فهرست مطالب فرناز شریعتی

Selection of soybean cultivars that have a higher grain yield under water deficit conditions, reduces the damage to soybean producers.

The response of soybean genotypes to water deficit stress was investigated in terms of agricultural characteristics and grain yield in Karaj (Iran), during two years. The experiment was carried out as a split plot based on randomized complete block design in three replications, with three irrigation levels (control, mild stress, and severe stress)  based on 50, 100, and 150 mm evaporation from a  Class A evaporation pan as the main plot and 10 soybean genotypes as the sub-plot.

The results showed that mild and severe stress caused the node number and inter-node to decrease in comparison with control irrigation. Under control irrigation, the highest grain yield (2585 kg/ha) was obtained from the early-maturing Saba cultivar, with the highest seed number per unit area. The early-maturing genotypes had the highest grain yield under control irrigation, and their grain yield decreased significantly with increasing stress intensity. The grain yield of the Saba cultivar reduced under mild and severe stress by 32 and 59% compared to control irrigation, respectively. Under stress conditions, the late-maturing genotypes had the highest grain yield and water deficit stress caused a slight decrease in their grain yield. Under mild and severe stress, the late-maturing Williams×A3935 line had the highest grain yield and protein yield, respectively.

Under control irrigation, the Saba cultivar, and under stress conditions (mild and severe) the Williams×A3935 line is recommended in Karaj and similar climates (moderately cold region).

Although sesame has traditionally been grown in southern Iran's warm and arid regions, its desirable agronomic traits and economic profitability have led to increased interest in cultivating this crop in the northern regions. However, sesame often exhibits low performance due to poor agronomic management, environmental stress, and limited use of improved varieties. Therefore, the use of improved sesame varieties, mainly those resistant to shattering, along with proper agronomic management, maybe the key to successful cultivation in various parts of the country. The seed of a non-dehiscent sesame genotype (S29) was imported into the country in 2016. Several years of studies related to this genotype confirm that it is resistant to seed shattering. In this regard, the present study was designed and conducted to investigate the effects of planting arrangement and plant density on the performance of a non-dehiscent sesame genotype. The experiment was conducted in research fields located in Mazandaran (Sari) and Ardabil (Moghan) in 2020 and 2021. The effects of three planting row distances (30 cm, 45 cm, and 60 cm) and four plant spacing on the rows (5 cm, 8 cm, 11 cm, and 14 cm), with a minimum density of 12 plants per square meter to a maximum density of 67 plants per square meter, were evaluated in terms of plant height, number of branches, yield components, seed yield and oil percentage of the shattering-resistant sesame genotype. The experiment was set up in a randomized complete block design with split-plot arrangements and three replications in each location. The results showed that the highest plant height in both regions was achieved with a row distance of 45 cm and a plant spacing of 8 cm. Additionally, increasing plant density up to 45 plants per square meter resulted in increased plant height, but further increase in density decreased plant height. Decreasing the distance between planting rows and plant spacing, equivalent to increasing planting density, reduced the number of branches, capsules per plant, and seeds per capsule in both regions. The maximum seed yield in the Moghan region (1465 kg/ha) was obtained from the 45×8 cm arrangement. However, there was no significant difference compared to the yield obtained from the 45×5 cm planting arrangement. In contrast, the highest seed yield in the Sari region (824 kg/ha) was achieved with the planting arrangement of 30×14 cm. Based on regression analysis of seed yield, the optimum density was estimated to be 23 plants per square meter for the Moghan region and 31 plants per square meter for the Sari region. The results indicated that the imported non-shattering sesame genotype did not exhibit desirable potential for cultivation in the Sari region due to its lower average yield than the regional average. However, in the Moghan region, this genotype showed a comparable average yield and even higher maximum yield (250 kg/ha) than the regional average, with the highest yield obtained from the 45×8 cm planting arrangement. Therefore, due to its suitable seed yield performance and the potential for mechanized harvesting, this genotype holds promise for cultivation in the Moghan region.

The new oilseed rape cultivar Nilofar (R15), is the result of screening and purifying single plants in segregating generations derived from the cross "Symbol×Orient". During five years of consecutive cultivation, screening of single plants was continued to access pure lines using pedigree method and pure lines were selected in F4 generation. During cropping season 2008-2009, 84 pure lines were evaluated in preliminary yield trial. Results showed that Nilofar variety with a mean yield of 3352 kgha-1 had higher grain yield by 45% compared to the Okapi control variety with a mean grain yield of 1833 kgha-1. In the Value for Cultivation and Use (VCU) trial in six research stations of cold and mid cold regions of Iran including Karaj, Isfahan, Hamedan, Islam abad-e- gharb, Khoy and Arak during two cropping seasons 2009-2011, Nilofar variety with an average grain yield of 3783 kgha-1, ranked first and had 16.1% grain yield more than the Okapi. Under delayed sowing date and stopping irrigation from silique development stage in Karaj during two cropping seasons 2012-2014, Nilofar with 1986 kgha-1 and 0.62 kgm-3 in term of grain yield and water use efficiency, respectively, was superior to Okapi with 1626 kgha-1 grain yield and 0.62 kgm-3 water use efficiency. The glucosinolate content of Nilofar variety was less than 10 μmolg-1 of dry matter and the erucic acid content of the oil was less than 2%. The results of the extension research project in Kermanshah province showed that the mean grain yield of the Nilofer variety at two sites of Sarab Nilofer and Mahidasht was 4004 kgha-1, which was 14.8% higher than the Okapi control cultivar. Due to its high grain yield potential and appropriate agronomic characteristics, line R15 was released under the name of Nilofar and is recommended for cultivation in the cold and mild cold regions of Iran.

