential is determined by phenotypic evaluation. With the availability of DNA tests for some agronomically important traits, breeders have the opportunity to include DNA information in their seedling selection operations—known as marker-assisted seedling selection. A major challenge in deploying marker-assisted seedling selection in clonally propagated crops is a lack of knowledge in genetic gain achievable from alternative strategies. Existing models based on additive effects considering seed-propagated crops are not directly relevant for seedling selection of clonally propagated crops, as clonal propagation captures all genetic effects, not just additive. This study modeled genetic gain from traditional and various marker-based seedling selection strategies on a single trait basis through analytical derivation and stochastic simulation, based on a generalized seedling selection scheme of clonally propagated crops. Various trait-test scenarios with a range of broad-sense heritability and proportion of genotypic variance explained by DNA markers were simulated for two populations with different segregation patterns. Both derived and simulated results indicated that marker-based strategies tended to achieve higher genetic gain than phenotypic seedling selection for a trait where the proportion of genotypic variance explained by marker information was greater than the broad-sense heritability. Results from this study provides guidance in optimizing genetic gain from seedling selection for single traits where DNA tests providing marker information are available. PMID:27148453
Jørgensen, T.; Hauser, Thure Pavlo; Bagger Jørgensen, Rikke
To obtain information on possible sources of contamination of the seed harvest of oilseed rape (Brassica napus L., spp. napus) by other varieties (adventitious presence), we investigated the purity of certified seed lots; the abundance and origin of volunteers; and longevity and origin of seeds...... in the soil seed-bank. This information was acquired through DNA analysis of volunteers collected in the field and seedlings derived from the soil seed-bank. DNA profiles of the volunteers and seedlings were obtained using Inter Simple Sequence Repeat (ISSR) markers, and the profiles were compared with ISSR...... profiles from an assortment of 14 of the most commonly cultivated oilseed rape varieties from 1985 to 2004. This comparison was performed using the assignment program, AFLPOP. The age of the seed bank germinating to become volunteers was assumed from information on previously cultivated oilseed rape...
Alejandro A. Royo; Walter P. Carson
In forests characterized by a dense woody and herbaceous understory layer, seedling recruitment is often directly suppressed via interspecific competition. Alternatively, these dense layers may indirectly lower tree recruitment by providing a haven for seed and seedling predators that prey on neighboring plant species. To simultaneously...
Kuznetsov, O.; Hasenstein, K.
Experiments for earth orbit are typically prepared on the ground and often germinated in orbit in order to study gravity effects on developing seedlings. Germination requires the breakdown of storage compounds and respiration. In orbit the formation of a water layer around the seed may further limit oxygen availability. Therefore, the oxygen content of the available gas volume is one of the limiting factors for seed germination. In preparation for an upcoming shuttle experiment (MICRO on STS-107) we studied germination and growth of flax (Linum usitatissimum L.) seedlings in the developed hardware. We tested per seed chamber (gas volume = 14 mL, O2 = 2.9 mL) between 4 to 32 seeds glued to germination paper by 1% (w/v) gum guar. A lexan cover and a gasket hermetically sealed each of the eight chambers. For imbibition of the seeds a previously optimized amount of distilled water was dispensed through sealed inlets. The seedlings were allowed to grow for either 32 to 48 h on a clinostat or without microgravity simulation. Then their root length was measured. With 32 seeds per chamber, four times the intended number of seeds for the flight, the germination rate decreased from 94 to 69%, and the root length was reduced by 20%. Experiments on the germination and root length in controlled atmospheres (5, 10, 15 and 21% O2 ) suggest that germination and growth for two days requires about 200 :l of O (1 mL air) per seed. Our2 experiments correlate oxygen dependency from seed mass and germination temperature, and analyze accumulation of gaseous metabolites (supported by NASA grant NAG10-0190).
Martins Cibele C.
Full Text Available The desiccation tolerance of Archontophoenix alexandrae (Wendl. & Drude seeds was determined and the most sensitive vigor test for assessing seed deterioration of this species was identified. Mature fruits were harvested in the palm collection of the Instituto Agronomico in Campinas, Brazil. Depulped fruits were transported in impermeable packages to the Faculdade de Agronomia in Botucatu, where the seeds were dried. As the seed moisture decreased, germination, seedling length, electrical conductivity and moisture were measured. The seeds of A. alexandrae are recalcitrant, with high germination percentage (over 67% when undried (47% seed moisture. Lowering seed moisture below 31.5% reduced the germination rate significantly (<52.5%. Total germination failure was observed when seed moisture reached 15.1%. The electrical conductivity was the most sensitive vigor test to identify seed deterioration.
Danielle Otte Carrara Castan
Full Text Available ABSTRACT: The refinement of vigor tests and the possibility of utilizing computer resources for the effective evaluation of the seed physiological potential have attracted considerable interest from research and seed technologists. The aim of this study was to evaluate the physiological potential of maize seeds using the newly-created Automated Analysis of Seed Vigor System (Vigor-S compared with other recommended seed vigor tests; two maize hybrids were used, each represented by seven seed lots. Germination and vigor (cold test, saturated salt accelerated aging, and field seedling emergence evaluations were conducted. For the evaluation of seed vigor with the use of seedling image analysis resources, two systems were compared: the Seed Vigor Imaging System (SVIS®, developed by Ohio State University, USA and the Vigor-S, resulting from collaboration between USP/ESALQ and EMBRAPA (Embrapa Instrumentation. Using these two systems, three day old seedlings were scanned and the images were analyzed. Similar results for the vigor index, uniformity of development, and seedling length were obtained. The computerized image analysis of seedlings using Vigor-S has advantages with respect to accuracy, speed, and the possibility of automatic application to a worksheet. It is a consistent alternative for the evaluation of maize seed vigor, and produces information compatible with that obtained by the accelerated aging test and SVIS®.
