Year:2001 | Volume:14 | Issue:51 (IN NATURAL RESOURCES)|Papers Count:22

In order to investigate genetic variation in Bromus tomentellus species twelve genotypes of the species available in forage gene bank which were collected from different parts of the country were surveyed for eleven morphological traits. The data were analysed using RCBD analysis of variance. After confident result of differences between populations for the morphological traits, the genotypes were classified based on the mentioned traits. Correlations between all combinations of genotypes were also estimated. Principal components analysis (P.C.A) presented two components, containing about 98 percentage of the total existing variation of the data. The two main components were used to produce scatter plot of the populations. Path analysis showed that leaf length, flowering date, and plant vigor were the most important factors affecting plant yield, and had dirrect effects of 1.044, 1.114 and 0.56 respectively. Applying UPGMA method of cluster analysis on the studied attributes, four groups of clusters were obtained. Regarding the morphological characteristics the least and the most similar populations were identified to be used in the future breeding projects.

The organizational and environmental dynamics and complexities or Turbulent for the new world, increased the changes in the knowledge, attitude, and behaviour in the individuals, groups and organizations. This research attempt to design the continious learning model by considering the conditions of public administration of Iran. The researchers and authors such as Peter Senge, Alan Mumford, Oavid Garvin, Alan George, Grice Argriss, David Colb, Ray Stata, Stewart and etc, designing the individual, group and organizational learning. The present research integrated the above mentioned models in the eight dimensional continious learning model for Jihad - E - Sazandegi managers, statistical analysis that used in this research are: 1- Sign test 2- X2 test 3- Friedman test 4- One - way anova test, 5- Tukey HSD test. The results of this research are: A- Essential dimensions of model that accepted with ordinal with rank means are: 1- System's thinking (5.24) -2 learning climate (4.39) 3- shared vision (4.81) 4- Action Learning (4.59) 5- Learning opportunity (4.55) 6- Team learning (4-48) 7-Self- development (4.2) 8- Mental model (3.21).B- Significance difference between existance and ideal state are accepted with the statistical analysis that were mentioned above. C- At Final: The researcher designed special interaction models for the continious learning model.

Fluctuation of hypericin and yield in Hypericum perforatum was examined in Karaj research station in 1989. In this study chemical fetilizer, organic manure and combination of them were alocated in subplot, and plant density was alocated as main plot with 4, 5.7 and 10 plant m-2. In a split plot design under CRBD with 3 replication hypericin in the tops from the first harvest was extracted and measured by soxhlet and spectrophotometer. Hypericin extraction was performed in two stages by CHCL3 and MeOH and measured by standard hypericin. The results showed that the combination of fertilizer and manure and also manure alone produced maximum hypericin, which were 2262 and 2197 ppm, respectively. Hypericin yields of the mentioned treatments with 4684 and 4534 gr/ha also showed significant difference with chemical fertilizer and control. The highest hypericin yield produced in 10 plant m-2 density. Sum of hypericin yields for combination of manure and fertilizer treatment in two harvests reaches to 8094 gr/ha. It seems that combination of chemical fertilizer and manure by improvement of the soil physical, chemical and biological properties are able to improve hypericin content without any toxicity in this medicinal plant.

Breeding perennial ryegrass (Lolium perenne L.) for improved yield and quality traits is an important goal for improving animal performance. The objectives of this research were to determine the extent and nature of genetic variability for three quality traits namely: Digestible organic matter in dry matter (DOMD), water soluble carbohydrates (WSC), crude protein (CP) as well as dry matter yield (DM yield). Near infrared spectroscopy (NIR) were used for estimation of the quality traits. Based on plant maturity, two mid season and late groups of full sib families were developed. The progenies were grown as dense swards under two cutting frequencies (conservation and simulated grazing) over two years. The estimated of broad sense heritability were relatively high for all traits especially in mid season group. Interpretation of these values is restricted because the experimental design(measurement of full sib families variance in dense swards) did not allow estimation of nonadditive genetic variance. Consequently the contribution of such gene effects are unknown. Genotype x Environment interactions (managements and years) were present for dry matter yield and to a lesser extent, for digestibility, water soluble carbohydrates but absent for crude protein. Genetic correlation between traits were consistent. Crude protein was negatively correlated with both dry matter yield and water soluble carbohydrates, while water soluble carbohydrates was positively correlated with dry matter yield and digestibility. The genetic correlation of digestibility with both dry matter yield and crude protein was in general negative. This negative relationship was weak and unconsistent over all cuts.

