Hamidreza Sarli; Abbas Biabani; Hossein Sabouri; Rahmatolah Mohammadi
Abstract
This experiment has been performed to study the effect of seed sowing density and different amounts of nitrogen fertilizer application on the remobilization indices in wheat (Qaboos cultivar) in the field of Gonbad Kavous Agricultural and Natural Resources Research Station in two years (2018-19 and 2019-20) ...
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This experiment has been performed to study the effect of seed sowing density and different amounts of nitrogen fertilizer application on the remobilization indices in wheat (Qaboos cultivar) in the field of Gonbad Kavous Agricultural and Natural Resources Research Station in two years (2018-19 and 2019-20) in three replications and as a split-plot in a randomized complete block design. The main plots include pure nitrogen at four levels, i.e., 0 (control), 46, 92, and 138 kg/ha of nitrogen from urea fertilizer source), and the subplots are planting density at six levels (150, 225, 300, 375, 450, and 525 seed/m2). The remobilization photosynthetic assimilate separately from leaves, main stem (without leaves), and seedless spike components are examined to study the process of photosynthetic material transfer to seed. Results show that there has been significant differences among planting density, nitrogen fertilizer, and interaction of planting density× fertilizer treatments in terms of grain nitrogen percentage and remobilization traits of wheat. The highest percentage of grain nitrogen (1.87%) has been obtained in the treatment of 138 kg/ha nitrogen and 450 seed/m2. In the first year, the highest remobilization from the plant is observed in the treatment of 92 kg/ha nitrogen and 375 seeds/m2 (0.528 gr/plant), and in the second year, in the control, the highest remobilization is observed in the planting density of 300 seeds/m2 (0.345 gr/plant), and then with increasing planting density, the remobilization from the plant is reduced.
Mehdi Joudi; shahram mehri
Abstract
The aim of this research is to study the pattern of dry matter partitioning to different above-ground plant parts during anthesis, two weeks after anthesis, and physiologic maturity among wheat cultivars and to investigate its possible relationship with grain yield. Eighteen well-watered wheat cultivars ...
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The aim of this research is to study the pattern of dry matter partitioning to different above-ground plant parts during anthesis, two weeks after anthesis, and physiologic maturity among wheat cultivars and to investigate its possible relationship with grain yield. Eighteen well-watered wheat cultivars have been grown at research farm of Moghan College of Agriculture and Natural Resources based on randomized complete block design with three replications during 2014-2015 growing season. At anthesis, total dry matter accumulated in the plant, range from 1.95 (Sumay3) to 3.33 g (Alvand). At this time, depending on the cultivar, dry matter partitioned to the stem which differ from 31% to 41%, vary from 37% to 50% in the leaves, and from 16% to 27% in the spike. From anthesis to two weeks post-anthesis, dry weight of stem and spike increase, while those of leaves, generally, remain constant. The highest (1.52 g) and the lowest (0.52 g) increases in the weight of stem and spike have been observed in the case of Shirodi and Sardari, respectively. During two post-anthesis weeks to physiologic maturity, the spike has been dominant; however, the cultivar differences in the amount of allocated photoassimilates to the spike as well as stem reserves remobilization change the pattern of dry matter partitioning among wheat population again. At anthesis, there has been no clear association between cultivar height and spike weight. At physiologic maturity, however, dwarf cultivar generally has had higher weight and proportion of the spike. These results show that the pattern of dry matter partitioning is varied depending on the plant developmental stages and cultivars. Therefore, partitioning pattern of a cultivar observed at one growth stage is not necessarily similar in other growth stages. At physiologic maturity, Crossed Alborz and Pishtaz are superior with respect to dry matter partitioning and yield performance. Analysis of correlation reveals that leaves dry weight at anthesis, stem dry weight at two weeks after anthesis, and partitioned photoassimiltes to the grain are correlated positively with square grain yield. Therefore, these traits deserve further attentions in wheat programs dealing with increased grain yield.
Rahim Naseri; Amir Mirzaei; Amin Abbasi
Abstract
In order to investigate the effect of mycorrhizl fungi on dry matter remobilization of barley in dryland conditions, a field experiment has been carried out in factorial analysis based on randomized complete block design with three replications at the farm station of Sarablah Agricultural Research Cente, ...
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In order to investigate the effect of mycorrhizl fungi on dry matter remobilization of barley in dryland conditions, a field experiment has been carried out in factorial analysis based on randomized complete block design with three replications at the farm station of Sarablah Agricultural Research Cente, Ilam during 2019-2020 cropping season. Experimental factors include different barley cultivars (Mahali, Mahoor, Khoram, and Fardan) and fertilizer application is the control (without fertilizer application), 50% P chemical fertilizer, mycorrhizal fungi (Glomus mosseae, Glomus etunicatum and Rhizophagus irregularis), mycorrhizal fungi along with 50% P chemical fertilizer and 100% P chemical fertilizer. The results of this study indicate that the interaction of cultivar along with fertilizer application have had significant influence on dry matter remobilization efficiency from spike, contribution of spike reserves to grain yield, dry matter remobilization efficiency from stem, contribution of stem reserves to grain yield, current photosynthesis rate, contribution of current photosynthesis, and grain filling rate. Thus, the interaction of Fardan cultivar and mycorrhizal fungi along with 50% P chemical fertilizer has had the highest dry matter remobilization effeciency from spike, contribution of spike reserves to grain yield, current photosynthesis rate, contribution of current photosynthesis, and grain filling rate. In return, in this study the highest stem dry matter remobilization effeciency, contribution of stem reserves to grain yield, have been obtained from the interaction of Mahali cultivar along with control treatment. According to the results, in dryland conditions of the region, new cultivar of Fardan as well as mycorrhizal fungi along with 50% P chemical fertilizer can be recommended.
