scholarly journals Breeding Polyploid Varieties of Acacia: Reproductive and Early Growth Characteristics of the Allotetraploid Hybrid (Acacia mangium × A. auriculiformis) in Comparison with Diploid Progenitors

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 778
Author(s):  
Son Le ◽  
Rod A. Griffin ◽  
Christopher E. Harwood ◽  
René E. Vaillancourt ◽  
Jane L. Harbard ◽  
...  
Keyword(s):  
Inbreeding Depression ◽  
Low Frequency ◽  
Acacia Mangium ◽  
Breeding Strategy ◽  
Hybrid Vigor ◽  
Diploid Hybrid ◽  
High Productivity ◽  
Hybrid Clones ◽  
Allotetraploid Hybrid

Diploid clones of the hybrid acacia (Acacia mangium × A. auriculiformis) are widely planted in Vietnam because of their high productivity, adaptability, and commercial wood yields. Polyploid breeding offers possibilities for further enhancing hybrid vigor and generating new high value genotypes. In a field trial, we compared three diploid hybrid clones with their respective colchicine-induced tetraploid lines. Flowering and seed production of each cytotype were observed and open pollinated seed collected for determination of outcrossing rate and ploidy, inbreeding depression and marker inheritance in the progeny. Comparisons are also made with published characteristics of autotetraploids derived from A. mangium. Compared with their corresponding diploid cytotypes, the allotetraploids flowered slightly later but more intensely; produced the same number of seeds per pod but larger seeds; and showed a greatly reduced level of outcrossing (an average of 14% compared with 87%). Inbreeding depression for height growth was less for progeny from the allotetraploid lines (17%) than for those from the original diploids (33%). 96% of seeds from the allotetraploid clones were also tetraploid, but we observed triploids at low frequency at both the seed and field progeny stages. The segregation of the molecular markers in outcrossed allotetraploid progenies demonstrated both disomic and tetrasomic inheritance, indicating that the hybrid behaves as a segmental allotetraploid. Results suggest that an open pollinated breeding strategy is a practical option for improving polyploid acacia hybrids.

Magnetic Permeability and Relaxation Frequency in High Frequency Magnetic Materials.

2001 ◽  
Vol 674 ◽  
Author(s):  
M.I. Rosales ◽  
H. Montiel ◽  
R. Valenzuela
Keyword(s):  
High Frequency ◽  
Domain Walls ◽  
Magnetocrystalline Anisotropy ◽  
Low Frequency ◽  
Frequency Dispersion ◽  
Anisotropy Constant ◽  
Relaxation Frequency ◽  
Resonance Relaxation ◽  
Frequency Behavior

ABSTRACTAn investigation of the frequency behavior of polycrystalline ferrites is presented. It is shown that the low frequency dispersion (f < 10 MHz) of permeability is associated with the bulging of pinned domain walls, and has a mixed resonance-relaxation character, closer to the latter. It is also shown that there is a linear relationship between the magnetocrystalline anisotropy constant, K1, and the relaxation frequency. The slope of this correlation depends on the grain size. Such a relationship could allow the determination of this basic parameter from polycrystalline samples.

The low frequency motions of solvated Mn(ii) and Ni(ii) ions and their halide complexes

2014 ◽  
Vol 16 (45) ◽  
pp. 25101-25110 ◽  
Author(s):  
Vinay Sharma ◽  
Fabian Böhm ◽  
Gerhard Schwaab ◽  
Martina Havenith
Keyword(s):  
Low Frequency ◽  
Hydration Water ◽  
P Concentration ◽  
Halide Complexes ◽  
Absorption Measurements

Concentration dependent THz/FIR absorption measurements allow determination of individual solvated ion resonances and their influence on the hydration water spectrum.

Methyl Isocyanide: The Low-Frequency Bands ν8 and ν7, and a Determination of the Rotational Constant A0

1995 ◽  
Vol 173 (2) ◽  
pp. 423-430 ◽  
Author(s):  
J. Pliva ◽  
L.D. Le ◽  
J.W.C. Johns ◽  
Z. Lu ◽  
R.A. Bernheim
Keyword(s):  
Low Frequency ◽  
Rotational Constant ◽  
Frequency Bands ◽  
Methyl Isocyanide

Determination of Electric and Magnetic Properties of Commercial LTCC Soft Ferrite Material

2011 ◽  
Vol 8 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Nelu Blaž ◽  
Andrea Marić ◽  
Goran Radosavljević ◽  
Nebojša Mitrović ◽  
Ibrahim Atassi ◽  
...  
Keyword(s):  
Electrical Properties ◽  
Low Frequency ◽  
Hysteresis Loops ◽  
Frequency Range ◽  
Dispersion Parameters ◽  
Simple Method ◽  
Component Design ◽  
Microwave Engineering ◽  
Characterization Procedure

