همبستگی

Intercropping as a current method in sustainable agriculture, in addition to increase the yield of traits compared to pure cultivation, increases biodiversity in agricultural ecosystems. The purpose of this research is to evaluate the yield components of beans in pure and mixed cultivation of cucumbers and identify the best cultivars of beans and cucumbers in terms of plant height, fruit weight, fruit dry weight, fruit pod length, plant height, plant fresh weight and number of fruits per plant. Also, the presence or absence of correlation as well as its level in the evaluated traits will be investigated. 

In order to evaluate the performance of bean (Phaseolus vulgaris L.) and cucumber (Cucumis sativus L.) intercropping, an experiment is conducted in the form of a randomized complete block design with three replications in Varamin region. The experimental treatments include 10 mixtures of beans and cucumbers as a mixed product and one pure bean as a control. Cucumber cultivars in this experiment include Viola, Mirsoltan, Mito, Emilie, CUB-9042, FC-21, CUB-9045, FC-27, Nagin and Negin, along with Cobra bean variety, which were cultivated and investigated. In order to evaluate mixed cultivation compared to pure cultivation at the end of the growing season, ten plants of beans and ten plants of cucumber are sampled from each plot. The samples are dried in an oven at 70°C for 24 hours and after evaluating the mixed and pure cultures, they are compared to each other using the Land Equality Ratio (LER) index.   

The results of analysis of variance showed that mixed culture is significant for all the evaluated traits at the level of one percent probability. Mixed cultivation of Cobra bean and Viola greenhouse cucumber cultivars has been selected as the most suitable cultivation in terms of all traits. Cultivations of Cobra bean with CUB-9042 greenhouse cucumber, Cobra bean with Nagin greenhouse cucumber, and Cobra bean were identified as undesirable crops. In terms of the stability of mixed crops, the cultivations of Cobra bean with Viola greenhouse cucumber and Cobra bean with Negin greenhouse cucumber were identified as stable crops in terms of traits. In general, it is possible to select the beans of the Cobra variety with the greenhouse cucumber of the Viola variety as the most desirable and stable crops in terms of all the traits evaluated in the experiment. The relationship between fruit fresh weight with fruit dry weight and pod length; and the number of fruits per plant with pod length and plant height are positive and significant. A polygon view was drawn to determine the best cultivation for the evaluated traits. This figure is drawn by connecting the cultures that had the greatest distance from the origin. From the origin, a line is perpendicular to each side of the polyhedron to divide the figure into several parts. In this form, crops that are located in a section with one or more specific traits show good performance relative to that trait. The multidimensional view also show that mixed crops of Cobra bean and greenhouse cucumber Viola cultivars, Cobra bean and greenhouse cucumber cultivar CUB-9042, and Cobra bean and greenhouse cucumber Nagin cultivars are suitable mixtures. Also, Cobra (bean) × Viola (cucumber) cultivar was more favorable in terms of pod length and plant fresh weight. In the ranking of mixed cultivation based on traits, mixed cultivation of beans of Cobra and greenhouse cucumber of Viola cultivars has been identified as the most desirable cultivation. Based on the grouping of bean and cucumber mixed crops in terms of all studied traits, the crops have been divided into four groups. Regarding land parity ratio (LER), mixed cultivation of Cobra bean and FC-27 greenhouse cucumber cultivars with 25% increase is more beneficial than pure cultivation.    

The mixed cultures of Cobra (bean) × Viola (cucumber) and Cobra (broad) × FC-21 (cucumber) were favorable in terms of the average traits studied. These two mixed crops of beans and cucumber were identified as crops with high utility in multivariate bi-plot analyses. In the study of the land equality ratio (LER), the cultivation of Cobra (broad) × FC-21 (cucumber) was selected as a beneficial crop with a 25% increase compared to pure cultivation. Finally, according to the results of this study, Cobra × Viola, Cobra × FC-21, Cobra × Nagin and Cobra × CUB-9042 can be considered as high yield and suitable crops.

