76 research outputs found
The use of SSR-markers in rice breeding for resistance to blast and submergence tolerance
Received: March 16th, 2022 ; Accepted: July 20th, 2022 ; Published: September 6th, 2022 ; Correspondence: [email protected] identification of effective specialized DNA markers providing the clear control of
target locus inheritance by the trait of submergence tolerance has been conducted. Among the
studied set of microsatellite markers, two the most informative SSR-markers - RM 7481, PrC3
showed high efficiency in detecting intraspecific polymorphism of rice varieties and lines used
in the work. With the use of these markers the clear genotype marking the obtained hybrid rice
plants by this trait has been conducted and it is has been verified by phenotype evaluation as a
result of laboratory trials. The plant samples carrying the target gene in heterozygous and
homozygous state has been selected. About 400 backcrossed self-pollinated rice lines with
introgressed and pyramided resistance genes Pi-1, Pi-2, Pi-33, Pi-ta, Pi-b to Pyricularia oryzae
Cav. were obtained within the frameworks of program to develop genetic rice sources resistant
to blast. The conducted testing for resistance to blast and the assessment by economically valuable
traits have allowed to select the prospective rice samples. The plant samples of F2 and BC1F1
generations with combination of resistance to blast genes (Pi) and submergence tolerance gene
(Sub1A) in homozygous and heterozygous state that is confirmed be the results of analysis of
their DNA have been obtained. The obtained hybrid plants are being tested in breeding nurseries
for a complex of economically valuable traits. The best plants will be selected and send to State
Variety Testing system. Their involving in rice industry will reduce the use of plant protection
chemicals against diseases and weeds, thereby increasing the ecology status of the rice industry
Properties of low-lying states in some high-nuclearity Mn, Fe and V clusters: Exact studies of Heisenberg models
Using an efficient numerical scheme that exploits spatial symmetries and spin
parity, we have obtained the exact low-lying eigenstates of exchange
Hamiltonians for the high nuclearity spin clusters, Mn_{12}, Fe_8 and V_{15}.
The largest calculation involves the Mn_{12} cluster which spans a Fock space
of a hundred million. Our results show that the earlier estimates of the
exchange constants need to be revised for the Mn_{12} cluster to explain the
level ordering of low-lying eigenstates. In the case of the Fe_8 cluster,
correct level ordering can be obtained which is consistent with the exchange
constants for the already known clusters with butterfly structure. In the
V_{15} cluster, we obtain an effective Hamiltonian that reproduces exactly, the
eight low-lying eigenvalues of the full Hamiltonian.Comment: Revtex, 12 pages, 16 eps figures; this is the final published versio
On the possibility of magneto-structural correlations: detailed studies of di-nickel carboxylate complexes
A series of water-bridged dinickel complexes of the general formula [Ni<sub>2</sub>(μ<sub>2</sub>-OH<sub>2</sub>)(μ2-
O<sub>2</sub>C<sup>t</sup>Bu)<sub>2</sub>(O<sub>2</sub>C<sup>t</sup>Bu)2(L)(L0)] (L = HO<sub>2</sub>C<sup>t</sup>Bu, L0 = HO<sub>2</sub>C<sup>t</sup>Bu (1), pyridine (2),
3-methylpyridine (4); L = L0 = pyridine (3), 3-methylpyridine (5)) has been synthesized
and structurally characterized by X-ray crystallography. The magnetic properties
have been probed by magnetometry and EPR spectroscopy, and detailed measurements
show that the axial zero-field splitting, D, of the nickel(ii) ions is on the same order as
the isotropic exchange interaction, J, between the nickel sites. The isotropic exchange
interaction can be related to the angle between the nickel centers and the bridging
water molecule, while the magnitude of D can be related to the coordination sphere at
the nickel sites
Hydrocarbon Oxidation with H2O2, Catalyzed by Iron Complexes with a Polydentate Pyridine-Based Ligand
On the Possibility of Magneto-Structural Correlations: Detailed Studies of Dinickel Carboxylate Complexes
Structure and Properties of Perfluoroalkylated Phthalocyanines. A Theoretical Study
Density functional theory (DFT) calculations are performed on a series of peripherally substituted free-base and fluorinated zinc phthalocyanines, namely FnPcM (M = 2H, Zn; n = 16, 32, 48, 64). F16PcM, F32PcM, and F48PcM all prefer a planar skeletal structure of the metallomacrocycle core. In the case of F64Pc, F64PcZn remains planar but F64PcH2 is domed. The occurrence of a dome distortion appears to be related, at least in part, to the orientation of the isopropyl -C3F7 substituents as well as to the intermolecular (packing) interactions. The trends in the calculated results of the Pc2-–M2+ binding energy, polarizabilities, and electron excitation energies in H16PcM, F16PcM, and F64PcM are in agreement with the experimental observations, as are the geometrical features. It is further confirmed that the simpler F32PcM or F48PcM mimic the basic electronic properties of F64PcM
Effects of Peripheral Substituents on the Electronic Structure and Properties of Unligated and Ligated Metal Phthalocyanines, Metal = Fe, Co, Zn
The effects of peripheral, multiple −F as well as −C2F5 substituents, on the electronic structure and properties of unligated and ligated metal phthalocyanines, PcM, PcM(acetone)2 (M = Fe, Co, Zn), PcZn(Cl), and PcZn(Cl-), have been investigated using a DFT method. The calculations provide a clear explanation for the changes in the ground state, molecular orbital (MO) energy levels, ionization potentials (IP), electron affinities (EA), charge distribution on the metal (QM), axial binding energies, and in electronic spectra. While the strongly electron-withdrawing −C2F5 groups on the Pc ring change the ground state of PcFe, they do not influence the ground state of PcCo. The IP is increased by 1.3 eV from H16PcM to F16PcM and by another 1.1 eV from F16PcM to F48PcM. A similar increase in the EA is also found on going from H16PcM to F48PcM. Substitution by the −C2F5 groups also considerably increases the binding strength between PcM and the electron-donating axial ligand(s). Numerous changes in chemical and physical properties observed for the F64PcM compounds can be accounted for by the calculated results
Photoelectrochemical behavior of phthalocyanine-sensitized TiO\u2082 in the presence of electron-shuttling mediators
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