جستجوی مقالات مرتبط با کلیدواژه « genetic diversity » در نشریات گروه « زراعت »

Barley is the fourth most common cereal crop in the world after wheat, maize, and rice, which is used for animal and human feed and malt production. This plant stands out among crops due to its unexpectedly wide range of adaptation and distribution compared to other cereals, earning it recognition as a model species.  Determining the variation in the morphological and physiological traits of roots and shoots in the collection of barley genotypes can provide the basis for breeding new cultivars with suitable traits for better adaptation to specific environments. So in this study, some morphophysiological characteristics of roots and shoots of commercial barley cultivars were studied to identify cultivars with a higher root-to-shoot ratio as donor parents for breeding projects.

In this study, 21 barley cultivars were grown in a randomized complete block design with six replications in greenhouse conditions. Morphological and physiological traits related to roots and shoots were measured during the tillering and heading stages. Also, some traits affecting photosynthesis and yield during reproductive growth and harvesting stages were measured. Analysis of variance, mean comparison by LSD test at 5% probability level, and multivariate statistical analyses including principal components analysis, cluster analysis by Ward method, correlation analysis, and path analysis were performed by JMP and R statistical software.

Significant genetic diversity was observed for most of the traits among cultivars (P < 0.05). At the tillering stage, Behrokh and Mehtab cultivars and in the heading stage, Jolgeh cultivar showed the highest dry weight of root to shoot ratio. Reyhan variety showed the lowest dry weight of root-to-shoot ratio in both stages. The carbohydrate content of the root in the tillering stage and leaf proline, root volume, and the ratio of chlorophyll a to carotenoid in the heading stage had the highest significant correlation coefficients with dry weight of root to shoot ratio (P < 0.05). Path analysis revealed that the root carbohydrate content in the tillering stage and the ratio of chlorophyll to carotenoids and proline in the heading stage are the most effective traits of the dry weight of root-to-shoot ratio. Principal components analysis showed that the first and second principal components explain 33.63% and the first seven principal components explain 72.66% of the total changes. Also, the first principal component showed a positive and significant correlation with root to root-to-shoot ratio in the heading stage, and the second principal component showed a negative and significant correlation with this ratio (P < 0.05). The studied cultivars were classified into four groups based on cluster analysis so that the fourth and second clusters in the tillering stage and the third and second clusters in the heading stage had the highest and the first cluster in both stages had the lowest dry weight of root to shoot ratio.

Based on the results, Jolgeh and Reyhan cultivars can be used in breeding programs to improve and produce cultivars with higher root-to-shoot ratio, optimal yield, and more adapted to specific environments. These cultivars had the highest and the lowest dry weight of root-to-shoot ratio in both stages, respectively. Also, they were placed in different dimensions of the biplot drawn based on the first two principal components. In addition, these cultivars were observed in different classes based on the cluster analysis.

Considering the high production potential of quinoa plant, especially under stressful conditions such as drought and salinity, it is necessary to introduce new and high-yielding genotypes for cultivation in different regions of Iran. The objective of this research was to evaluate the diversity of 26 new and foreign quinoa genotypes in terms of morphophenological characteristics. The experiment was carried out in a completely randomized design with three replications in greenhouse of Rice Research Institute of Iran (RRII), Rasht, in 2021. The results of analysis of variance showed that there was a very significant statistical difference among the studied genotypes for all measured traits. Factor analysis using the principal components method identified three main and independent factors that explained 39.19, 24.63, and 15.94%, respectively, and in total about 80% of the total variance. In addition, cluster analysis based on Ward's minimum variance grouped the studied 26 quinoa genotypes into three separate clusters; including 14, 7, and 5 genotypes, which very largely corresponded to grouping of the principal components. In total, the results of the current study showed that among the studied 26 quinoa genotypes, genotype No. 12 with 1000-grain weight, panicle length, and grain yield higher than the other genotypes as well as dwarfism and earliness characteristics was the most valuable genotype of this experiment. Furthermore, genotypes No. 4, 8, 17, and 18 for grain yield, genotypes No. 7, 13, and 15 for earliness, and genotype No. 14 for dwarfism, were the promising genotypes of this research, which can be used to transfer earliness and dwarfism to high-yielding genotypes in future breeding programs.

