ehsan kahneh

Monoculture and unbalanced use of some chemical fertilizers have upset the microbial activity of tea plantations. Change of mycorrhizal fungi status is a good indicator of measuring the sustainability of agricultural management. Thus, this study was carried out to determine the abundance of AMF spores and their relationship with some soil properties of Iranian tea plantation. For this purpose, 155 composite sample of soil was taken of 0-30 cm. Spores of AMF extracted by wet sieving and root colonization was determined by cross-sectional method. Soil properties including pH, soil texture, organic carbon and available potassium were determined.by conventional methods and available phosphorus by Bery-1 method. The results showed that only 66% of soils had AMF spores with an average 9.310-g. The identification of spores revealed that two morphotype Glomus sp was dominant in soil. Soil analysis showed that 37% of soils had pH<4.5. The mean of soils O.C and P content was 2.1%. 54.3 mgkg-1 respectively, so that 46% of soils have very high amounts of Pave and 49% of soils had Kexe <150 mgkg-1. The correlation coefficients showed that only pH and Pava had a positive (r=0.43, p<0.001) and negative (r=-0.54, p<0.001) correlation, respectively with AMF spores.The spore density were very low in studied soil, which indicates negative effect of long-term tea cultivation on the AMF in the rhizosphere. pH and Pava are among the influencing factors in reducing the AMF spore No. Therefore, by recommending the use of P fertilizers based on the soil test, the soil pH correction and application K fertilizers, inoculating tea seedlings with commercial bio-fertilizers of different species, mixed plantation of tea with N-fixing shaded trees such as Albizia and alder is one of the ways of proper management of plant nutrition, improvement of mycorrhizal status of tea seedlings and soil quality.

Diversifying products and increasing added value by producing new medicinal and health products from tea is a strategic method to improve the production situation and economize tea. In recent years, tea genotypes resulting from the natural selection of the purple-leafed variety have been introduced in some tea-growing countries. Considering that there is a possibility of the presence of such genotypes in the tea gardens of Gilan, the present research was carried out to identify and select the constant purple-colored tea plants that contain higher amounts of anthocyanins. For this purpose, through field monitoring, purple tea plants with stable color were identified and labeled from the cities of Gilan province, and then the leaves (one bud and two leaves) were examined to analyze the amount of pigments. The results showed that the environmental factors, soil nutrition and pruning operations in different places had a positive effect on the amount of pigments during the growth and development of purple tea plants. So that sample numbers 10 (12.5983 μg·g–1, DW), 19 (50.4865 μg·g–1, DW)) and 16 (10.4451 μg·g–1, DW) respectively in Lahijan and Astana Ashrafieh had the highest anthocyanin activity and the lowest anthocyanin activity in sample number 3 (1390/93 μg·g–1, DW) in Langrod city. The highest amount of chlorophyll a, total and carotenoid in sample number 35 (1.07, 1.53 and 2.49 mg·g −1 DW) respectively and the lowest amount of chlorophyll a, total and carotenoid in sample number 5, respectively (0.46, 0.71 and 1.26 mg·g −1 DW) were obtained in Astana Ashrafieh, and factors such as (radiation intensity, soil fertility, altitude above sea level and pruning operation) were involved in this phenomenon. Therefore, extractions with a higher amount and less temporal changes in the amount of anthocyanin can be monitored and studied for future research to produce tea seedlings rich in anthocyanin.

