نشریه علوم کشاورزی و منابع طبیعی
سال شانزدهم شماره 1 (پیاپی 71، فروردین و اردیبهشت 1388)

One of the important factors that its ignorance in the production function can make serious bias in the estimation of function parameters is that of energy. In present study, involving the important factor of energy in the production function of agricultural sector has prohibited bias in estimations and also it has made possible the analysis of this factor in the production of agricultural sector. In this study, first to adjust existent data to the definition of production function and to avoid the bias of coefficients, the potential production has been estimated using a synthetic method that is in fact the mixture of two methods of "Actual Production Trend" and "Modified Trend Through Peaks" and has been involved to the model as dependent variable instead of the actual production. Then, to estimate production function and also to avoid spurious regression, Auto Regressive Distributed Lag (ARDL) method has been used in the framework of the functional form of Cobb-Douglas due to the advantage of this approach in comparison with alternative methods. The results of the estimation of model coefficients indicate the significant and positive effect of all factors including energy on the potential value added of agricultural sector over study period (1967-2004); in such a way that the long-run coefficients have been estimated for labor, capital, and energy, 0.34, 0.15, and 0.48 respectively, and also short-run coefficients for mentioned factors have been estimated 0.035, 0.047, and 0.015 respectively. Also the values of standardized coefficients for mentioned factors have been 0.034, 0.17, and 0.83 respectively, which reveal the high relative importance of energy factor compared to the other factors. Also the comparison of short-run with long-run coefficients shows that although the effect of factors including energy on production has been considerable in long-run, but the efficacy on production has been trifle in short-run.

One of the important species of fescue is tall fescue. The great role of this plant to produce forages and its wild adaptation is due to consider about tall fescue to produce forages, pasturages revival and soil protection. The aim of this study was to characterize 45 genotypes of this plant which were evaluated among 2 years on morphological characteristics using AFLP markers. Ten primer combinations amplified 209 polymorphic bands. The maximum band number (36) was produced by P-GAG/M-GAG and the minimum band number (9) as produced by P-ACA/M-CAA. Grouping the genotypes was done by clustering analysis of NT SYS-pc Ver. 2.02 software and using Jaccard’s genetic similarity coefficients. The Maximum polymorphism information content (PIC) was found in P-GAC/M-CAA. The production of many bands and obtained high polymorphism suggest that AFLP marker is an efficient tool for identification of genetic relationships among different genotypes of forage plants.

This study was conducted at the research farm of Isfahan University of Technology in 2007 to investigate genetic variability for different agronomic traits among 16 cultivars of sesame. A randomized complete block design with three replications was used in this experiment. Significant differences were detected among the genotypes for all of the studied traits such as number of capsules per plant, number of seeds per capsule, 1000-seed weight, seed yield per plant and seed yield per plot. The phenotypic coefficient of variation was greater than the genetic once for all the traits, but their differences were so small in most of the traits. Days to flowering, number of capsules per plant, number of seeds per capsule, 1000-seed weight, biologic yield and harvest index had high and positive correlation with both seed yield per plant and seed yield per plot. The result of stepwise regression showed that number of capsules per plant, 1000-seed weight and number of seeds per capsule explained 79% of the variation for seed yield per plant. The results of path coefficient analysis indicated that 1000-seed weight had the most direct and positive genetic effects on seed yield per plant and seed yield per plot. In general, the result of this study showed that there was high genetic variation among cultivars for all of the studied traits and selection can be effective to improve them. In breeding programs of sesame, number of capsules per plant, number of seeds per capsule and 1000-seed weight can be used as selection criteria to improve seed yield.

In order to study the relationship of seed yield with its components, 11 genotypes of Bromus tomentellus were examined using complete block design with three replications. The data were collected and analyzed for ear emergence date, pollination date, maturity date, stem density, plant height, peduncle length, spikelet number, thousand grain weight, panicle length, seeds weight per panicle, seeds number per panicle, dry matter yield, seed yield, and harvest index. There were significant differences among genotypes for all the traits except for seeds weight per panicle. The genotypes 587P10, 587P6 and 587P3 originated from Esfahan, Iran, with average values of 3.12 to 3.75 ton/ha and 535 to 697 kg/ha had the highest dry matter and seed production, respectively. The results of phenotypic correlation analysis showed that seed yield had positive and significant correlation with stem density and dry matter yield. Results of principal component analysis for Bromus tomentellus showed that the first three components explained 89% of the total variation. Phonological traits and forage yield in the first and seed yield and stem density in the second and third components were the most important traits. Using cluster analysis the genotypes were grouped into 3 clusters. The genotypes in cluster 3 had higher values for seed and forage yield. Distribution of genotypes based on the first two components scores was in agreement with cluster analysis.

