فهرست مطالب سعدالله منصوری

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.

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.

Sesame is an important crop plant for harsh environmental conditions because it is relatively resistance to drought stress. Evaluation of different genotypes in different climate condition plays a fundamental role in selection of the best genotypes before the commercial release of a variety and helping in identify plant traits that should be monitored during breeding experiments. In the present study, 10 promising lines obtained from the preliminary yield test were investigated to evaluate the yield compatibility along with 6 local cultivars in a randomized complete block design experiment with three replications in two cropping years (2018 and 2019) in Dashtestan climate condition in Bushehr province. During the growing season, phenology traits, grain yield components and grain yield were measured. Based on the results of ANOVA, statistically significant difference was observed between different genotypes for plant height, height of the first sub branch, height of the first capsule, number of sub branches, number of capsules per plant, length of capsule, length of capsule bearing zone, number of seeds in capsule and grain yield. Based on the mean comparison and biplot analysis the genotype 12 (Local Dashtestan), 2 (SES97-103), 7 (SES97-110) and 15 (Local Jiroft), were identified as superior genotypes for grain yield. Genotype 5 (SES97-105) and genotypes 14 (SES97-124) with 104.5 days and 4 (Local Darab1) with 111 showed the highest and lowest number of days to maturity, respectively. First capsule height showed the highest positive and significant phenotype (0.56) and genetic (0.78) correlation with grain yield. Days to the end of flowering and days to physiological maturity traits showed a negative genetic correlation with yield. Cluster analysis separated 16 sesame genotypes into four separate groups. Based on regression analysis, the height of the first capsule was identified as the most sensitive trait in predicting the yield of sesame genotypes in Dashtestan region in Bushehr province, which seems it can be considered during breeding programs.

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.

Charcoal rot disease caused by Macrophomina phaseolina is the most destructive disease of sesame (Sesamum indicum) in Iran and other countries as well. The fungus has been more important in recent years because of climate change and global warming. In this research, 81 genotypes of sesame were sown in a hot spot farm at Behbahan Agricultural Research station in south of Khuzestan province as a simple lattice design during three successive years. Damping off was observed at all growth stages. None of the genotypes were immune of the disease. M. phaseolina was the dominant pathogen of sesame in soil of the disease plot. Damping-off was observed during all growth stages. None of the genotypes were immune to the disease. The corrected data were subjected to simple and compound analyses. The results indicated that Tarom landrace and Darab2 line had the highest level of resistance. 22 genotypes were determined as moderately resistant genotypes among which Potak-e- musian landrace had the lowest 3-years average of infection percent. The rest were recongnized as moderately susceptible, susceptible and highly susceptible genotypes.

Analysis of genotype by environment interaction using different statistical methods is very important in plant breeding. In order to evaluate the seed yield stability of promising sesame lines using different parametric and non-parametric statistics, an experiment was conducted using 13 promising sesame lines with check variety Oltan at three locations of Karaj, Mashhad, and Moghan (Iran) in a randomized complete block design with four replications over two years (2016 and 2017). Combined analysis of variance for seed yield of promising sesame lines showed that the effect of genotype and the three-way interaction of genotype × year × location at the level of 0.01% probability were statistically significant. Karaj-96 environment with 1346 kg/ha and Mashhad-96 environment with 1001 kg/ha had the highest and lowest mean yield, respectively. The highest and lowest mean seed yield among genotypes in all test environments were related to G6 line with 1444 kg/ha and G12 line with 762 kg/ha, respectively. Heatmap along with cluster analysis divided both genotypes and stability parameters into three groups. Based on cluster analysis, genotype G12 was clustered into the first group, genotypes G1, G3, G7, G8, and G13 were clustered into the second group and the rest of the genotypes along with the check cultivar Oltan were clustered into the third group. The genotypes of the second group with the highest rank in most criteria of stability stasistics were stable compared to other genotypes and among them, the genotypes G8, G1 and G3 (with mean yields 1417, 1398 and 1291 Kg/ha, repectively) were selected and recommended in the test locations due to their average yield above the average yield of all genotypes.