90% of Iran's land area is in arid and semi-arid areas. It is expected that by 2025, about two-thirds of the world's agricultural lands will face a water deficit. The yield also decreases by 50 to 90% under drought stress conditions compared to non-stressed conditions. Among the different types of stress, drought stress at the end of the season is the most important stress in Mediterranean areas such as many areas of Iran. Therefore, the yield of small grains cultivated in these areas is affected by drought stress at the terminal of the season. Salinity and drought stress increases the concentration of dissolved solutes in the root environment, increases the osmotic potential of the soil, decreases the absorption of nutrients and decreases the mobility of zinc and iron elements in the soil solution. Elements in the plant can be compensated and tolerance to saline conditions can be increased. Researchers reported that the application of zinc increased the grain yield of wheat and barley cultivars. Researchers reported that the application of zinc increased the grain yield of wheat and barley cultivars. In stress conditions due to reduction of stomatal conductance and limited access to CO2 for carboxylation reactions, the rate of photosynthesis decreases and increasing stomatal resistance is a suitable defense strategy for the survival of wheat and barley. Due to the cultivation of barley in these moderate areas and the role of the micronutrient element zinc in reducing the effects of drought and salinity stress, this research was carried out in different varieties of barley using different amounts of zinc sulfate. This research was carried out in November of the agricultural year 2017-2018 in two areas: 1) Kobutrabad Agricultural Research Station (drought stress by removing water after spike emergence); 2) Rudasht Station (rrigation with salt water 10 dS/m). Planting was carried out by machine planter in November in both regions. In the dry area of Kabutrabad, the plots containing 6 rows of 6 meters with the distance between the rows of 20 cm (the planting area of each plot is 7.2 square meters) with a density of 400 grains per square meter were done. Data analysis and step-by-step regression were performed using SAS9.1 software and mean comparison was performed by LSD test at 5% probability level. If the interaction effect is significant, cutting (slicing) and comparison of means was done by Lsmeans test at 5% probability level. The results showed that barley cultivars under drought stress had higher thousand-grain weight, grain yield and biological yield and lower proline content than under salt stress. Drought stress at the end of the season compared to salinity stress during the growing season had higher thousand-grain weight, grain yield and biological yield and lower proline content. Foliar application of 0.5% zinc sulfate had higher grain yield (4763 kg/ha about 34%) and biological yield (4763 kg/ha about 26%) than without foliar application and is recommended. It should be noted that there was no difference in the amount of proline between cultivars in drought stress, but in salt stress, tolerant and semi-tolerant cultivars had more proline content than the stress-sensitive line. In drought stress, Armaghan (semi drought tolerant) and Goharan (drought tolerant) cultivars had more chlorophyll a in the application of zinc sulfate. It seems that the mechanism of increasing the tolerance and performance of Armaghan and Goharan cultivars under drought stress conditions is the increase in the amount of chlorophyll a due to the application of zinc sulfate. For this purpose, foliar spraying of suitable cultivars (Armaghan and Goharan) is recommended in drought stress conditions.Grain yield had positive correlation with traits of plant height (p = 0.01, r = 0.33), spike length (p = 0.05, r = 0.31), number of grain per spike (p = 0.01, r = 0.35), biological yield (p = 0.01,  r = 0.96), amount of chlorophyll a (p = 0.01, r = 0.44), amount of chlorophyll b (p = 0.05, r = 0.29) and zinc element (p = 0.01, r = 0.39), which is the highest correlation between grain yield and biological yield (r2 = 0.99). In terms of grain and biological yield, Armaghan and Goharan cultivars are recommended under drought stress and Armaghan and Mehr cultivars are recommended under salt stress with a concentration of 0.5% zinc sulfate. In salinity stress, the minimum and maximum grain yield and biological yield were obtained respectively in foliar spraying of 0.1 and 0.5% zinc sulfate in all genotypes. It seems that foliar application of 0.5% zinc sulfate is sufficient for all barley cultivars under salinity stress, and foliar application with a higher concentration of zinc sulfate is not recommended due to the decrease in grain and biological yield in this stress.

In order to select their breeding goals among different physiological traits, plant breeders need to categorize the limitations as well as the capabilities of plants. This issue has led to the emergence of a concept called ideal type. Achieving the ideal type of agricultural plants requires the use of appropriate statistical methods. The aim of this study is to introduce the method of using regression modeling to determine the ideal type of crop plants on the rice plant.In breeding programs, it is very important to estimate the amount of yield based on the change in effective plant traits, which can be identified using regression modeling. In plant breeding, correlation between traits is of special importance, because it determines the amount and type of relationship between two or more traits. In plant breeding, correlation between traits is of particular importance, because it determines the degree and type of relationship between two or more traits. Correlation between different traits can help researchers in indirect selection using traits that are easier to measure in order to achieve self-sufficiency. For this purpose, a study on 124 lines of the ninth generation of two varieties of rice (Ahlomi Tarom and Dorfak) was conducted at Gonbad Kavus University, Iran, using a randomized complete block design with three replications in two growing seasons of 2015 and 2016. Irrigation was done until the maximum stage of tillering in stress-free conditions (flooding). From this stage until the end of the growth period, irrigation was completely stopped. Among the measured traits, using stepwise regression, four traits of plant weight, panicle weight, 100-seed weight, and harvest index were identified that had the greatest role in increasing yield. Then the correlation between the selected traits and the rate of increase in performance was evaluated and the rate of increase in performance (percentage) resulting from that trait in relation to the total increase in performance was calculated. Regarding negative correlation between the harvest index and plant weight, three hypotheses were evaluated, that in each assumption the amount of increase in yield was estimated. Data analysis was carried out using SAS software. Considering the existing negative correlation between the two variables of harvest index and plant weight, assumptions were made to determine the ideal type, The results indicated that if the correlation between the harvest index and plant weight, is not breakable, ideotype yield variation would have an increasing of 197.61 kg/ha. If with increasing plant weight, harvest index stay at moderate level, it would be an increasing of 314.64kg/ha and if correlation between plant weight and harvest index is breakable, it would be an increasing of 697.52 kg/ha. The method used in this study, due to the fact that the genetic differences between the lines are noticeable, can be a way for the breeders to move towards yield increasing in rice cultivars. The main purpose of this article is to introduce the method of using regression modeling in determining the ideal type of crops. In this study, the ideal type of rice was determined using regression modeling. And the four characteristics of plant weight, cluster weight, 100 seed weight and harvest index had the greatest role in increasing the yield. Considering the existing negative correlation between the two variables of harvest index and plant weight, assumptions were made to determine the ideal type. The results showed that if the relationship and correlation existing between some traits undergo changes, it can be used for the benefit of performance. If the main goal of the research is to determine the optimal type of rice for the Gonbad region, it is better to study and research more genotypes in a few years.