In this study the effects of temperatures (4 and 10˚C) and times (6, 12, 24 and 48 hours), on chemical composition and sensory quality of rainbow trout fillets during brine salting process in 13% of brine concentration was measured. Experiments were carried out in completely randomized design as a factorial with 3 replications was studied in order to produce the most significant salted production. Changes in the moisture, pH, salt and protein content were measured and sensory qualities by ten panel group were measured. The result of experiment during brine salting showed with increasing salting times from 6 hours to 48 hours, decreased protein content to 3% in 4 and 10 degree of centigrade (P≤0.05), also moisture content decreased and salt content were increased. But no significant changes were happened in pH. The results of experiment in sensory quality with increasing salting times and temperature showed that quality of aroma, flavor, color and tissue decreased but significant different did not see in some of the treatments. In this investigation seams the best treatment according to consumption in 13% brine salting concentration was salted treatment in 6 hours and 4 degree of centigrade.

In this study that was carried out on Farvardin 1386, spermatologocal parameters of Mahisefid semen in Shiroud, Tajan and Gorganroud were compared. For this purpose in the second half of Farvardin 10 male with same age and size were caught (temperature of 12˚C). The sperm samples by 5cc syringes was taken. Then the sperm duration was recorded by stero-microscope, the spermatocrite was measured by micro-hematocrit centrifuge method and the sperm density was calculated with hemacytometer standard method (×109 per ml semen). Sperm motility percent, spermatocrit and sperm volume at the spawning migration place were significant (P<0.05). Sperm motility (%) and sperm volume in broodstock migrated to Shirood was greater than Tajan and Gorganrood but spermatocrit in broodstock migrated to Gorganrood was greater than other groups. Sperm duration and sperm density in 3 rivers were not significant (P>0.05). According to spermatological parameters it seems, sperm quality in Shirood is better than the other rivers.

This research was carried out within 7 months in Dikjeh area of Gonbad in Golestan province and during that the relationship between unsaturated fatty acids of common carp (Cyprinus carpio) with average weight (705±136.93 g) and length (27.92±2.06 cm) in 15 ponds (10 ha) and value of fatty acids were investigated. Docosahexaenoic acid (0.44-4.47), eicosapantaenoic acid (0.16-3.62), arachidonic acid (1.23-4.61), linoleic acid (6.56-23.48) and linolenic acid (1.85-4.03) was measured. Sum of n-3 and n-6 was (5.15 and 20.91) respectively, DHA to EPA ratio (1.61) and ∑SFA (23.52) (mgr/gr dry weight) was calculated. Acording to the pearson statistics, between C18:2n-6 with C20:4n-6 (P<0.01), between C20:4n-6 with EPA and DHA (P<0.01) and between EPA with DHA (P<0.01) significant correlation were showed. So, fatty acids influence eachother.

Highly unsaturated fatty acids have critical role in their health maintenance, growth performance and survival rate. Enrichment of Artemia urmiana with ICES30/4 have been done in two stages, first stage was after hatching the artemia cysts and the second one was ten hours later for 24-hours. Sturgeon fish larvae (Acipenser persicus) with 300-400 mg including two groups were fed with unenriched artemia (control) and ICES 30/4 enriched artemia for five days. After enrichment, two groups, fed artemia and enriched artemia, were challenged by 3×108 cell/ml Aeromonas hydrophila for 1-hour. Following, fish larvae were fed artificially, 3-5% body weight for 3 weeks. Results showed that biochemical composition of Artemia urmiana had low level of EPA and trace amount of DHA, but amounts of EPA and DHA were increased by enrichment, but no significant differences observed in growth performance and survival rate of fish larvae.