In the Mediterranean climates with mild winters like Khuzestan province, Iran, wheat is planted in autumn, and heat stress occurs only during the reproductive growth stage of wheat. In these regions, delayed planting causes the flowering and grain filling stages to be exposed to high temperatures, and the quantitative and qualitative performance of wheat decreases. Genetic improvement is one of the strategies to combat heat stress. Considering the importance of genetic resources for tolerance to environmental stresses tolerance, the present research was conducted to screen the wheat genetic collection of the National Plant Gene Bank of Iran for tolerance to terminal heat stress and to identify tolerant accessions.

In plant materials of this experiment were 236 bread wheat accessions along with three control varieties (Chamran, Chamran2 and Aflak), which were planted in an augmented design in the research field of Agricultural and Natural Resources Research Center of Khuzestan province, Ahvaz, Iran, in 2015-2016 crop year. The experiment was carried out in two planting dates, on-time planting date according to the region's custom at late November as normal conditions, and delayed planting at early January with the aim of heat stress during the reproductive growth stage of wheat. The measured traits included spike length, 100-grain weight, plant height, number of grains per spike, number of spikelets per spike, number of florets per spikelet, number of days to heading, number of days to maturity, grain filling duration, and five spikes grain weight. For data statistical analysis, descriptive statistics were firstly estimated under both normal and heat stress conditions, and then the relationships among traits were investigated using correlation coefficients. Principal component analysis was used to reduce the volume of data and cluster analysis was perfomed to group the studied genotypes.

The results of this experiment showed that terminal heat stress reduced the average of all studied traits, so that the highest decrease was observed in five spikes grain weight and the number of grains per spike. Based on the results of correlation coefficients under both normal and heat stress conditions, a positive and significant correlation was observed between five spikes grain weight and yield components traits, and a negative and significant correlation between five spikes grain weight and days to heading and days to maturity. Based on the results of principal component analysis, 72.54% and 80.53% of the total variance were explained by two and three main components under normal and heat stress conditions, respectively. The results of principal component analysis also indicated that the wheat accessions KC12977, KC12980, KC13013, KC13043, and KC13087, with the characteristics of early flowering and early maturity and higher values of five spikes grain weight, number of grains per spike, grain filling duration and number of florets per spike, were valuable accessions and have the sufficient potential to be used in breeding programs for heat stress tolerance. The results of cluster analysis separated the studied accessions into six group, and the fourth group including 62 accessions along with the control cultivars, had the highest average for number of florets per spike, number of grains per spike, and five spikes grain weight, as well as the lowest average for days to heading and days to maturity under both normal and heat stress conditions. and were recognized as the most tolerant group to heat stress. by three main components. In addition, the studied accessions were divided into six groups using cluster analysis.

The results of this study showed that there was a high genetic diversity among the studied bread wheat accessions in terms of terminal heat stress tolerance. Some genetic samples such as KC12977, KC12980, KC13013, KC13043 and KC13087, were valuable genotypes for the traits of early flowering and early maturity, as well as grain yield and yield components. The high diversity in these genetic resources, especially the tolerant accessions identified in this experiment as above mentioned, can be used to improve heat stress tolerance in future breeding programs.

Bitter vetch (Vicia ervilia L.) is one of the grain products of the legume family. The crop in Iran is one of the old legumes in the North and Northwest of the country and is grown alternately with cereal crops. Bitter vetch contains energy and protein, which makes it as a potential economic source for poultry feed. Drought is the most important abiotic stress and the most important limiting factor for crop growth which reduces the crop production in approximately 25% of the world's lands. Genetic diversity has a critical role not only for plant resistance against pests and diseases but also against the environmental stresses. In this study, the genetic diversity of 15 bitter vetch genotypes along with Kermanshah landrace was investigated using multivariate analysis methods.