In this study in order to evaluate different methods of drying on saffron quality, an experiment was conducted in R.C.B.D. in 4 replicates. Saffron was dried with four different methods including 2 traditional methods and 2 industrial methods. After drying ammount of color, aroma and bitterness in samples was determined, by spectrophotometric method. Results indicated that there is a significant difference between drying methods; such that drying saffron with cabinet dryer in atmosphere pressure reserve quality of saffron better than other methods. Drying of saffron with Iranian traditional method caused decreases in quality of saffron. It is recommended that in small scales production, Spanish method is used for drying of saffron and in large scales and farms to be used industrial driers.

In order to find out plants which are suitable for rehabilitation of deteriorated rangelands of Persian Gulf and Oman sea (Hormozgan province) an experiment was carried out in Sarkhoon fourty kilometres far from north of the Bandarabbas with Annual rainfall of approximately 170 mm. The layout of this experiment was a split plot design with six irrigation period as main factors and three atriplex species. Irrigation treatments were as follows: A: Only onetime has been irrigated, B: irrigation every 10 days C: Irrigation every 20 days, D: irrigation every 30 days. E: Irrigation every fourty days, F: irrigation every 60 days. Different atriplex species were as follows: a: Atripex lentiformis b: Atripex halimus c: Atripex canescens. According to statistical analysis of the first year there is significant difference at the level of five and one percent between different species and irrigation treatments. Seedling death percent of species were recorded for four years but survival of different irrigation periods were few. So results of this experiment were not analysed at the end of experiment course.

This article presents the promising tool for the prediction of water erosion in the areas where availability of hydrological data is limited. The modeling includes the integration of MUSLE with SPANS-GIS for semi-arid zones particularly Syahrood one of the sub-basins of Damavand watershed in Iran where soil erosion by water is one of the land-related problems. Runoff erosivity, soil erodibility, slope length, slope steepness, cover management, and erosion control practice factors were computed and included in the digitized and computed Thiessen polygon, land component, slope and land-use maps of the watershed. The amount of sediment yield in each land-use was computed by overlaying these maps with the appropriate models in the SPANS-GIS. The result shows higher erosion rates are related to drylands that usually belong to steep slopes and are cultivated in rows parallel to the slope direction. The average sediment yield for the entire study area was 745 t/km2.yr with the higher and lower erosion rates of 978 and 221 t\km.gr2 in the drylands and orchards, respectively. This sub-basin is characterized with the lack of recorded rain gauge data, which limited the application of commonly used erosion models. Results demonstrated that interfacing MUSLE with a GIS in an effective method for the prediction of soil erosion in small watersheds with limited data sets. A GIS simplifies the extracting of necessary fators from databases. SPANS-GIS uses quadtree data model that provides compact raster representation by using a variable-sized grid cell, useful for having least file size when the data are relatively homogeneous and do not require frequent updating.

This study was carried out to investigate, cypress habitat (Cupressus sempervirens L.) in Darab district from Fars province in Iran. This cypress accumulation is an old trees. Distribution is single or groups of old trees. In this study investigated ecological and morphological characteristics of cypress trees. The ecological study included soil, climate and water condition and morphological study was contained, tree length, bassale, diameter at breast height and canopy diameter and length canopy has formed. The mean of rain in this habitat is 298 mm and rain distribution is in autumn and winter. The climate of habitat is and texture of soils are light. The length of trees were between 16.5-23.6 meter and average was 19.77 meter. Diameter at breast height was between 118-203 centimeter and average was 166 cm. The age of trees estimated more than 1000 years old. The morphological characteristics of trees showed this trees are elder and invalvable genetic resourses but external condition showed this trees go to won ward trend and on this habitat the trees were not reproduction.

A trial was conducted in order to study the effect of density and plant combination on yield and quality of performance of forage corn and soybean mixture on experimental farm of agronomy and plant breeding of agriculture college in Shahid Chamran University. A randomized complete block design (factorial experiment) with 4 replications was used in the trial. Factors were 3 densities (local optimum density, maximum and minimum density) and 5 mixture combinations (Monocultures of corn and soybean, 75% corn: 25% soybean, 50% corn: 50% soybean: 25% corn: 75% soybean). Strip planting procedure was used to form the mixture. Optimum density for corn and soybean were 75000 and 200000 respectively. Silage of corn and soybean was harvested simultaneously. Results from the study showed that in general from the viewpoint of dry matter yield, density treatments had a significant difference (p<0.01), but plant combination treatments and their interactions had no significant difference at the same level of probability. Treatment D3M4 (75% soybean: 25% corn, with maximum density)by a yield of 16 tons (DM/ha)and treatment D1M2 (25% soybean: 75% corn with minimum density) by a yield of 7.16 tons (DM/ha) had the highest and lowest production respectively. To calculating of land equilibrium ration (LER), it was cleared that treatment D3M4 by a 12% increase had the most profitability in comparison with monocultures of both crops with1719 kg crude protein and LER= 1.14 by a 14% increase of crude protein in comparison with monocultures of two crops. That above treatment showed preference over other treatments. The absorption of N, P and K in the plants by density is increased.