Elicitors are used more frequently to promote plant growth and secondary metabolites. One of the main challenges for tea producers is the slow growth and poor quality of green tea leaves (Camellia sinensis) in tea-growing regions of Iran. In many plants, foliar application of chitosan or nano-chitosan (NC) enhances secondary metabolite production. It has a positive impact on plants' physiological and biochemical indicators. This study investigated the impact of nano-chitosan on some biochemical and physiological parameters with and without mineral nutrition (NPK), as well as assessing the quality of green leaves by comparing the relative expression levels of three enzymes involved in the flavonoids pathway in the Kashef cv. tea plant in northern Iran. For this, two scenarios were used: four different concentrations of nano chitosan solution (0, 25, 50, and 100 mgL-1) were prepared and combined with NPK (1%-1%-0.5%), and without NPK were prepared. At the Lahijan Tea Research Center in Iran, two experiments were conducted as foliar treatments applied twice at two-week intervals, after the first season's harvest in 2021. Twenty days following the initial foliar treatment, plant sampling was conducted to examine physiological, biochemical, metabolic, and molecular characteristics. The first and second leaves, as well as the buds, were gathered for metabolic and molecular testing. The third and fourth leaves were collected for physiological and biochemical analyses. Chlorophyll content and relative water content were measured in physiological experiments. Protein content and the antioxidant enzymes CAT, SOD, and PPO were investigated biochemically. Additionally, metabolic properties were determined using the folin-sio-catheo method as well as HPLC to determine catechins, epigallocatechins, and gallocatechins. Molecular analysis was also performed by examining the relative expression of three critical enzymes in the flavonoid biosynthesis pathway, F3H, DFR, and LAR. The results showed that utilizing NC along with NPK significantly increased the content of total polyphenols in tea compared to the control (without NC and NPK). All treatments reduced catechin content 4- to 6-fold. With an increase in NC concentration, epigallocatechin content increased. Gallocatechin content also revealed a slight increase in 100 mg.L-1 NC concentration. Chlorophyll content indicated a significant difference with a falling trend in treatments with low concentrations of NC; however, a significant difference with a growing trend was seen in treatments with 100 mgL-1 of nano chitosan. In comparison to the control, various NC treatments had similar protein content. Except for the 50 mg.L-1 NC+NPK treatment, there was an apparent significant difference in the SOD enzyme activity in each NC treatment, with a positive trend. With increasing NC concentrations, CAT enzyme activity also rose in various treatments. In treatments with insignificant NC concentrations, PPO enzyme activity significantly decreased. In different treatments, leaf water content rose. Only at a dose of 100 mg.L-1 NC+NPK did the relative expression of the F3H enzyme rise nearly three times compared to the control; in contrast, other treatments had no meaningful effect on relative expression. Different NC+NPK treatments raised DFR relative expression, and 100 mg.L-1 NC demonstrated the highest expression (4 times). Compared to the control, LAR relative expression increased at 0, 50, and 100 mg.L-1 NC and NPK. The treatment without NC and with NPK displayed the highest level of LAR expression, with an expression almost 2.5 times higher than the control. In Kashef cultivar tea plants, chitosan nanoparticles in various concentrations coupled with NPK increased the production of catechin compounds. This effectively reduced oxidative stress and enhanced green tea leaf quality. In addition to addressing oxidative stress, NC may play a practical role in green tea quality. Due to its biodegradable properties, nano chitosan can be used instead of chemicals to improve tea plants' green leaves quality and lower environmental pollution.

Considering the high demand for tea in Iran and the insufficient local production, the use of chemical fertilizers to enhance production per unit area is increasing. The long-term use of chemical fertilizers, especially nitrogen fertilizers, in tea gardens has led to soil acidification which in turn impacted the soil quality and health. Therefore, searching for an alternative method that is as efficient as chemical fertilizers and compensates for the disadvantages caused by the excessive use of chemical fertilizers is essential in tea gardens nutrition

In this research, native nitrogen-fixing (Azospirillum) and phosphorus solubilizing rhizobacteria were isolated from the rhizosphere of tea plants and then used as biofertilizers for cultivation of Chinese hybrid tea seedlings at tea research center in 1400 under pot experiment. This experiment was conducted in a randomized complete block design with factorial arrangement and three replications. The factors include pH of soil at two levels (4.65 and 5.21), and fertilizer treatments at five levels including blank (B), control; where chemical fertilizer was applied based on soil analysis (C), nitrogen fixing bacteria was applied as biofertilizer (BN), phosphorus solubilizing bacteria was applied as biofertilizer (BP), and nitrogen fixing and phosphorus solubilizing bacteria were applied as biofertilizer (BNP). After three months of tea planting, the effect of applied biofertilizers on soil biochemical characteristics and yield of tea plant were investigated.

