Search

Introduction: Sesame is one of the oldest crops and probably the oldest oilseed in the world. In most regions, the landrace and local masses of sesame are used. To increase production and yield, the production of modified cultivars for different agricultural climates is extremely important. Material and Methods: Seven genotypes included Isfahan, Sirjan, Fars, Oltan, Jiroft, Sabzevar, TS-3 and 21 hybrids that were obtained from them were studied in the research farm of the Faculty of Agriculture of the University of Birjand under the drought stress conditions during 2015-2018. The experiment was conducted in a randomized complete block design with three replications as a 7 × 7 one-way diallel. In this study, several traits were measured. These traits were including plant height, height to the first fruiting capsule, number of capsules per plant, number of sub-branches, number of leaves, leaf length, number of seeds per capsule, capsule length, capsule weight, capsule width, days to 50% and 90% flowering, days to physiological maturity, thousand seed weight, oil percentage, protein percentage, amount of chlorophyll a, chlorophyll b, total chlorophyll, biological yield, economic yield and harvest index. Results: The investigation of the adequacy of the additive-dominance model showed that the model was sufficient in the traits including plant height, capsule length, capsule weight, number of leaves, number of sub-branches, number of capsules per plant, economic yield, biological yield, days to 50 flowering, days to 90% flowering and days to physiological maturity, and therefore diallel analysis was done on these traits. Hayman's variance analysis showed that were significant component a (additive effects of genes) in all traits and component b (dominant effects of genes) in all traits except plant height. Also, were significant the component b1 (mean dominance effects) in most traits except plant height, number of auxiliary branches, number of capsules and seed yield, the component b2 (other dominance deviation due to the parents) in most traits except plant height, number of auxiliary branches and number of capsules, and the component b3 (residual dominance variation) in all traits except plant height. The investigation of genetic parameters showed significant additive genetic component (D) and dominanant genetic components (H1 and H2) in most traits. Also were significant the component F (average covariance of additive and dominance effects) and the component h2 (the overall dominance effect of heterozygous loci) in half of the traits. The average degree of dominance (√ (H1/D)) in different traits was observed as additive, incomplete, and over dominance. In all characteristics, except capsule weight, the ratio of genes with positive and negative effects (H2/(4H1)) was not equal to 0.25; therefore, in all traits, increasing and decreasing genes did not have symmetrical distribution among parents. The ratio of dominant and recessive genes in parents ((√(4DH1)+F)/(√(4DH1)-F)) was more than unity in most of the traits, so there was an uneven distribution of dominant and recessive genes in most of the traits. The number of dominant gene groups (h2/H2) was obtained from 0 to 2.04; therefore, all traits were controlled by one or two gene blocks. Broad sense (hb 2) and narrow sense (hn 2) heritability were high in all traits. Conclusion: In the traits studied, the type of action of genes controlling the traits, the ratio of dominant and recessive genes, the ratio of genes with increasing and decreasing effects, additive effects and dominance were variable and were different in most of the traits. Generally, most traits were controlled by genes with additive and dominant effects. The high heritability estimate indicates the promising news of the studied genetic materials in future studies. Therefore, among these materials, better genotypes can be selected for the climatic conditions of Birjand, so that it can be further investigated in the future. [ABSTRACT FROM AUTHOR]

