A high-throughput regeneration protocol for recalcitrant tropical Indian maize (Zea mays L) inbreds

Immature embryos from five select recalcitrant maize (Zea mays L) inbreds used as explants were evaluated for their ability to form callus, somatic embryos and subsequent regeneration into plants. The embryos were placed on N6 basal media with varying levels of 2,4-D (0.5, 1.0, 1.5, 2.0, and 2.5 mg l-1) and were regenerated on MS me¬dium supplemented with BAP (2 - 10 mg l-1), 2,4-D (0.25 mg l-1) and silver nitrate (0.85 mg l-1). Explants cultured on N6 medium supplemented with 2,4-D (2.0 mg l-1) were associated with the highest frequency of embryogenic calli and that of UMI 29 were highly embryogenic (78.67%). When synergism between dicamba and 2,4-D on Type II callus production in UMI 29 was sought to be investigated using 2,4-D (1 or 2 mg l-1) individually and in combina¬tion with dicamba (3.7 mg l-1) production of Type II callus with the greatest frequency of 83.33% was observed on N6 medium containing 3.7 mg l-1 dicamba + 1 mg l-1 2,4-D. The greatest percentage of shoot induction (82.67%) was observed on MS medium supplemented with BAP (10 mg l-1). Among the five genotypes tested, UMI 29 was associated with the highest percentage of callus initiation, shoot induction and mean number of developed shoots. The protocol described in this study can reliably be used to transform tropical maize inbreds as a routine

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Not AvailableGlobally, maize is an important cereal food crop with the highest production and productivity. Among the biotic constraints that limit the productivity of maize, the recent invasion of fall armyworm (FAW) in India is a concern. The first line of strategy available for FAW management is to evaluate and exploit resistant genotypes for inclusion in an IPM schedule. Screening for resistant maize genotypes against FAW is in its infancy in India, considering its recent occurrence in the country. The present work attempts to optimize screening techniques suited to Indian conditions, which involve the description of leaf damage rating (LDR) by comparing injury levels among maize genotypes and to validate the result obtained from the optimized screening technique by identification of lines potentially resistant to FAW under artificial infestation. Exposure to 20 neonate FAW larvae at the V 5 phenological stage coupled with the adoption of LDR on a 1–9 scale aided in preliminary characterize maize rize maize genotypes as potentially resistant, moderately resistant, and susceptible. The LDR varies with genotype, neonate counts, and days after infestation. The genotypes, viz., DMRE 63, DML-163-1, CML 71, CML 141, CML 337, CML 346, and wild ancestor Zea mays ssp. parviglumis recorded lower LDR ratings against FAW and can be exploited for resistance breeding in maize.ICAR-NAS

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Not AvailablePhytic acid (PA) is an important antinutritional component in maize that affects the availability of major micro-nutrients like di- and multivalent mineral cations like iron (Fe) and zinc (Zn). The long-term consumption of maize as a staple food crop leads to micronutrient malnutrition especially iron and zinc deficiency in the human population. In addition, it also acts as a storehouse of a major part of mineral phosphorous (P), approximately 80% of the total P stored as phytate P is not available to monogastric animals like humans and poultry birds, and it gets excreted as such, leading to one of the major environmental pollution called eutrophication. Of the various low phytic acid (lpa) mutants, lpa2-2 generated through mutagenesis reduces PA by 30%. BML 6 and BML 45, the parents of the popular maize hybrid DHM 121 with high PA were selected to introgress lpa2-2 through marker-assisted backcross breeding (MABB). The percent recurrent parental genome (RPG) in the selected BC2F2 plants ranged from 88.68 to 91.04% and 90.09–91.51% in the genetic background of BML 6 and BML 45, respectively. Based on the highest percentage of RPG, best five BC2F2 plants, viz., #3190, #3283, #3230, #3263 and #3292 with RPG 88.68–91.04% in the genetic background of BML 6 and #3720, #3776, #3717, #3828 and #3832 with RPG 90.09–91.51% in the genetic background of BML 45 were advanced to BC2F3. The newly developed near-isogenic lines (NILs) possessed low phytate content (2.37 mg/g in BML 6 and 2.40 mg/g in BML 45) compared to 3.59 mg/g and 3.16 mg/g in recurrent parents BML 6 and BML 45, respectively thereby reducing the phytate by an average of 34 and 24 per cent, respectively. These newly developed progenies were similar to their recurrent parents for various morphological traits. These inbreds assume great significance in alleviating Fe and Zn deficiencies in worldwide.Not Availabl

