فصلنامه تحقیقات غلات
سال دهم شماره 3 (پاییز 1399)

Iron toxicity lead to oxidation of photosynthetic pigments, increasing of free radicals and as a result rice yield to be severely damaged. This study was performed to investigate the effect of iron toxicity on relative expression of alternative oxidase, external alternative NAD(P)H-ubiquinone oxidoreductase, internal alternative NAD(P)H-ubiquinone oxidoreductase, NADH dehydrogenase, NATPH-thioredoxin reductase and ferredoxin-thioredoxin reductase genes in two rice genotypes, IR64 (susceptible) and Pokkali (tolerant). Iron ion was applied at the levels of 0 (check), 100, 250, 400 and 500 mg.lit-1 under Yoshida hydroponic conditions. Results showed that the iron cosentration in leaves increased with increasing of stress levels. There was not a significant difference among IR64 treatments samples for leaves potassium cosentration. But it increased in Pokkali genotype relative to non stress samples .The expression levels of genes in Pokkali except NDH and IN-NDH in 250 and 400 mg li-1 and NTR in 500 mg li-1 samples were higher than IR64. In all, the difference of morphological traits and relative over expression of genes in Pokkali. In all, the difference of morphological traits and relative over expression of genes in Pokkali indicated that the gene could considerably effect on the tolerant level of pokkali by reducing ROS production under Fe-toxicity. Our results showed that high activity of the mitochondrial and genes, alone or together, could also be an important factor in iron tolerance in rice by detoxifying the harmful effects of the ROS.

Kernel shape and size are the most important characters related to the yield and domestication in bread wheat (Triticum aestivum L.). Understanding of genetic parameters of such important traits and its utilization is very important in breeding programs for this strategic crop. The aim of the present study was to identify quantitative trait loci (QTLs) corresponding to the kernel shape and size characteristics i.e. kernel weight, kernel length, kernel width, horizontal area proportion, sphericity, vertical perimeter, projection area, section area, and kernel volume within a mapping population of 118 recombinant inbred lines (RILs) of bread wheat resulting from a cross between an Iranian landrace, Tabassi, and a European wheat variety, Taifun. In total, nineteen QTLs were identified on chromosomes 1A, 2A, 2D, 3B, 4A, 4D, 5A, 5B, 5D, 6A, 7A and 7B. Genome A, B, and D were covered 53%, 26%, and 21% of the QTLs respectively. The highest number of QTL (5) and phenotypic value (42.3%), were respectively obtained for kernel length and kernel sphericity. Among the QTL regions identified, one region on chromosome 2A corresponding kernel length and volume and one region on chromosome 5D controlling sphericity and projection area are referred to as pleiotropic regions. The results of this study, in agreement with other studies, are recommended in marker-assisted selection (MAS) for grain shape and size traits in bread wheat breeding programs.

Given the importance of the agricultural sector in food production and security, countries around the world are using various policies to support the agricultural sector. One of the food security clauses is the dependence on food imports, especially cereals. Due to the growth of production in the last three decades in Iran, it is still forced to import some agricultural products to meet domestic demand. Success in increasing agricultural production requires the implementation of correct and codified policies to support producers. With the scientific implementation of supportive policies such as setting a guaranteed price for a strategic wheat crop, it can have positive effects on the production of this crop. As a result, given the importance of the issue, The purpose of this study is to investigate the policy of guaranteed price on wheat productivity in Yazd province in the period 1368-1395 using It is an indicator of Malm Quest and a self-explanatory model. The results showed that wheat yield and yield in the short term have a positive and significant relationship with guaranteed price, but gradually and in the long run the effect of this policy will decrease. As a result, given the different effects of guaranteed price on wheat productivity, it is suggested that this policy be reconsidered and continued.

