فصلنامه گیاه و زیست فناوری ایران
سال سیزدهم شماره 2 (تابستان 1397)

The limited availability, high cost and the adverse environmental impacts of fossil fuels, persuaded the researchers toward the use of renewable energies. Biofuels are considered as one of the main sources of renewable energies. Woody debris, agricultural waste, sugar cane, vegetables as well as oils of cereals and vegetables are among the primary sources for biofuels production. Biofuels are produced from living organisms or their metabolic byproducts (organic waste products or food). Lignocelluloses of plant cell wall are  interesting sources for production of sustainable biofuels. Theconversion of lignocellulose to biofuels using existing technologies is too expensive mainly because of the need for  chemical pretreatments and enzymatic hydrolysis required forcell wall deconstruction. Modification of cell wall composition by using biotechnological approaches resulted in the reduction of cell wall hardness in various plant species. These results are obtained by reducing the amount of lignin as well as changing the composition and structure of final polymer. In addition, in some cases the reduction of cell wall hardness has been achieved by altering the hemicellulose biosynthesis genes as well as the ectopic expression of microbial genes in the plants with the aim of breaking the connections between lignin and carbohydrates residues. So far, genetic engineering has been used to improve the enzymes involved in digestion of cellulose and lignocellulose sources and engineering metabolic pathways involved in the production of biofuels. Also, these transgenic plants often produced higher sugar yield and ethanol. Modification of the cell wall in transgenic plants can reduce the stiffness of the cell wall without negative impact on performance. This shows that cell wall modification can be resulted without affecting the cell wall integrity or plant performance. To better understanding of the cell walls structure, we need to modify the lignocellulosic components as well as to reduce the price of biofuels production. In this review we tried to give a comprehensive introduction of biofuels and to introduce different potent methods of genetic engineering for the efficient production of biofuels. We also tried to point out all the important points on the pathway that can be modify and improved by biotechnology engineering. Finally, by evaluation the ahead challenges, the appropriate methods are suggested.

Food security and sustainability of agricultural development are one of the most important challenges facing countries in the world, especially developing countries. In recent years, one of the strategies presented to combat this challenge has been precision farming. Considering the huge capabilities that precision farming in developing countries, including Iran, has to improve agriculture, is important. Precision farming can address many of the current agricultural weaknesses and use modern computational methods to make optimal use of agricultural inputs. In precision farming, managing inputs for crops such as chemical crops, herbicides, and so on, based on the spatial characteristics of the farm and with the goal of reducing waste, increasing income and maintaining environmental quality. Precision farming can affect inputs and product revenue.The purpose of this study was to study the feasibility of using precision agriculture in poultry industry from the viewpoint of Semnan Agricultural Jihad Experts. This research is a descriptive-correlative method. The statistical population of this research was experts in the Jihad-e-Agriculture Organization of Semnan province (N = 205). The sample size was 75 using Cochran's formula (n = 75). The research instrument was a researcher-made questionnaire. Content and appearance validity of the questionnaire was done using the views of the professors of Islamic Azad University of Garmsarah and necessary corrections. Cronbach's alpha coefficient was 94% to obtain reliability using a preliminary test (30 questionnaires in Pakdasht). Regression analysis showed that educational factors, technical factors, challenges and challenges, policy making, economic factors and social factors were respectively the most important variables that had the most share in exact agricultural application.

To study the Evaluation the effect of spray phenyl alanine and selenium in pre-harvest on Flowering and Stem Strength Alstroemeria(Alestromeria spp.), factorial experiment in a completely randomized design with 7 treatments, 3 replication and each treatment with 3 pots, a total 63 pots were conducted. Treatments includ Phenyl alanine with 3 level, 25, 50 and 100 ppm, selenium with 3 level, 2.5, 5 and 10 ppm and No spraying pot were used as controls. Spraying pots was done three times a week at the same base, so that the last Spraying about a week befor proper stage of harvesting the flowers for delivery to the market(a slight discovery of flower buds and vivid colors). Physicochemical and enzymatic traits of the plant traits such as fresh weight of flower, dry weight of flower, cell membrane stability index, number of flower, plant length, anthocyanine of petals, total chlorophyll of leaves, protein, superoxide dismutase, peroxidase and phenylalanine ammonia-lyase enzymes activity and flower life on plant were evaluated. The results showed that Selenium 2.5ppm treatment had the most effect on the improvement of traits such as flower fresh weight, flower dry weight, cell membrane stability index. Phenylalanine 100ppm treatment also had the most effect on the improvement of traits such as number of flower, plant length, protein, phenylalanine ammonia-lyase enzymes activity and flower life on plant and Phenylalanine 50ppm treatment had the most effect on the improvement of anthocyanine of petals, total chlorophyll of leaves. The highest activity of superoxide dismutase and peroxidase enzymes was obtained in selenium 10ppm treatment. The correlation between traits showed cell membrane stability index, anthocyanine of petals and total chlorophyll of leaves with number of flower and plant length and also protein, superoxide dismutase, peroxidase and phenylalanine ammonialyase enzymes activity with anthocyanine of petals and total chlorophyll of leaves, positive and significant at 5% level and other traits, positive and significant at 1% level.