 Sesame (Sesamum indicum L.) is an annual plant and an ancient plant that has been cultivated in Asia and Africa for about 7500 years. Sesame seeds contains 40-60% oil and for this reason, it is cultivated as an oil plant in many countries. Drought is a serious problem for crop production in arid and semi-arid regions of the world. One of the most important research programs in drought management in different plants is the identification and grouping of sensitive, drought-tolerant genotypes. Mehran region in Ilam province is one of the sesame growing regions in the country. Therefore, the purpose of this study was to cultivate sesame cultivars in Mehran under drought non- stress and stress  conditions in order to identify superior cultivars in terms of yield and tolerance to drought stress. 14 sesame cultivars were planted in the form of a split-plot design based on a randomized complete block with three replications in the Agricultural Research Farm of Ilam University in Mehran. The main factor of irrigation levels included irrigation after 100 mm of evaporation from the class a pan (conventional irrigation) and irrigation after 200 mm of evaporation from the class a pan, and the secondary factor was the studied sesame genotypes. Traits were measured based on 10 plants harvested from two central lines and taking into account the marginal effect. The measured traits were economic yield and number of capsules per plant, number of sub-branches, number of leaves, capsule length, capsule width, capsule weight and plant height. In order to determine resistant and sensitive cultivars to stress, various indices related to stress resistance were calculated. The studied genotypes showed a significant difference in terms of the traits measured in the conditions of no stress and drought stress. The results of the table show that the effect of irrigation for the characteristics of capsule fresh weight, seed weight and capsule width showed a significant difference at the level of 1% and for capsule dry weight and plant height showed a significant difference at the level of 5%. Which indicates that the studied traits change under stress conditions. Other traits did not have significant differences. In the evaluation of tolerance to drought stress in different genotypes of sesame, plant height, biological yield and grain yield per surface unit decreased significantly with increasing drought stress intensity. According to the correlation of performance under stress (YS) and no stress (YP) conditions with drought tolerance indices, GMP, STI and MP indices have a correlation coefficient of 0.93, 0.905 and 0.853, respectively. Performance as the best indicators of drought tolerance in stress conditions and MP, GMP, STI and TOL indicators with correlation coefficient of 0.984, 0.935, 0.925 and 0.735 respectively with performance as the best indicator. The tolerances were under stress-free conditions. These indices can be used to identify genotypes tolerant to water stress with high yield. Based on this, Holeil variety is introduced as the most tolerant variety to drought stress.  In water conditions, the cultivar Yellow white had the highest yield and the cultivar Nashkofa had the lowest yield. Under stress conditions, Holeil variety had the highest yield and Nazmultib had the lowest yield. GMP, STI and MP indices had the highest correlation with performance in water and stress conditions and therefore were chosen as the best indices. Based on this, Holeil variety is introduced as the most tolerant variety to drought stress.

Fennel (Foeniculum vulgare Mill.) is an old medicinal plant that is usually used as food and traditional medicine. The main goal of studying genetic diversity and relationships between germplasm sets is to use the information obtained from the diversity of native cultivars to develop and release cultivars with higher yields among cultivated species. To investigate genetic diversity and relationships among morphological traits, an experiment was performed using a completely randomized design with 3 replications on 11 fennel ecotypes in the greenhouse of Payame Noor University of Qom, in 2020. The measured traits included number of days to germination, number of days to 50% flowering, number of days to maturity, plant height, the number of branches per plant, the number of umbels per plant, the number of umbellets per umbel, the number of flowers per umbellets, 1000-seed weight, and grain yield per plant. After data collection, analysis of variance, mean comparison (with Duncan's test), correlation between traits (using Pearson's method) and stepwise regression were performed. In order to determine the relative contribution of each of the measured traits in creating diversity among the studied ecotypes, factor analysis was used, and Ward's cluster analysis was used to group them. SPSS software was used to analyze the data. Environmental, genetic and phenotypic variance components were estimated based on mathematical expectation of mean squares to calculate trait heritability with Excel software.Based on the results of the analysis of variance, a significant difference was observed among the studied ecotypes for all traits. Most of the studied traits had high broad-sense heritability. Seed yield per plant had a positive and significant correlation with the number of umbellets per umbel (0.64), number of umbels per plant (0.59), and number of branches per plant (0.56). Factor analysis showed that three main and independent factors explained 78.74 percent of the total variance in all ecotypes. Cluster analysis using the Ward method grouped 11 studied ecotypes into four separate clusters. The second cluster ecotypes (Ardebil and Moghan) are valuable due to their high values of plant height, number of branches per plant, number of umbels per plant, number of umbellets per umbel, number of flowers per umbellets, 1000-seed weight, and seed yield, and these ecotypes can be used to select of high yielding ecotypes and desirable morphological traits in breeding programs.The results showed that fennel ecotypes had many differences in terms of the studied traits. Among them, the early maturing ecotypes (Ardebil and Moghan) with high values of the number of umbels per plant, umbellets per umbels and flowers in umbellets, and number of branches per plant had high seed yield. While long maturing ecotypes (Hajiabad, Qazvin, Sardasht and Sari) with low values of the number of umbels per plant, umbellets per umbels and flowers per umbellets, the number of branches per plant had low seed yield. Therefore, in order to produce ecotypes with desirable agricultural characteristics in breeding and selection programs, crossing between superior ecotypes from different clusters and testing their results can be done. The results of stepwise regression analysis were consistent with correlation analysis, so that the number of umbellets per umbels, which had the highest correlation coefficient with yield, was entered into the model as the first trait. The next trait, the number of umbels per plant, was entered into the model, which had a positive and significant correlation with yield. Considering that the traits number of umbels per plant and number of umbellets per umbels were good indicators for yield, therefore, the selection of these traits can cause the maximum increase in yield compared to other traits of yield components. In this research, the ecotypes of Ardebil and Moghan are introduced as superior ecotypes, which can be used to apply all kinds of improvement methods on them and achieve the ecotypes with favorable morphological characteristics.

