جستجوی مقالات مرتبط با کلیدواژه "سطح ریشه" در نشریات گروه "زراعت"

canola (Brassica napus L.) is one of the most important oilseed plants that has been ranked third in the oil production after soybeans and oil palm. Drought is seriously the most important factor limiting the growth and production of canola in Iran. By foliar application of micronutrients, plant growth condition can be improved under stress. Salicylic(SA) acid plays an important role in abiotic stress tolerance, and more interests have been focused on SA due to its ability to induce a protective effect on plants under adverse environmental conditions. It is necessary to know the traits related to drought tolerance and their relationship with seed yield. due to the important role of roots in the absorption and conduction of water and nutrients, recognition the root system and how it is distributed in the soil is special importance. therefore, the purpose of the present study was to investigate the Effect of foliar application of some micronutrients and salicylic acid on root characteristics and seed yield of canola (Brassica napus L.) under water deficit stress.

the experiment was conducted as split factorial in a randomized complete block design with three replications in Lorestan University, Iran, in two cropping seasons (2016-2018). water deficit was considered as the main factor in levels irrigation at 80 (control) and 30% of field capacity, and the combination of foliar application of micronutrient fertilizer (non-consumption and spraying at a concentration of 0.2%) and salicylic acid concentration of 0, 0.5, 1 and 1.5 mM were considered in sub-plots. the time of water deficit stress coincided with the stage of the beginning of regrowth (BBCH32). foliar application of micronutrient fertilizer in rosette stage (BBCH29) and foliar application of salicylic acid in two stage of flowering beginning (BBCH60) and pod filling (BBCH72). the measured traits included root dry weight, root volume, root area, seed yield, oil percentage, and water use efficiency. the data was analyzed by statistical analysis system (SAS version: 9.1). the means were analyzed using the Duncan test at P=0.05.

the results of analysis of variance showed the effect of year on seed yield, effect of salicylic acid on seed yield and oil percentage, double interaction of micronutrient fertilizer in salicylic acid on root volume and triple interaction of stress in micronutrient fertilizer and salicylic acid on root weight, root volume and water use efficiency were significant. the results of comparative analysis of the mean data showed that the highest percentage of oil was obtained from concentration of 1 to 1.5 mM of salicylic acid.the highest root volume (49.90 cm3) was obtained from the treatment composition (foliar application of 1.5 mM salicylic acid and concentration of 2 per thousand micronutrient fertilizers). the highest root dry weight (28.95 gr), root area (4360 cm2) and water use efficiency (1.26 kg m-3) from the treatment composition (no stress + 1.5 mM salicylic acid spraying and concentration of 2 per thousand fertilizers Micronutrients) was obtained. the highest seed yield (4955.7 kg ha-1) was obtained from foliar application 1.5 mM of salicylic acid, In the first year, the highest seed yield (4427.7 kg ha-1) from the combination (no stress + foliar spraying of 1.5 mM salicylic acid and a concentration of 2 per thousand micronutrient fertilizers) and in the second year of the combination (no stress + foliar spraying of 1 mM salicylic acid) and a concentration of 2 per thousand micronutrient fertilizers with an average (4955.7 kg ha-1) was obtained.

therefore, a triple micronutrient fertilizer (iron+zinc+ manganese) with a concentration of 0.2% is recommended along with a concentration of 1.5 mM of salicylic acid to reduce the negative effects of water deficit stress and achieving acceptable seed yield.

The first factor limiting plant yield in many crop ecosystems is drought stress, and plant productivity under these conditions depends on the distribution of dry matter between plant organs and the spatial distribution of roots in the soil. Knowledge of root length conditions and its distribution in soil profile, which is an indicator of the ability of plants to absorb water from deeper layers and better root permeability in the soil, as well as understanding the shape of the root system, is important (Wasson et al., 2012). In general, the size, morphology, and architecture of the root system determine the plant's ability to absorb water and nutrients, as well as the relative size and growth rate of the shoot (Vamerali et al., 2003). Root growth is determined by the genetic characteristics of the plant as well as the physical and chemical characteristics of the soil. Even in wet areas in response to drought stress, root growth is limited to the topsoil, and when the soil dries, its infiltration resistance increases rapidly, resulting in a combination of drought stresses. Soil and its infiltration resistance (He et al., 2017). Reduction of root dry weight in rice (Nasiri et al., 2015), fresh weight of root in rapeseed (Razaviezadeh and Amoubeigi, 2013) indicate the negative effect of drought stress on root characteristics in Different plants. Tillage is the only crop method by which humans can directly affect soil properties. Moisture storage and aeration to the roots, depending on the desired or unfavorable application of tillage, affects the growth and development of plant roots and ultimately its yield (Bronick and Lal, 2005).

