Biodiversity of Pathogenic and Toxigenic Seed-Borne Mycoflora of Wheat in Egypt and Their Correlations with Weather Variables

Funding Information: Funding: This work was funded by the Egyptian Science, Technology, and Innovation Funding Authority (STIFA) through project No. 30691 (Egypt–UK Grants), the UK Department for Business, Energy, and Industrial Strategy through British Council Newton-Mosharafa (Project No. 332392589) and the UK Biotechnology and Biological Sciences Research Council, Grant/Award Number: BB-SRC/BB/P00489X/1; Innovate UK, Grant/Award Number: 102641. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Simple Summary: Pathogenic fungi cause yield and quality losses and threaten food security. In this study, 198 samples of wheat grains, representing 20 Egyptian wheat cultivars, were collected from 25 wheat-growing governorates across Egypt, and screened for their seed-borne fungi. Twenty genera and 44 species of seed-borne fungi were identified, and their biodiversity indicators and evolutionary relationships were studied based upon similarities in their genetic characteristics. The most frequent fungi were Alternaria alternata and Cladosporium spp., while Tilletia tritici and Ustilago tritici were the most common smut fungi. The highest fungal diversity was recorded for Sinai governorate, while the greatest species richness was recorded in Qena and Sohag governorates. Correlations of the detected fungi with weather variables (temperature, relative humidity, precipitation, wind speed, or solar radiation) were investigated. Our results indicated that the relative humidity was the most influential weather variable, followed by temperature, solar radiation, wind speed, and precipitation, respectively. Despite this study being conducted on the wheat-growing areas in Egypt, our findings are useful for other wheat-growing countries that share the same climatic conditions. The correlation between a given fungus and the climatic variables can be useful in other ecosystems. Abstract: Surveillance investigations for pathogenic and toxigenic fungi are important to refine our understanding of their epidemiology and help in predicting their outbreaks. During 2019, 198 samples of wheat grains were collected from 25 wheat-growing governorates in Egypt to detect and identify seed-borne mycoflora in vitro. Forty-four fungal species belonging to 20 genera were identified. Molecular data for these fungi were analyzed to construct a phylogenetic tree. Occurrence and biodiversity indicators were calculated. Two prevalent pathogens (average incidence > 40%) were Alternaria alternata and Cladosporium spp. Ustilago tritici was present in only seven of the 25 governorates, and less abundant than Tilletia tritici, the causal agent of stinking smut. Sinai governorate recorded the greatest species diversity, while the greatest species richness was in Qena and Sohag governorates. Canonical correspondence analysis of data for 20 fungal genera with temperature, relative humidity, precipitation, wind speed or solar radiation revealed that relative humidity was the most influential weather variable. It showed that occurrence and distribution of the 20 genera corresponded well with three out of four Egyptian climatic regions: Mediterranean, semi-arid, and arid. Knowing pathogen occurrence and distribution in Egypt is the first step to developing future disease management strategies to limit yield losses and improve food security. Despite this study being conducted on the wheat-growing areas in Egypt, our findings are useful for other wheat-growing countries that share the same climatic conditions. The correlation between a given fungus and the climatic variables can be useful in other ecosystems.Peer reviewedFinal Published versio

Micromechanical modeling of smart composites considering debonding of reinforcements

AbstractUsing the information of the microstructure, this paper presents the development of an incremental constitutive law governing the response of an electro-magneto-thermo-mechanical smart composite. In this development, different shapes of reinforcements that have magneto-electro-thermo-elastic properties that differ from the matrix material are considered. Shapes such as ellipsoidal (spherical, prolate and oblate) particles, elliptical and circular cylindrical fibers, disk and ribbon can be treated provided that the corresponding Eshelby tensor is used. The debonding of the reinforcements from the matrix is also a part of the microscopic process considered. The developed incremental constitutive law not only predicts the macroscopic and microscopic electro-magneto-thermo-mechanical-elastic behavior of composites while considering the debonding process, but it also characterizes their different macroscopic effective properties such as permittivity, permeability, stiffness moduli, pyroelectricity, pyromagnitivity and thermal expansion coefficient in different directions. Moreover, the developed constitutive law is applicable to porous materials and composites with multiple reinforcements and porosities. In the two examples considered below, particular attention is devoted to assessing the effects of both the shape and the concentration of the inclusion and/or porosity and the damage evolution on the multiphysical microscopic and macroscopic behaviors and the effective properties. The first example sheds light on obtaining the macroscopic effective properties, taking into account the piezoelectric BaTiO3 continuous fibers embedded in the piezomagnetic CoFe2O4 matrix. While in the second example, mechanical loading is considered, epoxy is taken as the matrix material and the response of the composite is presented while the evolution of damage in terms of debonding is taking place

Processing, characterization and modeling of recycled polypropylene/glass fibre/wood flour composites

Polypropylene (PP) is one of the most common thermoplastic materials in the world. There is a need to recycle the large amount of this used material. To overcome the environmental problems, related to the polymer waste, PP was recycled and used as a matrix material in different composites that can be used in high value applications. In this paper, composites made of recycled polypropylene (RPP) reinforced by glass fibres and/or wood flour of the palm tree were prepared, characterized and modeled. The mechanical and thermal properties of these recycled polymer matrix composites (RPMCs) were measured experimentally and modeled theoretically. The mechanical properties included tensile modulus, tensile strength and hardness, whereas thermal properties included thermal stability, melting and crystallinity percentage content were studied. In addition we applied the functionally graded materials concept, the elastic finite element analysis of a layered functionally graded pressurized pipe, which is one of the practical industrial applications, was accomplished in order to have some insight on the performance of such RPMCs. The results reveal that the desired mechanical and thermal properties met the requirements of a wide range of practical applications which can be attained by adding the considered fillers. Also, the proper selection of the layers of the pressurized pipe, which was made of RPMCs, led to decrease of the induced stresses and accordingly increased the operational safety.Qatar Science and Technology Park (QSTP), Center for Advanced MaterialsScopu