Current experiment was conducted to investigate the effect of propylene glycol supplement (PG) and calcium salt long chain fatty acids (Ca-LCFA) on milk production and blood metabolites of dairy cows. A change over design with 2×2 factorial arrangement including 2 levels of PG (0 and 450 gram/day) and 2 levels of Ca-LCFA (0 and 2.5%) were applied. Treats were recorded on 8 Holstein dairy cows in 4 different periods. The results showed that there was no significant interaction between PG and Ca-LCFA on recorded treats. The concentration of blood glucose increased significantly after using PG in the diet (P<0.05). The blood betahydroxy butirate (BHBA) content decreased significantly after using PG in the diet. Using PG had no significant effect on blood concentration of triglyceride, urea nitrogen (BUN) and cholesterol. In addition PG supplement had no effect on dry matter intake, milk yield, protein, lactose and fat percentage of milk, milk dry matter content and milk solid not fat (SNF). Using Ca-LCFA had no significant effect on blood concentration of BUN, glucose, triglyceride and BHBA, but the blood cholesterol content were significantly increased when Ca-LCFA was used. Ca-LCFA has also no effect on milk yield, protein, lactose and fat percentage of milk, milk dry matter content and milk solid not fat (SNF). In addition Ca-LCFA reduced dry matter intake.

Purpose of this study was determination of genetic diversity and genetic distance within and between two types of native chickens of Sistan and Baluchestan province, using five microsatellite markers. Extracted genomic DNA from feather samples were amplificated by the microsatellite primers and then their product electrophoresed using 8% polyacrylamide gel. In Khazak chickens were detected 26 alleles and in Dashtiari chicken 28 alleles with average of 5.4 and 6 alleles per locus, respectively. The mean of Shannon index were 1.627 and 1.587 for Dashtiari and Khazak, respectively. ADL225 and MCW5 loci had shown the highest Shannon index. The mean of PIC in the two types of native chickens was 0.656. The highest PIC values were observed in ADL225 in Khazak with 0.80 and in Dashtiari with 0.81. Results were indicated that Dashtiari and Khazak chicken might be in one genetic group.

Prebiotics are defined as non-digestible food ingredients that benefit their hosts by selective stimulation of growth or activity of one or limited number of bacteria in gut. Probiotic products, when administered in adequate amounts, by improving internal microflora of body, confer an effective influence on the host from nutritional and health view. Consuming synbiotic products (simultaneous presence of probiotics and prebiotics) has more beneficial effects on consumer's health. In this study effects of replacing soymilk with milk (as a product containing prebiotics) in 3 levels, 0, 30 and 50% (w/w) on the survival of lactobacillus acidophilus, during storage of probiotic yoghurt drink were studied. Statistical analysis showed that replacing soy milk, resulted in significant increase (P<0.05) in total count of live probiotic bacteria in comparison to control samples and score of flavour is decreased by increasing of soymilk in formulation. Generally in all samples, during storage period, total count of live probiotic bacteria, pH and acceptability of flavor decreased, while acidity increased. All samples obtained the least required number of live probiotics according to FIL/IDF standard (6 log CFU/g).

It is inevitable for the improvement and development of rangelands to conserve and protect range species especially key species and palatable ones. One of the successful projects in rangeland improvement and development is to apply seeding methods. It is very important to have technological knowledge about temperature and appropriate time of seed storage in barn and it’s relation with surviving the germination capacity. The aim of this study is to determine the effects of time and temperature on Eurotia ceratoides germination. This species regarded as a native plant in southern slop of Alborz Mountain. The seeds were collected from Shahkooh region in Golestan province (Iran). After gathering seeds in the site and separating them from litters and other defect seeds, they were kept in oven at a temperature 30 °C, and then taken out when their humidity was about 7-8 percent. 44 containers, all with their shutters, each filled with 150 random seeds were put in four treatments: 0-5, 5-10, 15, 20°C. Every eleven containers were placed in separate storage areas. Then a germination machine was used to measure the germination capacity with the intervals of (3, 6, 9, 12,…, 30) months. Results showed that all the temperatures had a significant difference at (P<0.001) and maximum ratio of germination was achieved at 0-5°C during 9 months. The interaction between temperature and time of storage showed that the percentage of germination capacity of the seeds stored till 9 months for temperatures 0-5 and 5-10°C, will increase and then decrease. But in the treatments with 15 and 20°C, with an increase in time of storage, the germination of Eurotia ceratoides will decrease. It seems that though, high temperature is one of the factors that decreases the after-ripening period, in a short time, it has a severe effect on the germination capacity of Eurotia ceratoides. Seeds of Eurotia ceratoides can sustain more than 50% of their germination capacity at temperatures 0-5 and 5-10°C during 2 years.

