فصلنامه علوم زراعی ایران
سال بیست و پنجم شماره 4 (پیاپی 100، زمستان 1402)

Multi-environmental trials (METs) and analysis of genotype-by-environment (GE) interaction have a critical role in breeding programs related to the release of high-yielding cultivars with high yield satbility for cultivation across different environments. Different statistical and graphical methods have been proposed to evaluate the GE interaction effects. In the present study, the effect of GE interaction on grain yield in set of new promising lines of barley was evaluated using the additive main effect and multiplicative interaction (AMMI) model.

A set of promising lines of barley including 18 new advanced lines along with two commercial cultivars (cv. Golchin and cv. Oxin) as reference checks were evaluated in the multi-environment trials. Experiments were carried out in five geographical regions in the warm agro-climatic of Iran which included Ahvaz (E1 and E2), Darab (E3 and E4), Gonbad (E5 and E6), Zabol (E7 and E8), and Moghan (E9 and E10) for two consecutive cropping seasons (2021-2022 and 2022-2023). The AMMI model and some stability and adaptability statistics were used to evaluate the effect of GE interaction on grain yield and identify the high yielding with yield stability promising lines.

The results indicated that grain yield was significantly affected by environments (E), genotypes (G), and their interaction (GEI). Environments and GE interaction effect explained the highest portion of observed variation of grain yield. Moreover, the GEI effect was further divided into three principal components (IPCAs) and accounted for 68.99 of the total GE interaction variation. Mean comparison showed that promising lines 14, 3, 10, and 17 had higher grain yield (4960, 4920, 4750, and 4670 kg.ha-1, respectively) when compared to the other promising lines and check cultivars. According to the AMMI-based stability statistics, promising lines 17 had the highest yield stability. Moreover, this genotype along with promising lines 1, 3, 10, and 14 were selected as superior promising lines based on the BLUP-based stability and adaptability statistics. Principle components analyisis based on biplot rendered using the WAASB index and grain yield clustered all studied promising lines and experimental environments into four quadrants. Accordingly, promising lines 3, 10, and 17 were placed into the highest yield stability group.

The results of this research revealed that promising lines 4 and 14 had specific adaptability to the northern regions (Moghan and Gonbad), and promising lines 3 and 10 showed specific adaptability to the southern regions (Ahvaz, Darab, and Zabol). Therefore, further evaluation of these promising lines, for selection and releasing some of them as new commercial cultivars as well as using them as parents in the national barley breeding programs, is required.

Drought stress constaints crop production in the world. Terminal season drought stress is one of the important environmental factors of yield reduction in durum wheat in semi-arid regions. Therefore, high yielding genotypes with drought tolerance is an efficient approach to mitigate its adverse effects. With declining resources of water and escalating intensity of drought, yield loss is an alarm in semi-arid regions. However, development of drought tolerance depends on complex traits and their interaction with environmental factors. Likewise, choosing genotypes with drought tolerant is a tricky task. Alternatively, some statistical parameters as well as drought tolerance indices can be employed to compare the changes in grain yield in normal and drought stress conditions for identification of high yielding genotypes with drought tolerance.

To identify terminal season drought-tolerant genotypes, 17 promising genotypes of durum wheat were evaluated at the Darab Agricultural Research Station, Iran. The evaluation was conducted in randomized complete block design with three replications and over two cropping seasons (2020-2022), both under non-stress conditions and terminal drought stress conditions by irrigation withdrawal at the flowering stage (GS 60). The indices of drought tolerance studied were yield under non-stress conditions (Yp); yield under stress conditions (Ys); tolerance index (TOL); stress susceptibility index (SSI); mean productivity (MP); geometric mean productivity (GMP); stress tolerance index (STI); harmonic mean (HM); percentage of yield decrease (R%); yield index (YI); yield stability index (YSI); relative drought index (RDI); abiotic-stress tolerance index (ATI); stress susceptibility percentage index (SSPI); stress non-stress production index (SNPI). SIIG (selection index of ideal genotype), CSI (combination of significant indices) and MGIDI (multi-trait genotype-ideotype distance index) indices were used in order to integrate different indices of drought tolerance and better selection of drought tolerant genotypes.