The soil pH values in all treatments that received biofertilizers were higher than that of the blank and control treatments. The highest and the lowest soil nitrogen (N) content were observed in BNP and B treatments, respectively. The highest content of soil phosphorus (P) was observed in BNP treatments, which P content in this treatment with BN was not significantly different. The soil available potassium content in treatments that receiving bio and chemical fertilizers did not show a statistically significant difference. The highest and the lowest values of fresh weight, dry weight and yield were observed in BNP and B treatments, respectively. The highest content of N and P in plant were observed in BNP (4.8%) and BP (0.24%) treatments, respectively. The potassium content of plant in treatments that received biofertilizers was lower than B, while the potassium content in all biofertilizer treatments were higher than that of the control.

In this study biofertilizer treatments, Azospirillum and phosphorus solubilizing bacteria, increased the nitrogen and phosphorus contents in tea plant and soil, respectively. Since these bacteria improved plant growth and soil properties, it seems that native rhizobacteria isolated from tea rhizosphere have the potential to be used as biofertilizers in tea gardens in line with sustainable agriculture. Although, long term investigation during the several growth periods and different seasons of the year is needed for further evaluations.

Maintaining the nutritional value and increasing the shelf life of citrus, fruit coating is important. Currently, small gardeners in the north of Iran to rising storage time and maintain fruit quality, use unconventional methods or materials. The use of natural and organic material to produce a healthy product free of contaminants is rising. Tea seed powder is the by-product of tea seeds after oiling, which has no negative or harmful effects on the environment and use on farms as an organic insecticide. Therefore, the present study aims to investigate the effect of different concentrations of aqueous extract of tea seed powder on quantitative and qualitative characteristics of Citrus sinensis</em> L. Osbeck. This research was done in the type of completely randomized design with five coating treatments as control (distilled water), commercial wax (XEDASOL- MX20), and three concentrations of aqueous extract of tea seed powder as 5, 10, and 15% w/v with three replications. After coating, the fruits were stored for 60 days in a cold house at 8 o</sup>C and 85% humidity. The weight of the shell, the juice content, the total soluble solids, the total acidity, and the anthocyanins concentration of the fruit were measured. The results showed that fruits coated with commercial wax had the lowest fruit weight loss. The treatments for tea seed powder extract are also significantly different from the control, and the treatment of 15% tea seed extract had the least weight loss. Fruits impregnated with commercial wax had the highest percentage of total soluble solids that did not significantly different from the tea seed powder extract but had 15% more total soluble solids than the control treatment. The fruits impregnated with commercial wax have the highest content of anthocyanins. The use of 5 and 10% tea seed extract has also had a positive and significant effect on the concentration of anthocyanins compared to control. As a result, it can state that the aqueous extracts of tea seed powder, compared to the control, improve and preserve the properties of the blood orange of the Moro cultivar during the post-harvest period. Therefore, tea seeds products can be promoted as an alternative to chemical pesticides currently used in ordinary warehouses.

When aerial parts of the plants, capable of storing and absorbing mineral salts in their leaves, fall, these dissolved materials are transferred to the soil surface, changing its physical and chemical properties. Plants have special effects on their habitat and study of these effects can be useful in planning projects. This study aimed to investigate the effect of different tree species on soil quality in 0-25 and 25-50 cm depths in Shalman poplar research station, Guilan province. The experimental design was as completely Randomized Block with seven treatments and three replicates. Two different plantations of hardwoods including Populus caspica, Alnus glutinosa, and Quercus castaneifolia) and softwoods (Taxidium disticum, Juniperus excelsa, Pinus taeda), and non-planted site as a control were selected. These sites have same physiography and parent material. Vegetation’s age is 37 years old. Totally 42 soil samples were taken from the distance 50-150 cm of three sites. Some soil properties including organic matter, total nitrogen, soil pH, cation exchange capacity (CEC), C/N ratio, electrical conductivity (EC), mean weight diameter, texture, bulk density and particle density of soil sample were measured. the results showed that, soil pH, organic matter, total nitrogen, CEC, EC, and C/N ratio (P<0.01) and percentage of clay and percentage of sand (p<0.05) were significantly different between the two plantations. The findings of this research indicate that the plantation has major impact on carbon sequestration and thereby controls quality indicators of soils. It is concluded that plantation could increase the soil quality.