Improving decisions in fire management requires a complete understanding of the spatio-temporal relationships between droughts and fires. To achieve this, the natural areas of Lorestan province were selected as the research site. The fire data from MODIS satellite products and monthly rainfall data of the province were extracted to estimate SPI drought index for the statistical period of 2000 to 2022. The spatial and temporal relationship between the frequency of fire occurrences and the spatial and temporal distribution of droughts in terms of annual and monthly scales was investigated with the Pearson correlation model in the province. The results showed that the trend of fires in the region is increasing. The months of June and July have experienced the highest frequency of fires in the natural areas of the province. Poldokhtar city has had the most frequent fires in natural areas. The whole region has tended to be dry, but the eastern parts mostly included classes with higher degrees of drought. The results of the correlation matrix showed that only the drought events in spring to summer had a significant but moderate negative correlation with the fire events in spring and summer. Despite the obtained results, this study emphasizes that the connection between fires with drought needs more studies and it is not possible to prove the real relationship between the two phenomena with just one calculation index.

Plants face a variety of environmental stresses during their growth and development phase, including biotic and abiotic stress factors. Sugar beet growth and productivity are severely affected by the lack of water resources and drought, which are among the most serious environmental stressors. However, the water productivity of sugar beet can be improved by using tolerant genotypes against water scarcity. A multi-year breeding program evaluated sugar beet pollinator lines to create drought-tolerant parents. The study aimed to improve and select drought-tolerant sugar beet pollinator lines. In this regard, an experiment was conducted to evaluate the drought tolerance of sugar beet pollinator lines. The experiment was performed in two normal irrigation and drought stress conditions, in 2014. The experiment was conducted in a randomized complete block design in three replications with 20 pollinator lines and three control lines. The root yield was estimated under normal and drought stress conditions, and different stress tolerance and sensitivity indices were calculated based on the results. The obtained results showed that normal and drought stress conditions caused different responses in terms of the root yield of the lines at the 1% probability level. A considerable variation was observed among the lines in terms of the trait at the 1% probability level. Genotype-environment interaction also caused a difference in terms of root yield at the 1% probability level. This indicates that the response of lines varies according to different environmental conditions. In other words, the environment causes a change in the yield of the lines from one environment to another. Based on the ranking of the lines under normal condition and drought stress, it can be concluded that drought stress caused a decrease in the root yield of the investigated lines by a certain amount. Additionally, the ranking of the lines changed significantly under drought stress compared to normal condition. This change in the rank of the lines can indicate the presence or absence of genes that are involved in stress tolerance. Therefore, it can be acknowledged that the lines that showed a decrease in root yield under drought stress condition probably carry genes that were inherited from the drought-tolerant parent. The MP, GMP, STI, HM, YI and DI had a significant positive correlation with root yield under both conditions. Principal component analysis (PCA) of root yield in both conditions and estimated indices showed that the first two components together explain more than 99% of the variance. Based on the coefficients obtained from PCA, the first component was named as the root yield potential component and drought tolerance and the second component was named as the drought susceptibility component. Based on the MGIDI index, by applying a selection pressure of 15%, S1-950116 ranked first and control 110, and S1-950077 ranked next as the most ideal genotypes in terms of root yield, both normal and stress conditions and 11 stress tolerance and sensitivity indices.Conclission: Based on the results of correlation analysis, principal component analysis, and the MGIDI index, the MP, GMP, STI, HM, YI, and DI indices were found to be the most suitable indices for selecting lines with high root yield potential and tolerance in drought stress environments. Among the 20 studied pollinator lines, S1-950077, S1-950123, S1-950116, S1-950074, and S1-950119 had the highest tolerance compared to other lines. These lines had the highest root yield potential under both normal and stress conditions, which could be due to the presence of drought tolerance genes inherited from the tolerant maternal parent (fodder beet 7221). Therefore, these lines can be suggested as the pollinator parents for the production of drought-tolerant hybrids.

Climate changes in Iran, which have mainly manifested in the form of intensifying periods of drought and increasing temperature, can have profound effects on the forest ecosystems of Zagros in the west of Iran. In this study, the drought trend (with PDSI index) and its effects on the spatial-temporal dynamics of EVI greenness index from MODIS sensor were investigated through correlational relationship in the statistical period from 2000 to 2020 in Zagros oak forests in Kohgiluyeh and Boyer-Ahmad province. To determine the greenness index threshold value, sampling at 20 points in the forests of the province and EVI index values in these areas were used. The results showed that the greenness threshold value of EVI in these forests was at the maximum level in June. The greenness index value and the area of the oak forests of the province have decreased during the study period. The peak greenness of the oak forests of the province had a significant sensitivity to changes in rainfall and drought at the end of the cold period of the year and in the spring season. The negative phases of the drought indices have been completely consistent with the periods of greenness loss. The EVI, as an index of forest greenness, has shown a high sensitivity to the PDSI drought index. The PDSI index has also been able to explain 0.74 of the spatial changes of EVI in the three months of April, May, and June.