The results of combined analysis of variance for grain yield under non-stress and terminal season drought stress conditions indicated that the effects of year, environment and genotype on grain yield were significant. Additionally, the heatmap analysis revealed that the lowest observed grain yield was associated with terminal season drought stress conditions in the 2020-2021, while the highest observed grain yield occurred in the 2021-2022 under non-stress conditions. Furthermore, the highest grain yield (kg.ha-1) under normal irrigation conditions (Yp) was observed for genotypes 2 (8178), 1 (7938), 17 (7698), 19 (7662), 18 (7659), 14 (7451), and 10 (7413), respectively. On the other hand, the highest grain yield (kg.ha-1) under drought stress (Ys) was related to genotypes 18 (5639), 4 (5489), 8 (5479), 10 (5473), 13 (5434), and 6 (5404), respectively. Moreover, based on the TOL, ATI, and SSPI indices, genotypes 9, 4, 12, and 15 with the lowest values of these indices were identified as stress-tolerant genotypes. In addition, based on the SSI and %R indices, genotypes 4 and 8, which had the lowest values of these indices, respectively, were also classified as stress-tolerant genotypes. Examining the MP, GMP, and HM indices revealed that genotypes 2, 18, 1, 17, and 10 exhibited the highest values and were identified as the best-performing genotypes, respectively. Similarly, based on the SNPI index, genotypes 4, 8, 18, 13, and 6 demonstrated the highest values and were among the drought tolerant genotypes. The results also showed that the genotypes 18, 4, 8, 10, and 13 had the highest values of the YI index, respectively. The results revealed that the SIIG and CSI indices had positive and significant correlation with Yp and Ys. Conversely, MGIDI index had negative and significant correlation with Yp and Ys. The results of principal component analysis (PCA) revealed that the investigated genotypes were placed in four areas of the biplot diagram. The genotypes of area one (5, 7, 9, 12 and 15) exhibited low yield potential under both non-stress and stress conditions. The genotypes of the second region (1, 2, 14 and 19) showed high grain yield potential under non stress conditions. The genotypes of the third region (6, 10, 13, 17 and 18) demonstrated high yield potential under both non-stress and stress conditions, leading to their selection as superior genotypes. Therefore, MP, GMP, HM and STI indices were positioned within the area of the three PCA diagrams, proved suitable in identifying high yielding and drought tolerant genotypes. Furthermore, genotypes in fourth area (3, 4, 8, 11, 13, 15 and 20) displayed higher grain yield under terminal season drought stress conditions.

The results of this experiment showed that MGIDI, CSI and SIIG indices had sufficient efficiency in selecting high yielding and tolerant durum wheat genotypes. Efficiency of SIIG, MGIDI and CSI indices in selection of high yielding terminal drought tolerant genotypes were similar, and genotypes 2, 10, 17 and 18 were selected. However, based on all three indices, only genotype 18 ranked first. Therefore, genotype 18 which was located in the third area of PCA diagram and performed higher than average grain yield under both and non stress and stress conditions, was identified as adapted drought tolerant genotype for the Darab region and similar areas.

Medicinal plants are among the most valuable natural resources in Iran which can play an important role in people health, job creation, and non-oil exports if they are properly identified, improved, cultivated and used. The increasing use of medicinal plants at the global level makes the importance of cultivation and production of these plants clearer. Currently, many researches are being conducted in the fields of identification of effective substances, therapeutic properties, cultivation and domestication of medicinal plants. Fennel (Foeniculum vulgare Mill.) is one of the medicinal plants that have many uses in foods, pharmaceutical and health industries, and is used in traditional Iranian medicine for long time. Therefore, the cultivation and production of this medicinal plant is of great importance.

To investigate the effect of direct seeding and transplanting on the yield and yield components of 10 fennel ecotypes, factorial experiment completely randomized complete block design with three replications. The experiment was carried out in the research field of the faculty of agriculture of the University of Tabriz, located eight kilometers east of Tabriz, Iran. Eight native fennel ecotypes of Iran from the provinces of Isfahan (Tatmaj Kashan), Isfahan (Zeyare), Alborz (Karaj), Lorestan (Khorramabad), East Azerbaijan (Bonab), North Khorasan (Shirvan), Hamadan and Ardabil (Meshkin Shahr) and two different foreign ecotypes from Germany (Saxony-Anhalt and Thuringia) were cultivated by two methods, direct seeding and transplanting.Seedlings were produced in winter in controlled environment and were transplaned in the field at the six leaf satge. In direct seeding, the seeds were sown in the mid April 2019. Hand weeding was done several times during the growing period. After harvesting the plants, sampling was done from the mid August until the late November 2019. Plant height, biological yield, seed yield, 1000 seed weight, essential oil content per hundred grams of dry matter and harvest index were measured and calculated.