This paper offers an effective, accurate, and simple method for permittivity and permeability determination of an LTCC (low temperature cofired ceramic) ferrite sample. The presented research can be of importance in the fields of ferrite component design and application, as well as for RF and microwave engineering. The characterization sample is a stack of LTCC tapes forming a toroid. Commercially available ferrite tape ESL 40012 was used and standard LTCC processing was applied for the sample fabrication. For the first time, the electrical properties of a ferrite toroid sample of ESL 40012 LTCC ferrite tape is presented at various frequencies. The electrical properties of LTCC ferrite materials, permittivity and specific resistivity, are shown in a frequency range from 10 kHz to 1 MHz using the capacitive method. The hysteresis properties of this material are also determined. B-H hysteresis loops were measured applying a maximum excitation of 2 kA/m and frequencies of 50 Hz, 500 Hz, and 1000 Hz. Permeability is determined in the frequency range from 10 kHz to 1 GHz and a characterization procedure is divided in two segments, for low and high frequencies. Low frequency measurements (from 10 kHz to 1 MHz) are performed using LCZ meter and discrete turns of wire, while a short coaxial sample holder and vector network analyzer were used for the higher frequency range (from 300 kHz to 1 GHz). In addition, another important factor required for the practical design of devices is presented, the temperature variation of the permeability dispersion parameters.

scholarly journals Increase of nutrients export and production of pitaya whit potassium fertilization

2020 ◽  
Vol 11 ◽  
pp. e3276
Author(s):  
Josimara Mendes Rabelo ◽  
Maria do Céu Monteiro Cruz ◽  
Nubia Cassiana Santos ◽  
Deilson de Almeida Alves ◽  
João Esdras Lima ◽  
...  
Keyword(s):  
Dry Matter ◽  
Nutritional Requirements ◽  
Nutrient Export ◽  
Plant Nutrient ◽  
High Productivity ◽  
Potassium Fertilization ◽  
Hylocereus Undatus ◽  
Hylocereus Polyrhizus

Characterization works of pitayas show that the potassium (K) is the nutrient most exported, thus, influences in the productivity and quality of this fruit. However, these researches do not report the nutrients export by pitaya's associating the fertilization carried out in the orchard, information that is relevant to make the nutrients reposition adequate at the time of fertilization. The research was carried out to evaluate the supply of K2O in the export of nutrients and productivity of the Hylocereus undatus and Hylocereus polyrhizus pitaya species. The analysis was carried out in the mature fruits harvested in two harvests. Potassium fertilization was performed at doses of 0; 50; 100 and 200 g of K2O per plant. Nutrient export per ton of fruit was calculated from the determination of the nutrient levels and the dry matter of the pitaya pulp. The export of nutrients by the pitaya of the species H. undatus and H. polyrhizus occurs in the following order: K>N>P>Ca>Mg> and Mn>Fe>Cu>Zn>B. These species of pitaya have similar nutritional requirements, enabling them to be receive same fertilization management. The amount of nutrients exported was higher in plants fertilized with potassium due to the higher productivity achieved. Orchards of pitaya that reach high productivity require a greater quantity of nutrients, due to the increase export by the fruits.

scholarly journals Polymorphisms in Brucella Carbonic anhydrase II mediate CO2 dependence and fitness in vivo

2019 ◽  
Author(s):  
JM García-Lobo ◽  
Y Ortiz ◽  
C González-Riancho ◽  
A Seoane ◽  
B Arellano-Reynoso ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Primary Cultures ◽  
Low Frequency ◽  
Carbonic Anhydrase Ii ◽  
Carbonic Anhydrases ◽  
Significant Difference ◽  
Dependent Strain

AbstractSome Brucella isolates are known to require an increased concentration of CO2 for growth, especially in the case of primary cultures obtained directly from infected animals. Moreover, the different Brucella species and biovars show a characteristic pattern of CO2 requirement, and this trait has been included among the routine typing tests used for species and biovar differentiation. By comparing the differences in gene content among different CO2-dependent and CO2-independent Brucella strains we have confirmed that carbonic anhydrase II (CA II), is the enzyme responsible for this phenotype in all the Brucella strains tested. Brucella species contain two carbonic anhydrases of the β family, CA I and CA II; genetic polymorphisms exist for both of them in different isolates, but only those putatively affecting the activity of CA II correlate with the CO2 requirement of the corresponding isolate. Analysis of these polymorphisms does not allow the determination of CA I functionality, while the polymorphisms in CA II consist of small deletions that cause a frameshift that changes the C-terminus of the protein, probably affecting its dimerization status, essential for the activity.CO2-independent mutants arise easily in vitro, although with a low frequency ranging from 10−6 to 10−10 depending on the strain. These mutants carry compensatory mutations that produce a full length CA II. At the same time, no change was observed in the sequence coding for CA I. A competitive index assay designed to evaluate the fitness of a CO2-dependent strain compared to its corresponding CO2-independent strain revealed that while there is no significant difference when the bacteria are grown in culture plates, growth in vivo in a mouse model of infection provides a significant advantage to the CO2-dependent strain. This could explain why some Brucella isolates are CO2-dependent in primary isolation. The polymorphism described here also allows the in silico determination of the CO2 requirement status of any Brucella strain.

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