scholarly journals CHARACTERIZATION OF SYMBIOTIC EFFECTIVENESS OF RHIZOBIA NODULATING FIELD PEA (PISUM SATIVUM).

2020 ◽  
pp. 305-312
Author(s):  
Asrat MekonnenTeto
Keyword(s):  
Dry Weight ◽  
Sole Source ◽  
Field Pea ◽  
Growth Time ◽  
Nodule Occupancy ◽  
Shoot Dry Weight ◽  
Glucose Agar ◽  
Good Strain ◽  
Almost All

Field Pea is one of the most important Legumes plants and widely grown in Ethiopia. A study was made to re- isolate, characterize, and select best rhizobia for field pea. Results showed that all the 25 isolates exhibited typical colony characteristics and presumptive reactions of fast growing rhizobia. Out of the 25 isolates, 3(KL3, BR1 andCF5) relatively superior isolates were selected in sterilized sand. All isolates characterized their morphological and physiological characteristics. All isolates formed watery and mucoid colonies on YEMA medium, their mean growth time mostly between 2 &4 hours and failed to grow on peptone glucose agar medium and to solubilize inorganic phosphate. Almost all isolates were tolerated to pH 5to 9, 2% and 3% salt concentration, and at temperature of 15oC to 35oC. The isolates were also tolerant to erythromycin, streptomycin and ampicillin, and relatively sensitive to penicillin and chloroamphenicol at concentration of 50μg/ml. All isolates utilized to sucrose, glucanate, galactose and fructose as the sole source of carbon, and almost all isolates grow on YEMA medium containing galactose (90%), fructose (88.9%) and glucanate (76.7%) and the isolates utilized many amino acids as the source of nitrogen. BR1 was the most competitive inoculant with nodule occupancy of 75%; followed by KL3 and CF5 with nodule occupancy of 60 and 50% respectively. The mean nodule number, nodule dry weight, mean shoot dry weight and N content and of the host plants inoculated with different isolates showed variations. Particularly BR1 can be recommended as inoculants and good strain for field pea in the future.

scholarly journals Assessing Quantitative Criteria for Characterization of Quality Categories for Grafted Watermelon Seedlings

Horticulturae ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 16 ◽  
Author(s):  
Filippos Bantis ◽  
Athanasios Koukounaras ◽  
Anastasios Siomos ◽  
Georgios Menexes ◽  
Christodoulos Dangitsis ◽  
...  
Keyword(s):  
Dry Weight ◽  
The Other ◽  
Time Intervals ◽  
Important Species ◽  
Shoot Dry Weight ◽  
Shoot Ratio ◽  
Quality Categories ◽  
Critical Limits ◽  
Experienced Personnel

Vegetable grafting is a practice employed worldwide since it helps prevent biotic and abiotic disorders, and watermelon is one of the most important species grafted. The objective of this study was to set critical limits for the characterization of quality categories for grafted watermelon seedlings. Specifically, watermelon (scion) seedlings were grafted onto squash (rootstock) seedlings, moved into a healing chamber for 7 days, and then transferred into a greenhouse for seven more days. At 7 and 14 days after grafting, experienced personnel assessed grafted seedling quality by categorizing them. The categories derived were Optimum and Acceptable for both time intervals, plus Not acceptable at 14 days after grafting. Optimum seedlings showed greater leaf area, and shoot and root fresh and dry weights at both time intervals. Moreover, they had greater stem diameter, root-to-shoot ratio, shoot dry weight-to-length ratio and Dickson’s quality index compared to the other category at 14 days after grafting. Therefore, Optimum seedlings would likely develop into marketable plants of high quality, with better establishment in the field. Not acceptable seedlings showed considerably inferior development, while Acceptable seedlings were between the other categories, but were still marketable.