Drought is undoubtedly one of the most important environmental stresses reducing the yield of agricultural plants worldwide. Drought is also a significant yield-limiting factor in chickpea (Cicer arietinum L.) production. This crop's yield may be reduced by intermittent drought during the vegetative phase, reproductive development drought, or terminal drought at the end of the crop cycle. Drought stress may reduce photosynthesis, CO2 fixation, and chlorophyll content, or it may damage the photosynthetic apparatus. The current research has been conducted in greenhouse as pot experiment for the purpose of evaluating the effect of drought on the yield and its components, as well as to investigate the relationship between physiological traits and seed yield under drought stress. The treatments included four levels of drought stress (40%, 60%, 80%, and 100% of the water requirement) in a completely randomized block design with three replications. Drought stress influences the leaf weight, stem weight, seed number, seed weight, pod weight, root weight, root volume, root length, root surface, and longitudinal density of the root at a probability level of 1%; it was also found to have a significant effect on the number of pods at a probability level of 5%, but no significant effect on the ratio of root weight to stem weight. The highest leaf weight, stem weight, seed number, seed weight, pod weight, root weight, root volume, and root length were observed at 100% and 40% of the water requirement, respectively. The studied characteristics were found to be manifested less strongly as the percentage of water requirements decreased. Under drought stress conditions, seed weight and pod number were found to be reduced by 36% and 58%, respectively, in comparison to relatively severe stresses. Seed number was found to be negatively correlated with root weight and longitudinal density of the root (respectively -0.366 and -0.018) and positively correlated with root surface and root volume in the absence of drought stress (100% and 80% of the water requirement) (respectively 0.619 and 0.527). In contrast, the seed weight was positively associated with root-related traits under drought stress conditions (60% and 40% of the water requirement), with the greatest effects observed for root volume (0.739) and root length (0.657). In addition, a positive correlation was found between the number of seeds and root characteristics such as root weight (0.823), root surface (0.804), and root volume (0.594). In the absence of drought stress, the results of stepwise regression indicate that an increase in pod number, seed number, and leaf weight has a positive effect on yield. under drought stress, there was a significant increase in pod number, seed number, leaf weight, and root weight. Therefore, under conditions of drought stress, root mass is crucial, as it allows the plant to absorb more water. According to the findings of this study, drought stress reduced the yield of chickpeas by decreasing the weight of stems and leaves, the weight and volume of roots, and the number and weight of pods. By decreasing the plant's water demand from 100 to 40%, all of the studied characteristics were diminished with the exception of the root -to -stem ratio. Since the parameters of pod number, seed number, and leaf weight under both stress and non-stress conditions influence plant yield, it is important to measure these traits precisely. The results also demonstrated the significance of root mass under drought stress, because it is indispensable for water absorption.

Wheat's economic significance and contribution to human and animal nutrition are indisputable. This makes it the third most important crop in terms of global production. The rising global demand for wheat is due to its ability to produce specialized foods. In particular, the unique properties of the gluten protein allow wheat to be processed into bread. Wheat contains and consists of numerous healthful components. Therefore, plant breeders should be able to select for both increased crop yield and improved health benefits. Wheat landrace genotypes are more genetically diverse than the majority of breeding programs, and this diversity includes adaptation to a variety of local conditions. Wheat breeders face the challenge of maximizing genetic productivity gains while minimizing yield gaps and ensuring environmental sustainability.Wheat's efficiency and utility in plant breeding programs are determined by its genetic diversity. Improving grain yield is regarded as the most important objective of wheat breeding and the most efficient method of increasing production. The estimation of genetic variation in crops is indispensable for breeding programs and the conservation of genetic resources. Hybridization and subsequent selection is one of the most essential wheat breeding techniques. Selecting the parents is the first step in a hybridization-based plant breeding program. The purpose of this research is to identify wheat genotypes with superior agronomic traits, classify them using cluster analysis, and reduce the measured traits using principal component analysis.

To evaluation of genetic diversity of rain-fed wheat genotypes, an experiment was carried out in a randomized complete block design with 24 genotypes and four replications in Research Station of Dryland Agricultural Research Institute (Maragheh) at 2015-2016. This study evaluated plant height, grain filling period, days to physiological maturity, days to spike emergence, vigor, grain yield, straw yield, number of spikes per m2, weight per 1000 grains, number of grains per spike, spike weight, number of spikelet per spike, spike length, biological yield, and harvest index. Before conducting an analysis of variance, assumptions were examined. Analysis of variance and comparison of means (Least Significant Difference) was performed. The relationship between the studied traits was determined using Pearson's coefficient of correlation. Principal component analysis (PCA) was utilized to reduce the data, and cluster analysis based on the Euclidean distance coefficient and Ward's algorithm was employed to classify the genotypes under study. The SPSS software was utilized for data analysis.

Difference between rain-fed wheat genotypes were significant for the majority of traits, indicating a high degree of genetic diversity. The genotypes 1 and 23 have the highest and lowest grain yield values, respectively. Positive and significant correlation exists between grain yield and vigor, straw yield, harvest index, number of spikelets per spike, spike weight, and number of grains per spike. Cluster analysis categorizes 24 genotypes into four groups based on their evaluated traits. The first cluster contains genotypes 22, 24, 1, 15, 7, 13, 3, 21 and 17. The second group included genotypes 2, 6, 20, 11, and 19. The third group consisted of the genotypes 9, 18, 14, 10, 8, and 16. The fourth group consists of extra genotypes. In principal components analysis, five main components account for 83.80% of the variation. High positive coefficients were observed for grain yield (0.702), harvest index (0.714), and vigor (0.797) in the first component. The initial component can be identified as the grain yield component.

Based on the results, the yield component was determined to be the first principal component. These genotypes are appropriate for selection and breeding programs and objectives in rain-fed environments, and can be used to boost wheat grain yield.

Spinach (Spinacea oleracea L.) is one of the most important vegetables that is rich in minerals and vitamins, and according to the nutritional value of this vegetable in the household basket. Increasing the yield per unit area with emphasis on the health of the product from the position is nececery. In this regard, combining organic fertilizers with chemical fertilizers can increase the yield of this plant. The results of many researches show that urban waste compost has the ability to be used in agricultural lands and can be an affordable organic fertilizer that can replace part of chemical fertilizers and has a special position in sustainable agriculture. Among the nutrients required by plants, nitrogen is the most limiting factor for plant growth and the key nutrient in achieving optimal performance in most crops, especially in dry areas. The most important method of providing nitrogen required in agriculture is the use of nitrogen fertilizers. Therefore, the most widely used fertilizer among chemical fertilizers is nitrogen fertilizers. Despite the role of nitrogen fertilizers as a tool to achieve the maximum production per unit area, the management of fertilizer consumption should be in a way that does not cause the accumulation of pollutants such as nitrates in the consuming organs of the products.This research was conducted with the aim of field evaluation of urban waste compost in combination with nitrogen on spinach yield and nitrate content of the product and soil.