Introduction Considering the lack of food in the world, increasing the production of rice is one of the demands of the global market and one of the important goals of many countries producing this crop plant. The final performance of each organism is affected by the genotypic potential, the environmental effects and the interaction between genotype and environment. The interaction of genotype and environment causes that different genotypes do not have the same reaction under different environmental conditions. Genotypes that can produce higher yields in different regions or under different environmental conditions and maintain their performance stability are considered as successful genotypes. In this study, nine promising rice lines originating from the Hashemi variety, along with two varieties Hashemi and Gilaneh, were evaluated for grain yield in two regions during two years. The objective of this study was to evaluate the stability of the studied lines and introduce the most stable ones in order to introduce the new varieties. Materials and methods The plant materials of this experiment were nine promising rice lines originating from the Hashemi variety, as a Iranian local variety with good quality, along with two varieties Hashemi and Gilaneh as control varieties. The experiment was conducted in a randomized complete block design with four replications in two regions, Rice Research Institute of Iran (Guilan province, Iran) and Chaparsar Research Station (Mazandaran province, Iran), in two years, 2017 and 2018. The studied traits included grain yield, days to 50% flowering, head rice percentage, milling efficiency, grain length, amylose content and gelatinization temperature. For data statistical analysis, simple analysis of variance was firstly performed for grain yield, and then Bartlett's test was done to check the uniformity of the experimental errors. Combined analysis of variance and comparison of means by Duncan's method was performed with SAS software. To evaluate the stability of the studied lines, Lin and Binns and GGE-biplot methods were used. Research findings The results of combined analysis of variance showed that the effects of genotype and year as well as the interaction of year×place and year×place×genotype on grain yield were significant. Therefore, grain yied stability of the studied genotypes was evaluated using Lin and Binns and GGE-biplot methods. The results of Lin and Binns method indicated that two genotypes Gilaneh and 19603 (Hashemi/IR74720-85-1-2-1), with the lowest intra-location variance, were the most stable genotypes in this experiment. The results of GGE-biplot graphical method also showed that the genotypes 19607, Hashemi and Gilaneh, which formed the vertices of the polygon in the grain yield biplot, were the best or the weakest genotypes in some environments or in all environments. Also, the simultaneous evaluation of stability and grain yield of the studied genotypes identified the promising line 19603 as the best genotype. The graph of ideal genotype also showed that the promising line 19603 had the smallest distance from the hypothetical ideal genotype compared to other genotypes, so it was the best genotype of this experiment. Conclusion The results of stability analysis of rice genotypes using Lin and Binns and GGE-biplot methods introduced genotype 19603 as the most stable genotype of this experiment. This promising line along with the promising line 19607 produced the highest average paddy yield in all studied environments. These genotypes with the number of days to 50% flowering less than 95 days, grain length more than seven mm, and medium amylose content and gelatinization temperature, were considered as genotypes with mid-maturing, long-grain (Sadri) and good cooking quality. Therefore, two promising lines 19603 and 19607 are suggested for cultivar introduction programs. [ABSTRACT FROM AUTHOR]

Introduction Traditionally the classical estimators of unknown parameters of the linear regression model are based exclusively on the sample information, like the maximum likelihood method. Sometimes, in practice the researcher has some prior information about the unknown intercept parameter as a guess that is called non-sample prior information. In this case, the shrinkage and shrinkage preliminary test estimators are introduced by a linear combination of sample and non-sample prior information. Now, if the non-sample prior information is available according to the experimenter's experiences or the results of previous experiments, it can be expressed in the form of a preliminary hypothesis test and the desired parameter can be estimated using the shrinkage pretest estimator. The results show that the closer the guessed value to the real parameter, the better shrinkage pretest estimator performs compared to the maximum likelihood estimator. In the past years, in the regression estimation problem, the behavior of the shrinkage and shrinkage pretest estimators under the squared error loss (SEL) and LINEX loss functions was investigated. The squared error loss (SEL) function is popularly used for estimating the unknown parameter in decision theory because of its mathematical and interpretational convenience. Due to the symmetric nature, the use of SEL function may not be appropriate, when positive and negative errors have different consequences. The SEL and LINEX loss functions are symmetric and asymmetric loss functions, respectively, but both are unbounded. Also, The SEL and LINEX loss functions have an infinite maximum value which isn’t always appropriate. Sometimes in practice it is necessary to use bounded loss functions to estimate parameters. So we used the reflected normal loss function to estimate parameters, which is the bounded loss function. Material and methods In this article, the shrinkage and shrinkage pretest estimators are introduced for the intercept parameter of the simple linear regression according to the non-sample prior information and their risk functions and relative efficiencies are derived under the reflected normal loss function. The behavior of shrinkage pretest estimator is compared with respect to the shrinkage and maximum likelihood estimator using graphical method. The intervals where the shrinkage pretest estimator has less risk compared to the maximum likelihood estimator are presented. The optimum value of the significant level of test is determined using the max-min method. Besides, several methods of finding shrinkage coefficient of the shrinkage pretest estimators are proposed. Then, the application of the proposed estimators is shown using a real data set. Results and discussion In comparison between the desired estimators, our findings show that the shrinkage and shrinkage pretest estimator are better than the maximum likelihood estimator when non-sample prior information is close to the real value. Also, the shrinkage pretest estimator with smaller level of significance has higher efficiency. An important issue for the shrinkage pretest estimator is the proper selection of the shrinkage coefficient. So, we applied several methods for finding the shrinkage coefficient to obtain shrinkage pretest estimator. Conclusion According to the reported results, the shrinkage pretest estimator has smaller risk than the maximum likelihood estimator in neighborhood of null hypothesis. Therefore, in practice, if the researcher can have prior information of the unknown intercept parameter from previous knowledge or experience that is not far from the real value, the shrinkage pretest estimator would be the best choice as intercept estimator. The effective intervals where the shrinkage pretest estimator has less risk compared to the maximum likelihood estimator was presented. By increasing the significant level of the test and the sample size, the length of the effective interval decreases. The optimal value of the significant level of the test was obtained using the max-min method. Then, the application of the proposed estimators is shown using a real data set. [ABSTRACT FROM AUTHOR]