Rheological and functional characterization of a biopolymer obtained from Beijerinckia sp. / Caracterización reológica y funcional de un biopolímero obtenido de Beijerinckia sp

1996 ◽  
Vol 2 (6) ◽  
pp. 405-411
Author(s):  
L.P. Martínez-Padilla ◽  
N. Cabada-Celis
Keyword(s):  
Food Industry ◽  
Culture Media ◽  
Functional Characterization ◽  
Dry Weight ◽  
Rheological Parameters ◽  
Power Law Model ◽  
Condi Tions ◽  
Almost All ◽  
Potential Use

An exopolysaccharide producer, Beijerinckia sp. was isolated and identified from a sample of soil. A sample of 10.3 g (dry weight) of polysaccharide/L was obtained by fermentation on liquid Czapek culture media supplemented with yeast extract. The functionality of the biopolymer was characterized for its potential use by the food industry. It showed shear thinning behaviour (pseudoplastic). The effects of concentration, temperature and pH were evaluated; almost all of the salts had no effect on rheological parameters of the power law model. There was a linear rela tionship between the percent of remaining emulsion after centrifugation and the polysaccharide biopolymer concentration, demonstrating the stabilizing effect of biopolymer on the emulsion. In contrast, the biopolymer was not able to form a gel under various pH and temperature condi tions, or with the addition of ions.

scholarly journals Competitiveness of Bradyrhizobium japonicum inoculation strain for soybean nodule occupancy  

2022 ◽  
Author(s):  
Dragana Miljakovic ◽  
Jelena Marinković ◽  
Maja Ignjatov ◽  
Dragana Milosević ◽  
Zorica Nikolić ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Bradyrhizobium Japonicum ◽  
Dry Weight ◽  
Soil Conditions ◽  
Nodule Occupancy ◽  
Enterobacterial Repetitive Intergenic Consensus ◽  
Shoot Dry Weight ◽  
Soybean Nodule ◽  
Commercial Inoculant ◽  
Selection For

The competitiveness of Bradyrhizobium japonicum inoculation strain against indigenous rhizobia was examined in a soil pot experiment. The effect of inoculation strain was evaluated under different soil conditions: with or without previously grown soybean and applied commercial inoculant. Molecular identification of inoculation strain and investigated rhizobial isolates, obtained from nodules representing inoculated treatments, was performed based on 16S rDNA and enterobacterial repetitive intergenic consensus (ERIC) sequencing. Inoculation strain showed a significant effect on the investigated parameters in both soils. Higher nodule occupancy (45% vs. 18%), nodule number (111% vs. 5%), nodule dry weight (49% vs. 9%), shoot length (15% vs. 7%), root length (31% vs. 13%), shoot dry weight (34% vs. 11%), shoot nitrogen content (27% vs. 2%), and nodule nitrogen content (9% vs. 5%) was detected in soil without previously grown soybean and applied commercial inoculant. Soil had a significant effect on the shoot, root and nodule nitrogen content, while interaction of experimental factors significantly altered dry weight and nitrogen content of shoots, roots and nodules, as well as number of nodules. Nodulation parameters were significantly related with shoot dry weight, shoot and nodule nitrogen content. Symbiotic performance of inoculation strains in the field could be improved through co-selection for their competitiveness and effectiveness.  

scholarly journals Mitigation of Salt Stress in Lettuce (Lactuca sativa L. var. Crispa) by Seed and Foliar 24-epibrassinolide Treatments

HortScience ◽  
2012 ◽  
Vol 47 (5) ◽  
pp. 631-636 ◽  
Author(s):  
Melek Ekinci ◽  
Ertan Yildirim ◽  
Atilla Dursun ◽  
Metin Turan
Keyword(s):  
Salt Stress ◽  
Lactuca Sativa ◽  
Electrolyte Leakage ◽  
Mineral Content ◽  
Dry Weight ◽  
Nutrient Content ◽  
Fresh Weight ◽  
Shoot Dry Weight ◽  
Negative Effect ◽  
Almost All