Oilseed rape (Brassica napus L.) is a traditional oil crop in Iran. Conventional oilseed rape production during the past decades has been performed through manual sowing, transplanting, and harvesting. In cold and temperate regions of the Iran in the Karaj region, due to delays in harvesting the previous crop such as corn, canola planting date is delay and it is not possible to planting oilseed rape seeds directly. Problems such as supplying primary soil water for crop establishment of canola fields, possibility of damage from cold and frost stress and late season drought due to delayed planting are the main problems of canola cultivation in Karaj region (Jabbari et al., 2022). Because of this, canola transplanting can solve the problems and be a good choice in these kinds of situations (Zeinalzadeh-Tabrizi et al., 2022). Although there have been many seeding rate studies done for canola, the optimum seeding rate and plant population for canola is not known. Optimum density for canola depends on both biological and economic factors. verall economic optimum plant density for canola was 30 to 40 plants m-2 (French et al., 2016). On the other hand, the transplanting method (bare-root or potted-root transplant), transplanting density and the number of seedlings per hole one seedling or two seedlings are very important to achieve the highest seed yield.

In order to agronomic evaluation of winter canola in seeding and transplanting systems with different plant densities under delayed cultivation conditions in the Karaj region, an experiment was conducted as a randomized complete block design with three replications in two cropping years, 2019-2020 and 2020-2021. Experimental treatments included direct sowing of seeds as a control at a rate of 6 kg/ha; transplanting with densities of 20, 30, and 40 plants per square meter, each density with both bare-root transplant and potted-root transplant; and also with one seedling or two seedlings in the planting hole. During the experiment, traits including Days to flowering time, flowering duration, growth period, plant height, stem diameter, branch number, silique length and diameter, silique per plant, seed number per silique, 1000-seed weight and seed yield were recorded. Combined analysis of variance carried out by SAS statistical analysis software and the least significant difference (LSD) test was used to compare treatment means with a probability threshold of 0.05.

The results of combined analysis showed that seed yield in the treatments of potted-root and bare-root seedling was between 686 and 1142 kg.ha-1 more than seeding cultivation. Yield reduction in seeding cultivation was due to the reduction of yield components, especially the number of silique per plant. Also, among all the investigated treatments, the highest seed yield (4395 kg.ha-1) was observed in the treatment of bare-root seedlings with a density of 40 plants with one seedling in the hole, which this issue was related to the relatively long flowering duration, noticeable superiority for silique per plant and high 1000 seeds weight. An independent comparison of bare-root and potted-root transplant treatments showed that in the total of two experimental years, bare-root treatments caused a significant decrease of 7.3% in days to beginning of flowering and 13.3% increase in the length of the flowering period, 7.2% in plant height, 42.7% in siliques per plant and 17.1% in the seed yield. Early maturity and higher of siliques number and number of seeds in siliques led to the superiority of seed yield in the bare-root treatment compared to the potted-root treatment. Mentioned issue was related to more competition between seedlings in the pot at the the potted-root treatment and the greater use of soil space for root development and less competition between seedlings in bare-root treatment.

Generally, results showed that bare-root transplant treatments were superior to potted-root transplant treatments for yield components and seed yield. Therefore, in the conditions of delayed cultivation of canola, it is recommended to bare-root transplanting with a density of 40 plants per square meter and one seedling in the planting hole, especially in the Karaj region.

Saffar (Zabol 10b line) variety was obtained by pedigree method from Goliath×19H cross. Based on preliminary evaluation, this variety showed significant earlier maturity (13 day), in 2010-2011, compared to the other lines of canola. Based on adaptability expieriments in Zabol, Safiabad, Behbahan, Boushehr, Gorgan, Gonbad, Sari and Moghan regions in 2011-2012, its grain yield had not significant difference from control variety RGS, but had a high early maturity. The new variety had a lower rank variance which indicates the Less performance fluctuations and stability in different years and regions compared to control variety RGS. Saffar cultivar with 165 days growth period was 12 days earlier in maturity than control variety RGS in warm south and north regions. The oil content of new variety was 43.15%, which has not significant difference with control variety RGS but in terms of having higher amounts of oleic acid and lower amounts of linolenic acid, it has a better quality. The field response of new variety to stem sclerotinia disease showed good relative tolerance in the north climate, which has significant difference with control variety RGS. Based on outstanding features such as yield stability, early maturity, possibility of escaping from drought and heat in the last season, saving at least one irrigation stage and uniformity in maturity, this line was released with the name of Saffar in 2018 and recommended for late cultivation in warm areas with short growing seasons in warm south and north climate zones of the country such as the south of Kerman, Sistan and Baluchestan, Hormozgan, Khuzestan and Gorgan.