In order to investigate the effect of different levels of urban waste compost and nitrogen in spinach cultivation, a factorial field experiment based on a randomized complete block design with 9 treatments and 3 replications under a calcareous soil in the research farm of the research and education center for agriculture and natural resources, and it was implemented in Tehran province in 2014. The waste compost factor included three levels of urban waste compost consumption (0, 10 and 20 tons per hectare) and the nitrogen factor included three levels of pure nitrogen consumption (zero, 100 and 200 kg per hectare). Each experimental plot consisted of six crop lines with a length of three meters and a distance between the rows of 60 cm. Planting operations were carried out in the second half of September with Varamin broadleaf spinach variety. Harvesting took place on November 30. The data obtained from the experiment were analyzed using F test and SAS software version 9.1. The average of the data was also performed using Duncan's multi-range test at the five percent probability level.

The results showed that the highest fresh yield of spinach was 67.3 ton.ha-1 due to the use of 10 ton.ha-1 of MSWC whit 200 kg.ha-1 nitrogen. Nitrate concentration in spinach and soil was increased by use of MSWC and nitrogen. Data showed that the highest nitrate concentration in spinach was 3200 mg.kg-1 fresh weight due to the application of 20 tons per hectare of MSWC and 200 kg.ha-1 nitrogen, which was more than the national standard of Iran. Assessing the health risk of nitrate in spinach showed that in the consumption of municipal waste compost at a rate of 10 tons per hectare with a consumption of 100 kg.ha-1 nitrogen, the nitrate content of the spinach product is 1900 mg. kg-1 fresh weight which was less than the maximum permissible standard for nitrate in national Iranian standard. The base of the results, the maximum daily intake of spinach was 137 g for the person and 47 g for the baby. Excessive amounts of these levels will endanger their health. Meanwhile, data showed that in 20 ton. ha-1 MSWC whit use of 200 kg.ha-1 nitrogen treatment, the maximum allowed consumption of spinach was only 81 grams per day for adults and 28 grams per day for a child. Therefore, to order to maintain the health of the consumer, use of 10 ton.ha-1 MSWC with 100 kg.ha-1 nitrogen is recommended.

The results of this research showed that in the same soil conditions as the place where this research was carried out, the consumption of more than 10 tons per hectare of municipal waste compost and the consumption of more than 100 kg of pure nitrogen caused an increase in the nitrate limit in spinach and increased the risk for consumption. Therefore, it is recommended to use 10 tons per hectare of municipal waste compost and 100 kg per hectare of pure nitrogen to produce spinach while respecting the maximum allowed nitrate concentration.

It is crucial  to introduce and develop new high-yielding dryland wheat cultivars with resistance to biotic and abiotic stresses, given the extent of wheat cultivation in tropical regions and the occurrence of drought in recent years. On-farm experimentation provides new insights and is a suitable method for informing farmers about novel technologies, such as new crop varieties. Using the SIIG index and cluster analysis, the current study aimed to identify the superior wheat genotypes for grain yield and other agronomic traits in tropical drylands and introduce them to farmers. In current study, 33 varieties/ pure lines selected from the DARI and ICARDA wheat breeding programs were cultivated on farmers' fields of Lorestan province using a randomized complete block design (RCBD) with two replications during 2017-18 cropping season. The genotypes evaluated consisted of 12 cultivars and 21 pure lines of bread wheat and durum wheat, respectively. The pedigree of all genotypes is presented in table 1. The following nine characteristics were recorded: days to heading (DH), plant height (PH), Days to maturity (DM), spikes per square meter (SSM), number of grains per spike (NGPS), 1000 kernel weight (TKW), biological yield (BY), Grain yield (GY), and harvest index (HI). Using ANOVA, all investigated characteristics were analyzed. Genotypes means were compared using the least significance difference (LSD) at 5% and 1% probability level. Correlation analysis was performed using the Pearson method. Selection index of ideal genotype (SIIG) was utilized to select the genotypes with the highest yield and agronomic traits. In addition, cluster analysis using the WARD method and principal component analysis were employed to categorize genotypes. To analyze the data, MSTATC, IBM SPSS Statistics ver. 22 and Excel were utilized.  Paya and Kabir varieties and G17, G18, and G31 lines had the highest average grain yields, with yields of 5,280, 3,985, 4,210, 4,003, and 3,950 kg/ha, respectively. The SIIG index indicated that Kabir and Paya varieties, and G31, G18, G29, G17 and G16 lines with a high SIIG value (0.822, 0.720, 0.791, 0.779, 0.767, 0.736 and 0.745, respectively) were superior genotypes, whereas G13 and G17 lines with a low SIIG (0.582 and 0.576, respectively) were the weakest genotypes for the majority of traits evaluated in the current study. Grain yield exhibited a significant and positive correlation with biological yield (BY), number of grains per spike (NGPS), and harvest index, according to correlation analysis (HI). Days to heading and maturity correlated negatively with grain yield. Therefore, BY, NGPS, HI, and early maturity may be suitable indicators for selecting high-performing genotypes in wheat breeding programs under rainfed conditions. Strong and positive correlation was observed between the SIIG index and grain yield. This issue reflected a larger proportion of grain yield in the SIIG index. Cluster analysis classified genotypes into three primary classes. Class 1 consisted of maturity date genotypes with high yield, Class 2 consisted of early maturity genotypes with low yield, and Class 3 consisted of early maturity genotypes with low yield. In the current study, first -class genotypes with high yield and earliness were deemed promising genotypes for planting in tropical regions under rainfed conditions or as parents for improving yield and desirable agronomic traits in wheat breeding programs. The best genotypes, as determined by the SIIG index and cluster analysis, are the Kabir and Paya varieties and the G31, G18, G29, G17, and G16 lines, which are suitable for planting in drylands and further breeding programs. Significant and positive correlations between grain yield and biological yield (BY), number of grains per spike (NGPS), and harvest index (HI) indicated that these traits could be regarded as suitable indicators for enhancing grain yield in wheat under rainfed conditions. In the current study, genotypes with higher grain yield and desirable agronomic traits had the highest SIIG index. SIIG index could therefore be utilized as a suitable method for identifying the best genotypes on various crops.