Interaction of model inhibitor compounds with minimalist cluster representations of hydroxyl terminated metal oxide surfaces

© 2018 by the authors. Licensee MDPI, Basel, Switzerland. The computational modeling of corrosion inhibitors at the level of molecular interactions has been pursued for decades, and recent developments are allowing increasingly realistic models to be developed for inhibitor-inhibitor, inhibitor-solvent and inhibitor-metal interactions. At the same time, there remains a need for simplistic models to be used for the purpose of screening molecules for proposed inhibitor performance. Herein, we apply a reductionist model for metal surfaces consisting of a metal cation with hydroxide ligands and use quantum chemical modeling to approximate the free energy of adsorption for several imidazoline class candidate corrosion inhibitors. The approximation is made using the binding energy and the partition coefficient. As in some previous work, we consider different methods for incorporating solvent and reference systems for the partition coefficient. We compare the findings from this short study with some previous theoretical work on similar systems. The binding energies for the inhibitors to the metal hydroxide clusters are found to be intermediate to the binding energies calculated in other work for bare metal vs. metal oxide surfaces. The method is applied to copper, iron, aluminum and nickel metal systems

Interaction of Model Inhibitor Compounds with Minimalist Cluster Representations of Hydroxyl Terminated Metal Oxide Surfaces

The computational modeling of corrosion inhibitors at the level of molecular interactions has been pursued for decades, and recent developments are allowing increasingly realistic models to be developed for inhibitor–inhibitor, inhibitor–solvent and inhibitor–metal interactions. At the same time, there remains a need for simplistic models to be used for the purpose of screening molecules for proposed inhibitor performance. Herein, we apply a reductionist model for metal surfaces consisting of a metal cation with hydroxide ligands and use quantum chemical modeling to approximate the free energy of adsorption for several imidazoline class candidate corrosion inhibitors. The approximation is made using the binding energy and the partition coefficient. As in some previous work, we consider different methods for incorporating solvent and reference systems for the partition coefficient. We compare the findings from this short study with some previous theoretical work on similar systems. The binding energies for the inhibitors to the metal hydroxide clusters are found to be intermediate to the binding energies calculated in other work for bare metal vs. metal oxide surfaces. The method is applied to copper, iron, aluminum and nickel metal systems

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Not AvailableThe huge genetic resources among all the crop species is still underutilized in meeting the worldwide challenges of agriculture production systems. In maize only 5% of world’s maize germplasm has been used. The utilization of the maize genetic resources, which hold the answers to most of the threats and challenges, would be enhanced by their precise characterization and evaluation. Also, the data needs to be generated at a faster rate to meet the onset challenges. In this study, we discussed and demonstrated the use of an imaging phenotyping platformLeasyScan, coupled with lysimeters, to measure precise plant height and canopy traits viz., leaf area and leaf area index (LAI) affecting water use in six experimental and two released maize hybrids viz., 14746185, 8315622, 22525674, 18270413, 4695575, 783527, 900MG and 30V92. Of these, experimental hybrids 2 & 5 i.e 8315622 4695575 showed promising 3D-leaf area and LAI. We conclude that LeasyScan –phenotyping platform can be effectively used in the identification of genotypes/germplasm lines with high vigour (Plant height), efficient 3D-leaf area and LAI at early stage of around one month old seedlings. Identification of such genetic stocks/ germplasm lines can be an important step towards effective utilization of the genetic resources in pre-breeding programme.Not Availabl