Background and Objectives: Determining the minimum number of samples and parameters required for acceptable results is crucial in rangeland vegetation studies. The common methods for determining Article history: sampling intensity are graphical methods and statistical characteristics. This RReecveisievde:d:101.00.40.32.2020222 study aims to compare these two methods in desert ecosystems dominated Accepted: 16.04.2022 by Salsola richteri and Ammotamnus lehmannii in South Khorasan. Methodology: An area of 100 hectares was randomly sampled using 10 Keyods: initial plots of 1010 meters. The number of sampling units was determined Sampling intensity, species accumulation curve, Cochran's sample size formula, coefficient of variation. using conventional graphical methods and the species accumulation curve (SAC). Statistical methods including the first and second Cochran's sample size formula, Yamane's sample size formula, confidence interval, and coefficient of variation (CV) were also used. All statistical calculations were performed in the biotools package in R software environment. Results: The appropriate number of sampling units determined using the SAC and conventional graphical method were 40 and 50, respectively. The first and second Cochran's sample size formula with an acceptable error rate of 10% required 78 to 92 plots, respectively. The range method suggested 53 to 160 plots, with an optimal number of 75. The CV method indicated that 10 plots had the lowest CV and were the most appropriate number of plots in the study area. The optimal sampling design was determined to be 75 plots, providing maximal information with minimal effort. Conclusion: The SAC method is suggested for determining sampling intensity in the desert ecosystems in this region due to its lower cost. The study revealed no significant relationship between the CV and the number of initial plots, and it is suggested not to use graphical methods or the CV method if the number of initial plots is less than 40. [ABSTRACT FROM AUTHOR]

Introduction: The sustainability of agricultural systems plays a key role in adapting to climate change. There is ample evidence that biodiversity can increase the stability of ecosystem processes by changing environmental conditions. Therefore, the effectiveness of breeding programs requires a correct understanding of the reaction of breeding cultivars to environments with different climatic and soil conditions. Therefore, this study was conducted to assess the response of some new maize hybrids to divergent environmental conditions and determine their grain yield stability. Material and methods: This study was conducted with 16 maize hybrids using a randomized complete block design with three replications in six locations, during the 2017 cropping season. Considering significant differences for hybrid × environment (GxE) interaction, stability analyses were performed using AMMI and GGE-biplot methods to determine stable and high-yielding hybrids. Results and discussion: The results of the AMMI model showed that only the first two principal components of AMMI (AMMI1and AMMI2) were significant and described 68.53% of the variance of G×E interaction. Based on the results of statistics of the AMMI model (ASV and SPCA1), hybrids No. 16 (SC704) and 1 (KLM77002/3-1-1-1-1-1-1-3 × K18) were recognized as the most stable hybrids. Stability analysis by GGE biplot procedure explained 71.5% of grain yield variation due to two components of GGE. In addition, hybrids No. 16 and 1 were identified as superior and stable hybrids by the GGE biplot graphical method. Conclusion: Generally, results of grain yield and stability analyses showed that hybrids No. 16 and 1 with 12.76 and 11.72 t/ha yields, respectively, were better than other hybrids across environments for yield and stability with wide adaptation and thus can be cultivated in Iran. Also, biplot analysis of correlation among environments revealed that Kermanshah, Esfahan, and Shiraz, as well as and Moghan and Miyandoab were closer and similar in ranking, grouping, and assessing stability. Also, Kerman and Karaj regions were less similar to other regions in terms of hybrids discrimination. Considering the high discriminate power of hybrids in Shiraz, Miyandoab, Kerman, and Karaj environments, and in order to decrease the costs, it is recommended to conduct future trials in the aforementioned environments. [ABSTRACT FROM AUTHOR]

