Analysis of Genetic Diversity in the North Eastern Himalayan Maize Landraces using Microsatellite Markers

Population DNA fingerprinting of 48 selected North Eastern Himalayan (NEH) landrace accessions was undertaken using 41 polymorphic fluorescent dye-labelled microsatellite/Simple Sequence Repeat (SSR) markers, using a DNA Sequencer. The analysis revealed a large number of SSR alleles (576), with high mean number of alleles per locus (13.8), and Polymorphism Information Content (PIC) of 0.63, reflecting the level of diversity in the NEH accessions and the informativeness of the SSR markers. The study also led to identification of 135 unique alleles, differentiating 44 out of the 48 accessions. Five highly frequent (major) SSR alleles (umc1545 _80bp, phi062 _162bp, umc1367 _159bp, umc2250 _152bp and phi112 _152bp) were detected indicating that chromosomal regions harbouring these S SR alleles might not be selectively neutral. Analysis of population genetic parameters, including Wright’s F statistics, revealed high level of genetic differentiation, very low levels of inbreeding, and restricted gene flow between the NEH landraces. AMOVA (Analysis of Molecular Variance) showed that 67 per cent of the total variation in the accessions could be attributed to within-population diversity, and the rest between the accessions. Cluster analysis of SSR data using Rogers’ genetic distance and UPGMA, showed significant genetic diversity among the landraces from Sikkim. This is the first detailed study of SSR allele frequency-based analysis of genetic diversity in the NEH maize landraces of India.     

Synthesis, antioxidant and toxicological study of novel pyrimido quinoline derivatives from 4-hydroxy-3-acyl quinolin-2-one

A series of novel pyrimido and other fused quinoline derivatives like 4-methyl pyrimido [5,4-c]quinoline-2,5(1H,6H)-dione (4a), 4-methyl-2-thioxo-1,2-dihydropyrimido [5,4-c]quinoline-5(6H)-one (4b), 2-amino-4-methyl-1,2-dihydropyrimido [5,4-c]quinolin-5(6H)-one (4c), 3-methylisoxazolo [4,5-c]quinolin-4(5H)-one (4d), 3-methyl-1H-pyrazolo [4,3-c]quinoline-4(5H)-one (5e), 5-methyl-1H-[1,2,4] triazepino [6,5-c]quinoline-2,6(3H,7H)-dione (5f), 5-methyl-2-thioxo-2,3-dihydro-1H-[1,2,4]triazepino [6,5-c]quinolin-6(7H)-one (5 g) were synthesized regioselectively from 4-hydroxy-3-acyl quinolin-2-one 3. They were screened for their in vitro antioxidant activities against radical scavenging capacity using DPPH(), Trolox equivalent antioxidant capacity (TEAC), total antioxidant activity by FRAP, superoxide radical (O(2)(°-)) scavenging activity, metal chelating activity and nitric oxide scavenging activity. Among the compounds screened, 4c and 5 g exhibited significant antioxidant activities.     

Functional characterization of ecdysone receptor gene switches in mammalian cells

Regulated expression of transgene is essential in basic research as well as for many therapeutic applications. The main purpose of the present study is to understand the functioning of the ecdysone receptor (EcR)-based gene switch in mammalian cells and to develop improved versions of EcR gene switches. We utilized EcR mutants to develop new EcR gene switches that showed higher ligand sensitivity and higher magnitude of induction of reporter gene expression in the presence of ligand. We also developed monopartite versions of EcR gene switches with reduced size of the components that are accommodated into viral vectors. Ligand binding assays revealed that EcR alone could not bind to the nonsteroidal ligand, RH-2485. The EcR's heterodimeric partner, ultraspiracle, is required for efficient binding of EcR to the ligand. The essential role of retinoid X receptor (RXR) or its insect homolog, ultraspiracle, in EcR function is shown by RXR knockdown experiments using RNAi. Chromatin immunoprecipitation assays demonstrated that VP16 (activation domain, AD):GAL4(DNA binding domain, DBD):EcR(ligand binding domain, LBD) or GAL4(DBD):EcR(LBD) fusion proteins can bind to GAL4 response elements in the absence of ligand. The VP16(AD) fusion protein of a chimera between human and locust RXR could heterodimerize with GAL4(DBD):EcR(LBD) in the absence of ligand but the VP16(AD) fusion protein of Homo sapiens RXR requires ligand for its heterodimerization with GAL4(DBD):EcR(LBD).     

