A germplasm collection of 33 entries comprising 22 sesame (Sesamum indicum L.) cultivars, 4 landraces of S. mulayanum and 7 other accessions of 4 wild species were analyzed for the fatty acid compositions of their seed oil. The entries varied widely in their fatty acid compositions. The percentage content of oleic, linoleic, palmitic and erucic acids ranged between 36.7-52.4, 30.4-51.6, 9.1-14.8 and 0.0-8.0, respectively. Linolenic and arachidonic acids were the minor constituents but varied widely in wild species. Oleic and linoleic were the major fatty acids with mean values of 45.9 and 40.5%, respectively and the mean of their combined values was 86.4%. The polyunsaturated fatty acid (PUFA) compositions ranged from 30.9 to 52.5% showing high variation in PUFA in the germplasm. Linoleic acid content was very high in one landrace (47.8) and one accession each of three wild species, S. mulayanum (49.3), S. malabaricum (48.2) and S. radiatum (51.6%). Use of fatty acid ratios to estimate the efficiency of biosynthetic pathways resulted in high oleic and low linoleic desaturation ratios and consequently high linoleic and very low linolenic acid contents in seed oil. The results of this study provided useful background information on the germplasm and also identified a few accessions having high linoleic acid which can be used for developing cultivars with desirable fatty acid compositions.

An efficient somatic embryogenesis system has been established in six date palm (Phoenix dactylifera L.) cultivars (Barhee, Zardai, Khalasah, Muzati, Shishi and Zart). Somatic embryogenesis (SE) was growth regulators and cultivars dependent. Friable embryogenic callus was induced from excised shoot tips on MS medium supplemented with various auxins particularly 2,4-dichlorophenoxyacetic acid (2,4-D, 1.5 mg 1(-l)). Suspension culture increased embryogenesis potentiality. Only a-naphthaleneacetic acid (NAA, 0.5 mg 1(-1)) produced somatic embryos in culture. Somatic embryos germinated and converted into plantlets in N(6)-benzyladenine (BAP, 0.75 mg 1(-l)) added medium following a treatment with thidiazuron (TDZ, 1.0 mg 1(-l)) for maturation. Scanning electron microscopy showed early stages of somatic embryo particularly, globular types, and was in masses. Different developing stages of embryogenesis (heart, torpedo and cotyledonary) were observed under histological preparation of embryogenic callus. Biochemical screening at various stages of somatic embryogenesis (embryogenic callus, somatic embryos, matured, germinated embryos and converted plantlets) of date palm cultivars has been conducted and discussed in detail. The result discussed in this paper indicates that somatic embryos were produced in numbers and converted plantlets can be used as a good source of alternative propagation. Genetic modification to the embryo precursor cell may improve the fruit quality and yield further.

Perovskite light-emitting diodes have almost reached the threshold for potential commercialization within a few years of research. However, there are still some unsolved puzzles such as large ideality factor and the presence of large negative capacitance especially at the low-frequency regime yet to be addressed. Here, we have fabricated a methylammonium lead tri-bromide perovskite n–i–p structure for light-emitting diodes from a smooth and textured emissive layer and demonstrated for the first time that these two factors are strongly dependent on the perovskite film morphology. Bias-dependent capacitance measurement also reveals the transition between negative to positive capacitance in textured films at the low-frequency regime. We have observed an anomalous capacitive behavior at the mid-frequency regime in smooth perovskite films but not in textured films. The relatively large ideality factor and anomalous capacitive behavior observed in perovskite light-emitting diodes are due to the presence of strong coupling between ions and electrons near the electrode interface. Therefore, the ideality factor and anomalous capacitance at the mid-frequency regime can be decreased by minimizing electronic–ionic coupling in textured perovskite films, while light outcoupling can be improved significantly.