The present study was conducted to compare the genetic diversity of 158 foreign and iranian safflower genotypes with six Iranian safflower cultivars.

The experiment was carried out in the Augment design with three replications during the 2017-17 at Zahak Agricultural and Natural Resources Research Station in Zabol county.

In principal components analysis (PCA), the first component was named grain yield and dry matter and the second component was named phenology. Based on the results of biplot, genotypes were classified into four groups. The first group includes late matutity and tall genotypes, the second group includes genotypes with high grain yield and harvest index (HI), the third group includes late matutity genotypes with low grain yield and the fourth group includes early matutity genotypes with lowest grain yield and HI. Genotype No. 100 with unknown origin (6044 kg.ha-1) had the highest grain yield and genotypes No. 153 (Mexico), 169 (Mexico), 134 (North Korea), 122 (Poland), 124 (unknown), 130 (unknown) and 131 (North Korea) had high grain yield. The orthogonal comparison of 20 Iranian genotypes versus 138 foreign genotypes showed that no difference was observed for plant height, but in terms of grain yield, biomass and harvest index, foreign genotypes were significantly higher than Iranian genotypes.

Genetic diversity by different statistical analyzes was well able to differentiate safflower genotypes and can be used from grouping obtained from statistical methods for select appropriate parents genotypes in safflower breeding programs.

Like many other sesame-producing countries, Iran has numerous local sesame populations adapted to their respective production regions' climatic and soil conditions. However, these populations are not suitable for large-scale cultivation and mechanized farming. In 2016, a sesame genotype resistant to seed shattering was imported into the Iran suggesting its potential contribution to sesame cultivation programs in the country. Due to the lack of information regarding the appropriate planting arrangements and densities for this imported shatter-resistant genotype, especially in Golestan province, this research was conducted.

The experiment was carried out in 2020 and 2021 in the research fields of the Golestan Agricultural and Natural Resources Research and Education Center (Gorgan), located at 54° 24' longitude and 36° 53' latitude, with an elevation of 5.5 meters above sea level and temperate climate with hot and dry summers. The experiment was set up as a split-plot design in an RCBD with three replications. The main plots consisted of three-row spacings (30, 45, and 60 cm), and the sub-plots included four plant spacings (5, 8, 11, and 14 cm). The morphological traits, yield components, seed yield, seed oil percentage, and oil yield of the imported shatter-resistant genotype were evaluated. The data were analyzed using a mixed model approach assuming the random effect of year, and the analysis was performed using SAS software version 9.4. Mean comparisons of main effects were conducted using the LSD test at a significance level of 5%, and in the case of significant interaction effects, mean separation and comparison were performed using the LS-means test.

The results showed that in the first year, the tallest plants were obtained from the 60×8 cm planting arrangement (193 cm), while in the second year; the tallest plants were obtained from the 30×11 cm planting arrangement (211 cm). Increasing the planting density from 10 to 35 plants per square meter increased the plant height by 22 cm, but further increases in density due to increased competition decreased plant height. Furthermore, the highest number of capsules per plant (201 capsules) in the first year was obtained from the 60×14 cm planting arrangement, and in the second year (169 capsules), it was obtained from the 60×11 cm planting arrangement. Decreasing the distance between rows and plants, which corresponds to increased planting density, reduced the number of capsules per plant, the number of seeds per capsule, and the thousand-seed weight. The results indicated a significant interaction effect of row spacing and plant spacing on seed yield. The highest seed yield of 3025 kg.ha-1 was achieved with the 30×11 cm planting arrangement. Although increasing the planting density decreased the number of branches and yield components, this decrease was compensated for by increasing the number of plants per unit area, and the highest seed yield was obtained at a density of 30 plants per square meter. Additionally, the results showed that increasing the planting density beyond 30 plants per square meter led to a decrease in seed oil percentage.

The results of this study revealed that the average and maximum seed yield of the shatter-resistant genotype were approximately 3 and 4 times higher, respectively, compared to the average sesame yield in the Gorgan region. Therefore, considering the mechanized harvesting potential of this genotype and its high seed yield, it is recommended to cultivate this genotype using the 30×11cm planting arrangement and a density of 30 plants per square meter in the Gorgan region.

Sesame is a low-expected and low-input crop among oilseed crops, which holds economic significance not only in subsistence agriculture in arid and semi-arid regions of Iran but also in terms of its agronomical characteristics. Shattering tolerant sesame genotypes are crucial for developing sesame cultivation in countries such as Iran. There is a lack of comprehensive information on crop management, including the optimal planting arrangement for imported shattering tolerant sesame genotypes. Therefore, this research was planned and executed to answer the questions regarding the proper planting arrangement of this genotype in two crucial sesame producing provinces, Khuzestan and Fars.