PAF antagonism modifies neuroprotective action of histone deacetylase and calcineurin phosphatase inhibitors in mice

To evaluate the hypothesis that platelet activating factor (PAF) antagonism may affect the functional recovery following the nerve injuries and also to evaluate the effect of PAF receptor antagonism on the neuroprotective effect of tacrolimus and sodium valproate, effect of PAF receptor antagonist, WEB2086 was evaluated in animal models of sciatic nerve crush and endothelin-1 induced focal cerebral ischemia. WEB2086, per se, while attenuating spontaneous sensory motor recovery after sciatic nerve crush, enhanced functional recovery after focal cerebral ischemia. WEB2086 also attenuated the neuroprotective effect of tacrolimus and sodium valproate subsequent to peripheral nerve injury, while it significantly improved the neuroprotective action of tacrolimus and sodium valproate following cerebral ischemia reperfusion injury. These results suggest that PAF receptor antagonists alone and in combination with tacrolimus/sodium valproate could be used in the treatment of cerebral ischemia reperfusion injuries however, their use following peripheral nerve injuries could be detrimental.     

Extraction of Y2O3:Cr3+ nanophosphor by eco‐friendly approach and its suitability for white light‐emitting diode applications

Cr³⁺‐doped Y₂O₃ (0.5–9 mol%) was synthesized by a simple solution combustion method using Aloe vera gel as a fuel/surfactant. The final obtained product was calcined at 750°C for 3 h, which is the lowest temperature reported so far for the synthesis of this compound. The calcined product was confirmed for its crystallinity and purity by powder X‐ray diffraction (PXRD) studies which showed a single‐phase nano cubic phosphor. The particles size estimated by Scherrer formula was in the range of 6–19 nm. The UV–vis spectra showed absorption bands at 198, 272 and 372 nm having band gap energy in the range 4.00–4.26 eV. In order to investigate the possibility of its use in white light emitting display applications, the photoluminescence properties of Cr³⁺‐doped Y₂O₃ nanophosphors were studied at an excitation wavelength in the near ultraviolet (UV) light region (361 nm). The emission spectra consisted of emission peaks in the blue (⁴F_9/2 → ⁶H_15/2), orange (⁴F_9/2 → ⁶H_13/2) and red (⁴F_9/2 → ⁶H_11/2) regions. The CIE coordinates (0.33, 0.33) lie in the white light region. Hence Y₂O₃:Cr³⁺ can be used for white light‐emitting diode (LED) applications.     

Characterisation,screening and selection of Bacillus subtilis isolates for its biocontrol efficiency against major rice diseases

A Soil bacterium, Bacillus subtilis, isolated from the rhizosphere of rice, showed high biocontrol activity against blast, sheath blight and bacterial blight. In the present study, four B. subtilis strains isolated from paddy soil were studied under laboratory, greenhouse and field conditions. Among the four strains assayed, UASP17 gave maximum inhibition of paddy pathogens and was validated under field trials. B. subtilis (UASP17) under different doses and methods of applications was evaluated for two seasons at Agriculture Research Station (UAS, Raichur). UASP17 was effective in reducing the severity of blast (9.00% and 15.57%), bacterial leaf blight (BLB) (5.00% and 6.11%) and sheath blight (11.93% and 4.17%) diseases for two seasons. The application of bioagent also increased the paddy grain yield (61.00 and 64.30?Q/ha) in the two seasons, respectively. Taken together, these results indicate that B. subtilis UASP17 as seedling dip for 30?min (10?mL/L of water) prior to transplanting and 2.50?L/ha foliar application was effective in managing the diseases of paddy.     

Open‐Circuit Voltage in Organic Solar Cells: The Impacts of Donor Semicrystallinity and Coexistence of Multiple Interfacial Charge‐Transfer Bands

In organic solar cells (OSCs), the energy of the charge‐transfer (CT) complexes at the donor–acceptor interface, E _CT, determines the maximum open‐circuit voltage (V _OC). The coexistence of phases with different degrees of order in the donor or the acceptor, as in blends of semi‐crystalline donors and fullerenes in bulk heterojunction layers, influences the distribution of CT states and the V _OC enormously. Yet, the question of how structural heterogeneities alter CT states and the V _OC is seldom addressed systematically. In this work, we combine experimental measurements of vacuum‐deposited rubrene/C₆₀ bilayer OSCs, with varying microstructure and texture, with density functional theory calculations to determine how relative molecular orientations and extents of structural order influence E _CT and V _OC. We find that varying the microstructure of rubrene gives rise to CT bands with varying energies. The CT band that originates from crystalline rubrene lies up to ≈0.4 eV lower in energy compared to the one that arises from amorphous rubrene. These low‐lying CT states contribute strongly to V _OC losses and result mainly from hole delocalization in aggregated rubrene. This work points to the importance of realizing interfacial structural control that prevents the formation of low E _CT configurations and maximizes V _OC.