جستجوی مقالات مرتبط با کلیدواژه « altitude » در نشریات گروه « زیست شناسی »

Plants are one of the important sources of fatty acids. Types of saturated and unsaturated fatty acids are widely used in food industry, health, plant ecophysiology and chemotaxonomy. This research was conducted with the aim of investigating the oil content, fatty acid profile and chemotaxonomic relationships of some plant species of the Apiaceae family in Iran. Oil extraction was done by soxhlet method and compounds were separated by gas chromatography (GC) after derivatization in the form of methyl ester. Species cluster analysis was done with distance algorithm between two data and Euclidean similarity matrix using PAST 3.17 software. Based on the results, the average oil yield of plant species was estimated between 5.1% and 26.18% and there was a high positive correlation between the altitude of the habitats and the oil yield. Petroselinic acid (C18:1(n-6)) and alpha-linolenic acid (C18:3(n-3)) were the main compositions of fatty acids of all species. Oleic acid and gamma-linolenic acid were detected only in Ferula and Pimpinella species, respectively. The percentage of total omega-3 fatty acids varied from 10.42 to 17.99 among species. Smyrnium cordifolium, Ferulago angulata, Tetrataenium lasiopetalum and Conium maculatum were rich in petroselinic acid (60-78%). Chemical dendrogram based on 18 fatty acids with high similarity coefficient distinguished Ferula species in one group and Conium in a separate group similar to botanical classification. The results show that the fatty acid composition of the seeds of some genera of the Apiaceae family, together with the morphological and molecular characteristics, can be used as a tool to solve the taxonomic complexities between the tribes and genera of the Apiaceae family. to be used in the flora of Iran.

Considering the critical conditions of Lake Urmia, identifying bacteria with the ability to live in extreme environments is valuable in terms of microbial applications and tolerance of the existing biological conditions, and it helps us to better understand the surrounding environment. In this study, the most abundant microbial branch in the soil samples obtained from three different heights of 10, 150 and 250 meters of Qale Kazem Khan Mountain, which is located on the shore of a very salty lake in Urmia, has been investigated.

The soil samples were collected to identify and classify Proteobacteria    subgroups using 16S rRNA sequencing using Next Generation Sequencing (NGS) as well as FLASH genetic software and UCHIME algorithm to identify the obtained sequences.

Altitude change affects the abundance of Alphaproteobacteria and Betaproteobacteria. The abundance percentage of Alphaproteobacteria has a direct relationship with altitude, while the abundance percentage of Betaproteobacteria increased with the decrease in altitude.

in the overview the percentage of Proteobacteria abundance the samples has an inverse relationship with the increase in height, whereas in the separate examination of the microbial groups, a significant relationship between the increase and decrease in abundance and the height of sampling is observed. Also, two unknown and unclassified genera in the  Deltaproteobacteria order were also identified which a very high frequency percentage (18-27%) among the data had related to the three samples.

Seed production is one of the key factors in the seed regeneration of plants and trees and is widely used in regeneration, forest development, afforestation and especially seedling production in nurseries. Therefore, it is very important to select quality and ripe seeds with suitable physical shape. The aim of this study was to investigate the effect of altitude factor on the physical properties of pistacia seeds in Sustan Reserve, which is one of the four pistacia reserves in West Azerbaijan Province. The reserve was divided into 4 altitude classes including 1515, 1615, 1715and 1815 meters above sea level. Also, in order to increase the altitude, the reserve area was divided into one-hectare sample plots (100 m * 100 m) In each sample piece, Three seed-giving trees including the diameter, the smallest diameter and a medium diameter were selected (Slope, direction and soil factor were equalized). A total of 60 trees were selected and 5 clusters from each tree were randomly collected in the north, south, east, west and center of the crown and the physical characteristics of the seeds included: cluster length, ‌ number of fruits per cluster, fruit length, fruit width, Fruit weight, grain weight and seedlessness percentage in each altitude class were evaluated. Data were analyzed using Excel and SPSS software and the means were compared and the analysis of variance was performed using F-test, Duncan multiple comparison test and Kruskal-Wallis test. The results showed that all traits except the percentage of seedless at different altitudes above s

The study of flora characteristics and their relationship with ecological factors in habitats has a particular importance, especially in protected areas. This study aims to analyze chorological and endemism of the Central Alborz protected area flora. The study area is the slopes of Welwesht, Dahla, and Azadkouh heights in the protected area of Central Alborz, Mazandaran province. The total number of collected and identified taxa is 331, which belong to 197 genera and 46 families. During the floristic studies of the region, Nepeta azadkouhensis Saberamoli from Lamiaceae family was identified and introduced as a new species. About 49.25% of taxa are hemicryptophytes, 57.40% of all species belong to Irano-Turanian chorotype. Forty-six taxa, equal to 13.9% of all taxa, are endemic to Iran. Of these, 37 species, equal to 82.22% of endemic species, belong to the vegetation zone of Irano-Turanian. The habitat of mountain steppes, mainly with grasses and cushion-shaped plants with 24.47% of the total taxa, has the highest species richness. The results of the species richness study in the altitude classes of the endemic taxa showed that, in total, more than 70% of the taxa are located in medium to semi-high habitats. The study of the presence of endemic species in vegetation elements confirms the dominance of the Irano-Turanian vegetation zone in the region, with the significant presence and influence of European-Siberian elements.

Capers (Capparis spinosa) are one of the valuable medicinal plants that can grow in a wide range of ecological situations. In order to investigate the effect of climate on the physiological compounds of this plant, plant samples were collected in late summer with three replications from the mountainous areas of Amol city (Nemarestaq, Delarestaq and Behrestaq) at four altitudes with a difference of 150 meters (minimum altitude 850 meters). Some physiological traits of leaves and fruits were measured and analyzed by compound analysis in a completely randomized design. Data analysis showed that all the measured traits were affected by climate and were statistically significant, so that the highest amount of chlorophyll a, chlorophyll b, carotenoids, vitamin C, phenol, flavonoids, anthocyanins, antioxidants at an altitude of 1650 meters in Behrestagh region with 6.75, 10.56, 3.59, 15.60, 24.66 mg/g fresh weight, 4.51, 2.55 μmol/g fresh weight and 81.78% inhibition, respectively, and the lowest was observed at an altitude of 850 meters in Nemarstagh area. Regression slope also proved the significant relationship between traits and region and altitude, and antioxidant capacity which is the most important medicinal property of this plant, along with chlorophyll a, had the highest relationship (r² = 0.93). Also, the analysis of Pearson simple correlation coefficients showed a positive and significant effect between the traits. In general, with increasing altitude, an increase in the amount of measured physiological compounds that have medicinal effects was observed, so it is possible to develop the cultivation of some medicinal plants close to this family in the highlands.