Background and Objective Land use/cover changes have been considered to be one of the most important parts of global environmental changes. These changes are complex and dynamic in relation to other environmental changes (global warming, drought, erosion, and ecosystem degradation). In this context, the impacts of land use/cover changes on hydrologic processes are one of the most important environmental issues and challenges, so the extent of dependency on agriculture and other water-related activities on streams has become a major concern in watershed management. So, Assessing long-term hydrological impacts of land use/land cover (LULC) change is of critical importance for land use planning and water resource management. For example, Increased runoff due to the conversion of forests to other land covers, especially agriculture, as well as increased runoff and flood discharge resulting from the expansion of urban and residential use has been repeatedly reported by various researchers. The present study was aimed at identifying and determining the quantity and quality of land use changes and their relationship with flow discharge changes in catchments of Binalud county in order to guide water resources management and conservation of natural resources at the catchment scale, considering the evidence of land use changes as well as the hydrological regime variations in the catchments. Materials and Methods The data used in this study were as follows: the average monthly discharge of hydrometric stations, including 3 stations of ZirbandGolestan, Hesar, and SarasyabShandiz that were collected during 1990, 2000, 2010, and 2018, and the Landsat satellite images, including 4 satellite images for the years 1990, 2000, 2010 and 2020, acquired in the spring (May). The monthly discharge values of two seasons, winter and spring, were selected to study hydrological regime changes, considering the low and close to zero values of the average monthly discharge during summer and autumn and very small variance in the relevant values. The data were tested for normality at the significance level of 0.05 before entering the correlation test based on the Smirnov-Kolmograph method. In regard to satellite images, the processing steps were as follows: firstly, the atmospheric correction of the images was performed based on the conventional FLAASH method in the ENVI software environment. Then, the combination of visible green, red, and near-infrared bands in false color (4-3-2 in Landsat 5 and 7; 5-4-3 in Landsat 8) was used for classification based on the maximum likelihood algorithm. The land use classes were as follows: 1-garden, 2-residential, 3-water area, 4-rock outcrop, 5-moderate range, 6-poor range, and 7-barren land. The selection of training samples for classification was based on Google Earth images, visual interpretation of satellite images, and of course familiarity with the study area. After classification, the maps were validated based on general accuracy statistics and the Kappa coefficient. However, in order to know the relationship between land use changes and the hydrological regime of the catchments, Pearson two-way correlation test was used in the SPSS software environment. This test was performed at a significance level of 0.05 and between the percentages of the area of each land use and the monthly discharge values (6 months) of hydrometric stations during 4 year. Results and Discussion Preliminary results showed good accuracy of the classification method of the images so that kappa coefficients ranged from 0.78 to 0.95. According to the maps, it is characterized that most area of the catchments belongs to rangelands and barren lands so the changes and conversions of land use occurred mainly between these two land uses. The minimum area percentage of the catchments belonged to the water areas, which at its highest proportion occupied 0.16% and 0.1% of the area of ZirbandGolestan and SarasyabShandiz catchments, respectively. Reagards to land use changes, a decrease in rangelands and the increase of barren lands during the first (1990-2000) and the third (2010-2020) decades have been very considerable, so that 38% and 13% of the moderate rangelands of the Zirband catchment have decreased during the two decades, respectively. In contrast, barren lands have grown by 31% and 15 % over the two decades. Along with these changes, the 8% increase in the area of settlements has been proposed as the most prominent land use change during the second decade (2000-2010) in the catchments. In addition to land use changes, a review of the monthly discharge variations in the catchments showed that the winter months have been experiencing a decreasing trend and, in contrast, the spring months have been experiencing an increasing trend of discharge over the last two decades. The results of the correlation test showed that there are significant relationships between changes in areas of rock outcrop, moderate range, poor range, and discharge variations in the Zirband catchment. In contrast, no significant relationships were found between land uses and monthly discharges in the Sarasyab catchment. In regard to the quality of relationships, positive correlation between the areas of 3 land uses, including residential, rock outcrop, and barren land, and discharges in April and May, and in contrast, a negative correlation between rangeland areas and discharge of the mentioned months was another important result of the study. In general, the increase in human encroachment and occupation in the form of residential and barren land uses has increased the risks of the occurrence of flooding runoff. On the contrary, the rangeland expansion with its protective and moderating effect has reduced the occurrence of spring floods in the studied catchments. Conclusion The results indicate that an important focus of land use change in the catchments has been on rangeland and barren land, so in the last decades, the area of rangelands, which play an effective role in protecting water and soil resources, has been much larger than today. However, due to the lack of protection of pastures and human encroachment on the environment, as well as overgrazing of livestock, the rangelands have gradually retreated to the upstream areas and were replaced by barren lands and residential areas. The existence of a positive correlation between the areas of the residential, rock outcrop, and barren land and discharges in April and May is indicative of acceleration and intensification of the rainfall-runoff process due to the increase in the areas of the land uses. Therefore, the irregular and sprawling growth and expansion of residential areas, as well as barren and abandoned lands, must be prevented. On the other hand, the negative correlation between the percentage area of rangeland and monthly discharge refers to the positive effect of rangelands on the environmental conditions of the catchments in the context of accelerated runoff and erosion processes, which ultimately requires the protection and preservation of natural areas. In general, more attention and focus on the effects of land use change on discharge variations in wet seasons due to the semi-arid climate of the region is necessary.