Comparative identification of relations among yield components under stress and normal situation can provide novel breeding strategies to plant breeders. Sesame is an oil crop with high quantity and quality of edible oil, suitable for human food. In this study, effects of limiting in avalibility of water to 15 sesame genotypes from germplasm collection of Oil Seed Crop Res. Dep on yields components was investigated. Regression analysis of seed yield on various phonologic and yield components revealed significant effects of fertile axillary branch and number of seed per capsule under normal condition and merely fertile axillary branch under water limiting situation. Comparative factor analysis between normal and water limiting conditions revealed shifting in the priority of photosynthate allocating to various organs and sinks upon water limitation. Nevertheless, axillary branches constitute the first and primary target for allocating assimilates under both normal and water limiting conditions. Under water limiting condition, plant focuses itchr('39')s most strong and primary control system on number of axillary branches, followed by two successive less important and less strong control systems, which affect on seed weight, a parameter that determines plant maintenance in the nature and guarantee survival of the next generations. Focusing on the biologic behavior and relations among the behaviorchr('39')s components on one hand, and shifting from biometrical point of view to biometrical-physiological concepts will increase efficiency of stress breeding programs.

Identification of genotypes adapted to a particular region is of special interest to breeders and plant geneticists. In order to identify adapted genotypes in sesame lines based on multi-trait selection, an experiment was conducted in a completely randomized block design with four replications at Moghan Agricultural Research Station of Ardabil Agricultural and Natural Resources Research and Education Center during the years 2017 and 2018. The genetic materials evaluated in this study were consisted of 14 superior lines from preliminary yield trails of the three different regions evaluated in 2016 (Derived from the management of segregated generations in a pedigree way) and Oltan cultivar as a check. Combined analysis of variance showed that the genotype and genotype × year interaction effects were significant for all of the studied traits. Biplot analysis of sesame genotypes showed that the first two components explained the 55.3% of the total variations of traits. Which-won-where/what polygon pattern based on different traits of sesame genotypes showed that G3 and G8 had the highest yield and yield components such as plant height, number of capsules per plant and oil content, respectively. Based on comparing of genotypes with ideal genotypes biplot, Shukla stability index, superiority index and heat map analysis, genotypes G3, G8 and G9 were better than Oltan cultivar, thus identified as the best genotypes. These genotypes have the potential to be used in research-extension trials for introduction as a new cultivar for cultivation in Moghan region.

The fungi, Macrophomina  phaseolina  and Fusarium oxysporum are the main causal agents of sesame wilt making a great loss in Iran and worldwide. In this research, 25 cultivars and genotypes of sesame including 14 yield comparison test lines, four improved lines and six commercial cultivars (Dashtestan2, Darab1, Halil, Naz-uniculm and Naz branched grew in 3 replicates in randomized complete blocks in a hotspot field in 400-ha farm of Seed and Plant Improvement Institute (SPII) in Karaj. Each genotype was cultivated in two meters length. Disease scores were recorded at the maturity stage. The results showed that all genotypes were affected by disease to some extent among which Dashtestan 2 had the highest mean of disease score. The lines 92-10 and 90-10 with the lowest record of wilting (less than 20%) were grouped as resistant lines. Correlation analysis between five important agronomic traits related to yield with wilt disease data showed that damping-off data has a significant correlation with the number of seeds per capsule. Although a significant correlation was observed between wilting with capsule length, the coefficient was low. There was a non-significant correlation between wilt disease and 1000 seed weight, SPAD no. and capsule weight without seeds.

In order to evaluate the yield, agronomic characteristics and response of sesame promising lines to wilting disease using multivariate methods, an experiment was conducted in a randomized complete block design with three replications in 2019. The genetic plant materials evaluated in this study included the superior 20 selected lines along with Oltan as the control cultivar. During the growing season, different traits such as germination percentage, days to flowering, days to maturity, plant height, branching height, first capsule height, number of capsules per plant, capsule length, stem diameter, number of seeds per capsule, number of branches, leaf chlorophyll content, 1000-seed weight and seed yield per hectare were measured. The response of genotypes to fusarium wilt disease was also scored. The results showed that line 20 with 1604 kg/ha had the highest seed yield among the compared genotypes. Evaluation of lines showed that lines 1, 4, 19 and 20 were the most tolerant genotypes to fusarium wilt disease. The most positive and significant correlation was observed between seed yield and number of capsules per plant, leaf chlorophyll content, number of seeds per capsule, plant height, 1000-seed weight, capsule length and germination percentage, but with the number of days to flowering, days to maturity and first capsule height, it was negatively significant. The results of stepwise regression and path analysis of seed yield as a dependent variable and other agronomic traits as independent variables showed that the three traits including number of capsules per plant, number of seed per capsule and stem diameter had the most positive and significant direct effect on yield, respectively. The most indirect effect on seed yield was by the number of seeds per capsule through the number of capsules per plant. Cluster analysis grouped the genotypes into three distinct groups. The first group, including lines 1, 4, 13 and 20, were among the desirable genotypes in most agronomic traits and were well-distinguished from other genotypes by cluster analysis. In general, the results of this study showed that lines 20, 4 and 1 with the highest seed yield per hectare and superior in terms of important agronomic characteristics and tolerant to plant wilting disease, compared to the control cultivar Oltan, were recommended as promising lines in Moghan region.