The experiment was conducted in the Khuzestan (Dezful) and Fars (Darab) Agricultural and Natural Resources Research Center fields during 2019 and 2020. A split-block randomized complete block design with three replications was implemented at each location to investigate the effects of 30, 45, and 60 cm row spacing and 5, 8, 11, and 14 cm plant spacing on yield and yield components of shattering tolerant sesame genotypes. The collected data were analyzed using SAS software (version 9.4), and Bartlett's test confirmed homogeneity in the variance of all studied traits. The mean values for both years were presented since the data were consistent. It is important to note that the data from each region were analyzed separately due to inconsistent variances between regions. Statistical significance was determined using an F-test, and protected LSD was used to separate the main effects when necessary. Furthermore, significant interaction effects were separated using the slicing method.

The experiment results indicate that reducing the distance between rows and plants increased plant height in both locations. In Darab, increasing the row distance from 30 to 45 cm increased grain yield by 6%, while a further increase in distance to 60 cm decreased grain yield. The highest seed yield of 659 kg per hectare was obtained in Darab using a planting arrangement of 45x5 cm, and the lowest yield was observed with a 21% decrease in yield for the planting arrangement of 60x14 cm. In Dezful, the maximum seed yield of 684 kg per hectare was obtained with a planting arrangement of 45x11 cm. The study results showed that in both locations, the highest grain yields were achieved with a row distance of 45 cm, and the commonly used row distance of 60 cm did not produce the highest yield in either location. Additionally, in Darab, increasing planting density by up to 42 plants per square meter increased seed yield. In Dezful, the maximum seed yield was obtained at a density of 38 plants per square meter.

This research suggests that reducing the row distance while maintaining appropriate plant spacing can be a practical approach to achieving high sesame yields. Moreover, increasing plant density can lead to a certain extent of increase in grain yield. However, beyond a certain threshold, as the density further increases, yield decreases due to increased competition among plants. Thus, optimizing planting arrangements, including row and plant spacing, is essential to achieve maximum yields in sesame cultivation.

Since there is no information available regarding crop management, including proper planting arrangement and optimal planting density, of the imported shattering tolerant sesame genotypes, field experiments were carried out in research fields of Seed and Plant Improvement Institute, Karaj, and Khorasan Razavi Agricultural and Natural Resources Research Center, Mashhad, Iran, in 2019 and 2020. The effect of experimental factors including; 30, 45 and 60 cm inter row spacing, and 5, 8, 11 and 14 cm intra row spacing were evaluated as split blocks (strips) arrangements in randomized complete block design with three replications. The results showed that there was reduction in number of sub-branches in both locations due to reduction in inter row spacing and intra row spacing. On the other hand, the reduction in plant density m-2 increased the number of capsules plant-1 and seed number capsule-1. The highest seed yield (1342 and 604 kg ha-1 in Karaj and Mashhad, respectively) obtained from the 45 × 8 and 45 × 11 planting arrangement in Karaj and Mashhad, respectively. Generally, the results indicated that there is an optimal planting arrangement and planting density for each location. Therefore, due to increased competition between plants in high plant density and lack of proper utilization of resources in low plant density, it would not be possible to attain the highest yield potential of shattering tolerant sesame genotype in high and low plant density.

In order to evaluate the quantity and quality of safflower cultivars forage in three forage harvesting times based on plant phenological stages, the present study has been conducted in a randomized complete block design with split-plot in time arrangements with three replications at the Seed and Plant Improvement Institute (SPII), Karaj, Iran, during 2018-2019 and 2019-2020 cropping seasons. The main factor includes three safflower cultivars (Goldasht, Golmehr, and Parnian), with three forage harvesting time (namely stem elongation, branching, and flowering stages) considered as the sub-factor. The effect of year only on plant height and water-soluble carbohydrates (WSC) has been significant (P≤0.05). The results show that the interaction effect of cultivar × harvesting time on the fresh forage yield, plant height, WSC, and neutral detergent fiber (NDF) has been significant (P≤0.01). The highest fresh forage yield (52103 kg ha-1) is obtained by harvesting the Golmehr cultivar at the beginning of flowering; however, the highest dry matter yield is observed in Golmehr and Parnian cultivars. The highest dry matter yield has been observed in the branching stage (11900 kg ha-1), with the crude protein content in this stage being 14.57%. In contrast, the maximum crude protein content is observed in the flowering stage (19.22%), even though the mean dry matter yield at this stage has been 9937 kg ha-1. The maximum and minimum RFV (130.3% and 92.3%) are recorded in the forage of Goldasht and Golmehr cultivars, respectively. Therefore, among the studied cultivars, Parnian, and among the growth stages, forage harvesting at the branching stage is introduced as the superior treatment to achieve maximum yield and quality of safflower forage.