To determine the yield stability of barley promising lines, 17 lines along with three control genotypes were evaluated in five warm zone stations during two years (2017-2019) in randomized complete block design with three replications and their stability was determined using AMMI (additive main effects and multiplicative interaction) and SHMM (Shifted multiplicative model). Analysis of variance of grain yield using AMMI model showed that the effect of genotype, environment and genotype × environment interaction was significant at 1% probability level. Genotype × environment interaction analysis based on AMMI model showed that the four main components of interaction were significant at the level of 1% probability. These four components explained 84.7% of the changes in genotype × environment interaction. The lowest value of RMS PD was related to AMMI1 model. Therefore, the interpretation of the results using the AMMI1 model is more valid than the AMMI2 model. According to the AMMI2 model, lines WB-96-8 and WB-96-9 had specific adaptability with the Zabol region and line WB-96-12 had specific adaptability with Moghan. Lines WB-96-10, WB-96-17, WB-96-18 and WB-96-19 were the high-performance lines in this study. The grouping of locations based on the SHMM model created two groups. The first group includes Darab, Ahvaz and Zabol, which are part of the warm zone stations in the south of the country. The second group included Moghan and Gonbad stations (warm northern zone).

Due to the growing need to increase the area under cultivation of Maize and reduce the use of chemical fertilizers to achieve sustainable agriculture, the purpose of this study was to investigate the effect of nano-biofertilizer as new eco-friendly technology along with cattle manure on increasing nutrient efficiency and maize yield in a saline calcareous soil with low organic matter. For this purpose, a field experiment was performed as split-plot factorial in a randomized complete block design with three replications. The factors included nano-biofertilizer at three levels of zero, 1, and 2 (Nb0, Nb1, and Nb2) ton/ha, and cattle manure in three levels 0, 10, and 20 (M0, M1, and M2) ton/ha. The results showed that the independent and interaction effects of these fertilizers on soil properties and yield and growth traits of maize were significant at 1% probability level. The results of interactions showed that Nb2M2 treatment compared to control could increase grain yield (101 %), straw weight (78 %), total yield (82.82 %), grain nitrogen (135 %), grain protein (136 %), protein yield (377 %), soil respiration (61.18 %), soil organic carbon (126.20 %), soil organic matter (125.50 %) and soil nitrogen (140.30 %). Nb1M1 treatment was able to reduce soil C/N by 22.7 %. In the case of soil EC, Nb2M0 treatment had the best performance with a reduction of 41.7 % in soil salinity. Besides, Nb0M2 treatment could reduce soil pH from 7.90 to 7.65. The results of this study showed that the use of nano-biofertilizers with organic matter while having a high potential for increasing the yield (quantitative-qualitative) of corn also can significantly improve the biological and chemical properties of saline calcareous soils.

To evaluate the tolerance to low irrigation stress in advanced forage-grain sorghum lines, an experiment was performed as split plots in randomized complete block design with three replications in Seed and Plant Improvement Institute (SPII), Karaj, Iran. In this experiment, low irrigation regimes as the main factor at two levels (120- and 240-mm evaporation from the surface of the Class A evaporation pan) and sorghum lines as sub-plot at 8 levels (KDFGS1, KDFGS6, KDFGS9, KGFGS10, KDFFGSD, KDFGS14, KDFGS16) were evaluated. There was a significant difference among the studied sorghum lines in terms of all traits except stem diameter and 1000-seed weight. The effect of the interaction of irrigation regimes and lines was significant at plant height and dry forage weight and was not significant in others. The correlation between panicle weight and forage yield was not significant in both irrigation regimes.  In both irrigation regimes, although the lines KDFGS1, KDFGS6, KDFGS9, KGFGS10, KDFGS12, KDFGS13, KDFGS14, KDFGS16 were grouped in the first cluster and the KDFGS14 line alone was arranged in the second cluster, but the genetic distance among lines was different in irrigation conditions.  In factor analysis, although, the studied traits were reduced to three factors in both irrigation regimes, in irrigation 120 mm panicle weight, forage weight and stem diameter, and in irrigation 240 mm panicle weight, harvest index, forage weight, and amount of stem and panicle were determined the most effective traits. KDFGS14 sorghum line is recommended as a superior line due to its superiority in traits related to yield.