In this research, species richness, life forms and platability of plant species in the key and critical areas was investigated. Two Whittaker, plots of 0.1-ha were established in each of mentioned areas. In each of Whittaker, plots from 0.1 to 1000 m2 respectively, species name as well as life forms, the number of each species and their palatability classes were recorded. By using linear regression models, two appropriate equations were calculated for species richness in critical and key areas. In order to compare the regression equetions of species richness, the group regression model was used. The results show that the species richness in key area is significantly different from critical area (P<0.05) so the species richness in key area is higher than the critical area. To find the relationships of the life forms and palatability of plant species in the key and critical areas, biplots were provided by using Principal Component Analysis (PCA). The correlation between palatability of species in key and critical areas are positive and negative respectively. Also the phanerophyts and chamaphyts have a positive correlation in key area but the geophytes has a negative correlation in it. This issue in the critical area is vice versa.

In this research, effect of two species of mycoparasite including one isolate of Trichoderma virens, and three isolates of T. harzianum (T99,110,112) was studied against causal agent of canola (Sclerotinia sclerotiorum) in laboratory condition. Mycoparasitism mechanisms, growth rate of mycelia, power of colonization, and effect of volatiles and non-volatiles metabolites of these isolates were considered on S. sclerotiorum. Dual cultures studies were indicated that, these isolates have antibiosis and hyperparasitism activity. Among two species of Trichoderma, T. virens was better for purposes growth rate of mycelia and power of colonization than the other isolates like T. harzianum (T99, 110, 112). It was covered more than 50% of colony of S. sclerotiorum. T. harzianum (rn 120) decreased growth rate of mycelia of S. sclerotiorum 60-71.5% in cultural medium. In the test of volatile compounds, T. virens prevented mycelia growth of S. sclerotiorum on the basis of 40-55%. Also, it was prevented sclerotia germination, by means of intercellular secretories. Microscopic studies were indicated that, T. virens and T. harzianum can penetrate into mycelium of S. sclerotiorum by coiling and appressorium formation. For the first time, it was specified that T. harzianum rn120 from Gorgan field can destroyed sclerotia of S. sclerotiorum.

In this study 285 specimens of rodents were collected from various areas of zanjan province between the years 2006-2007. These specimens were evaluated based on karyological, ecological and biological characters. The results of these studies shows that 21 species have distribution in Zanjan province: Spermophilus fulvus, Histrix indica, Allactaga elater, Allactaga euphratica, Dryomys nitedula Glis glis, Apodemus sylvaticus, Rattus rattus, Rattus norvegicus, Mus musculus, Nesokia indica, Cricetulus migratorius, Mesocricetus auratus, Meriones tristrami, Meriones vinogrodovi, Meriones libycus, Ellobius lutescens, Arvicola terrestris, Chionomys nivalis It was determined that of them 9 species: Spermophilus fulvus, Cricetulus migratorius, Ellobius lutescens, Meriones tristrami, Meriones vinogradovi, Meriones libycus, Arvicola terrestris, Microtus socialis, Microtus arvalis. Might be occurred in grain fields. Fron this species, Meriones tristrami, Meriones vinogradovi, Ellobius lutescens, Microtus socialis, Microtus arvalis. It was also revealed by the providing some knowledge about species mentioned that deep ploughing 0.5-1 meters width and 0.5-0.6 meters deep of field edges is effectable method for taking measures against to their harmful effects.