Mao, Peili; Han, Guangxuan; Wang, Guangmei; Yu, Junbao; Shao, Hongbo
Effects of age and stand density of mother tree on seed germination, seedling biomass allocation, and seedling growth of Pinus thunbergii were studied. The results showed that age of mother tree did not have significant influences on seed germination, but it was significant on seedling biomass allocation and growth. Seedlings from the minimum and maximum age of mother tree had higher leaf mass ratio and lower root mass ratio than from the middle age of mother tree. Moreover, they also had higher relative height growth rate and slenderness, which were related to their biomass allocation. Stand density of mother tree mainly demonstrated significant effects on seed germination and seedling growth. Seed from higher stand density of mother tree did not decrease germination rate, but had higher mean germination time, indicating that it delayed germination process. Seedlings of higher stand density of mother tree showed higher relative height growth rate and slenderness. These traits of offspring from higher stand density of mother tree were similar to its mother, indicating significant environmental maternal effects. So, mother tree identity of maternal age and environments had important effects on natural regeneration of the coastal P. thunbergii forest.
Adriano Gonçalves Pereira
Full Text Available Seed dormancy is a phenomenon observed in several tropical species. This condition causes low and non-uniform germination. The present study was designed to identify an efficient method of breaking seed dormancy in Stryphnodendron pulcherrimum. Seeds of four mother plants were subjected to the following treatments: immersion in sulfuric acid for 2, 4, 6, 8, 10 and 12 min and scarification on 150-grit sandpaper. Seeds were sown on substrate containing sand and sawdust (1:1. It was evaluate the days to onset seedlings emergence, seedlings emergence (SE, emergence speed index (ESI, germination (G, hard seeds (HS, dead seeds (DS, dormant seeds (DMS, abnormal seedlings (AS and dry mass of aerial part (DMAP and roots (DMR. The experimental design was completely randomized with four replications of 25 seeds for each treatment. Data were subjected to analysis of variance and means compared by Tukey’s test (p < 0.05. Significant differences among treatments were observed for ESI, SE, G, HS, DMAP and DMR. Highest HS was observed in control treatment (85%. Highest G was observed in seeds scarified with sulfuric acid for 10 min (82% and 12 min (74%. These treatments also showed highest ESI, DMAP and DMR, indicating that these scarification treatments were the most efficient in overcoming dormancy.
Efeito do tratamento de sementes com fungicidas e acibenzolar-S-methyl no controle da ferrugem asiática e crescimento de plântulas em cultivares de soja Effect of seed treatment with fungicides and acibenzolar-S-methyl in soybean cultivars on Asian rust control and seedlings growth
Full Text Available A influência de acibenzolar-S-methyl (ASM, e fungicidas aplicados via tratamento de sementes sobre a ferrugem asiática bem como o crescimento de plântulas de soja foi avaliada em experimento conduzido em casa de vegetação em delineamento inteiramente casualizado com três repetições, utilizando as cultivares de soja 'Agiara', 'M-soy 8000' e 'M-soy 8080'. Os tratamentos foram três doses de ASM (0,05; 0,1 e 0,2 g de i.a. por kg de sementes, ASM (na dose de 0,1 g de i.a. por kg de sementes combinado aos fungicidas flutriafol, pyraclostrobin e azoxystrobin, e a aplicação isolada destes, além de uma testemunha tratada com água. Os resultados mostraram redução da Área Abaixo da Curva de Progresso da Ferrugem (AACPF com o aumento da dose de ASM nas três cultivares de soja. A utilização isolada do ASM em diferentes doses proporcionou uma redução da AACPF além de apresentar, na maioria dos casos, um efeito sinérgico com os fungicidas, aumentando a eficiência de controle quando comparada às aplicações isoladas. Com exceção do ASM na menor dosagem, todos os tratamentos apresentaram controle superior a 77 % comparados à testemunha. Em geral, o tratamento de sementes com ASM e fungicidas resultou numa redução da massa seca (MS em relação à testemunha. A utilização de ASM associado a fungicidas na tentativa de atrasar a infecção da ferrugem asiática da soja nos períodos iniciais da cultura constitui-se em uma alternativa viável para redução do inóculo inicial, entretanto possíveis efeitos fitotóxicos devem ser considerados.The influence of acibenzolar-S-methyl (ASM and fungicides ASM in different doses provided reduction of AUPRC as well as it applied as seed treatment on Asian rust control as well as on growth presented synergism with the fungicides, increasing the control of soybean seedlings were evaluated in a completely randomized efficiency when compared to single applications. Except for ASM experiment with
Wen, Daxing; Hou, Hongcun; Meng, Aiju; Meng, Jie; Xie, Liuyong; Zhang, Chunqing
Seed vigor, an important index of seed quality, determines the potential for rapid and uniform emergence of plants. The objective of this study was to explore a rapid method for evaluating seed vigor. To analyze the correlation of seed traits and seedling traits related to seed vigor, we d