Maintaining the nutritional value and increasing the shelf life of citrus, fruit coating is important. Currently, small gardeners in the north of Iran to rising storage time and maintain fruit quality, use unconventional methods or materials. The use of natural and organic material to produce a healthy product free of contaminants is rising. Tea seed powder is the by-product of tea seeds after oiling, which has no negative or harmful effects on the environment and use on farms as an organic insecticide. Therefore, the present study aims to investigate the effect of different concentrations of aqueous extract of tea seed powder on quantitative and qualitative characteristics of Citrus sinensis L. Osbeck. This research was done in the type of completely randomized design with five coating treatments as control (distilled water), commercial wax (XEDASOL- MX20), and three concentrations of aqueous extract of tea seed powder as 5, 10, and 15% w/v with three replications. After coating, the fruits were stored for 60 days in a cold house at 8 oC and 85% humidity. The weight of the shell, the juice content, the total soluble solids, the total acidity, and the anthocyanins concentration of the fruit were measured. The results showed that fruits coated with commercial wax had the lowest fruit weight loss. The treatments for tea seed powder extract are also significantly different from the control, and the treatment of 15% tea seed extract had the least weight loss. Fruits impregnated with commercial wax had the highest percentage of total soluble solids that did not significantly different from the tea seed powder extract but had 15% more total soluble solids than the control treatment. The fruits impregnated with commercial wax have the highest content of anthocyanins. The use of 5 and 10% tea seed extract has also had a positive and significant effect on the concentration of anthocyanins compared to control. As a result, it can state that the aqueous extracts of tea seed powder, compared to the control, improve and preserve the properties of the blood orange of the Moro cultivar during the post-harvest period. Therefore, tea seeds products can be promoted as an alternative to chemical pesticides currently used in ordinary warehouses.

During the study of the habitats and ecosystems of Gilan province (north of Ian), an invasive and alien species, namely, Tradescantia fluminensis (Commelinaceae) was observed and identified which is reported for the first time for the flora of Iran. In recent years, T. fluminensis has been developed as a weed in tea gardens and an invasive plant in the neighboring plains of the northern parts of Iran. In addition, the report of the growth localities as well as the risk assessment of the invasive plant were examined using the protocols provided by Virtue & Meland (2003), and Stone (2008). According to the risk score obtained for this invasive plant (205.86), it stands within the group of plants with "very high risk". By studying the soil of habitats, it was found that, there is a positive and significant correlation between the amount of available soil phosphorus and the wet biomass of the plant. Due to the ecological behavior of this plant, biological control and mechanical removal are the most appropriate methods of managing this plant in the northern habitats of the country.

Most of the biological nitrogen fixation rate among forest species is related to the symbiosis of Frankia actinomycetes with actinorhizal plants such as Alder. In the present study, we investigated changes in vegetative characteristics, biomass and nutrients of Alnus subcordata  and Alnus glutinosa affected by three treatments including: symbiosis with Frankia nodes (T1), symbiosis with Frankia nodes and fertilization with urea fertilizer equivalent to 50 kg per hectare (T2), symbiosis with Frankia and fertilization with Urea fertilizer equivalent to 100 kg ha (T3) and without symbiosis with Frankia and without fertilizer (control) for 60 days in research greenhouse of faculty of natural sciences of University of Guilan. At the end of the study, the collar diameter and height of the seedlings were measured and biomass of their different parts was calculated by drying in the oven. The percentage of nitrogen, phosphorus and potassium in the components of the plant were also calculated using Kjeldahl, extraction and colorimetric methods, respectively. According to the results of analysis of variance, significant differences were observed between vegetative characteristics, biomass and nutrients of the species under different treatments. Comparison of means with Turkey’s test showed the best performance of 50 kg / ha fertilizer treatment among the treatments. In addition, the performance of Alnus subcordata in the most of cases was better than Alnus glutinosa. The results of the present study indicate the positive effect of nitrogen fertilization on alder seedlings in early stages of growth and in nursery environment and for alder species, 50 kg urea fertilizer per hectare is sufficient. Of course, considering the environmental considerations, the use of nitrogen-containing organic fertilizers is preferable if fertilization is required.

