ساختار

Metropolises are emerging phenomena that affect a wide range of surrounding space. This effect over time leads to the expansion of the metropolitan area. The current research has been compiled with a general descriptive-analytical approach and using available documentary data and statistical data. Excel and Spss statistical software and ArcGis spatial processing and description software were used in database preparation and data analysis, and ANN nearest neighbor index was used to determine the activity distribution pattern, and Moran's Spatial Autocorrelation Model was used to check the distribution rate. Is. Based on the results of the research and investigations of the Qazvin metropolitan area in terms of activity, it can be said that the Qazvin metropolitan area has a dominant linear structure with a trend and development towards the formation of a radial-annular structure in its southern half. Also, the spatial structure of the metropolitan area of Qazvin has been made in connection with the expansion of relations and economic connections with cities and rural areas, especially in the southern part of the area.

It is very important in forest planning to recognize forest types and their classification in similar or different groups, their distribution pattern, mixture, frequency, dominance and abundance at the various area. Therefore, the purpose of current research is to identify, classify and introduce forest types, also determine some structural parameters and, other statistical components on these types. For this study, randomized-systematic sampling was used. After the statistical calculations, eighty sample plots were deployed. To understand the natural regeneration condition, five sub-plots were measured in each plot in four directions and the center of the plot. The seedlings height includes <30, 30-130 and, >130 cm was measured with decimeter precision. In this study, forest types have been classified based on factors such as physiognomy, dominance, species composition, physiographic conditions, and forest type extension. The results showed that 17 tree species belonging to 17 genera and 13 plant families were identified. The mean volume per hectare was equal to 317 silv, which beech, maple and hornbeam species have the highest proportion. The volume per hectare of beech stands includes 440.8 silv. Totally, the number of trees per hectare comprises 485 trees. More than 52% of the total regeneration belongs >130 cm height, 17.62% belongs 30-130 cm height and 30% belongs <30 cm height. Among the species, Diospyros lotus, Box-plants, Ironwood, maple, and beech constitute the majority of regeneration, respectively.

Measuring the forest structural diversity is a useful and important way to predict the growth and the future development activities of the forest stands. Calculating structural indices are the most common methods for estimating the forest structure. These indices provide a quantitative estimation of the situation of stands variations. The aim of this study was to investigate the structural diversity of Acer campestre L. stands as one of the most important species in Arasbaran forests in order to identify the condition of this species and improve its structural diversity. The structural diversity index (S-index) was calculated by using summing three indices consist of uniform angle index, mingling index and diameter differentiation index in distance method. The results showed that the uniform angle index (Wt=0.36) indicated a uniform -random distribution. The diameter differentiation index (Dt=0.16) showed a low diameter differentiation among the reference trees and the neighbor trees species and mingling index (Mt=0.57) showed the high amount of species mixture in the study area. Finally, the structural diversity index showed high structural variation (0.479) in the study area. This study can be considered as the basic information for improving the conditions, recognizing the ecological relationships between tree species and a pattern for restoration activities.

Abstract Analysis of population genetic structure using multilocus data, is generally performed by sequential run of the three computer programs, namely STRUCTURE, CLUMPP, and Distruct. The two latter programs lack Graphical User Interface (GUI), and the user must manually create inputs and settings files, using text editors out of the program environment. A number of facilitating programs have been developed, which are online, or dependent on statistical packages such as R. In this paper, after reviewing the aims and methods for analyzing the structure of populations using dominant molecular marker data, a new computer program, STRUCTUREasy is introduced. This program simplifies the analysis procedures, with no need for programing skills. STRUCTUREasy is an open source program with a simple user interface, running in Microsoft Office. Its application is for the extraction of Q-matrices of STRUCTURE and connecting the input files to downstream software, for providing ease of use, and more accuracy and pace, in population structure analysis using multilocus markers. This program runs in Microsoft Access 2016, and performs well in extracting data and settings between STRUCTURE, CLUMPP and Distruct software, for accuracy and pace.

Essence of oil secretory cavities (glands) have been reported in all Citrus species of the Rutaceae family. The present study has focused on the histological aspect of the oil gland ontogeny during flower and fruit development in lemon(Citrus limon(L.)Burm.f.). Samples taken at six successive ontogenic stages were processed according to routine transmission electron microscope procedure, and viewed under the light microscope. Oil glands in sepals, petals and ovary wall appeared different time intervals, but showed the same histological aspect. In fruits, oil gland appearance was restricted to the immature stage. No new gland was formed during the fruit maturation process, and the preformed ones continued to enlarge. Secretory glands of the flower and fruit peel showed a similar developmental pattern and separated into four stages, based on cell features and the degree of gland differentiation. Oil gland ontogeny started from the divisions in some epidermal and hypoepidermal cells, and ended with an expended central cavity. The flattened cells bordering the central cavitiy were structurally distinguishable and had probably different functions. Wall separation and autolysis overlapped each other; the oil gland ontogeny in Citrus limon is therefore of schizolysigenous type.

This study was designed to determine the effects of drought stress and exogenous abscisic acid on the structure of reproductive meristem, pollen grains, morphological traits, yield and yield components of Brassica napus. Plants were grown in Karaj Seed and Plant Improvement Institute in a randomized blocks design with 3 replications. Treatments included irrigated plants without exogenous abscisic acid, under drought stress without exogenous abscisic acid and under drought stress with 3 concentrations of exogenous abscisic acid. Reproductive meristem and anthers of control and treated plants were fixed in proper fixative for cyto-histological studies. Plants were collected for studying the morphological traits, yield components and seed yield. Results showed that drought stress plus the lowest concentration of exogenous abscisic acid prematured the meristem, increased the number of pollen grains and their viability. More ribosomes and mithochondria were observed in pollen grains. Drought stress plus the lowest concentration of exogenous abscisic acid showed an increase in yield in comparison with other plants under drought stress also showed 2-3 percent increase in oil percentage.