Different parts (leaflet, flower and fruit) of neem and Persian lilac trees (Meliaceae) extracted with soxhlet apparatus. The antifeeding effect of oil extracts was tested against adult grain weevil. The fruit oil extracts of neem and Persian lilac and flower oil extract of neem caused 96, 56 and 50 percent mortality in adult grain weevils, respectively, where it was 14 percent for control treatment. The differences between means of mortality was significant at P>%5.

The effect of four levels of salinity (0, 50, 100 and 150 mM NaCI) on growth, ions accumulation and nitrogen assimilation in three grasses "Lolium multiflorum, "Lolium perenne and Festuca arundinacea" was studied. Festuca was found to be more resistant than Lolium species. The high concentration of Na+ was not observed in shoots of F. arundinacea. Also, the decrease in K+ /Na+ ratios were more severe in lolium species than F. arundinacea. The total - Nand N03 - -N concentration decreased drastically in lolium species due to salinity. However, such an effect was observed only at 150 mM NaCI in F. arundinacea. The NH4+ -N concentration was increased in all species under salinity. the results indicate that Na+ exclusion probably rescued the festuca plant from severe stress while in the lolium species such a resistance mechanism was not established. Our results suggested that there exist potential to utilize festuca in pastureland management in saline areas.

The genus of mentha is one of the important of medicinal plant used in medicinal and food industries. Plant materials were collected from cultivated Mentha X piperita L. in two different growing locations, one from Karadj city, Kalak (sample 1) at the begining of june 1998 and other sample from Kamoo village 70 km away from Kashan city (sample 2) at the begining of june 1999, and essential oils obtained from leaves by steam distillation method. The oil yields of two samples were 1% v/w calculated on the weight of fresh plant. The oils were analyzed by capillary GC and GC/MS. Main components from sample 1 representing 93. 55% of total oil were, Neo - menthol (42.62%), 1, 8 - Cineole(16.81%) and piperitone (12.25%), and for second sample, main components are L-menthol (37. 55%), L-menthone (19.13%), 1,8- Cineole (11. 48%) and menthofuran (4.45%).

In this research ecological capabilities (collection of environmental characteristics such as soil, aspect, slope, micro climate and elevation that shows potential of forest area) of Iranian conifers' forests were evaluated. "Taxus baccata", in Vaz and Afratakhteh sites forests were studied. Study in three parts of trees, natural regeneration and vegetation was performed. Inventory was performed in 2500 m2 random plots. For analysis of data's, basal area, tree's distribution in diameter classes, number of trees in per hectare and height curve were prepared. For vegetation, biodiversity common indices were studied. The results show. Vaz site has better situation in tree's distribution in diameter classes, basal area, regeneration, HD index and height curve and it has more amount of biodiversity index.

The flowering shoot and seeds of cultivated Anethum graveolens (dill) were harvested from the research center of Alborz near Tehran. The essential oils, obtained by distillation methods, were evaluated for their chemical composition by GC and GC/MS. Thirteen compounds were identified. The main constituent of the flowering shoot oil was α-phellandrene (56.1 %), while that of seed oil was carvone (57.3%). Carvone was not found in the flowering shoot oil and α-phellandrene represented only 1.6% of the seed oil. The second main component was limonene, 23.8% in the flowering shoot oil and 33.2% in the seed oil.

The importance of maintenance of naval construction and their intensity of destruction have taken our attention to carry out a research project on this connection. The aim of this research shoud be described as follows: 1- Study on natural durability of the exotic wood species (Teak, Keruing, Balau, Chengal) against marine borers. 2- Study on the effect of treatment on increasing of durability of those species. Among those species, some sampling have been choosen using C.R.S. Method. Samples, were treated (impregnated) by coal tar oil (Creosot) in Gazvin impregnation plan. The treated samplings were compared with control samples of exotic wood, also beech and oak (Iranian wood species) which have been installed in sea water according to IRG/WP. During 6, 9, 19,21,27 months, the samplings were inspected according with recommandation of IRG/WP. During this instalation period, all the control samplings (no treated), expect chengal, have been seriously attacked by marine borers. All the treated samplings, after 20 months instalation in sea water, were completely safe.