Fifteen bitter vetch genotypes along with Kermanshah landrace were studied in a randomized complete block design with three replications at the research farm of Razi University, Kermanshah under two non-stress and water deficit stress conditions in 2016. The measured traits included phenological and morphological characters, yield and yield components. Combined analysis of variance (ANOVA) was performed using SAS 9.1 software, assuming the genotype and location as fixed effects. Correlation analysis, path analysis, factor analysis and clustering method were performed using SPSS 16 software.

The combined analysis of variance showed that the effect of environment was significant for all the traits except the number of sub-branches. The results of the correlation coefficient showed that there was a positive and significant correlation between the yield in non-stress conditions and the number of sub-branches, the number of seeds per pod, the number of pods per plant and the number of seeds per plant. Also, the yield under stress conditions was positively correlated with the number of seeds per pod and number of seeds per plant. Based on path analysis under non-stress conditions, the number of pods per plant had the greatest direct effect (0.54) on seed yield. Under stress conditions, the seed number in pod had the most direct effect (0.69) on the yield. The results of factor analysis in non-stress conditions led to the identification of three factors that accounted for 76.59% of the total diversity of the data. In the stress condition, four factors were identified, which determined 85.96% of the total diversity. In non-stress conditions, yield, yield components and phenological characteristics were important factors that accounted for the total variation. In cluster analysis, the grouping of the genotypes in the two conditions of non-stress and water deficit stress was partly different, showing the different reactions of the bitter vetch genotypes to the water deficit stress.

The grouping of the bitter vetch genotypes under non-stress and water deficit stress was partly different in the cluster analysis, showing the different reactions of the genotypes to the water stress. Under the water deficit conditions that happens from late flowering stage, earliness along with suitable vegetative growth should be noticed to achieve higher yield. Genotypes 13 and 2 were identified as semi-precocious and superior accessions under the non-stress and terminal water deficit stress conditions.

In order to estimate the heritability and genetic diversity of some seedling biometric traits in response to black rust (stem rust) disease, 24 wheat genotypes in the 2020 at the research greenhouse of the Seedling and Seed Breeding Research Institute was evaluated in the form of a randomized complete block design with four replications under the conditions of infection and non- infection to the native race TKTTF black rust. Based on the results, the genotype ´ disease condition interaction, was significant for all traits at the 1% probability level. Also, a significant difference between the genotypes in terms of seedling height, seedling fresh weight, seedling dry weight, and seedling fresh weight to dry weight ratio was observed. The results showed that pathogen infection causes a decrease in seedling height and an increase in seedling fresh weight, seedling dry weight, and seedling fresh weight to dry weight ratio due to the presence of pustules caused by disease. Under black rust infection, the highest heritability was observed for seedling dry weight (42.85%) and the lowest heritability was related to seedling height trait (8.78%). In the absence of black rust disease, the highest heritability was observed for the ratio of fresh weight to dry weight of seedlings (53.66%) and the lowest heritability was related to seedling height (51.25%). The results showed that black rust infection affects seedling traits and the diversity between genotypes can be used to improve wheat genotypes.

In order to investigate phenotypic and genotypic correlations between Characteristics affecting the germination stage and genetic variation and estimating the genetic parameters of these indices in Drought and normal conditions, 19 genotypes of bread wheat were cultivated inCompletely randomized design with three replications in the Laboratories, Department of Agronomy and Plant Breeding of Agricultural Research Campus Natural Resources of Razi University of Kermanshah, Iran In the germination stage was evaluated. The results of variance analysis (ANOVA) showed significant differences for the Germination Percentage (GP), coleoptile Length (KL), Mean Germination Time (MGT), Cofficent of Velocity of Germination (CVG), Average Velocity of Germination (AVG) and Vigor index (SV) under stress and normal condition indicating. The presence of a considerable genotypic variation and possibility of selection of drought tolerant genotypes. The presence of a considerable genotypic variation and possibility of selection of drought tolerant genotypes. According to the biplot obtained in the laboratory conditions (germination test) genotype (16) was located in group A. A high positive genetic and phenotypic relation was observed between GP, AVG, SV and RL, which is completely in line with results of the relation between traits by GTbiplot. High heritability and genetic gain were observed for GP, AVG and SV that reflect the additive gene action. Accordingly, the selection method for studied traits in examined genotypes effective. Cluster analysis using Ward method, based on the traits, classified the genotypes in three different groups.