Investigation of environmental factors and stresses on the fatty acid composition of soybean oil and identification of water deficit tolerant cultivars is one of the strategies to improve the fatty acid composition of its oil.Effect of water deficit stress on quality characteristics and oil yield of 13 soybean genotypes were evaluated as a split plot based on randomized complete block design in three replicates in Karaj in two years.In this work irrigation was conducted at three levels including routine irrigation (control),mild and severe stress were based on 50, 100 and 150mm evaporation from ClassA evaporation pan, respectively,in main plots and soybean genotypes in sub-plots.The results showed that effect of year×irrigation×genotype on oil yield, oil content, oleic acid, linolenic acid and arachidic acid was significant.Oilyeild of soybean decreased under mild and severe stress, 27 and 38%, respectively.Saba and Williams×A3935 had the highest oilyield with an average of 422 and 427 kg/ha, respectively. palmitic acid in mild and severe stress compared to control irrigation decreased by2.6% and 1.2%.While stearic acid increased by9.5% and 10.8%in mild and severe stress conditions, respectively.In control irrigation, L425002 line with 0.22%, in mild stress conditions,Williams×Century and L425002 with 24.6% and 24.1%, and in severe stress conditions, Saba and L425002 genotypes with 24.1% and 24.5%, had the highest percentages of oleic acid and high oil content.In control irrigation, Saba cultivar,in mild stress conditions,Saba cultivar and Williams×A3935 and in severe stress conditions Williams×A3935 had the highest oil yield.L425002 and Williams×Century had the highest oil quality in all stress conditions.

Genetic diversity is key to breeding programs and increasing selection efficiency. In this study, 19 promising advanced lines (F7 generation) along with two cultivars, Dalgan and, RGS003 were evaluated in a randomized complete block design with three replications in three experimental field stations (Gorgan, Sari and, Zabol) during the 2020–2021 growing season. The highest phenotypic and genotypic coefficient of variations was found for number of lateral branches and number of pods per plant, respectively. The highest broad sense heritability was estimated for days to end of flowering, and days to start of flowering and the lowest broad sense heritability was estimated for the plant height. The genotypes G16, G18, G15, G1, G2, G5, and G20 with a higher SIIG values as well as a higher seed yield above average were introduced as superior genotypes with respect to yield and other agronomic traits. Therefore, these genotypes can be used for further testing, including adaptation tests. Also, the results of factor analysis and genetic correlation coefficients indicated a positive relationship between number of lateral branches, number of pods per plant and number of seeds per pod with seed yield and seed yield. Generally, it can be concluded that number of lateral branches, number of pods per plant and number of seeds per pod traits could be used as the appropriate criteria to select for increasing seed yield in rapeseed breeding programs.

Dry matter Partitioning in vegetative and reproductive organs and yield of 11 sunflower hybrids were evaluated in different irrigation program during 2013 and 2013 in Karaj, Iran. Three separate experiments including irrigation after 60, 120 and 180 mm evaporation from evaporation pan, Class A as base of randomized complete block design were sutdied as control, mild and severe stress conditions, respectively. The results showed the plant height was decreased by 10.1% under mild stress and 17.2% under severe stress compared to control. Although, increasing of the height had a positive effect on grain yield, but the stem weight was more effective than head weight on grain yield. In control irrigation, plants produced thicker stems that made to translocate more dry matter to the grain. But under severe stress conditions, the  head diameter decreased, and the most of the dry matters were used in the head development. The highest grain to head weight ratio was obtained from mild stress. In severe stress conditions, the grain to head weight ratio  went up and it caused to rise linear growth of grain number and weight. Grain yield was diminished on average of 18% and 33% under mild and severe stress conditions, respectively. In the stress conditions, Barzegar hybrid had the highest grain yield for maintaining the number and weight of grain in the heads. The evaluation of strees susceptibility and tolerant showed that STI, MP and GMP indices had a positive and significant correlation to yield and, Barzegar and Sunbro hybrids were superior thant Cultivars and hybrids.

Safflower (Carthamus tictorius) is one of the oldest domesticated plants in the world, which is mainly cultivated as an oil seed in arid and semi-arid regions of the world. Given the climatic conditions of the world where water scarcity is always limiting cultivation, the importance of drought tolerant plants such as safflower will be very high. The basis of genetic modification of cultivars is based on creating diversity and using genetic diversity. In this study, we will investigate the genetic diversity of genotypes collected from different parts of the world in order to identify superior genotypes and identify effective relationships between traits.

This study aimed to investigate 273 diverse safflower genotypes collected from different parts of the world during the crop season 2020-2021, in the form of augmented design with five controls of Goldasht, Sofeh, Parnian, Faraman and Golmehr, which are all introduced cultivars. Various traits such as seed yield, plant height, 1000-seed weight, oil percentage, number of sub-branches, flowering date, boll diameter, prickly and flower color were recorded.