Introduction: The sustainability of agricultural systems plays a key role in adapting to climate change. There is ample evidence that biodiversity can increase the stability of ecosystem processes by changing environmental conditions. Therefore, the effectiveness of breeding programs requires a correct understanding of the reaction of breeding cultivars to environments with different climatic and soil conditions. Therefore, this study was conducted to assess the response of some new maize hybrids to divergent environmental conditions and determine their grain yield stability. Material and methods: This study was conducted with 16 maize hybrids using a randomized complete block design with three replicates in six locations, during the 2017 cropping season. Considering significant differences in hybrid x environment (GxE) interaction, stability analyses were performed using AMMI and GGE-biplot methods to determine stable and high-yielding hybrids. Results and discussion: The results of the AMMI model showed that only the first two principal components of AMMI (AMMI1and AMMI2) were significant and described 68.53% of the variance of GxE interaction. Based on the results of statistics of the AMMI model (ASV and SPCA1), hybrids No. 16 (SC704) and 1 (KLM77002/3-1-1-1-1-1-1-3 x K18) were recognized as the most stable hybrids. Stability analysis by GGE biplot procedure explained 71.5% of grain yield variation due to two components of GGE. In addition, hybrids No. 16 and 1 were identified as superior and stable hybrids by the GGE biplot graphical method. Conclusion: Generally, results of grain yield and stability analyses showed that hybrids No. 16 and 1 with 12.76 and 11.72 t/ha yields, respectively, were better than other hybrids across environments for yield and stability with wide adaptation and thus can be cultivated in Iran. Also, biplot analysis of correlation among environments revealed that Kermanshah, Esfahan, and Shiraz, as well as and Moghan and Miyandoab were closer and similar in ranking, grouping, and assessing stability. Also, Kerman and Karaj regions were less similar to other regions in terms of hybrids discrimination. Considering the high discriminate power of hybrids in Shiraz, Miyandoab, Kerman, and Karaj environments, and in order to decrease the costs, it is recommended to conduct future trials in the aforementioned environments. [ABSTRACT FROM AUTHOR]