Rice is one of the oldest and most important cereals in the world and is a desirable model plant for genetic and molecular studies. Drought is one of the important risks for the successful production of crops, especially rice, in the world, which can be created at any time during the growing season. One of the main challenges in agriculture is to produce more food with less water consumption, and therefore, the production of rice genotypes that can have more tolerance to drought stress is one of the main goals of breeding projects.

In order to evaluate the effect of drought stress (zero (control), -3 and -5 bar using Polyethylene Glycol) on some genetic, morphological, and biochemical characteristics of rice at the germination stage, 38 lines with their parents (MousaTarom and 304) were investigated in randomized complete block design with three replications during 2022.

Morphological traits were decreased under -5 bar drought stress compared to the control. The germination rate and percentage were increased by 9.6 and 1.1% under -3 bar stress, and 37.8 and 33% under -5 bar stress, respectively. The rootlet length, rootlet fresh weight, and dry weight increased under - bar stress compared to the control, indicating that the rice plant can tolerate such a stress intensity, and it may even be used as a priming. Catalase, peroxidase and superoxide dismutase enzyme activities increased by 59, 51 and 81%, respectively, by increasing the stress to -5 bar compared to the control. This increase shows the increase of the plant's resistance to the active oxygen and drought tolerance. The highest phenotypic correlation in non-stressed conditions was between seedling weight and length vigor (0.92), under -3 bar stress was detected between shootlet length and fresh weight (0.91), and under -5 bar stress the highest one was between seed germination percentage and rate (0.94). The factor analysis for each of the zero, -3 and -5 bar drought stress levels introduced three factors that explained 73.68, 81.13 and 81.73 percent of the variance, respectively.

The high diversity of traits at the -5 bar drought stress indicates that it is possible to use germination rate and percentage, length and weight indices, and shootlet length and fresh weight as criteria for genotype selection under -5 bar drought stress. Such traits could be used as effective ones in the selection of tolerant rice genotypes at the germination stage and in order to establish the rice plant optimally.

Quinoa (Chenopodium quinoa Willd.) is a beneficial plant with high nutritional value with high tolerance to salinity and drought stress. Most of the experiments performed on the study of quinoa salinity stress tolerance in pot and greenhouse conditions were not comparable to the results of cereal experiment such as wheat and barley performed in field conditions. The purpose of this experiment is to determine the threshold value of quinoa to salinity stress under field conditions.

An experiment was performed as a split plot in a randomized complete block design with three replications on August 7, 2017 at Sadough Salinity Research Station of Yazd National Salinity Research Center. Experimental treatments including five quinoa genotypes including three quinoa lines (NSRCQE, NSRCQB, NSRCQC) with Titicaca and Sadough cultivars as subplots and irrigation water salinity at five levels of 2, 5, 10, 15 and 17 dS m-1 in the main plot. During the growing season, soil samples were taken from the plant root development area. Seed yield and yield components were measured. The percentage of saponin, seed vigor, 1000-seed weight and grain size were also measured.

