Journal of Plant Process and Function

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Construction and function of active substances of medicinal plants is influenced by environmental factors such as deficiency or increasing of nutrients in the soil and substrates type. Thus, an experiment was carried out in factorial experiment in the base of randomized complete with 16 treatments and 3 replications . The aim of this research was Influence of vermicompost and nano potassium fertilizer on morphological and phytochemical characteristics in Aloe vera . The treatments were four levels of vermicompost (0,15, 30 and 45), in the Volume percents with soil of culture and Nano potassium in 3 levels 2, 4, 6 gr/l and 0 as control. The results showed that the maximum amount of gel weight, gel moisture content, gel glucomannan and anthocyanin of cortex was obtained in 30% of vermicompost and 4 g/l of nano potassium. The interaction of these two factors was increased the gel antioxidant capacity and moisture content and showed maximum amount in 30% vermicompost and 2g/l nano potassium. The maximum of weight leaf was belonged in 30% of vermicompost and 6g/l nano potassium and maximum amount of gel flavonoid showed in 15 % of vermicompost and 4g/l nano potassium. Thus, using of combination substrateand of vermicompost ana foliar application of nano potassium fertilizer in aloe vera cultivation. has an effective role in the production leaves and gel high quality and the way influence it depending on characteristics is function of combination vermicompost substrate and nano-potassium fertilizer concentration.

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With respect to arid and semi-arid climatic conditions of the country, it is important to apply appropriate management methods in order to increase yield and water use efficiency. For this purpose, the effect of kaolin with three levels (0, 5 and 7 percent) and with three levels of moisture condition (100, 75 and 50 percent of field capacity) on page mandarin as a factorial experiment based on a completely randomized design with three replications was evaluated in 2017 at the Citrus and Subtropical Fruits Research Center of Ramsar. The results showed that under moisture stress, fruit yield, water use efficiency, chlorophyll a and total contents, the relative water content of leaves, leaf water potential, and stomatal conductance were decreased significantly. While kaolin application increased the total soluble solids, fruit yield, and water use efficiency it decreased the proline content, carbohydrates, leaf surface temperature, stomatal conductance, superoxide dismutase activity, and fruit sunburn significantly. Also, in the treatment of 50% of field capacity, 5% Kaolin application, increased fruit yield (91%), chlorophyll a (70), total chlorophyll (52%), leaf relative water content (76%), stomatal conductivity (87%) and leaf water potential (19%) compared to the treatment without applying kaolin. Therefore, kaolin application in summer with severe moisture stress conditions (50% field capacity), are recommended to create a positive effect on the reduction of production of reactive oxygen species resulting from of oxidative stress, reduction of fruit sunburn, the increase of fruit yield and water use efficiency.

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Deficiency of nitrogen may lead to decrease in yield and yield potential of crop plants. An experiment was done under glasshouse conditions in order to investigate nitrogen levels and salicylic acid interaction on some physiologic traits of borage (Borago officinials L.). In this experiment various levels of nitrogen (including; 27.5, 55, 110, 220 and 330 mg/L from ammonium nitrate) and salicylic acid (including; zero, 400, 800 and 1200 µM) was used. The results indicated that stomatal conductance, photosynthesis rate, respiration rate, chlorophyll a, chlorophyll b, carotenoids, proline, and ascorbate peroxidase, were increased by increasing of nitrogen level. However, intercellular CO₂ concentration, anthocyanin, flavonoids, soluble carbohydrates, catalase, and peroxidase were decreased. Among nitrogen levels, the maximum effect was obtained by 220 and 330 ppm treatments. Furthermore, salicylic acid spraying led to promote stomatal conductance, photosynthesis rate, transpiration rate, photosynthetic pigment content, proline, anthocyanin, flavonoids, soluble carbohydrates, and catalase, peroxidase and ascorbate peroxidase enzyme, but not intercellular CO₂ concentration. The highest values of stomatal conductance, photosynthesis rate, transpiration rate, photosynthetic pigment content, proline, anthocyanin, flavonoids, soluble carbohydrates, and activities of catalase, peroxidase, and ascorbate peroxidase enzymes were achieved by 800 and 1200 µM concentrations of salicylic acid and 330 ppm of nitrogen. The results showed that appropriate concentrations of salicylic acid can recover nitrogen shortage and improve the measured traits.