Ectomycorrhizal fungi can increase the quality and quantity of seedlings by increasing plant resistance to environmental stresses, and increasing growth and nutrient uptake in forest nurseries. In order to study the effect of ectomycorrhizal fungi on phosphate (P) uptake and growth of Alnus glutinosa seedlings, an experiment was conducted in a completely randomized design with four treatments including ectomycorrhizal fungi: Cenoccum geophilum, Lactarius sp, 150 kg/ha phosphate and control in three replications. A soil with low available P content were collected from Shalman Forest Seed and Seedling Research Station, and after sterilization by autoclave, was distributed in pots. In each pot, one seedling of Alnus glutinosa were planted and inoculated with the desired treatment. After ten weeks of inoculation, seedlings were harvested and their growth and nutritional characteristics were measured. The results showed that fungi inoculations significantly increased diameter, height and dry weight of seedlings by 30% compared with the control. In addition, ectomycorrhizal fungi increased nitrogen, phosphorus and potassium concentration in alder seedlings by 18, 82 and 61%, respectively. There was a significant difference between the percentages of alder root colonization between two fungi, but there was no significant difference in the efficiency of inoculation between the ectomycorrhizal fungi. It looks like that Lactarius is more effective compared with Cenococcum geophilum. Therefore, it can be concluded that ectomycorrhizal fungi improve growth and nutrition of alder seedlings, but further studies are needed to identify more efficient ectomycorrhizal fungi.

The use of natural and organic products increases to produce a healthy product free of pollutants. Tea seeds contain 15-20% oil, which used as edible oil and an organic pesticide. In previous years, these seeds were used to produce tea seedlings. But now, cuttings are used for tea propagation and seeds are a byproduct of tea production. Therefore, this study aims to compare the effect of TSO with commercial wax on post-harvest quality of Citrus sinensis cv. Moro. 

Research method:

An experiment was done as Completely Randomized Design; fruits were coated with control (distilled water), commercial wax (XEDASOL- MX20), and tea seed oil. The fruits were stored for 60 days in cold storage. The weight of the fruit skin, the contents of juice, total soluble solids, titratable acidity, and anthocyanins of the fruit were measured.

The results showed that fruits coated with commercial wax and tea seed oil have the lowest fruit weight loss, the highest percentage of TSS (10.42%), the most top content of anthocyanins (15.17 mg/l) and flavonoids (196.17 mg/l) that there was a significant difference with control. The lowest titratable acidity (2.28%) was observed in fruits impregnated with tea seed oil, and there was a considerable difference with control. In general, the effect of tea seed oil was similar to commercial wax. Limitations: No limitations were founded. 

Originality/Value:

 These results indicate that the application of tea seed oil proved to be effective in extending the quality and storage time of Citrus sinensis (cv. Moro).

Tea (Camellia sinensis (L.) O. Kuntze) is one of the most important crops in nourth of Iran. Todays, many tea plants are being destroyed for various reasons, so having information about their genetics is helpful in designing breeding programs to reach appropriate plants for specific purposes. Therefore, in this research, the genetic diversity of some tea genotypes were identified in major cultivation regions of this crop in nourth of Iran with comparison by eight imported clones.

In this study genetic diversity of 42 tea plants were investigated by useing of two morphological and ISSR markers. Morphological study was performed by descriptor that registered form for tea and 31 traits were checked out. After selecting young and well expanded leaves, their genomic DNA were extracted and 10 ISSR primer were used for investigation of genetic relationships between 42 tea genotypes. Collected data was analysed by Euclidean distances for Morphological markers and SM similarity coefficient for ISSR and clusters were designed based on UPGMA algorithm. PCA anayesd were done by SPSS.

Comparative analysis on 31 morphological characteristics in tea genotypes and clone showed moderate variations and showed a narrow range. In cluster analysis at a difference of 6.6, the samples were divided into six groups; the main group consisted of the sixth group, which contained 88% of the samples. The results of PCA on morphological characters showed that the first, five principal components accounted for 54.21% of the total variance. Used of 10 ISSR primers produced 92 scorable bands that 72 of them were showed polymorphism pattern (78.26%). The PIC analysis showed ranging from 0.43 to 0.50. cophenetic test showed that SM similarity coefficient and UPGMA algorithm was the best for cluster analyses. According to ISSR data calculated similarity were range between 0.28- 0.93. In cluster analyses, samples at similarity 0.55 divided to four group that fourth group was the main created group and coverd 66.66% of samples. The results of PCA on ISSR data showed that the first, five principal components accounted for 72.98% of the total variance.