The objective of this study was to determine the effect of 24-epibrassinolide (24-EBL) applications on growth, chlorophyll, and mineral content of lettuce (Lactuca sativa L. var. Crispa) grown under salt stress. The study was conducted in pot experiments under greenhouse conditions. Lettuce seedlings were treated with seed and foliar 24-EBL applications at different concentrations (0, 1, 2, and 3 μM). Salinity treatments were established by adding 0, 50, and 100 mm of sodium chloride (NaCl) to a base complete nutrient solution. Results showed that salt stress negatively affected the growth and mineral content of lettuce plants. However, seed and foliar applications of 24-EBL resulted in greater shoot fresh weight, shoot dry weight, root fresh weight, and root dry weight as well as higher stem diameter than the control under salt stress. Salinity treatments induced significant increases in electrolyte leakage of plant, but foliar 24-EBL application reduced leaf electrolyte leakage and has determined lower values of leaf electrolyte leakage than non-treated ones. In regard to nutrient content, it can be inferred that 24-EBL applications increased almost all nutrient content in leaves and roots of lettuce plants under salt stress. Generally, the greatest values were obtained from 3 μM 24-EBL application. Treatments of 24-EBL alleviated the negative effect of salinity on the growth of lettuce.

scholarly journals Isolation and Characterization of Chickpea (Cicer arietinum L.) Nodulating Rhizobia Collected from South Wollo Zone, Ethiopia

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Gedefaw Wubie ◽  
Mussa Adal
Keyword(s):  
Nitrogen Source ◽  
Carbon Sources ◽  
Dry Weight ◽  
Maximum Temperature ◽  
High Concentration ◽  
Carbohydrate Utilization ◽  
Shoot Dry Weight ◽  
Isolation And Characterization ◽  
Almost All

This study aimed at screening rhizobial isolates of chickpea and evaluating their symbiotic nitrogen fixation efficiency and tolerance to abiotic stresses. A total of 107 (100%) isolates were collected of which 52 (48.6%) were confirmed as chickpea rhizobia using preliminary tests. Among 52 (48.6%) isolates, 46 (88.5%) have induced nodulation on chickpea under greenhouse and were screened under in vitro conditions and 6 (11.5%) of them were discarded due to fail to nodulate. The greenhouse data showed the highest nodule number (68.67 plant−1), nodule dry weight (0.17 g plant−1), and shoot dry weight (0.81 g plant−1) were scored by plants inoculated with isolates WUCR 17, WUCR 1, and WUCR 66, respectively. Among authenticated isolates, 73.9%, 21.7%, and 4.3% were highly effective, effective, and lowly effective, respectively. The physiological test showed 15% of isolates tolerated 13% salt concentration and 10.9% of isolates grew at pH 4–10 range. All isolates grew at 20–35°C and 13% grew at maximum temperature (50°C). The isolates showed better resistance to the tested antibiotics at low concentration (2.5 μg/ml) but the majorities were sensitive at high concentration (10 μg/ml). Among the isolates, 13% tolerated all tested heavy metals but 48% were sensitive to mercury. Regarding the carbohydrate utilization test, 52.2% catabolized all the tested 11 carbon sources but 6.5% of them utilized only 63.6% carbon sources. Amino acid utilization showed isolates (85%) utilized D-alanine except WUCR (14, 25, 31, 34, 39, 59, and 76) and 76% of the isolates utilized arginine and phenylalanine and 74% utilized leucine as a nitrogen source. Of the isolates, 43.5% of them utilized both D-alanine and arginine as a nitrogen source. In almost all tests conducted, isolates WUCR 1 and 5 performed top and were recommended as potential candidates for microbial inoculants.

scholarly journals Variation in Terpene Profiles of Thymus vulgaris in Water Deficit Stress Response

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1091 ◽  
Author(s):  
Atiyeh Mahdavi ◽  
Parviz Moradi ◽  
Andrea Mastinu
Keyword(s):  
Drought Stress ◽  
Stress Response ◽  
Water Deficit ◽  
Abiotic Stress Tolerance ◽  
Dry Weight ◽  
Water Deficit Stress ◽  
Thymus Vulgaris ◽  
Shoot Dry Weight ◽  
Tolerant Plants ◽  
Almost All