The results of analysis of variance of the measured traits showed that the effect of salinity stress on plant height, 1000-seed weight and grain yield was significant at the level of 1%. The effect of salinity stress on grain size was not significant. Differences between genotypes in terms of plant height, grain yield, 1000-seed weight, biomass and grain size were significant at the level of 1% and panicle length and number of lateral panicles at the level of 5%. The interaction effect of genotype and salinity on biomass was not significant at 5% level and on other traits was not significant. The percentage of saponin between genotypes was significant at the level of 5%. The interaction effect of salinity and genotype on biomass and saponin percentage was significant at 5% level. The percentage of grain saponin increased significantly with increasing salinity in NSRCQB genotype and was not affected by salinity stress in other genotypes. Biomass of all genotypes except Titicaca was not significantly different up to salinity of 10 dS m-1. The highest biomass production in non-saline conditions was related to NSERCQE and Sadough cultivar and These two genotypes had the lowest decrease in biomass production with increasing salinity. Seed viability was not affected by salinity increase except in NSRCQB genotype seed vigour decreased by 15%. The lowest 1000-seed weight in non-saline conditions was related to NSRCQB genotype and the trend of 1000-seed weight loss with increasing salinity was similar to all genotypes and decreased by an average of 16%. The results of mean comparison showed that the highest yield at all salinity levels was observed in Sadough cultivar. Based on the results of the fitted linear equation, changes in quinoa seed yield to salinity showed that the salinity tolerance thresholds of quinoa genotypes were 4.3, 8.7, 4.1, 4.8, and 6.8 dS m-1 of electrical conductivity of saturated soil extracts, respectively. The soil and slope of the line were 3.5, 2.4, 0.1, 0.7 and 0.9%. Fifty percent reduction in wheat yield of Kavir and barley cultivars of Marvdasht cultivar has been reported at 15 and 20 dS m-1  of soil salinity, while Quinoa Sadough cultivar at 24 dS m-1  of electrical conductivity of soil saturated extract was 80% seed yield in non-saline conditions. Sadaogh cultivar not only have suitable agronomic characteristics and high production potential in saline conditions, but also has a higher salinity tolerance.

Quinoa has a higher tolerance to salinity stress than wheat and barley and can be a promising plant for using saline water and soil resources that are not economically viable for crop production. There is also a good variety among quinoa genotypes to select for using saline water.
Acknowledgments
This project has been done with the financial support of the Researchers Support Fund and the Agricultural Education and Extension Research Organization (AREEO).

Drought stress is known as one of the most important factors limiting the growth and production of agricultural plants in most parts of the world and Iran. It is a multidimensional stress and affects plants at different levels. From a physiological point of view, drought stress causes several changes in the relative water content of leaves and photosynthetic pigments of plants, which in turn causes a decrease in the efficiency of photosynthesis and a significant reduction in plant growth parameters and ultimately grain yield. In Iran, drought stress usually occurs during the filling stage of wheat grains, and due to the limitation of irrigation, supplementary irrigation can play an important role in dealing with drought stress. Durum wheat (Triticum durum, Desf) is an important food product due to its heavy gluten properties and non-sticky dough, ideal for preparing pasta products such as macaroni and spaghetti.
To investigate the physiological characteristics, yield, and yield components of durum wheat cultivars under drought conditions and supplemental irrigation, 10 durum wheat genotypes were evaluated in the form of a split-plot design with the basis of randomized complete blocks in dryland and supplemental irrigation with 3 replications during Crop years 2017-2018 and 2018-2019 in Kohdasht city of Lorestan province. Grain yield and yield components (weight of 1000 seeds, number of seeds per spike, number of spikes per plant) as well as biochemical and physiological properties of photosynthetic pigments, greenness index, relative leaf water, leaf protein and light consumption efficiency were investigated.
Variance analysis showed a significant variation among the examined cultivars, moisture conditions, as well as the interaction of cultivar × humidity conditions for most of the traits except the interaction effect of cultivar × humidity conditions for chlorophyll b and leaf protein. The effect of year and interaction effects of year with other factors were not significant for most of the traits. Performing supplementary irrigation compared to rainfed conditions caused all traits to increase significantly, except greenness index and protein content. Mean comparison of interaction effect of cultivar × moisture environment with Duncan's method at 5% level showed that the genotypes reacted differently for the traits in two moisture conditions and in dry conditions, Omrabi3, Hana, Aria and Saji genotypes were superior to other genotypes in terms of agricultural and physiological traits, and with supplementary irrigation, these for genotypes maintained their superiority, and two genotypes, Shabrang and Behrang, were added to this group.
In general, it can be said that the results were almost the same in the two years studied. Supplementary irrigation compared to rainfed conditions improved the agronomic and physiological characteristics of the cultivars. Among the genotypes, there was a high diversity for all the examined traits and this diversity was different in two humidity conditions. Considering the two-year mean yield, the genotypes of Omrabi3, Saji, Arya and Hana for rainfed conditions and Omrabi3, Hana and Behrang for supplementary irrigation conditions of the studied area are recommended.