A significant variability was observed in the selected tea genotypes at morphological and molecular levels. Morphological study showed that distribution of tea plant in the past, although based on desirable characteristics, but due to the limited initial source of this plant, there is little variation among the genotypes of the regions. In relation to the ISSR marker, the polymorphism percentage and t polymorphic information content from the primers used in this study indicate the ability of these markers to differentiate the tea genotypes. From these results it could be understood that these series of characters and primers can distinguish genetic differences very well. Using these markers, genetic variation was observed between the genotypes of tea, but this diversity was not such as to be able to disrupt the genotypes of different regions. It seems that this separation could be achieved by increasing the number of primer combinations and using other markers such as SSR and SNP. Also, the results of this study showed that Iranian tea genotypes have high genetic variation because they are mostly reproduced sexually.

Characterization of biological attributes of poplars is of essential values for planning afforestation and wood farming projects. Therefore, this study focused on the assessment of their phenology and vegetative potential in Safrabasteh region of Gilan province. The studied trees were planted at 4×4 m intervals in each experimental plot. Each plot was assigned to one poplar clone. Recording the phenology began in the second half of March and ended in December each year. Measuring the growth factors of diameter and height was performed following the annual growth period. The earliest bud opening was observed in P. euramericana 45.51 and P. e. Pacher clones, whereas the latest was observed in P. e. Blanc clone. The seeds distribution of the studied clones started within the first 10 days of June. The biological periods of the clones were different and ranged from the minimum 203 days in P. e. 87m119 clone to a maximum of 240 days in P. e. Pacher clone. Significant differences were observed amongst the growth factors. The highest diameter, height and volume growths with average production of 22.4 and 21 m3 ha-1 y-1 were observed in two clones of P. deltoides Marquette and P. interamericana, respectively, While wood production in the control clone (P. d. 69.55) was 15.5 m3 ha-1 y-1. The results of this research could be used to guide the future planning on the phenology and growth of poplar clones in Iran.

Frankia symbiosis with Alnus glutinosa improves the growth and nutrition of the host plant. Therefore, the establishment of high N2-fixing activities, active nodule-forming populations of Frankia in soil is desirable. In this study, seedlings of A. glutinosa were inoculated with Frankia isolated from twenty-five root nodules of A. glutinosa in different sites of Guilan province, northern Iran. The seedlings were grown in pots filled with sterilized sand in a green-house. The seedling growth, N2-fixation and nodulation were measured 10 weeks after inoculation. The Inoculated seedling had higher dry weight of shoots, roots and nodules, and nutrients content compared to control. The N2-fixing activity varied from 0.017 to 0.337 mg N mg-1 nodules. The greatest N2-fixing capacity was observed in seedlings inoculated with AG6 Frankia crushed nodules compared with other treatments. There was a significant positive correlation coefficient between nodule dry weight, plant biomass and nutrients contents, that resulted of microbial inoculation effects. The results revealed that introduced Frankia could improve the growth and N2-fixation of A. glutinosa. Thus, selection true sources of inoculums that have a considerable influence to A. glutinosa and optimizing the sustainable production of these inoculums are needed. We concluded that AG6 had a superior effect on A. glutinosa seedlings and can be used for future studies.

Urbanization and population growth increased the demand for wood, which can be partially supplied via wood culture. Poplar plantation with fast growing clones of poplar is thus required to investigate their compatibility and wood production potential. This study was carried out with 12 treatments (11 new clones and one control clone) and three replications in a Randomized Complete Block designto determine the compatibility and wood production in Lasht-e Nesha agriculture research station in Gilan province. In each experimental plot, 12 one-year-old seedlings were planted at a 4×4 m distance. Then the diameter growth, height, volume and survival percentage of trees were calculated, followed by a statistical analysis. The results showed good compatibility of all clones, yet with different growth quantities. The P. x. Intreramericana, P. d. Marquette, P. d. 92.258, and P. e. Ita199 with diameter of 12.8, 12.35, 10.58 and 9.42 cm and height of 11.08, 12.58, 12.22, and 10.76 m were superior compared to the control clone (diameter = 9.65 cm, height=10.62 m and volume =5.83 m³/ha). In addition, the volume production of the studied as well as the control clones were 9.35, 9.76, 6.84 and 5.11 m³ha-1 year-1 in a five year period, respectively. The survival percentage of the clones were different, with the lowest survival rate =66.6 % for P. e. Blanc de Poitou and the highest rate of 97.2 % for P. e. 45.51, P. e. 92.160, P. d. Marquette and P. e. 87m119. The clones surveyed here can therefore be introduced as competent and successful clones in the comprehensive program of agri-wood development across the study site.

