Dry Sliding-Friction and Wear Behavior of Hot-Extruded Al6061/Si3N4/Cf Hybrid Metal Matrix Composite.

The effects of reinforcement addition and hot extrusion on the microstructures, micro hardness, friction, and wear behavior of aluminium (Al) hybrid composite were investigated. Al6061 dispersed with electroless nickel-coated Si3N4 (6wt.%) and copper-coated carbon fiber (Cf) (1wt.%) hybrid composites was developed through stir casting followed by hot extrusion. Optical micro structural studies confirmed that the size of reinforcements decreased, and their orientations were in the extrusion direction. The decrease in the grain size (29%) of hybrid composites was larger than that in the grain size of matrix alloys under hot-extruded conditions. The synthesized hot-extruded Al6061 hybrid composite exhibited a lower coefficient of friction (51%) and high wear resistance (39%) compared with the hotextruded Al6061base alloy

Variation in grain Zn concentration, and the grain ionome, in field-grown Indian wheat

Wheat is an important dietary source of zinc (Zn) and other mineral elements in many countries. Dietary Zn deficiency is widespread, especially in developing countries, and breeding (genetic biofortification) through the HarvestPlus programme has recently started to deliver new wheat varieties to help alleviate this problem in South Asia. To better understand the potential of wheat to alleviate dietary Zn deficiency, this study aimed to characterise the baseline effects of genotype (G), site (E), and genotype by site interactions (GxE) on grain Zn concentration under a wide range of soil conditions in India. Field experiments were conducted on a diverse panel of 36 Indian-adapted wheat genotypes, grown on a range of soil types (pH range 4.5–9.5), in 2013–14 (five sites) and 2014–15 (six sites). Grain samples were analysed using inductively coupled plasma-mass spectrometry (ICP-MS). The mean grain Zn concentration of the genotypes ranged from 24.9–34.8 mg kg-1, averaged across site and year. Genotype and site effects were associated with 10% and 6% of the overall variation in grain Zn concentration, respectively. Whilst G x E interaction effects were evident across the panel, some genotypes had consistent rankings between sites and years. Grain Zn concentration correlated positively with grain concentrations of iron (Fe), sulphur (S), and eight other elements, but did not correlate negatively with grain yield, i.e. no yield dilution was observed. Despite a relatively small contribution of genotype to the overall variation in grain Zn concentration, due to experiments being conducted across many contrasting sites and two years, our data are consistent with reports that biofortifying wheat through breeding is likely to be effective at scale given that some genotypes performed consistently across diverse soil types. Notably, all soils in this study were probably Zn deficient and interactions between wheat genotypes and soil Zn availability/management (e.g. the use of Zn-containing fertilisers) need to be better-understood to improve Zn supply in food systems

Screening methods, genetic variability and correlation studies for Aspergillus flavus resistance in sub-tropical maize (Zea mays L.)

Maize is an important cereal crop and a significant contributor to global food and nutritional security. The consumption and nutritional qualities of maize are severely affected by aflatoxin B1. Aflatoxin B1 is a potent carcinogenic,mutagenic and teratogenic secondary metabolite produced by Aspergillus flavus. Nonchemical and sustainable management of aflatoxin B1 contamination necessitates resistant maize inbred lines for aflatoxigenicA. flavus and subsequent production of aflatoxin B1. In the present investigation, we have screened thirty diverse Indian maize inbred against aflatoxigenic isolates AF1 and AF3 using kernel screening assay (KSA) method and indirect competitive ELISA (Enzyme-Linked Immunosorbent Assay). The results showed the lower A. flavus colonization (13.33-23.33%) in five maize inbred lines viz., M6, M7, M9, M17 and M22. Similarly, the inbred lines M3, M8, M14, M15 and M17 showed lower aflatoxin B1 concentration (0.09-7.03 μg/g) under both AF1 and AF3 infections. We showed the association and reliability between the rapid lab based KSA screening Side Needle Spore Suspension (SNSS) inoculation methods with five tolerant inbred lines and susceptible lines M2, M4 and M5 and check line M24. The five inbred lines viz., M6, M7, M9, M17 and M22 showed the least infection in field condition (1-2%) compared to M2, M4, M5 and check M24 (92%). Our investigation showed that KSA could be employed for rapid screening of maize genotypes for aflatoxin tolerance and the SNSS inoculation method is more effective in the field. Further, five inbred lines M6, M7, M9, M17 and M22, identified as the resistant source to aflatoxin,could be employed as candidates for basic and applied maize research in the Indian maize breeding programme