To identify salinity tolerant cultivated genotypes, 50 barley genotypes originated from Iran were evaluated in a field experiment during 2019-2020 and 2020-2021 cropping seasons in Yazd; Optimum experiment at Yazd central field station, and stress experiment in Ardakan field station, Iran. Six improved barley cultivars; Mehr and Khatam (Salinity tolerant), Nosrat, Nimrooz, Yousef and Gohran were also included in the experiments. The experiments were carried out using 8×7 rectangular lattice design with three replications. Phenological traits, grain yield and 1000-kernel weight were measured in all genotypes under optimum and salinity stress conditions. The electrical conductivity of soil and irrigation water in optimum condition was 3.4 and 3.6 dS m-1, and in the salinity condition, it was 14 and 10 dS m-1, respectively. The stress intensity index (SI) was 0.21 and 0.32 in 2019-20 and 2020-21 cropping seasons, repectively, which indicated higher stress intensity in the second year in the stress experiment. The mean grain yield under optimum and salt stress conditions in 2019-20 was 215 and 174 g m-2, respectively. In 2020-21 cropping season, mean grain yiled under optimum stress conditions were 271.9 and 184 g m-2, respectively. Combined analysis of traits showed that the of year × salinity stress × genotype interaction effect was significant on evaluated traits. Based on the results of principle component analysis and stress indices in 2019-20 cropping season, genotypes no. 50 (TN5008), 33 (TN4247) and 38 (TN4357) were superior genotypes. While in 2020-21 cropping season genotypes no. 24 (TN3474) and 27 (TN3643) together with salinity tolerant barley cultivars; Khatam and Mehr had higher grain yield. The collecting site of these two genotypes is Kerman province and Fars province, respectively. Based on the results of this research, tolerant cultivated barley genotypes were identified for further studies.

Coriandrum sativum L. is a medicinal, aromatic, annual plant of the Apiaceae family. The seeds and vegetative body of this plant contain essential oil that is used in cosmetics, health, chocolate and soft drinks. It has shown antispasmodic, antidiarrheal, antioxidant, and antimicrobial properties. The basic requirement for plant breeding programs is a diverse germplasm that provides necessary facilities for breeding species with desirable features. Therefore, accurate identification of genotypes is considered as a prerequisite in this manner. The morphological and phytochemical characteristics are the important traits that have been used for diversity research.

In order to evaluate genetic diversity of coriander based on morphological, antioxidant and physiological traits, 12 coriander accessions were collected from different parts of the country. This experiment was conducted based on a randomized complete block design with three replications in research farm of University of Mohaghegh Ardabili in April 2020. The morphological and antioxidant traits were studied also the seeds of accession were dried in the shade. The 50 g of dried seeds of different accessions were exposed to hydro-distillation to extract the essential oil by Clevenger apparatus for 3 hours. The essential oils were kept in the dark condition at 4 ◦C, and then 1 µl of them were injected into a Thermoquest- Finnigan GC-MS to determine the type of the constituents. The compositions were identified based on the comparison of mass spectra and NIST and Wiley libraries.

The Results of morphological, antioxidant and physiological studies showed that the mashhad accession had the highest leaf area (2.8 cm2), fresh and dry weight of aerial part of plants (4.52 and 0.56 g respectively) and leaf fresh weight. The meshkinshahr and mianeh had the highest antioxidant activity.The Results of physiological studies showed that the essential oil compounds were high variable and mashhad accessions were best in Butanoic acid (2.56 %), Limonene (0.44 %), Linaloloxide (1.7 %),Thymol (0.08 %),Geraniol (0.38 %),alpha.-Methyl-.alpha (0.54 %), Eicosane (0.16 %) and Isophytol (0.2 %).Correlation coefficients among traits showed that Isophytol had highest correlation with Geraniol (0.98) and minimum correlation was observed between Camphor and Butanoic acid (0.001). Factor analysis indicated that the five factors explained 100 of the variability among the accessions. Cluster analysis based on Euclidean distance, divided the accessions into three major groups. The results suggested that there is a considerable genetic variation among coriander accessions.