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Hybrid perovskite materials are mixed electronic–ionic conductors which enhance the complexity of conduction in these materials. Complete understanding of ionic conductivity along with electronic conductivity is crucial. Herein, we employed photoelectrochemical impedance spectroscopy on a perovskite/electrolyte interface-based device to investigate the role of an A-site cation and X-site halide ion in dictating the charge and ionic conductivity of the perovskite material. It was noted that ionic conductivity of the perovskite material can be tuned either by changing the A-site cation (MA+/FA+) or by changing the X-site halide ion (I–/Br–). Photoinduced ionic conductivity can be significantly different (opposite) in different cation perovskites or different halide-based perovskites. Therefore, mixed-cation perovskites can be utilized to reduce photoinduced ion conductivity. Furthermore, very fine tuning is also possible by modulating with the external applied bias. The influence of ion accumulation and migration on the charge storage and transport property of the device is analyzed using vacancy hopping and the jump relaxation model. Ionic conductivity spectra revealed Jonscher’s law dependence in the mid- and low-frequency range with a constant plateau at high frequencies. It can be concluded that the interplay of ion migration and accumulation decides the resulting conduction and storage property of the complete device. These perovskite/electrolyte-based devices can therefore be promising candidates for electrolyte-gated perovskite field-effect transistors where switchable ion conductivity can be achieved either by photoexcitation or external electric field.

Mixed-cation mixed-halide perovskites have gained a lot of attention due to their superior device properties, optoelectronic properties, and improved structural stabilities over methyl ammonium lead trihalide-based devices. However, understanding the interfacial charge and ion transport kinetics remains elusive. In this article, we have synthesized (MA) x (FA) x−1 Pb(Br) 2+x (I) 1−x stoichiometric compositions by varying x between 0.2 and 1.0. We have chosen two compositions with x = 0.6 and 0.8 due to their similar morphologies and optical absorption properties. We have demonstrated that increasing MA + for x = 0.6−0.8 can reduce the ion migration by a factor of two while the activation energy for ion migration is increased from 0.36 eV to 0.47 eV. The ideality factor can be reduced upon increasing methylammonium bromide concentrations. We have measured ionic conductivity as a function of frequency to demonstrate that the interplay between A-site cation and X-site halide ion leads to opposite behavior in the low-frequency regime upon increasing bias voltage. This could be due to two competing processes; interfacial polarization and cation-halide hydrogen bonding in two samples. MA + and FA + migration lead to Jonscher's power law at the mid-frequency regime. High-frequency AC conductivity follows the nearly constant (dielectric) loss regime with exponent (slope) exceeding one due to the presence of multiple ions in the systems. This kind of superlinear power law behavior of AC ionic conductivity at operating temperature is reported for the first time in these perovskite materials.

Objectives: This study describes Zinc biofortification of wheat using a rhizospheric isolate, Pseudomonas fluorescens strain Psd.Methods: The strain was used as a bio-ionculant in soil deficient in zinc and the plant-growth promoting potential and biofortification was assessed using a number of physical and biochemical parameters. The enzymatic studies indicated towards the zinc supply mediated by the strain Result: This plant-growth-promoting strain, apart from the Zn accumulation potential, has the ability to solubilise Zn and was also able to leach out Zn from ore-tailings. The application of a Zn-laden biomass of the strain in soil resulted in increased growth and productivity of wheat crop as demonstrated by pot experiments. The beneficial effect was also reflected in increased activities of some enzymes. In addition, grain Zn 2+ content was enhanced by ~85% in comparison to wheat grown in Zn 2+ -deficient soil.

Dioscorea bulbifera L. containing the pharmaceutically important compound, diosgenin, was regenerated in vitro through nodal segments on supplemented Murashige and Skoog medium (MS). Diosgenin was at 12 mg g(-1)dry wt in 12-week-old plantlets raised on MS with various growth hormones. Random amplified polymorphic DNA (RAPD) analysis showed genetic fidelity of regenerants. Encapsulation of shoot tips in 3% (w/v) calcium alginate for storage and germplasm exchange was achieved.