The results of analysis of variance showed that main effect of ecotype and planting method were significant on seed yield and essential oil contents. The interaction effect of planting method × ecotypes was significant for all traits except for seed yield and essential oil content. The average seed yield in direct planting method was higher than that of transplanting, however, the essential oil content in transplanting method was higher than in direct seeding. The highest seed yield was related to the ecotype from Shirvan and the highest essential oil was related to the ecotypes from Germany (Saxony-Anhalt). The observed genetic variation for seed yield, important agronomic traits and the essential oil content among studied fennel ecotypes makes it possible to use these ecotypes in fennel breeding programs to develop cultivars with high seed yield and essential oil content.

The results of this experiment showed that there was considerable variation for most of the studied traits. Since the heritability for most traits was high, it can be concluded that most of this variation is probably related to genetic factors. Therefore, the selection of these traits can be effective for the development of fennel cultivars with higher seed and biological yields and essential oil content. The significant correlation coefficients between traits facilitates the indirect selection for important agronomic traits. The results of the cluster analysis showed that the morphological and phenological traits, to some extent, separated the fennel ecotypes based on geographical and climatic regions. The genetic variation among the studied ecotypes makes it possible to use these ecotypes in fennel breeding programs to develop new cultivars with high seed yield and essential oil content.

One of the important goals of rice breeding programs is to develop new high yielding cultivars with high quality properties as well as desirable agronomic traits. Introducing of such cultivars and adoption them by farmers will lead to increased production. This experiment evaluated new hybrid rice cultivars under different transplanting bed methods in the Khuzestan climate conditions in Iran.

The experiment was carried out as split plot arrangements in randomized complete block design with three replications in 2020-2021 and 2021-2022 growing seasons at the Shaawor agricultural research station, Ahvaz, Iran. The main plots were wet and dry transplanting bed methods, and the sub-plots consisted of seven hybrid rice cultivars (L66S, F168S, Quan2, XinerPS, Hs–3, Shen51S and Hui34S). SPAD value, leaf area index (LAI), number of tillers, growth duration, panicle fertility, plant height, grain yield and yield components and biological yield were measured.

The results indicated that the SPAD value, leaf area index, number of tillers, growth duration, panicle fertility, plant height, grain yield and yield components and biological yield were significantly affected by the interaction effect of year × transplanting bed × cultivar. SPAD value, LAI, number of tillers, growth duration, panicle fertility, plant height, yield components and grain yield and biological yield were higher in wet bed transplanting method. Also, Quan2S and Hui34S hybrid cultivars were superior than the remaining five hybrids. in 2021, the tallest plant height (84.3 and 81 cm) and LAI (4.3 and 4.2), the greatest number of grains per panicle (189 and 160), and the weight of 1000 grain weight (24.4 and 25.8 g) were observed in Quan2S and Hui34S cultivars, respectively, in wet bed transplanting method. However, in 2022, most of the studied hybrid rice cultivars did not show significant differences. The highest grain yield (5200 and 4675 kg.ha-1) and biological yield (12380 and 10143 kg.ha-1) were obtained from Quan2S and Hui34S hybrid rice cultivars, respectively, in the 2021 and wet bed transplanting. The results of cluster analysis showed that seven hybrid rice cultivars were separated into three different groups. The first group comprised XinerPS, L66S, and F168S, the second group included Hs-3 and Shen 51S and third group comprised Quan2S and Hui34S hybrid rice cultivars.

The results of this experiment showed that while the hybrid rice cultivars did not perform successful and are of low adaptability in Khuzestan environmental conditions. The results also indicated that wet bed transplanting method is suitable for Khuzestan environmental conditions and led to higher grain yield of rice hybrid cultivars.

Increasing rice production is one of the demands of the world market and one of the goals of many countries that produce this staple crop. Development of high yielding cultivars is one approach and perhaps the only one to supply the country's rice demand. Knowledge of the genetic parameters that control different traits, including heritability, the average degree of dominance, and gene action is very important in choosing a breeding scheme that lwads to development of improved high yielding cultivars. The diallel designs proposed by Griffing, Jinks, and Hayman provide information about the genetic suitability of parents to be used in breeding programs. This experiment was carried out to estimate the combining ability and the type of gene action of eight Central and Western Asian rice varieties using diallel crossing design.