Introduction Sesame is one of the most important oil plants in the world, especially in arid and semi-arid regions and is known as the queen of oil seeds. The high percentage of oil with the combination of suitable fatty acids, medicinal properties and very low water requirement are the characteristics of this oil plant. The main challenge for the lack of development of sesame cultivation all over the world is seed shattering at the time of ripening. Many efforts have been made to obtain non-shattering sesame cultivars with the characteristics of indehiscent capsule at the ripening stage and resistance to seed loss. In this article, we introduce and evaluate the agronomic characteristics of new indehiscent sesame cultivars named Barkat, Mohajer, Chamran and Dezful. Material and Methods Indehiscent sesame cultivars with the proposed names of Barkat, Mohajer, Chamran and Dezful have been improved during a breeding program at Shahid Chamran University of Ahvaz in collaboration with Shahid Rajaei Agriculture Company. For registration and commercialization, these cultivars were subjected to Distinctness, Uniformity and Stability (DUS) tests and agricultural Value of Cultivation and Use (VCU) experiments under the supervision of the Seed & Plant Certification and Registration Research Institute during the two cropping years 2022- 2023. In these experiments, new indehiscent sesame cultivars along with commercial cultivars of dehiscent sesame named Oltan, Sardar and Shevin as control cultivars were evaluated in four regions with different climatic conditions of Iran, including Dezful, Darab, Mughan and Gorgan in the frame of complete blocks design with four replications. In addition, the mechanized cultivation of four promising indehiscent sesame cultivars was performed separately in 100- hectare fields in the Dezful region, and harvesting was done with a combine harvester.Results and Discussion The highest plant height was obtained in Barkat with an average of 144 cm and the lowest in Chamran with 140 cm. The highest number of capsules per plant, with an average of 89.8 and the highest number of seeds per capsule, with an average of 72.3, was observed in the Mohajer. The thousand-seed weight was reported between 2.41 and 3.72 g in Dezful and Mohajer respectively. A significant difference (P≤0.01) was observed in the group comparison between indehiscent and dehiscent (control) sesame cultivars, whilst dehiscent cultivars with an average of 1.05 tons per hectare were completely superior to the control cultivars with 0.80 tons per hectare. The highest average seed yield of cultivars in different regions during two years of experiment was obtained with 1.08 tons per hectare in Barkat and Mohajer cultivars. In the mechanized harvesting of indehiscent sesame cultivars with a combine harvester, the amount of seed loss was estimated to be less than 2.8%. The evaluation of morphological traits showed that indehiscent sesame cultivars had indeterminate growth habits and could produce 1-6 sub-branches per plant depending on the genotype and plant density. The superiority of seed yield for all indehiscent sesame cultivars was observed in compare with the control cultivars. The indehiscent sesame cultivars had appropriate agronomic features and could increasing about 24% seed yield in compare to control cultivars. This issue promises a significant increase in sesame production in Iran. Conclusion Finally, Barkat, Mohajer, Chamran and Dezful sesame cultivars were introduced as the first cultivars with resistance to seed shattering during ripening in the country. In addition to the higher seed yield in compare to the control cultivars. These cultivars are able to be harvested using a combine harvester in the mechanized systems at the time of full ripening. Ultimately, the widespread use of these cultivars in the agricultural cultivation pattern of the country promises food security in oil production and water consumption reduction in the stressful season of summer. [ABSTRACT FROM AUTHOR]

Objective: This experiment was conducted to investigate the effects of drought stress and foliar application of Fe and Zn on agronomical characteristics of sunflower. Methods: a farm experiment was carried out in the Fars agricultural research center in the split plots form base on a randomized complete block design with three replications during 2014. Irrigation at three levels (irrigation after 60, 120, and 180 mm of evaporation from A class evaporation pan) as the main plots and foliar application at four levels (water, iron sulfate, zinc sulfate, and iron sulfate+ zinc sulfate) were used as sub-plots. Results: The results showed that the delay in irrigation from 60 to 180 mm of evaporation caused a decrease in the number of seeds per head, grain yield and biological yield by 24.8%, 37.5% and 30%, respectively. The foliar application of iron sulfate+ zinc sulfate compared to the control treatment increased the number of seeds per head, 1000-seed weight and grain yield by 24.1%, 16.6 percent and 14.3 percent, respectively. The delay in irrigation, increased the water use efficiency by 50.9%. The interaction between irrigation and foliar application had a significant effect on leaf and grain iron concentration and leaf zinc concentration, so that with delay in irrigation, absorption of nutrients decreased, but foliar application under drought stress conditions increased iron and zinc absorption in sunflower. Conclusion: According to these results, it can be stated that with micronutrient foliar spraying, the severe drop in sunflower yield can be prevented under drought stress conditions. [ABSTRACT FROM AUTHOR]