Prosopis koelziana Burkart (Mimosaceac) is endemic of dry and semidry regions of Iran. Regeneration of this plant due to the hard seed coat and self incompatibility is very weak in nature. We tried to produced many plants in short time by in vitro culture. After production of sterile seedlings, different parts of seedlings were cultured on MS medium having different ranges of plant growth regulators. Node, stem, and hypocotyle had almost equal potential of, callus production on MS medium with BAP & NAA (2 & 0.5 mg/I respectively) but in media containing (2, 4-D & Kin) and (NAA & Kin), hypocotyle was more responsive. The most effecting medium for shoot production was MS supplemented with 2, 4-D (0.5 mg/I) & Kin (1 mg/I) from stem segments and for root generation was MS medium that had NAA (0.2 mg/l) & Kin (0.5 mg/l) from hypocotyle segments. The most number of whole plants was produced from stem segments on MS medium supplemented with BAP (1mg/I) & NAA E (0.1mg/I) 70-90% of these sterile plants survived for one month after transfer to green house conditions.

In order to study the allelopathic effect of the roots of wheat, cotton, and sunflower on different phases of growth and development and sunflower yield, this research was carried out based on a completely randomized design, including a factorial experiment with 3 replications under growth chamber conditions in the Institute of Biochemistry and Biophysics at Tehran University (I.B.B.) in 1376. the irrigation treatments consisted of the exudation components of the roots of wheat, cotton, and sunflower. The amounts of those components were measured in four water levels: 0, 50, 100, and 150 mg/lit. some charateristics, like the height of plant, number of floweres in anthodium, number of seeds, dry matter of foliage, and seed yield were determined. The findings of this research indicated that most of the characteristics, due to the exudation components of wheat root residue with the density of 150 mg/lit, made important changes in the root matter. Thus, the effect of the exudation components of wheat root residue whit 150 mg/lit on the yield of sunflower seed with the mean of 300 kg/hec, in comparison with that of the exudation components of wheat root residue with the density of 0 mg/lit with the mean of 1100 kg/hec in the control group, was significantly different in 1% level. In general, the experiments carried out in this study showed that among the irrigation treatments, the impact of the exudation components of wheat root residue, especially with the density of 150 mg/lit on the studied characteristics, as compared with the irrigation treatments of other plants, was more negative. In this investigation, the positive allelopathic effects of some treatments on the characteristics were determined. Therefore, the irrigation treatment of the exudation of sunflower root with the density of 150 mg/lit had an increasing impact on the number of sunflower leaves. Generally, the phenolic components, which exude from different parts of the plant, can have both negative and, sometimes, positive effects on the growth of neighboring plants. For instance, in this study, the phenolic exudation components of wheat root residue in water affected the growth and development of the sunflower seed most negatively.

Hypericum perforatum L. (St. John's Wort) is being used and cultivated as a medicinial plant. The importance of this plant is, in particular due to the content of hypericin and its derivatives. It has recently been found that hypericin is effective against certain viruses, antineoplastic activity, protein kinase and based on the formation of singlet oxygen upon exposure to the visible light. Hypericin and its derivatives are accumulated in the multicellular nodules, around the leaf margin and around the margins of petals. Also formation of hypericins in species varies significantly depending on the origin of the plants. After collection and dried flowers of plants H. perforatum and H. scabrum from different area (Hamedan and Noshahre) wear powdered and extracted repeatedly with hot ethanol and petrol ether by soxhlet. The Hypericin content of plants are determined by uv. spectrophotometry. A significant variability with in the different species were calculated, 1692 ppm and different area were 335 ppm.

The rangelands of  "Vaz" with 5150 hectar extension is in the Chamestan region of Mazandaran province. Twenty plant communities distincted at the rangelands by using of physiognomic-floristic method. The relationship between plant communities determined by using of ordination and calculation of Gleason similarity index, with considering of quantity amounts  (frequency-cover). Location of each plant community on axes determined by Beal's method and relationship of them has showed in the dimension place. Results explain that plant communities (specially numbers 7and 8) are distincted by some different charactristics such as cover, frequency, stratification and diversity.