In this experiment, eight rice varieties from Central and West Asia were used as the parents of the crosses. The progenies obtained from the diallel crossing design along with their parents were grown using randomized complete block design with three replications in the experimental field of Rice Research Institute of Iran, Rasht, Iran. During the growth duration, according to the standard evaluation method of the International Rice Research Institute (IRRI), the necessary evaluations for agro-morphological characteristics were carried out. Diallele analysis was performed using the second Griffing method under the first model (with fixed effect). Baker's ratio was used to determine the contribution of additive variance in the genetic control of studied traits. Also, diallel analysis proposed by Morley Jones method done to estimate gene actions and genetic variance components (additive and dominant). SAS 9.4 and DIAL98 softwares were used to perform preliminary variance and diallel analysis.

The results of diallel analysis by Griffing method to estimate combining ability showed that general and specific combining ability were significant for all studied traits which indicated the importance of additive and non-additive effects in the genetic control of these traits. Baker's ratio for grain yield, number of fertile tiller number per plant and number of filled grains per panicle showed that non-additive gene effects had a significant contribution in the genetic control of these traits. The value of Baker's ratio in plant height, panicle length and number of days to 50% of flowering indicated the presence of additive and non-additive gene effects in the genetic control of the aforementioned traits. Evaluation of general combining ability showed that the highest combining ability was observed in D3, Ghadeer, Atai-1 and Hashemi cultivars for grain yield, fertile tiller number per plant, filled grains per panicle and panicle length, respectively. Also, D3 and Marjan cultivars had the lowest general combining ability for plant height and days to 50% of flowering. The estimation of specific combining ability showed that for grain yield, Atai-1×Marjan cross, for fertile tiller number per plant, Ghadeer×Atai-1 cross, for filled grains per panicle, Marjan×Atai-1 cross and for panicle length, Ghadeer×Marjan cross had the highest specific combining ability. The estimation of genetic parameters of diallel genetic analysis showed that the contribution of non-additive gene effect in the genetic control of grain yield, fertile tillers per plant, plant height, filled gains pe panicle and panicle length was higher than additive gene effect.

considering the resuts of this experiment, it can besuggested that D3 cultivar is suitable parent for increasing grain yield as well as reducing plant height, and Marjan cultivar is suitable parent for shortening growth duration, in targeted crosses. The results also showed that Atai-1×Marjan cross had the highest specific combining ability for grain yield. Therefore, this combination is suggested for the development of high yield potential hybrid rice cultivars. The best combination for shorter plant height was Jalal×Atai-1 cross. The estimation of genetic parameters of diallel analysis showed that designing breeding schemesfor development of hybrid rice cultivars to improve grain yield and reduce plant height will be promising. The results also indicated that the use of selection method to reduce the length of growth duration will be possible.

Nitrogen is one of the important nutrient elements necessary for the production of agricultural products, but the excessive application of nitrogenous chemical fertilizers and their leaching cause environmental pollution. Crops’ cultivars with high nitrogen use efficiency is one of the environmental friendly aproaches to mitigate this problem.

To evaluate grain yield and nitrogen use efficiency in barley genotypes under low input conditions (without fertilizer application), a field experiment was conducted in research field of the agricultural faculty of Shahed University, Tehran, Iran in 2016-2017 cropping season. Thirty six barley genotypes, purified for three cropping seasons, were planted using simple alpha lattice design with two replications.

The results showed that genotypes; 106, 107, and 68 had the highest grain yield (7963, 7920 and 7900 kg ha-1, respectively), the highest nitrogen use efficiency (58.6, 58.5 and 56.9 kg.kg-1, respectively) and the highest nitrogen uptake efficiency (2, 2 and 2.25 kg.kg-1, respectively). The results of multiple regression analysis showed that the three variables of nitrogen use efficiency, nitrogen uptake efficiency, and biomass yield explained 98.2% of variation in grain yield. Principle component analysis revealed that barely genotypes divided into four groups. The first group included genotypes; 88, 119, 54, 107, and 68 for nitrogen uptake efficiency and nitrogen use efficiency, grain yield and quality. These genotypes are suitable for low input cropping systems to increase nitrogen use efficiency.

The results of this experiment indicated that further investigations are required for recommendation of barley genotypes with higher nitrogen efficiency and grain yield for low input cropping systems.