The results showed the existence of high diversity in terms of all traits evaluated so that genotypes with more than 40% oil (genotypes 190, 226 and 227) and genotypes with more seed yield and earlier than the controls were observed. For example, code 187: with 100 days until flowering, code 167: with 105 days until flowering and code 37: with 106 days until flowering, were earlier than Goldasht with 113 days until flowering. The results of principal component analysis showed that the first three components were able to explain more than 50% of the changes. The first component explained 21%, the second component 18% and the third component 12%. The results of component correlation analysis showed that there is a significant relationship between many traits that can be used in the modification process. The most important of them are the relationship between flower color and oil percentage, as well as the relationship between 1000-seed weight and oil percentage.

In general, the results showed that the diversity of safflower genetic material can provide targeted breeding activities.

Studying the reaction of the different genotypes under different environmental conditions helps breeders to detect stable and high-yielding genotypes. In this regard, 11 new sunflower hybrids along with four cultivars (Golsa, Ghasem, Shams, and Farrokh) were evaluated in a randomized complete block design with four replications in four experimental field stations (Karaj, Sari, Kermanshah, and Dezful) during two cropping seasons. GGE biplot statistical method (genotype effect + genotype × environment interaction) was used to study the adaptation of genotypes in the studied environments. Results of combined analysis of variance indicated that the effects of environments, genotypes, and genotype × environment interaction were significant, suggesting that the genotypes responded differently in the studied environment conditions. Results of the GGE biplot method showed that the two first and second principal components of the GGE biplot explained 66.4% of the total seed yield variation. Based on the biplot polygon view, the hybrid RGK15×AGK1221 in Sari and Karaj locations and the hybrid RGK25×AGK330 and Shams cultivar in Dezful location were superior genotypes with the high specific adaptation. Besides, all environments had high discriminating ability so that could able to show differences between genotypes. Sari environment was the nearest environment to the ideal environment that had the highest discriminating ability and representativeness.

Despite the high potential of sesame production in the country, its yield and water use efficiency is low. Therefore, identifying genotypes with high grain yield, especially under drought stress conditions, is essential for developing this crop. For this purpose, field experiments were conducted to investigate the qualitative and quantitative response of 21 sesame genotypes to drought stress conditions at Seed and Plant Improvement Institute, Karaj, located in the semi-arid region of Iran, during the 2017 and 2018 growing seasons. The experiment was a split-plot based on a randomized complete block design with three replications. The irrigation treatments consisting of normal irrigation and drought stress were assigned to the main plots and the sesame genotypes (20 imported genotypes with one Iranian cultivar as a control) were allocated to the sub-plots. Dongeuy, Local 123, Hail 2 and Anthalya 1 genotypes were found as early maturing, Gynum 11, Kubarez 55, Uusu 1, Songhak, Hoechon 2, Dunae, Pachequero, Haibuk and Sunhua 1 genotypes as the medium maturing, Lao hong zhi ma, Bian gan, Bukbak, Margo, Amaliada, Jungkyung and Black chil sung genotypes as the late maturing and Oltan genotype as the very late maturing group. The Margo genotype showed the highest LAI (3.2), and Sunhua 1 genotype showed the lowest value (1.0). The results also revealed that drought stress decreased the number of capsules per plant, the number of seeds per capsule and 1000-seed weight by 35, 44 and 35%, respectively. On the other hand, drought stress caused a reduction in grain and dry matter yield in all genotypes. The Dongeuy genotype with 50% reduction and Songhak genotype with 26% reduction in grain yield showed the highest and lowest sufferings from drought stress, respectively. The Margo genotype produced the highest grain yield in both irrigation treatments (1531 and 1107 kg ha-1 under normal irrigation and drought stress treatments, respectively). In conclusion, the Songhak genotype was considered as one of the superior genotypes due to its shorter growing period, less grain yield loss under drought stress, and high oil yield.

Evaluating of sunflower genotypes under different environmental conditions would be useful to identify genotypes with high stability and yield potential. In order to study yield stability of sunflower genotypes, 11 new hybrids along with four cultivars (namely Golsa, Ghasem, Shams and Farrokh) were evaluated in a randomized complete block design with four replications under four experimental field stations across Iran including Karaj, Sari, Kermanshah and Dezful during 2018-2020. The results of combined analysis of variance indicated that the effects of environments, genotypes and genotype × environment interaction were significant for seed yield. Existence of genotype × environment interaction, suggested that genotypes responded differently to the studied environment conditions. Therefore, there is the possibility of stability analysis. Cluster analysis based on the nonparametric stability statistics grouped genotypes in to three main clusters. According to the mean rank of all studied nonparametric stability parameters, the genotypes No. 5 and 14 with the lowest value of mean rank were distinguished as stable genotypes, meanwhile genotypes No. 1, 11, 12 and 9 with the highest values of mean rank were identified as non-stable genotypes. Also, the results indicated that the nonparametric statistics Si, NPi and NPi were associated with mean seed yield and the dynamic concept of stability. Therefore, these methods would be suitable for selecting stable and high yielding genotypes in sunflower. Finally, the genotype No. 5 with mean seed yield of 3355 kg ha-1 and high broad stability was distinguished as superior hybrid which can be used in the future breeding programs for producing the new cultivar with high yield and stability potential.

