Multiple interval mapping of QTLs and epistasis for iron toxicity tolerance in segregating population of Indica rice

The global average temperature has increased by approximately 0.5 °C, over a last few decades and is projected to continue to increase. Environmental stress factors such as, elevated temperature, salinity, toxic elements (Fe, Al, Cd, Cr, Pb, Zn and As), drought and rising CO2 affect plant growth and make a growing threat to agriculture. Rice is a primary food crop in the world and the establishment of rice crop in acidic soil and in marginal soil is a major goal for the improvement of rice production to fulfill the food security. Among environmental stresses, Fe2+ toxicity is one of the main stresses in limiting the cereal crops production. Tolerant rice genotypes that can tolerate the high concentration of Fe2+ toxicity are the potential source genes for rice tolerance improvement in Fe2+ toxicity. In this research work, the genetic basis of seed germination traits and growth traits was investigated in rice using (multiple interval mapping) MIM. Many rice genotypes serve as source of tolerant against toxic metal ion like Fe2+, could be an important factor in controlling the sever effect of Fe2+ toxicity on germination and seedling growth traits.  The F3 progenies of cross between Fe2+ toxicity tolerant cultivar ‘Pokkali’ and susceptible cultivar ‘Pak basmati’ were test against the optimized level of Fe2+ toxicity at germination, to determine the mode of inheritance to Fe2+ toxicity tolerance. Wide range of continues variation was found in F3 progenies. Among the 49 quantitative germination trait and 23 growth trait loci (QTLs) on chromosomes 1, 2, 4, 6, 8 and 9 linked with tolerance to Fe2+ toxicity was mapped. Additionally, 21 QTLs for germination traits and 9 QTLs for growth traits were classified as major QTLs using MIM. For germination and growth traits, notable epistasis between the chromosome 1, 2, 4, 6 and 11 was detected across germination and growth traits. Our results suggest that the tolerance mechanisms at germination and seedling phases could differ for Fe2+ toxicity. QTLs detected in this study for germination and seedling growth could be a source of new alleles for development of tolerance rice to Fe2+ toxicity varieties and transformation, gene cloning and gene editing in the futur

Structural, Physical, and Mechanical Analysis of ZnO and TiO₂ Nanoparticle-Reinforced Self-Adhesive Coating Restorative Material

This study aimed to modify an EQUIA coat (EC; GC, Japan) by incorporating 1 and 2 wt.% of zinc oxide (ZnO; EC-Z1 and EC-Z2) and titanium dioxide (TiO2; EC-T1 and EC-T2) nanoparticles, whereby structural and phase analyses were assessed using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), respectively. Thermogravimetric analysis/differential scanning calorimetry, micro-hardness, and water absorption analyses were conducted, and the microstructure was studied by scanning electron microscopy/energy-dispersive spectroscopy. FTIR spectra showed a reduction in peak heights of amide (1521 cm−1) and carbonyl (1716 cm−1) groups. XRD showed peaks of ZnO (2θ ~ 31.3°, 34.0°, 35.8°, 47.1°, 56.2°, 62.5°, 67.6°, and 68.7°) and TiO2 (2θ ~ 25.3°, 37.8°, 47.9, 54.5°, 62.8°, 69.5°, and 75.1°) corresponding to a hexagonal phase with a wurtzite structure and an anatase phase, respectively. Thermal stability was improved in newly modified materials in comparison to the control group. The sequence of obtained glass transitions was EC-T2 (111 °C), EC-T1 (102 °C), EC-Z2 (98 °C), EC-Z1 (92 °C), and EC-C (90 °C). EC-T2 and EC-T1 showed the highest (43.76 ± 2.78) and lowest (29.58 ± 3.2) micro-hardness values. EC showed the maximum water absorption (1.6%) at day 7 followed by EC-T1 (0.82%) and EC-Z1 (0.61%). These results suggest that EC with ZnO and TiO2 nanoparticles has the potential to be used clinically as a coating material