Eggplant (Solanum melongena L.) is one of the most important crops in tropical and subtropical areas. Study of variation among existing varieties is essential for development of new varieties. This study was conducted to investigate the quantitative characteristics and trait correlations in 14 eggplant genotypes. The cultivars and genotypes were grown in a randomized complete block design with three replications at research farm of Sari Agricultural Sciences and Natural Resources University during 2018. Various traits including plant height, fruit weight, number of fruits per plant, day to 50 % flowering, number of branches per plant, fruit length, fruit diameter and fruit yield were measured. The results showed that there were significant differences among the genotypes for all measured traits at 1 % probability level. According to the results of mean comparisons AVF1 was identified as the best genotype with high fruit yield per plant. The study of trait correlations revealed that fruit yield had a positive and significant correlation with fruit weight, number of fruit per plant, number of branches per plant and fruit length. Using the stepwise regression analysis number of fruits per plant and fruit weight were selected as the significant variable in the model. The biplot analysis based on the first two components showed that there is a suitable genetic diversity among the studied genotypes, which can be used in eggplant breeding programs. Also, according to the direct relationship between the number of fruits per plant and the weight of fruit with fruit yield, these two characteristics can be used as a selection indicator to improve yield in eggplant.

Salinity stress is one of the most constraints for agricultural production in arid and semi-arid regions. Thus, genetically improved tolerance bred cultivars tolerant to salinity are needed for the future. The identification and selection of salt-tolerant genotypes is the starting point for such breeding purposes. Therefore, nineteen onion cultivars were selected and tested in two salinity levels (0 and 100 mM NaCl) in a completely randomized design with three replications in a hydroponic culture environment. The experiment was conducted at Horticulture Department of the Agricultural Sciences and Natural Resources University of Khuzestan during 2016-2017. The results analysis of variance revealed significant differences among yield of cultivars in no salinity (Yp) and salinity stress (Ys) conditions indicating the presence of genetic variation among the cultivars. In addition, in order to assess the salinity tolerance of cultivars, various stress tolerance indices were calculated based on Yp and Ys. Thus, the Esfahan and Azarshahr cultivars were identified as the most salt-tolerant cultivars. Principal component analysis showed that 94.3 % of total variance is explained by the first two components. The cluster analysis based on salinity tolerance indices divided the cultivars into three groups. In overall, stress tolerance index, geometric mean productivity, harmonic mean and yield index can be introduced as the most desirable indices for screening salt tolerant cultivars.

Percentage and rate of seed germination in laboratory are usually different from field, especially under rainfed conditions. Therefore, to assessment of standard germination test to predict seedling emergence and establishment of lentil, two separate experiments were conducted under laboratory and farm conditions. Eight lentil seed lots (includes four cultivars Kimia, Bilesavar, Qazvin and Local with different storage periods) were evaluated by the standard germination test and the rainfed farm and some indices related to seedling emergence (includes seedling emergence rate, mean time to emergence, mean daily emergence and final emergence percentage) were measured. The results of the laboratory and the farm tests showed that the seed lots were different significantly in terms of seed and seedling vigor characteristics. The correlation coefficients illustrated that the final germination percentage, the normal seedling percentage and the seed storage usage in laboratory test had positive correlations with the seedling emergence percentage in the farm experiment. The mean daily germination and the germination rate in the laboratory test had the positive correlations with the seedling emergence rate in the farm test. So it seems that, the above mentioned traits in standard germination test can use to predict seedling emergence of lentil in rainfed farm.

The temperature is one of the factors that can influence of the growth of crops including wheat. In this study, heat indices such as growing degree days, heliothermal unit, heat use efficiency and phenothermal index was calculated for ten irrigated wheat cultivars includes Gonbad, Morvarid, N-87-20, N- 90-7, N-91-8, N-91-9, N-91-10, N-91-17, Tiger and Natasha in Gonbad City in 2014. The highest yield was observed to N-90-7 variety and the lowest yield was to N-91-10 variety. Analysis variance showed that there was no significant difference in yield between Gonbad and Morvarid, N-87-20, N-91-9 ,N-91-17 and N-90-7, Natasha varieties. Also, it was found that there was a positive significant correlation at 0.01 level between wheat yield and heat use efficiency. On the other hand, Heliothermal unit and Phenothermal index has no significant effect on wheat yield. On the other hand, there was a negative correlation between GDD recived at the time of first node formation and value of grain yield. This study showed that N-90-7 and Natasha varieties has high potential to make good use of thermal energy, but N-87-20 variety was weak in this context.

In order to study the effect of drought stress on parent plant of soybean commercial cultivars on seed germination and seedling field emergence, field and laboratory experiments were conducted during 2014-2015. Seeds of six soybean commercial cultivars including Williams, M-11, M-9, Saba (L-17), Clarke, and Zane were produced at three drought stress levels on parent plant including irrigation after 50 (optimum irrigation), 100 (medium stress), and 150(sever stress) mm evaporation from Class A pan. After harvest, normal seedlings percent were determined by standard germination, cold and accelerated ageing tests in laboratory. Also, field emergence index was calculated. Results revealed that by increasing drought stress on parent plant intensity, normal seedlings’ percentage and field emergence index of studied cultivars at laboratory and field increased. The most normal seedlings’ percentage was related to the produced seeds of Zane and Saba (L-17) cultivars under 100 mm and Clark cultivar seeds produced at 150 mm drought stress of evaporation from Class A pan. Also, Zane cultivar seeds produced at 150 mm drought stress of evaporation from Class A pan had the most field emergence index. Normal seedlings’ percentage after accelerated ageing test had the most correlation with seedling field emergence and therefore this test could provide us with a more precious estimation of seedling field emergence.