Main purpose of this study was determination of morphological, antioxidant and physiological diversity among coriander accessions in Iran. Significant differences were found among the accessions in all of compounds that were measured.

Protein patterns of SDS-PAGE have been widely used to determine genetic variation in cereals. This study was carried out at The Payame-Noor University of Asadabad to study genetic diversity and protein pattern in bread wheat cultivars before and after flowering. 13 bread wheat cultivars were applied to prepare protein patterns based on SDS-PAGE electrophoresis. The highest genetic distance before bolting was between Zare and Gascogen (8 units). The lowest genetic distance before flowering was between cultivars with a distance equal to zero. This result indicates high genetic similarity between wheat cultivars. The most similarity between the cultivars is the value of one, such as Pishgam and Sayson (one means one hundred percent similarity) or Pishgam and Bezustaya (with one). The least similarity is 0.2 between Zare and Gascogen. Based on cluster analysis these 13 bread wheat cultivars were divided into three groups. The results after bolting were largely similar to the protein pattern before blooming. The most similarity between the cultivars is the value of one. Pishgam and Sayson was one hundred percent similar, and Pishgam and Bezustaya as well. The lowest similarity was observed between Zare and Gascogen cultivars with zero and 0.25 between Zare and other cultivars. Based on cluster analysis, 13 wheat cultivars were grouped into four clusters. Zare, Gascogen and Omid cultivars were placed in separate clusters and the rest of the cultivars were classified in one group. Increasing one group indicates the effect of some proteins that are effective in the developmental stages before and after wheat flowering.

Rice is an important crop that is considered a staple meal for 2.7 billion people worldwide. Therefore, the demand for it will increase with the increase of population. Environmental constraints always pose a serious threat to crop production, including rice. Drought is one of the most important challenges that limits the production of high-yielding cultivars in arid and rainfed areas. Global warming has also become a factor in limiting rice production in rain-dependent areas. Therefore, researchers are looking for a way to stabilize rice production in arid regions. In this study, informative markers related to the desired agronomic traits were identified in 59 rice genotypes using microsatellite marking system.

In order to evaluate the tolerance of rice genotypes to drought stress and to identify tolerant and sensitive genotypes, 59 genotypes received from the National Rice Research Institute and the International Rice Research Institute in a randomized complete block design with three replications in two separate conditions, without Stress (flood) and drought stress were performed in a research farm located in Aliabad Katoul city in 2013. In both conditions (normal and drought stress), the genotypes were planted in five rows of 25 × 25 cm in rows one meter long. Thirty days after planting in the nursery, healthy and strong seedlings were transferred to the main land. The required agronomic operations were carried out equally during the growth and development period of the plants under stress and normal conditions and only in terms of irrigation of the experimental field in both flood and stress environments, until the tillering stage of the cultivars were equally flooded. Then, to create stress, irrigation was done from 40 days after transplanting (maximum tillering stage) to the end of the growing season at 25-day intervals. Phenotypic values of grain yield and 1000-grain weight were measured under two conditions according to standard guidelines for evaluation of traits in rice. In order to investigate the relationship between agronomic traits and microsatellite markers with 59 rice genotypes out of 36 microsatellite molecular markers were performed in the Plant Breeding and Genetics Laboratory of Gonbad Kavous University, Faculty of Agriculture and Natural Resources. Young leaves of 21-day-old seedlings were extracted in four-leaf stage using CTAB method. Touchdown PCR reaction was studied and evaluated randomly using 36 microsatellite primers for 3 markers from each chromosome. To separate PCR products, 6% polyacrylamide gel electrophoresis was used and to reveal the banding pattern, silver nitrate staining method was used. The content of polymorphic information was calculated. The relationship between molecular data and traits of studied rice genotypes was investigated using multiple regression. Thus, each quantitative trait was considered as a dependent variable and microsatellite markers were considered as independent variables.