This experiment was conducted in split -split plots based on randomized complete block design with three replications. Tillage systems as the main -plot in two factors was including no tillage and conventional tillage, Water stress as the subplot in three levels by 30, 60 and 90 Percent of moisture requirement and nitrogen urea as the sub-sub plot at three levels by 0, 50 and 100 percent of the recommended rate.

The combined variance analyses indicated that the maximum root length (4147 cm per plant), root volume (158.13 cm3 per plant), root area (3055.7 cm2 per plant), root length density (0.44 cm2. cm-3), root dry weight (24.32 gr pl-1) and plant fresh weight (6732.6 gr. m-2) was obtained from the interaction of conventional tillage in mild drought stress (90% of the plant's water requirement) in 100% of the plant's nitrogen fertilizer requirement. Also, the interaction effect of severe drought stress (30% of plant water requirement) in 100% of plant nitrogen fertilizer requirement led to a sharp decrease in studied traits in both studied tillage systems. Although the conventional tillage system in this study ultimately increased the root growth characteristics and fresh weight of the forage maize plant, but because no significant difference in wet forage yield was observed in both studied tillage systems, the system no tillage is recommended because it can improve the physical and chemical properties of the soil in the long turn.

Current estimates indicate that 25% of the world agricultural lands are affected by water stress. Iran, with an annual 228 mm of rainfall, is classified as a dry region in the word. Wheat is one of the main cereal crops, cultivated for human feeding. In order to increase crop yield per unit area, largely chemical fertilizers are used. The result of these activities in recent years has been the crisis of environmental pollution, especially water and soil pollution that threatens human society. Phosphorus is one of the limiting elements for crop production. It is essential for energy transfer, photosynthesis and other biochemical and genetic activities of plant. Biofertilizers have been used as source to improve plant nutrients in sustainable agriculture. Phosphorus Solubilizing Bacteria (PSB) plays an important role in phosphorus nutrition by enhancing its availability to plants through release from inorganic and organic soils phosphorus pools by solubilizing and mineralization. Mycorrhizal crops often have greater tolerance to drought than nonmycorrhizal crops. The use of arbuscular mycorrhizal fungi capable of forming symbiotic associations with most agricultural crops and has potential under such systems due to its higher binding capabilities and mineral nutrition. Therefore, the main of this study was to study the effect of phosphate solubilizing bacteria and mycorrhizal fungi on root characteristics and grain yield in dryland wheat cultivars. This experiment was carried out as factorial arrangement based on a randomized complete block design with three replications at the Agricultural Research Station of Ilam University (46*28' N, 33*37 E; elevation 1174 m) and Sarableh Agricultural Research, Recources Center (34*46 N, 33*45 E; elevation 975 m) during growing season 2013-2014. Experiment factors consisted of two dry land cultivars (Keras Sablan and Saji) and fertilizer sources including of 1: without application of phosphorious chemical fertilizer, 2: 50 kg.ha-1 phosphorous chemical fertilizer, 3: pseudomonas putida (PSB), 4: Glomus mosseae (GM), 5: PSB+GM, 6:PSB+GM+25 kg.ha-1phosphorous chemical fertilizer, 7: PSB+ 25 kg.ha-1 phosphorous chemical fertilizer and 8: GM+25 kg.ha-1phosphorous chemical fertilizer. At flowering stage root traits such as root volume, root area, root diameter, root length density and root surface area density were studied and measured. At full maturity, agronomic traits such as spikes.m-2, grains.spike-1, 1000-grain weight, grain yield and biomass yield were recorded using a sample of ten random guarded plants from the middle ridges of each plot. The data were analyzed statistically by SAS program and the data means were compared by Duncan's multiple range test (DMRT). Results indicated that interaction effect between cultivar× fertilizer sources had significant effect on root length total, root volume, root area, root diameter, root length density, root surface area density, spike.m-2, grains.spike-1, 1000-grain weight, grain yield and biomass yield. Using fertilizer sources had  positive and significant effect on root traits and grain yield in two dryland wheat under dry land condition, so that Saji cultivar ×GM+25 kg.ha-1 had the highest root volume (4.6 cm3), root area (70.9 cm-2), root length density (0.158 cm root length.cm-3 soil), root surface area density (84.3 cm2.cm-3), spike.m-2 (257.5 spikes), grains.spike-1 (42.7 grains), 1000-grain weight (39.7 g), grain yield (3571.6 kg.ha-1) and biomass yield (7840.6 kg.ha-1) and the lowest root traits and grain yield belonged to Keras Sabalan×check treatment. There was significant different between cultivars to response of Using of phosphate solubilizing bacteria and mycorrhizal fungi, so that Saji cultivars had the best response to mycorrhizal fungi. Therefore with regard to cultivation of wheat is facing to drought and heat stress indicated that Saji cultivar and using of mycorrhizal fungi can be the best result under dry land conditions. The results indicated phosphate solubilizing bacteria (PSB) and mycorrhizal fungi (GM) had positive effect on root system and grain yield, so that root traits and grain yield had the better status in presence of inoculation with GM. In fact PSB and GM could alleviate the partial of grain yield in presence of dry land farming. Recent studies indicated that symbiosis bio-fertilizers also improved soil physical and chemical traits and increaced organic matters content, root system and P available to coexistent plant.