Maryam Saraei; Morteza Moballeghi; Morteza Nasiri; Mojtaba Nashaeemoghaddam
Abstract
The remobilization of carbohydrates in shoots is one of the effective factors to grain filling in rice. To determine the contribution of dry matter remobilization of shoots in different rice genotypes, a research has been carried out with seven rice genotypes and two controls in RCBD design with three ...
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The remobilization of carbohydrates in shoots is one of the effective factors to grain filling in rice. To determine the contribution of dry matter remobilization of shoots in different rice genotypes, a research has been carried out with seven rice genotypes and two controls in RCBD design with three replications during 2017-2018 at rice research station of Shahid Shiroodi in Tonekabon county. Results show that among all genotypes, rate of dry matter remobilization via the flag leaf, stem, and total shoot has differed significantly at (p<0.01) percent and from other leaves at (p<0.05) percent level. Mean comparison among the genotypes indicates that the highest dry matter remobilization from flag leaf belongs to Genotype 952 with 56 g.m-2. The maximum carbohydrates remobilization in other leaves, stem and total shoots are assigned to Genotype 953 at 123, 230, and 398 g.m-2, respectively. Highest grain yield belongs to Genotype 952 with 7206 kg.ha-1. Correlation analysis results show that grain yield is positively and significantly correlated with dry matter remobilization from flag leaf, stem, and total shoots, as well as 1000-grain weight, having coefficients of 0.37, 0.55, 0.51, and 0.44, respectively. As a result of yield and dry matter remobilization rate, and the positive and significant correlation between them, both Genotypes 952 and 953 are suitable for continuing research activity and introduce a new rice cultivar especially in drought and hot stress conditions at the grain filling stage.
S. Javad Talebzadeh; Hashem Hadi; Reza Aminia; Mehdi Tajbakhsh; Mohammad Rezaie
Abstract
In order to evaluation the pattern of assimilates distribution to seed under late season drought stress, 11 promising lines of winter wheat along with Orum, Zareh, Mihan, Zarrin and Pishgam cultivars were evaluated in two levels of irrigation (full irrigation and cutting irrigation from flowering to ...
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In order to evaluation the pattern of assimilates distribution to seed under late season drought stress, 11 promising lines of winter wheat along with Orum, Zareh, Mihan, Zarrin and Pishgam cultivars were evaluated in two levels of irrigation (full irrigation and cutting irrigation from flowering to maturity) at the Agricultural Research Station of Miandoab during 2013-2015 growing seasons. Experiments were conducted in split plot based on randomized complete block design with three replications. Results showed that water deficit stress significantly increased remobilization rate, contribution of remobilization and source restriction and decreased the amount of spike weight, peduncle weight, sink restriction by removing leaves other than flag leaf, sink restrictions by removing flag leaf, grain yield and harvest index, so that terminal water deficit stress increased remobilization by 45.45% and the total yield contribution of remobilization of 18.30% in normal conditions increased to 43.33% under stress conditions. Among the genotypes, ‘Zarrin’ and ‘Mihan’ under normal moisture conditions and ‘Mihan’ genotype under terminal drought stress conditions produced the highest grain yield. In this study under terminal drought stress conditions, there were significant positive correlations between grain yield with remobilization rate and contribution of remobilization. It can be concluded that the varieties and genotypes afforded adequate remobilization and contribution of remobilization in grain yield in both conditions are appropriate for cultivation in optimal conditions, as well as areas that are faced with terminal water deficit stress.
Farnaz Faraji; Masoud Esfahani; Mohammad Reza Alizadeh; Ali Alami
Abstract
In order to evaluate the morphological characteristics and lodging related traits and carbohydrate content of culm and carbohydrate remobilization in traditional and improved rice cultivars, a field experiment was laid out in randomized complete block design with three replications at Rice Research Institute ...
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In order to evaluate the morphological characteristics and lodging related traits and carbohydrate content of culm and carbohydrate remobilization in traditional and improved rice cultivars, a field experiment was laid out in randomized complete block design with three replications at Rice Research Institute of Iran )Rasht( in 2012 and 2013. Rice genotypes included three native rice cultivars (Hashemi, Sangjo and Alikazemi) and six improved (Kadous, Gohar, Khazar, Sepidrood, Deylam and Dorfak) and three promising lines (831, 841 and 416). On the basis of this results, the greatest amount of breaking resistance were observed in third and fourth internods of Khazar. Furthermore, significant positive correlation were observed between average diameter of internode, fresh weight/length of internode and unsoluble carbohydrate content of culm in anthesis and maturity stages with breaking resistance of third and forth internods. Also, significant positive correlation was observed between number of parenchyma cells and unsoluble carbohydrate content of culm in anthesis and maturity stages. On the other hand, there was significant negative correlation between carbohydrate remobilization and breaking resistance of third and forth internods. Principal component analysis classified plant characteristics to two groups. The first factor was named as lodgigng resistance factor and included 71.01 percent of total variation. The second factor with 19.74 percent of total variation was named as morphological lodging sensitivity factor. According to the results of this experiment, it seems that average diameter, thikness and weight/length of internode, have major roles in rice plant resistance to lodging.