Large demand of wood and restrictions on the efficiency forest’s wood production caused attention to fast growing trees poplars. Poplar genus trees because of dioecious, have insemination ability and hybridization that wood production of them are more than their parents that known as heterosis phenomena. The most properties of this hybrids are fast grow, smooth and cylindrical trunk for having a flexibility ecological and significant resistance against pests and diseases. In order to select superior varieties of hybrid poplar, four consecutive years of collection poplar clones that are growing on the bank of Sefidroud river have growing strong form that have longitudinal and diametrical growth than the others, cuttings were prepared. They planted in the nursery that already had been prepared for this purpose. Also, from female clone (P.d.69.55) in ripping seeds were collected and they were regenerated and planted in chassis greenhouse and then transferred to fields and planted. Analyze of data were done by analysis of variance for variables and variables mean comparison were done in SAS software by LSD test. The results of this research identified 13 hybrids clones of poplar with two base cutting (preparation of Sefidroud river bank) and seed (the seeds that collected and planted from deltoides clone). Selected clones in comparison with control clone (P.d.69/55) that had superior characteristics, were distinguished. Hybrid clones with superior diameter growth were: P.x.87.1.S, P.x.89.3.C, P.x.88.4.C, P.x.88.5.Cand superior height growth P.x.88.1.S, P.x.89.3.C.

Nowadays, nitrogen-fixing tree species are often planted in combination with poplar to provide nutrients, though this can reduce the number of host plants and have a negative impact on soil Frankia population. In order to study the effects of mixed plantation of Caucasian alder (Alnus subcordata) and poplar (Populus deltoides) on Frankia nodulation potential, an experiment was carried out within a randomized block design. Five different mixtures of 17–years old P. deltoides (P) and A. subcordata (A) (100A, 70A30p, 50A50P, 30A70 and 100P) were established in Safrabasteh Poplar Research Station in Guilan province of Iran. The results showed that the presence of alder in mixture with poplar positively affected the diameter at breast height (DBH) and height of poplar trees. Mixed plantations with alder can improve Soil pH and the amount of soil nutrients and organic carbon. Furthermore, foliar nutrient concentrations of poplar trees were higher in mixed plantations than in pure plantations. The results of Frankia population analysis showed significant difference between the soils across different species mixture classes. The highest and lowest levels of Frankia population were observed in the rhizosphere soil of pure alder (49.17 g-1 soil) and pure poplar (0.89 g-1 soil), respectively. The Frankia population was negatively correlated with amounts of available P and K, yet it was positively correlated with pH. In addition, Frankia population showed positive and negative correlations with alder DBH and height, respectively. These results confirmed the effects of plant-host density on the viability and population of Frankia.

This study was carried out as completely randomized block in order to study influence of fourpoplar clone plantation on availability of some soil nutrients in Safrabasteh (Astaneh, Guilan Province). Four poplar clones as: 1.Populus euruamerican 214 2.Populus euruamerican 45/51 3.Populus deltoeides77/51 4.Populus deltoeides69/55 were selected in Safrabasteh Poplar Research Station. pH, O.M, N, P, K, Ca and Mg in rhizosphere soil were determined. Results show that difference between clones are significant on soil nutrients except N and Ca. Means comparison show that the Populus euruamerican 45/51 had greater effects on the soil parameters. Comparison the growth characteristics the minimum diameter and height of 15 cm and 12.9 m respectively, with p.e45.51 is dedicated to clone which may indicate less use of plant nutrients to the soil is mostly or returned.