Thyme (Thymus spp.) volatiles predominantly consisting of monoterpenes and sesquiterpenes, serve as antimicrobial, antiseptic and antioxidant in phytomedicine. They also play a key role in plants as secondary metabolites via their potential role against herbivores, attracting pollinators and abiotic stress tolerance. Plant volatiles are affected by different environmental factors including drought. Here, the effect of prolonged water deficit stress on volatile composition was studied on the sensitive and tolerant thyme plant cultivars (T. vulgaris Var. Wagner and T. vulgaris Var. Varico3, respectively). Volatile sampling along with morpho–physiological parameters such as soil moisture, water potential, shoot dry weight, photosynthetic rate and water content measurements were performed on one-month-old plants subsequent to water withholding at 4-day intervals until the plants wilted. The tolerant and sensitive plants had clearly different responses at physiological and volatile levels. The most stress-induced changes on the plants’ physiological traits occurred in the photosynthetic rates, where the tolerant plants maintained their photosynthesis similar to the control ones until the 8th day of the drought stress period. While the analysis of the volatile compounds (VOCs) of the sensitive thyme plants displayed the same pattern for almost all of them, in the tolerant plants, the comparison of the pattern of changes in the tolerant plants revealed that the changes could be classified into three separate groups. Our experimental and theoretical studies totally revealed that the most determinant compounds involved in drought stress adaptation included α-phellandrene, O-cymene, γ-terpinene and β-caryophyelene. Overall, it can be concluded that in the sensitive plants trade-off between growth and defense, the tolerant ones simultaneously activate their stress response mechanism and continue their growth.

Characterization of frozen hydrated biological specimens by low-loss EELS

1992 ◽  
Vol 50 (2) ◽  
pp. 1572-1573
Author(s):  
Songquan Sun ◽  
Richard D. Leapman
Keyword(s):  
Water Content ◽  
Direct Method ◽  
Internal Standard ◽  
Dry Weight ◽  
Dark Field ◽  
Protein Solutions ◽  
Subcellular Compartment ◽  
Differential Shrinkage ◽  
Electron Energy Loss

Analyses of ultrathin cryosections are generally performed after freeze-drying because the presence of water renders the specimens highly susceptible to radiation damage. The water content of a subcellular compartment is an important quantity that must be known, for example, to convert the dry weight concentrations of ions to the physiologically more relevant molar concentrations. Water content can be determined indirectly from dark-field mass measurements provided that there is no differential shrinkage between compartments and that there exists a suitable internal standard. The potential advantage of a more direct method for measuring water has led us to explore the use of electron energy loss spectroscopy (EELS) for characterizing biological specimens in their frozen hydrated state.We have obtained preliminary EELS measurements from pure amorphous ice and from cryosectioned frozen protein solutions. The specimens were cryotransfered into a VG-HB501 field-emission STEM equipped with a 666 Gatan parallel-detection spectrometer and analyzed at approximately −160 C.

A Thorough Theoretical Exploration of Intriguing Characteristics of Cyclo[18]carbon: Geometry, Bonding Nature, Aromaticity, Weak Interaction, Reactivity, Excited States, Vibrations, Molecular Dynamics and Various Molecular Properties

2019 ◽  
Author(s):  
Tian Lu ◽  
Qinxue Chen ◽  
Zeyu Liu
Keyword(s):  
Molecular Dynamics ◽  
Excited States ◽  
Electronic Excitation ◽  
Ring Structure ◽  
Molecular Properties ◽  
Molecular Vibration ◽  
Full Characterization ◽  
Long Time ◽  
Almost All