Fourteen sesame lines that have preferred in primary evaluation, with local mass of Birjand (as test) and Ooltan cultivar (as overall test) were compared for two years in completely block design with 4 replication. Traits measured in this study were germination percent, number of flower per axis, number of sub branch, capsule length, plant height, number of capsules per plant, height of first capsule, height of branching, flowering branch height, flowering capsule height/plant, growth period, 1000 grain weight, total grain yield. 1000 grain weight was positively and significantly correlated with plant height (r=0.697, P

Fusarium vascular wilt of sesame is one of the destructive soilborn diseases of this crop in Iran and worldwide. Infected tissues of sesame were collected from the experimental field of Seed and Plant Improvement Institute in Karaj, then pieces of stem and roots were excised and cultured on the media. Fusarium oxysporum f.sp. sesame (Fos) was recovered frequently from the tissues up to 81% of the isolated fungi, while F. solani was isolated in some few cases. Pathogenicity of the isolates was evaluated on the SNA Petri plates in the lab condition. The disease resistance assessment carried out using two different methods. For the laboratory method, the SNA plates were used for 12 cultivars and lines. The line Jiroft-13 had the highest level of disease resistance in this test. In the second method of inoculation, roots of the seedlings of 26 cultivars and lines were dipped into the spore suspension for 5 minutes and then planted in pots in greenhouse. Disease severity was recorded after 15 days using a 1-5 scale. Observations of each genotype was statistically analyzed using non-parametric Chi-square test. None of the genotypes were immune to the disease. Among the less infected genotypes, Moghan 19, Shahed-e- Gijuye, Mahali Moghan Shahed, Hindi-11, Moghan 13, Mahalli Moghan and B5γM7 showed considerably low infection, so regarded as moderately resistant cultivars.

In this study, half diallel cross method with Grifing method II and model mixed B was used to evaluate genetic parameters for physiological and morphological traits in seven lines of sesame and their 21 F2 populations under normal irrigation and water limited (water withholding before flowering) conditions. Mean of evaluated GCA/SCA under normal irrigation indicated that days to flowering, days to end of flowering, flowering duration, days to maturity, number of capsule per main stem, 1000-seed weight, main stem yield, capsule length, internode lengh, number of infertile nodes, number of capsule bearing nodes, and total number of nodes were mostly controlled by additive gene effects, some by non-additive gene effects and in some cases by a balance between the two genes mode of actions. Heritability in the broad sence varied from 58.4% for internode length to 97.7% for number of capsule per plant. Narrow sense heritability was high for number of capsule per plant (82.5%) and days to maturity (80.5%), indicated high selection efficiency for these traits under water limited condition. All the evaluated traits were governed by additive effects which indicated a shift in genetic control of the traits compared to normal irrigated condition. Broad sense heritability appeared to be unchanged but evaluation of narrow sense heritability was lower in water limited condition compared to normal irrigated, which may indicate reduction in breeding progress rate.

One of the important problems of sesame cultivation is the usage of local varieties and new cultivars shortage. Tolerant to wilt disease and grain shattering, adaptability to warm and arid climate and high yield are the most important purposes of sesame breeding. Accordingly, the breeding program to select and release of the Halil cultivar, began by selection of single plants from sesame native populations from south of Kerman province. In 1999, the selective single plants were evaluated based on breeding purposes and among them 54 single plant (lines) were selected. The selected lines were evaluated and purified during 2000 and 2001 years. The results showed that 21 lines had significant difference with controls (Darab14 and local variety), which these lines were selected for final yield trials. The final yield trials conducted during 2002 and 2003 and the results revealed that JL16, JL2, JL13 and JL1 lines were superior than control (Darab14) by producing 1771, 1729, 1534 and 1466 kg/ha, respectively. Then, in comparison of different genotype yield in drought and non- drought stress in Jiroft, Dezful and Karaj regions during two years, the JL13 line had significant difference in non- drought stress condition compared to other studied genotypes such as Darab14. In assessing the relative resistance of sesame genotypes to Fusarium wilt disease in terms of micro-plots with artificially infected and naturally infected farm, the JL13 line was identified as tolerant genotypes. Finally, JL13 line as the top line was selected for the on-farm trial. JL13 line in the on-farm trial by 1520 kg/ha yield, showed a 24% increase in yield, compared to the local variety. The JL13 line released and approved under the name of "Halil" in 2014. Halil variety recommended for warm and dry regions of south of the country, Iran.