Tomato (Solanum lycopersicum L.) is widely grown in Iran and recently cultivation of this crop is progressively increased in commercial greenhouses. Virus diseases are one of the most causes of damage in tomato plants. In this survey 1307 and 603 symptomatic samples of tomato plant were collected from tomato fields and greenhouses, respectively. The samples were collected in five provinces in southeast and central of Iran including Kerman, Hormozgan, Sistan-Baluchestan, Yazd and Boushehr to test the infection of different tomato cultivars against Cucumber mosaic virus (CMV), Beet curly top virus (BCTV), Tomato yellow leaf curl virus (TYLCV), Tomato chlorotic spot virus (TcSV), Potato virus Y (PVY), Tomato spotted wilt virus (TSWV), Arabis mosaic virus (ArMV), Tobacco mosaic virus (TMV) and Tomato mosaic virus (ToMV). The infection of samples were analyzed by double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA), triple antibody sandwich ELISA (TAS-ELISA) and plate-trapped antigen (PTA)-ELISA using specific polyclonal antibodies. With the exception of TcSV, all viruses were detected in Petoearly CH cultivar. In contrast, samples of the two other cultivars grown in the fields including Chef and Y reacted only to four antisera. Greenhouses grown cultivars including Norma and Falcato were shown to be infected by six and three of the viruses, respectively. In contrast, samples of Gavrish and Kavir cultivars reacted to four antisera. Double infections were detected in all cultivars. Where as triple infection including TMV+CMV+ArMV, ArMV+CMV+PVY and ToMV+CMV+ArMV were detected only in Petoearly CH, Chef and Norma cultivars. In this study ArMV and CMV were the most frequently viruses. These results showed that susceptibility of field and greenhouse grown tomato cultivars to viral infection is different.

In most Heteroptera, the salivary glands complex consists of two principal and two accessory glands. Principal glands are structurally bilobed and are divided into anterior and posterior lobes. They are located at the thorax on each side of the midgut. Accessory glands are of two types: tubular and vesicular. In the present study, we investigated the sizes of different parts of the salivary glands of second to fifth instar nymphs and newly emerged, 10-days old, and 30-days old adults of the stripped bug, Graphosoma lineatum (L.), including the length of the salivary gland, length of anterior and posterior lobes, width of anterior and posterior lobes, and width of accessory gland. All sizes were measured by using a calibrated micrometer and a stereomicroscope. Experiments were carried out as factorial in CRD. With each instar and stage, gland size grows larger, whereas the ratio of its length to the body length decreases. Both in nymphs and adults, the effect of salivary glands situation on the size of its different parts was not significant which shows that the shape and size of right and left salivary glands of nymphs and adults are completely similar to each other. In the case of nymphs, the effect of instar was significant at 1% level which shows that an increase in developmental stages significantly increases the length of their salivary glands. In the case of adults, the effects of sexuality and adults’ life span were significant at 1% level. These show that the sizes of different parts of the females’ salivary glands are greater than that of the same age males and an increase in the adults’ life span would increase their salivary glands length.

The effect of egg of Sitotroga cerealella, dead body of adult S. cerealella, green aphid of cotton and Planococcus citri on some biological parameters of Chrysoperla carnea in a CRD with 50 replicates was studied in laboratory conditions. The collected eggs of C. carnea from tomato and cucurbite fields after hatching were reared on eggs of Anagasta kuehniella for 5 succesive generation to provide pure generation .The larvae were fed individually on above mentioned foods under 27±1oC, 60±5% RH and at 16:8 hours (L:D) conditions. The results indicated that the larvae fed on eggs of S. cerealella and green aphids of cotton had shorter larval and pupal period, increase in weight of larvae and pupae and decrease in larval mortality as compared with larvae fed on dead bodies of adult S. cerealella and Planococcus citri. Therefore these foods were suitable for mass rearing of C. carnea. The morphological unsuitability of dead bodies of adult S. cerealella and adhesive body of Planococcus citri had adverse effect on larvae of C. carnea to feed on them and these conditions resulted longer larval period and increase in rate of mortality. Hence, These were found to be unsuitable as food for mass rearing of the predator.