The average content of polymorphic corrections (PIC) was estimated to be 0.58, which showed RM 5647 with 0.81 the highest and RM 6022 with 0.32 the lowest polymorphism (PIC). The results of stepwise regression analysis showed that a total of 90 markers for normal conditions and 69 markers for drought stress conditions for morphological traits were identified. Under normal conditions, the number of spikes and the number of days to flowering with 9 markers and under drought stress, the weight of the cluster with 9 markers showed the most positive markers. The most explanation for variation in normal conditions is related to the total number of grains (0.83) by gene loci RM6324-E, RM5652-E, RM5761-D, RM6179-F, RM549-B, RM462-B, RM7420-D Explained. In drought stress conditions, the most explanation for variation related to panicle weight (0.70) by gene loci RM519-D, RM7545-A, RM6179-E, RM7118-G, RM3525-B, RM5761-B, RM38-C, RM7091-A, RM5647-B explained.

The results showed that some markers are associated with more than one trait, which indicates that these traits are very closely related to each other or may be influenced by multi-effect genes. To understand this, it is necessary to develop transgressive generations and linkage.

This study aimed to investigate the genetic parameters of ten Cucurbita pepo L. hybrid cultivars, including seven foreign hybrid cultivars (F1 Shiraz, F1 Khaleej, F1 Samar, F1 Roham, F1 Daphne, F1 Asma and F1 Oto) and three domestic hybrid cultivars (F1 Peronesh, F1 BL and F1 CL) in the form of a randomized complete block design with 3 replications at the Pest Investigation Research Station and the Shahid Fozveh Research Station of Isfahan, central Iran, in 2019. The bed preparation operation was done and the seeds were sown in the mid-June. The results showed that the highest fruits/plant was observed in CL and Shiraz genotypes and the highest yield/plant in four harvests was observed in Peronesh genotype. Roham and Otto genotypes showed the lowest total yield/plant. BL genotype showed the highest mean fruit diameter in four harvests and the highest fruit weight of the seed sample. The highest seed weight was obtained in Shiraz and Asma genotypes and the highest seed-to-fruit weight ratio was obtained in Samar genotype. BL, Asma and Shiraz genotypes showed the highest seed dry weight. The highest seed length and the highest dry weight of 100 seeds were observed in Peronesh and BL genotypes. A positive and significant correlation was also observed between some traits. Among the investigated genotypes, Peronesh and BL genotypes outranked the other genotypes in most of the traits. Also, Shiraz genotype had a significant advantage in some seed traits compared to other genotypes. According to the presented results, different genotypes of the pumpkin plant were significantly different from each other in terms of various traits, indicating that the ground is prepared to employ these resources for improving the yield of this plant species.

In this research, 50 quinoa genotypes were investigated using 40 pairs of microsatellite markers (SSR) to identify the superior genotypes in terms of grain yield, the components affecting it, and the features linked to the studied traits were also introduced using Association Analysis. The study of grain yield traits and the factors affecting it showed that the traits of day to physiological maturity, panicle length, number of panicle per plant, and 1000 -grain weight were the most important traits affecting grain yield, and finally genotypes 1, 32 and 49 were the essential traits in terms of these traits. They were introduced as superior genotypes. Studying the population structure using Structure software showed two possible subgroups (K=2) in the studied population and the results of the bar plot confirmed it. The results of the correlation analysis using the general linear model (GLM) and the mixed linear model (MLM) numbers 49, 53 (GLM) and number 48, 52 (MLM) showed a significant indicator-adjective relationship, respectively, for the first year (2018) and the second (2019). Among the significant marker-trait relationships identified for different traits, the highest number of meaningful relationships were identified for grain yield and 1000-grain weight traits with 6 and 5 relationships, respectively. In conclusion, based on the results of the correlation analysis, 12 continuous markers were identified with a significant relationship with the evaluated traits during both years. Therefore, these markers can be used as fixed and stable markers in different quinoa breeding programs.