The sunflower is one of the most important oilseed plants in the world and its oil has nutritional and high economic value. Identification and selection of high-yielding genotypes with desirable characteristics are especially important in this plant. Evaluating sunflower genotypes under different environmental conditions would be useful to identify genotypes with high stability and yield potential. Therefore, this study was conducted to the selection of the best sunflower hybrids.

In this study, 24 new sunflower hybrids along with Golsa cultivar were evaluated in a simple lattice design with two replications in four experimental field stations (Karaj, Boroujerd, Shahroud, and Gorgan) during the 2020 cropping season. GGE biplot statistical method (genotype effect + genotype × environment interaction) was used to study the stability of genotypes in the studied environments.

Results of combined analysis of variance indicated that the effects of environments, genotypes, and genotype × environment interaction were significant, suggesting that the genotypes responded differently in the studied environment conditions. So, there was the possibility of stability analysis. Results of stability analysis using the GGE biplot method indicated that the two first and second principal components of the GGE biplot explained 67.7% of the total seed yield variation. Based on the polygon view of biplot, the genotype G13 in shahroud environment, the genotype G6 in Karaj and boroujerd environments, and genotypes G5 and G19 in Gorgan environment were superior genotypes with the high specific adaptation. Based on the hypothetical ideal genotype biplot, the genotypes G6, G14, G3, and G4 were better than the other genotypes for seed yield and stability and had the high general adaptation to all environments. Also, the results showed that all environments had high discriminating ability so that could able to show differences between genotypes. The Boroujerd environment was the nearest environment to the ideal environment that had the highest discriminating ability and representativeness.

Consequently, the genotypes G6, G14, G3, and G4 were better than the other genotypes for seed yield and stability. Therefore, these genotypes can be used for further testing, including adaptation tests.

In this study, the genetic diversity of 122 safflower genotypes from the institute of plant genetics and crop plant research (IPK) and International Maize and Wheat Improvement Center (CIMMYT) were evaluated and their agronomic characteristics were compared with five Iranian Safflower cultivars. This experiment was conducted at research field of Seed and Plant Improvement Research Institute using a Augmented with randomized complete block design in Karaj during 2017-2018 year. The results indicated high genetic variation in the germplasm. Among safflower genotypes, 36 genotypes without thistle, 81 genotypes with thorns and 10 genotypes with few thistle were observed. Principal component analysis led to the identification of three main components that accounted for 56.5% of the total varition. The first and second components accounted for 29.5% and 15.9% of the total variation, respectively. The first and second components were named as a yield components and phenology and plant architecture, respectively. Safflower genotypes divided into four groups by principal components analysis (PCA). Genotypes in the first groups had the higher grain yield than others. Genotype No. 70 with the highest grain yield (5667 kg.ha-1) was placed in this group. Numerical values of yield components such as 1000-seed weight, number of heads and number of seeds per plant in the third group were higher than other groups. Generally, german genotype No. 70 with high yield and genotype No. 45 with early flowering can be used in safflower breeding programs.

The genotype × environment interaction is a major challenge in the study of quantitative traits because it reduces yield stability in different environments and also it complicates the interpretation of genetic experiments and is difficult to makes predictions. In this regard, to analysis of genotype × environment interaction and determine the yield stability of sunflower genotypes, 11 new sunflower hybrids along with 4 cultivars were evaluated in a randomized complete block design with four replications in four experimental field stations (Karaj, Sari, Kermanshah and Dezful) during two cropping seasons. In order to analysis of genotype × environment interaction was used the multivariate method of additive main effects and multiplicative interaction (AMMI). The results of combined analysis of variance indicated that 57.68, 7.60 and 16.93 percent of total variation were related to the environment, genotype and genotype × environment interaction effects, respectively. Also, the results showed that the first five principal components of AMMI were significant and described 97.64% of the variance of genotype × environment interaction. Based on biplot graph of mean seed yield and the first interaction principle, the genotypes G3 and G5 were identified as a high yield and stable genotypes. Also, the Dezful and Kermanshah environments due to their high interaction were recognized as the most ideal environments for distinguishing and separating sunflower genotypes. The cluster analysis of the studied environments was divided into two groups. According to the results of cluster analysis, Karaj, Sari, Kermanshah and Dezful locations were located in a group that indicates these locations had the high predictability and repeatability power.