Improper land utilization and overexploitation of resources along the coastal areas of Caspian Sea have degraded the quality and quantity of these areas for ecotourism. An environmental land evaluation was used for ecotourism site selection in the coastal areas of four towns in the Guilan province, north of Iran. The method follows that developed by Ian McHarg and adapted and advanced by M. Makhdoum for use in Iran. The method is conducted in three steps: preparation of simplified maps of the environmental resources, map overlay, and ecological assessment of the units on the combined map, the latter being done using models developed by M. Makhdoum. The study was done using maps at the scale 1:100,000. Using GIS for implementation of the three steps of the method, it was found that a total land area of 0.07 percent of Rudsar, 0.26 percent of Langeroud, and 0.11 percent of Lahidjan are ecologically suitable for intensive ecotourism. No map unit was found suitable for intensive ecotourism in the Astaneh Ashrafieh township area. I also found that a total land area of 3.7 percent of Rudsar, 18.3 percent of Langeroud, 28.7 percent of Lahidjan and 31.7 percent of Astaneh Ashrafieh are ecologically suitable for extensive ecotourism. The areas ecologically suitable were prioritized using information on socio-economic parameters developed as maps and tables. Based on a combination of ecological and socio-economic potentials, it was showed that in terms of suitability for intensive ecotourism, Lahidjan comes first followed by Langeroud, Rudsar and Astaneh Ashrafieh. For extensive ecotourism, Lahidjan was first followed by Astaneh Ashrafieh, Langeroud and Rudsar.

A study was conducted to determine intraspecific variation of Coots, based on morphologic and skeletal characters, in three important wetlands of the northern Iran. The wetlands were Anzali, Ferydoon Kenar and Gomishan located at South West, South Central and Eastern Caspian Sea, respectively. Numbers of collected samples were 32, 17 and 17 from wetlands Anzali, Gomishan and Ferydon Kenar respectively. The Sum of samples was 66 numbers. Then 11 morphologic and 23 skeletal characters were measured and samples compared with each other. Means for 19 skeletal and 10 morphologic characters were statistically highly significant between 6 groups (3 Sites and 2 Sexes); (P<0.01). Also results of discriminant analysis revealed that coots of studied wetlands could be separated with respect to 11 morphologic and 23 skeletal characters (P<0.05). It was concluded that migration populations who visit these three wetlands are different and separate. Wintering populations of Coot individuals have decreased in wetlands of Iran in recently decades. On the other hand, the migration populations of these wetlands are separate. Therefore these populations need to specific management programs. Environment managers of Iran should take actions for population restoration before critical decreasing of birds.

A precise Groundwater level interpolation is one of the attractive subjects in groundwater studies. In this study the performance of different approaches such as geostatistics (Kriging), neural networks (MLP and RBF) and adaptive neuro-fuzzy inference system (ANFIS) in a groundwater level estimation is examined in order to identify the best approach for interpolation. Ghazvin aquifer was chosen as the case study for this study. The coordinate of monitoring wells are used as input and groundwater level is used as output parameter in neural networks and adaptive neuro-fuzzy inference system. In all of approaches, 20 percent of monitoring wells are used as test data. The results showed that accurate predictions can be achieved with an adaptive neuro- fuzzy with R2=0.98. Duo to smaller amount of MSE, the MLP neural networks with R2=0.93 can give more accurate results than RBF (R2=0.9) and kriging methods (R2=0.95). The results also showed that geostatistic approach can give more accurate results than RBF neural networks.

Extraction of high quality DNA is very important for genetic research. The extraction of high quality DNA from potato plant tissues is very difficult due to a high amount of polysaccharides, proteins and inhibiting compounds such as phenolic compounds and other secondary metabolites which have negative effects on DNA digestion, PCR and DNA cloning. To overcome these problems an efficient and simple protocol for DNA isolation from potato plant was developed by optimizing the existing methods. The results of this study showed that, the contaminants and pigments were limited to minimum in isolated DNAs from different parts of potato plants by adding 2-mercaptoethanol, PVP and 2.5 M NaCl into extraction buffer, and also the increasing of washing steps such as using of washing buffers, 5 M NaCl and 8 M LiCl. The quality of extracted DNA from tuber, root, stem and leaf of potato plants with this method were compared with Dellaporta et al. (1983) and Doyle and Doyle (1990) methods in 0.8% agarose gels. In addition, the results of PCR analysis showed that the isolated DNA of tuber, root, stem and leaf by this protocol consistently had high quality and functional in comparision with two other tested methods.