Although cyclo[18]carbon has been theoretically and experimentally investigated since long time ago, only very recently it was prepared and directly observed by means of STM/AFM in condensed phase (Kaiser et al., <i>Science</i>, <b>365</b>, 1299 (2019)). The unique ring structure and dual 18-center π delocalization feature bring a variety of unusual characteristics and properties to the cyclo[18]carbon, which are quite worth to be explored. In this work, we present an extremely comprehensive and detailed investigation on almost all aspects of the cyclo[18]carbon, including (1) Geometric characteristics (2) Bonding nature (3) Electron delocalization and aromaticity (4) Intermolecular interaction (5) Reactivity (6) Electronic excitation and UV/Vis spectrum (7) Molecular vibration and IR/Raman spectrum (8) Molecular dynamics (9) Response to external field (10) Electron ionization, affinity and accompanied process (11) Various molecular properties. We believe that our full characterization of the cyclo[18]carbon will greatly deepen researchers' understanding of this system, and thereby help them to utilize it in practice and design its various valuable derivatives.

A Thorough Theoretical Exploration of Intriguing Characteristics of Cyclo[18]carbon: Geometry, Bonding Nature, Aromaticity, Weak Interaction, Reactivity, Excited States, Vibrations, Molecular Dynamics and Various Molecular Properties

2019 ◽  
Author(s):  
Tian Lu ◽  
Qinxue Chen ◽  
Zeyu Liu
Keyword(s):  
Molecular Dynamics ◽  
Excited States ◽  
Electronic Excitation ◽  
Ring Structure ◽  
Molecular Properties ◽  
Molecular Vibration ◽  
Full Characterization ◽  
Long Time ◽  
Almost All

Although cyclo[18]carbon has been theoretically and experimentally investigated since long time ago, only very recently it was prepared and directly observed by means of STM/AFM in condensed phase (Kaiser et al., <i>Science</i>, <b>365</b>, 1299 (2019)). The unique ring structure and dual 18-center π delocalization feature bring a variety of unusual characteristics and properties to the cyclo[18]carbon, which are quite worth to be explored. In this work, we present an extremely comprehensive and detailed investigation on almost all aspects of the cyclo[18]carbon, including (1) Geometric characteristics (2) Bonding nature (3) Electron delocalization and aromaticity (4) Intermolecular interaction (5) Reactivity (6) Electronic excitation and UV/Vis spectrum (7) Molecular vibration and IR/Raman spectrum (8) Molecular dynamics (9) Response to external field (10) Electron ionization, affinity and accompanied process (11) Various molecular properties. We believe that our full characterization of the cyclo[18]carbon will greatly deepen researchers' understanding of this system, and thereby help them to utilize it in practice and design its various valuable derivatives.

Physicochemical and bacteriological characterization of hospital effluents and their impact on the environment

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Human Health ◽  
Fecal Coliforms ◽  
Chemical Pollution ◽  
Hospital Effluents ◽  
Biological Contaminants ◽  
Almost All ◽  
Direct Discharge ◽  
Significant Chemical

Liquid effluents discharged by hospitals may contain chemical and biological contaminants whose main source is the different substances used for the treatment of patients. This type of rejection can present a sanitary potentially dangerous risk for human health and can provoke a strong degradation of diverse environmental compartments mainly water and soils. The present study focuses on the quality of the liquid effluents of Hassani Abdelkader’s hospital of Sidi Bel-Abbes (West of Algeria). The results reveal a significant chemical pollution (COD: 879 mgO2/L, BOD5: 850 mgO2/L, NH4+ : 47.9 mg/l, NO2- : 4.2 mg/l, NO3- : 56.8 mg/l with respect to WHO standard of 90 mgO2/L, 30 mgO2/L, 0.5 mg/l, 1 mg/l and 1 mg/l respectively). However, these effluents are biodegradable since the ratio COD/BOD5 do not exceeded the value of 2 in almost all samples. The presence of pathogen germs is put into evidence such as pseudomonas, the clostridium, the staphylococcus, the fecal coliforms and fecal streptococcus. These results show that the direct discharge of these effluents constitutes a major threat to human health and the environment.

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