To investigate the possible individual and combined effects of selenium (Se) and methionine in basil plants, the current study was carried out. Seedlings were foliarly treated with 2 concentrations of Se (0 and 40 mgl-1) and/or 2 levels of mrthionine (0 and 200 mgl-1). The obtained findings indicated that contents of photosynthetic pigments, including Chla, Chlb, and carotenoid was influenced by the applied supplements, in way Se had an increasing effect, contrasted with methionine. The applications of Se and/or methionine led to induction of peroxidase enzyme. Methionine provoked reduction in growth related charachtristics, including plant height and leaf fresh mass. The applied level of Se did not have condiserable beneficial effect on the plant growth. Therefore, this concenteration of Se may be utilized for biofortification to improve plant resistance via inducing antioxidant enzymes, and enhancing carotenoid content.

Phytohormones are responsible for regulating and coordinating processes that occur in different parts of plants. The natural growth of a plant is regulated more by the interaction of stimulating and inhibiting phytohormones. Euphorbia lactea a member of Euphorbiaceae is a beautiful and popular ornamental plant with high demand and good market. Therefore, current research was carried out to improve the vegetative traits of this plant in a completely randomized design with three replications in greenhouse conditions in the year 2017. Effect of twelve experimental treatments were investigated which were comprised of control, 2,4-D (25, 50 and 100 mg/l), TDZ (5, 10 and 20 mg/l), GA3 (100, 200 and 400 mg/l) and a combination of 2,4-D and TDZ (5 and 10 mg/l). Treatments were applied eight times at intervals of seven days on the scions of the grafted plants. In the treatments with 2,4-D, the growth form of the scion was as granular bumps, in TDZ, was sporadically, in GA3, was as antler of a hart and in 2,4-D plus TDZ, it was a combination of granular and cone protrusions. Based on the results, the highest final weight of the scion was obtained from 400 mg/l GA3 treatment with average of 20.1 g. Also, among different plant growth regulators treatments, the highest amount of total chlorophyll content was achieved from 100 mg/l GA3 treatment with the mean of 0.94 mg/g fresh weight. K and P were maximum in 5 mg/l TDZ. Calcium amount was also maximum in 400 mg/l GA3 treatment.

In order to investigate the effects various levels of organic and nitroxin biological fertilizer on quantitative characteristics and yield of Silybum marianum L., This experiment was conducted in a randomized complete block design with seven treatments and three replications at the Agricultural Research Station of Firdausi University of Mashhad, Iran, in 2012. Treatments consisted of: control (no fertilizer), two levels of cow manure (30, 15 t/ha), two levels of poultry manure (15, 7.5 t/ha), integrated fertilizer (cow manure 15 T/ha and poultry manure 7.5 t/ha) and nitroxin biological fertilizer (400 mg/m2).plant responses consisted of plant highet, flowering stem highet, capitol diameter, main capitol number, subordinate capitol number, total capital number, number of seed in per capitol, 1000-seed weight, seed yield, oil yield and oil percentage per hectare. The highest number of seed in capitol, plant height, flowering stem height, capitol diameter, 1000seed weight (27/66 Gr), and highest seed (2024 Kg/ha) and oil (476 Kg/ha) yield found at 30 T/ha of cow manure. The Nitroxin biological fertilizer application on the seed number and 1000-seed weight had a significant.The result showed to obtain the highest yield and organic production in cultivated of Sylibum marianum and replacement for chemical fertilizers the application of cow manure (30 T/ha) recommended.