Background and objectives: The wild species of safflower have different degrees of non-deep physiological dormancy, which affects the seeds germinability under different environmental conditions. Afterripening (dry storage) of seeds with non-deep physiological dormancy can increase their germination by releasing of seed dormancy. Also, it has been found that according to the afterripening period, the germination response of some species changes to temperature and water potential. Wild species of plants are of great importance due to their use as genetic resources in breeding programs. On the other hand, knowing the characteristics and needs of their germination under different environmental conditions leads to facilitating the reproduction and preservation of these valuable genetic resources. Therefore, the present study was conducted to investigate the germination response of safflower wild species to temperature and water potential during different afterripening period. Materials and methods: In this study, the seeds of two wild species, C. oxycanthus and C. glaucus, were Afterripened for 0, 2, 4, 6, and 12 months at 25°C. After each afterripening period, the percentage and rate of seed germination at temperatures of 5, 10, 15, 20, 25, 30 and 35 ℃ were checked and the cardinal temperatures of germination were calculated. Also, the response of germination to different water potential levels including zero, -0.2, -0.4, -0.6 and -0.8 MPa was investigated. Results: The results showed that afterripening the seeds for 2-6 months increased the germination percentage of the seeds compared to the control, while the germination percentage decreased in the treatment of 12 months afterripening. In addition, the seeds of C. oxycanthus and C. glaucus species were sensitive to light and gibberellic acid application, and in the presence of these treatments, the germination percentage increased. These findings showed that both species have different degrees of non-deep physiological dormancy. However, the species C. glaucus had higher dormancy. Also, different afterripening periods led to an increase in basic, optimum and germination ceiling temperatures compared to fresh seeds. Examination of the germination response of the seeds of the two studied species showed that in both species, with the increase in the duration of the afterripening period, the base water potential for 50% germination (ψb50) became more negative, and hence, tolerance to water stress increased during the afterripening period. Nevertheless, afterripening for 12 months significantly increased the hydrotime coefficient (θH) and actually decreased the germination rate compared to other treatments. Conclusion: In summary, afterripening of seeds in safflower wild species during a suitable period of time (2-6 months) can lead to the improvement of their germination characteristics under different temperature and humidity conditions. In addition, it should be noted that long-term storage of seeds can lead to a decrease in the quality of seeds. [ABSTRACT FROM AUTHOR]

Objective: Attention to economic dimensions is one of the most important factors for the success the field of art. The purpose of this study is strategically analysis of the economic status of higher art education in Iran with emphasis on postgraduate education and providing appropriate strategies. Methods: Based on the status quo, the strategic issues in this area identified in 45 propositions and analyzed in the framework of the PESTEL strategic model. In order to prioritize the strategic issues system, a questionnaire provided to 30 specialists in strategic cultural, artistic, economic and higher education studies. After analyzing the responses, the Maxi-Max method used to prioritize the strategic issues system. Results: Finally, 11 strategies provided to realize the dynamic economics and sustainable development in higher education with emphasis on postgraduate education as following: 1. Institutional-functional independence of academic centers. 2. Effective interaction of university art centers with economic and industrial sectors. 3. Planning courses in university centers of art with the labor market. 4. Adopting a financing approach based on inbound economy of the university. 5. Informing about the functional importance of the entrepreneurship. 6. Use of new technologies in order to generate income. 7. Use of the existing capacities in the informal course of education and artistic skills. 8. Creating an innovative environment for entrepreneurship activities. 9. The establishment of higher education institutions and research centers of the economic arts and entrepreneurship. 10. The establishment of supportive and facilitating laws. 11. Standardization of Entrepreneurship in the laws of staff attracting Conclusion: Facilitating the movement of university art centers from the current situation towards the University of Art Entrepreneurs requires the expansion of management structures and policy-making of the country as the main stakeholders of the higher education system. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

This study was conducted for create genetic diversity and access to suitable hybrids in terms of agronomic traits, marketability and adaptation to climatic conditions and tolerance to water deficit stress in Ardabil region during two years (2017 and 2018). The experiment was splitplot based on randomized complete blocks design with three replications. The main plot was deficit irrigationat three levels (100, 80 and 60% of plant water requirement) and the sub plot consisted of 12 potato populations. Results of analysis of variance showed that there was significant difference between different levels of deficit irrigation, genotypes and their interactions in terms of number and weight of tuber per plant, tuber yield, number of main stems per plant and length of stolon and in terms of tuber dry matter percentage, only significant difference was observed between genotypes. In this experiment of the 279 successful crossings 244 hybrids were selected. Selected hybrids had an average of 975.5 g and 7.5 tubers per plant. I؟n all three environmental conditions, the highest tuber weight per plant and tuber yield was related to Agria X Ceaser hybrid, and in normal and moderate stress conditionsbelonged to Savalan X ؟Ceaser hybrid. The highest water use efficiency was observed in all three environmental conditions in hybrids 2 [Agria (mother parent) X Caeser (mother parent)] and 9 [Caeser (mother parent) X Savalan (father parent)]. [ABSTRACT FROM AUTHOR]

