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Mesquite is an invasive and problematic weed in warm and dry areas and so its management is very important. In order to study the effective factors on mesquite seed germination, the following studies were conducted to investigate: 1- seed viability; 2- the effect of constant temperatures on seed germination including 5, 10, 15, 20, 25, 30, 35 and 40°C independent dark and independent light conditions; 3- Effect of temperature fluctuations on seed germination including 10/0, 20/10 and 30/20°C; 4- the effect of scarification with concentrated sulphuric acid and physiacal scarification on seed germination; 5- the effect of planting depth seed on seedling emergence; 6- the effect of drought stress including 0, 100, 200, 300, 400, 500, and 600 Mm PEG on seed germination; and finally 7- the effect of salt stress including 0, 100, 200, 300, 400, 500, 600, and 700 mM NaCl on seed germination. All experiments were performed as completely randomized designs with 4 replications. The results showed that seed viability of mesquite was 81%. The optimum temperature for seed germination was a constant temperature- 30°C. In general, constant temperature was more suitable than temperature fluctuations for seed germination. The best seed planting depth for seedling emergence was 2 cm. The most seed germination was observed under the effect of 20 min scarification with concentrated sulphuric acid. Physical scarification had no significant effect on seed germination. While the study of salt and drought stresses effect showed that the most seed germination (after control without NaCl and PEG), was due to concentrations of 100 and 200 mM, seed germination decreased with the increase of NaCl and PEG concentrations. Based on the present results, light did not play a crucial role on seed germination. Therefore, mesquite seeds were not photoblastic. These characteristics are very important in making mesquite an invasive weed. Having precise information of these traits, enables us to have a better control over the management of this troublesome weed.

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Main agent orange-red coloured pigment of henna is a molecule called Lawson which is responsible for anti-microbial, anti-tumor, anti-inflammatory and analgesic activity. Chitosan is a biopolymer with high strength, biocom-patibility and biodegradability, non-toxicity and antimicrobial properties. Electrospinning is a method of producing su-bmicron polymeric fibers with high porosity and high surface/volume ratio. In this study, electrospinning of chitos-an/polyethylene oxide (Chit/PEO) nanofibers with the addition of henna extract to create nanofibers with antimicrobial properties were examined. Nanofibers was constructed by electrospinning of polymeric solution with proper size and si-ze distribution of Chit/PEO with a ratio 90/10. Then, Lawsonia inermis (henna) extract as an additive to Chit/PEO co-polymer was added and electrospined on the surface. After characterization of nanofibers using SEM, the antimicrobial properties of polymeric solution and nanofibers were investigated. The scanning electron micrographs showed that Ch-it/PEO nanofibres with a low percentage of henna extract have suitable diameters and size distribution similar to Ch-it/PEO nanofibres without adding extract. In bacteriological studies, it was found that chitosan polymer solutions cont-aining 1% of henna extract has bactericidal properties against Staphylococcus aureus, Escherichia coli and Pseudo-monas aeruginosa bacteries better than polymer chitosan solution without adding the extract.

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In this study, the effects of seaweed extract (Ascophyllum nodosum) on seed germination stimulation and growth indices in chickpea were studied. A factorial experiment was performed on the basis of a completely randomized design with 3 replications. Treatments consisted of seaweed extract at four levels (0, 1.5, 2.5 and 3.5%) and drought stress at four levels (0, -0.3, -0.6 and -0.9 MP). Drought stress was induced by PEG 6000. Results showed that drought stress at -0.6 and -0.9 MP reduced the germination traits significantly compared with the controls. Seaweed extract at 2.5 and 3.5% resulted in a significant increase in the germination percentage (+18%, +24%), germination rate (+15%, +20%), seedling length (+13.3%, +15.7%), radicle area (+10.4%, +12.8%), radicle diameter (+14.2%, +25%), plumule length (+14%, +16.6%) and plumule dry weight (+10.3%, +12.6%). Under non-stress and -0.3 MP, seaweed extract levels at 2.5 and 3.5% could significantly increase the germination vigor, seed vigor index, consumed endosperm, radicle length and radicle dry weight. The application of seaweed extract at 3.5% improved the germination vigor, seed vigor index and radicle dry weight under -0.6 MP conditions. It also improved the consumed endosperm, length and radicle dry weight in samples affected by -0.9 MP conditions. According to the results, the use of seaweed extract (Ascophyllum nodosum) in the seed germination of beans is recommended for the reduction of the negative effects of drought stress.
 

 

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Tomato (Solanum lycopersicum) is one of the most important crops and a known host of broomrapes. The species of genus Orobanche are biotic stress factors restricting plant growth and crop production. Some natural compounds and chemicals affect this biological relationship. Therefore, in the present study, the effect of gallic acid and kiwi fruit extract on the biological relationship between broomrape and tomato plant was investigated. To this end, first, the symbiotic effect of the broomrape species, Orobanche aegytica, on growth parameters of tomato plant and the amount of soluble sugar and photosynthetic pigments were evaluated. Then, the effect of concentrations of gallic acid and kiwi fruit extract at different levels on this biological relationship was investigated by measuring the growth parameters of tomato and broomrape, photosynthetic pigments and the amount of soluble sugar in tomatoes. The results demonstrated that the broomrapes reduced the fresh weight and dry weight of the stem, leaves and roots of tomato, diminished the leaf area of the host plant, and decreased the amount of photosynthetic pigments and its soluble sugar content. Gallic acid treatment and kiwi fruit extract lessened the growth parameters of the broomrape species and its overall growth, in addition to increasing the growth of tomato plants. This process could be associated with the constraint of the biological relationship between the parasite and the host, as the soluble sugar content as well as the amount of the photosynthetic pigments of tomato plants were increased and the tomato plants remained highly resistant.