Production of high yielding hybrid cultivars is the main objectives of breeding programs in sunflower. Therefore, the selection of high yielding hybrids is essential in this plant. In this regard, 24 new sunflower hybrids and Golsa cultivar were evaluated in a simple lattice design with two replications in the Gorgan Agricultural Research Station during 2020 cropping season. In this study, the selection index of ideal genotype (SIIG) and factor analysis was used to select new sunflower hybrids and finding interrelationships among them. Based on the SIIG index, the genotypes G5, G10, G2, G12, G3 and G19 with the highest SIIG values (0.747, 0.689, 0.660, 0.641, 0.640 and 0.572, respectively) were the best genotypes. On the other hand, G23, G15, G24, G25 and G18 genotypes with the least amount of SIIG value (0.233, 0.264, 0.277, 0.278 and 0.285, respectively) were the weakest genotypes for most studied traits. The genotypes of G5, G19, G2, G10, G3, G9 and G11 with high SIIG value and higher seed yield that total average were recognized as superior genotypes from the point of yield and other agronomic traits. Therefore, these genotypes can be used for further testing, including adaptation tests in warm wet areas. Also, the results of factor analysis indicated a positive relationship between stem diameters, head diameter and seed number per head with seed yield. Generally, it can be concluded that traits of stem diameter, head diameter and seed number per head could be used as suitable criteria in selecting for increased seed yield in sunflower breeding programs.

The effect of water deficit stress has been evaluated on oil quality and yield of 11 sunflower hybrids in Karaj during 2012 and 2013. Three separate experiments have been carried out as the base of randomized complete block design with three replications to apply water deficit stress treatments. Irrigation of control, mild, and severe stress treatments are performed on the base of 60, 120, and 180 mm evaporation from Class A evaporation pan, respectively. Results show that seed yield has decreased about 18% and 33% in mild and sever water deficit stresses, respectively. Yield and oil percentage are affected by hybrids and the interaction of year and stress. Barzegar hybrid, with an average of 2846 kg/ha, has had the highest grain yield. It is also in the top group with 43.65% oil. Yield and seed oil percentage are affected by environmental conditions of years, while water deficict stress has no significant effect on oleic and linoleic acids. However, there is a strong negative correlation between oleic and linoleic acids. Hysun 25 and Sirena cultivars are suitable for oil production with higher oleic acid and Barzegar and G6×R-43 are suitable for oil production with higher linoleic acid.

Nafis variety (line L72), suitable for cultivation in the cold and moderately cold regions of Iran, is the result of the selection and purification in segregating generations derived from the cross Orient×Modena. Selection of single plants was carried out during five consecutive years using pedigree method until accessing pure lines and then pure lines were screened in F6 generation. Pure lines along with Okapi as check cultivar were evaluated in the preliminary yield trial in experimental farm of Seed and Plant Improvement Institute in 2009. The result showed that mean seed yield of L72 with 3650 kgha-1 was 30.7% higher than Okapi. The study of adaptability of selected lines in Karaj, Hamedan, Zarghan and Kermanshah during 2012-2013 and 2013-2014 showed that line L72 with seed yield of 4137 kgha-1 had the highest grain yield among studies genotypes where its seed yield was 6.7% higher than Okapi and had a good yield stability based on environmental variance statistic. Results of complementary trials for line L72 in Karaj, Hamedan, Zarghan, Isfahan, Khoy and Kermanshah during 2014-2015 and 2015-2016 indicated that this line with grain yield of 4336 kgha-1 had higher yield compared to other genotypes. Field disease assessments indicated high tolerance of L72 to sclerotinia compared to check cultivar Okapi. Results of on-farm trials in farmers' field of Kermanshah province showed that line L72 had 13.7% higher grain yield compared to Ahmadi as check cultivar. Results of on-farm trials in farmers' field of Isfahan province under normal irrigation and irrigation cutting from pod setting stage showed that line L72 had 1.2 and 9.1% higher seed yield than Okapi as check cultivar, respectively. Therefore, due to desirable characteristics of line L72 such as higher seed yield and yield stability and relative tolerance to sclerotinia stem rot compared to Okapi as check cultivar, this line was released as Nafis and is recommended for cultivation in the cold and moderately cold regions of the country.

Determining the optimum planting pattern plays a critical role to achieve optimal yield in crops such as sesame. In this study effects of different planting patterns including one, two and three-row cultivation on quantitative and qualitative traits of six sesame cultivars including Halil, Dashtestan 2, Darab 1, Oltan, Yellow white and Naz takshakhe were evaluated using a factorial experiment based on a randomized complete block design with three replications in the research farm of Seed and Plant Improvement Institute. The results showed that the effect of planting pattern was significant for all traits measured except seed oil percentage. Also, the effect of cultivar for all traits was significant. The interaction between planting pattern and cultivar was significant (p≤ 0.01) only for branching number. The highest grain yield obtained from one and two-row planting patterns having 1000 and 1092 kgha-1 grain yields, respectively. In contrast, the lowest grain yield (481 kgha-1) was obtained from three-row planting pattern. Moreover, the maximum grain yield (957 kgha-1) and seed oil percentage (53.3 %), as the most important traits of sesame, obtained from Dashtestan 2 and Darab 1 cultivars, respectively. The results suggested that in selecting the best planting patterns, cultivars characteristics and planting density should be taken into account so that plants can efficiently use environmental factors, which reduce competition among plants in order to reach to the maximum economic yield.