The purpose of this study was to compare the statistical parameters of maximum annual precipitation in the watershed of Haraz River located in the central part of the Alborz Mountains. After reviewing the data of precipitation in Haraz watershed and considering lack of long-term statistics in the study area, Panjab-Haraz, Karsang-Haraz and Mahmoudabad-Haraz stations in different parts of the river from mountain to plain in 44-year statistical period from the water year of 1968-69 to 2011-2012 were selected. The annual precipitation frequency analysis of the selected stations was performed and the results of the Residual sum of squares (RSS) test were extracted by the method of ordinary moments and the maximum likelihood at this stage to be compared with the linear moments method. Residual sum of the squares in the linear moment method were also calculated by a computer program for the studied distributions. The results showed that in general, normal moment and maximum likelihood methods in selected stations have better fit and less RSS. The results of scoring and ranking the best selected method and distribution also showed that in all three selected stations, the maximum likelihood method with the minimum RSS was the best fit with the annual maximum precipitation data. [ABSTRACT FROM AUTHOR]

Selection of high yielding genotypes is very important in sunflower. Thus, 24 new sunflower hybrids along with Golsa cultivar were evaluated in a simple lattice design (5×5) with two replications in the Agriculture Research Station of Gorgan, north of Iran, during 2020. The genotype by yield × trait (GYT) biplot method was used in order to study the relationships between different traits and to select the new hybrids of sunflower based on yield-trait combinations. The result of polygon view of GYT biplot indicated that G19 was the best genotype in terms of the combination of seed yield with traits such as stem diameter, head diameter, seed number per head, thousand seed weight, early maturity and leaf number. Similarity, G5 also was superior genotype in terms of the combination of seed yield with a number of traits, including plant height, head height from ground level, leaf length, leaf width and petiole length. Based on average tester coordinate (ATC) view of GYT biplot, the genotypes G19 and G5 in terms of all positive yield-trait combinations were recognized as the best genotypes and genotypes G24, G23 and G25 as the weakest genotypes. A significant positive correlation was observed between seed number per head, thousand seed weight and early maturity in combination with seed yield. Moreover, these traits had high broad sense heritability. Therefore, it seems that traits such as seed number per head, thousand seed weight and early maturity could be used as suitable selection criterions for increasing seed yield in sunflower. [ABSTRACT FROM AUTHOR]

Sunflower is an important crop that its oil has high nutritional and economic value. In this study, genotype-trait biplot method was used to study interrelationships between different traits and new sunflower hybrids. For this study, 24 new sunflower hybrids along with Golsa cultivar were evaluated in a simple lattice design with two replications in Gorgan Agriculture Research Station, Gorgan, north of Iran, during 2020 cropping season. The results showed that thousand seed weight, head diameter, seed number per head, stem diameter, leaf length, leaf width and petiole length had a positive correlation with seed yield. Also, a negative correlation was observed between seed yield and phonological traits and plant height. Therefore, it can be concluded that improving seed yield may simultaneously lead to improve in the early maturity and dwarfism. Based on biplot polygon view, the genotypes No. 5 and 19 had superior characteristics in terms of seed yield and its attributes. Also, based on a hypothetical ideal genotype biplot, the genotypes No. 3, 2 and 10 outranked the other genotypes in terms of all examined traits. A majority of the examined traits had high discriminating ability and were able to show differences between genotypes. The stem diameter was the nearest trait to an ideal trait and, therefore, it has the highest discriminating ability and representativeness. [ABSTRACT FROM AUTHOR]