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This study investigates the ability of two bioagents namely Trichoderma harzianum and Streptomyces viridosporus to induce elevated levels of resistance in two susceptible genotypes Morocco and Sids-1 against leaf rust disease of wheat. Bioagents were tested at seedling and adult stage of two susceptible wheat genotypes (Morocco and Sids-1) under greenhouse and open field conditions in 2013/2014 growing season. It was indicated that all bioagents and combined effect between them, increased both Incubation Period (IP) and Latent Period (LP) of the disease and decreased the number of pustule cmG 2 , than the control. The results revealed that the amounts of photosynthetic pigments, chlorophyll a, b were lower in the infected plants than in healthy ones. It was, also indicated that spraying the plants of both the genotypes with the tested bioagents decreased leaf rust severity (%), increased spike weight (g), grains weight/spike (g) and 1000 kernel weight (g) significantly, as compared with control.

Wheat stem rust causes by Puccinia graminis f. sp. tritici is a serious threat to wheat production all over the world. This study evaluated the efficacy of Bacillus subtilis, B. polymyxa and B. megaterium, Eugenol and leaf extract of Artemisia cina against the disease, and the involved mechanisms in disease resistance. B. subtilis and Eugenol treatments inhibited spore germination and increased incubation and latent periods than other treatments. Additionally, the lowest infection type, pustule length and pustule width, and receptivity (no. of pustules) were recorded in case of B. subtilis and Eugenol treatments compared with the check control. The best results in disease assessment were achieved by foliar spray application 24 h before and after inoculation. Abnormalities, lysis, collapse, and shrinking of urediniospores were recorded in treated leaves. The activities of antioxidant defense enzymes, i.e., catalase (CAT), peroxidase (POX), and polyphenoloxidase (PPO), were significantly increased in B. subtilis and Eugenol treatments. On the other hand, electrolyte leakage was decreased. The active compounds in B. subtilis were revealed by utilizing GC-MS analysis.

Abstract:The effect of pulse laser welding parameters and filler metal on microstructure and mechanical properties of the new heat-treatable, wieldable, cryogenic Al-4.7Mg-0.32Mn-0.21Sc-0.1Zr alloy were investigated. The optimum parameters of pulsed laser welding were found. They were 330-340 V in voltage, 0.2-0.25 mm in pulse overlap with 12 ms duration, and 2 mm/s speed and ramp-down pulse shape. Pulsed laser welding without and with Al-5Mg filler metal led to the formation of duplex (columnar and fine grains) as-cast structures with hot cracks and gas porosity as defects in the weld zone. Using Al-5Ti-1B filler metal for welding led to the formation of the fine grain structure with an average grain size of 4 ± 0.2 µm and without any weld defects. The average concentration of Mg is 2.8%; Mn, 0.2%; Zr, 0.1%; Sc, 0.15%; and Ti, 2.1% were formed in the weld. The ultimate tensile strength (UTS) of the welded alloy with AlTiB was 260 MPa, which was equal to the base metal in the as-cast condition. The UTS was increased by 60 MPa after annealing at 370 • C for 6 h that was 85% of UTS of the base alloy.