In order to evaluate the response root of safflower to concentration, time and method of use of seaweed extract, a factorial experiment in a completely randomized design with three replications a greenhouse at the Agricultural Faculty of Ferdowsi University of Mashhad in 2014 was carried. Factors included concentration of seaweed extract on four levels , Stages of use seaweed extract in two levels and the use method of seaweed extract on two levels were. The results showed that the concentration of seaweed extract on the characteristics root volume, root surface, shoot to root ratio, plant height, stem diameter, number of bolls per plant and biological yield of un-direct boll very significant side effect found (p

Seed priming is a method which is effective in improving germination and seedling establishment under stress conditions. To investigate the effects of seed priming on emergence and morphological characteristics of root of three canola cultivars, an experiment was arranged in a randomized complete block design in split plot with three replications. Main factors including five sowing dates with an interval of ten days and three canola cultivars and priming treatments including priming with water, zinc sulfate and control as sub plots were arranged in a factorial experiment. Results showed the highest emergence rate was achieved in Okapi by zinc sulfate priming with an average increase of 32 percent in all sowing dates. The most of the fresh and dry weight of three cultivars resulted from the first sowing date, 6 September. Sowing date October 16 under the hydropriming and primed with zinc sulfate increased root length by 7 and 10 percent in the Okapi, 18 and 23 percent in Zarfam and 32 and 35 percent in Talayeh compared with their controls, respectively. Root volume of Okapi on September 26, October 6 and 16, increased respectively 38, 61 and 71 percent in hydropriming and 51, 67 and 47 percent by priming with zinc sulfate compared with their control treatments. The highest root area on 6 and 16 September in all three cultivars was achieved by priming with zinc sulfate. Despite the decrease in root diameter of delay sowing date, priming treatments could increase root diameters compared with controls in each sowing date.

Salinity is a major abiotic stress affecting agricultural production. Barley is one of the most tolerant species among glycophyte plants to salt stress. High tolerance of barley to salinity stress is related to its rapid phonological growth and development. Understanding of growth and development of different organs of plant, especially root, is important for optimal management of halophytes (Chen et al., 2008). Root systems can exhibit enormous plasticity on the level of biomass, morphology, and or physiology in response to different environmental parameters such as water and nutrient availability. Because root system traits, such as water uptake rates per surface area, are defined by the properties of individual root segments detailed studies about the abundance, morphology, anatomy, and physiology of individual roots are needed (Rewald et al., 2012). Root length can be the most important characteristics because many researchers believe that the root length per unit volume of soil is the best feature to calculate water uptake by the plant (White and Kirkegaard, 2010). The root diameter reduces in salt stress conditions. It varies in different species (Eshel and Beeckman, 2013). Grouping of accessions by multivariate methods in would be of practical value to wheat breeders in that representative accessions may be chosen from different clusters for breeding purpose and it also helps to define strategies for further collection of germ plasm (Alavi siney et al., 2013).
The objectives of this study were to evaluate effect of NaCl salinity on seedling root traits in doubled haploid barley, grouping, ranking and selecting of superior genotypes based on studied traits.
In order to investigate the effect of NaCl salinity on seedling root traits in doubled haploid barley, a study was carried out as a factorial experiment based on completely randomized design with three replications in the green house of Zanjan University in 2012. Fifty doubled haploid lines were studied in zero (control) and 150 mM salinity levels. Traits of the root area, root angle, cumulative root length, length of the longest root, diameter root were measured with daily imaging of the seedling. Data were analyzed by the analysis of variance (ANOVA) with using SPSS (21). Cluster analysis and Aronachalam and Bandyopadhyay(1984) were used for grouping and ranking the doubled haploid lines respectively.
Results and DiscussionThe results of the variance analysis showed significant differences between lines and interaction of line × salinity for all of traits. The significant differences among lines for the studied traits refer to the presence of considerable variation among lines and give a chance to plant breeders for betterment of these characters through breeding. The significant interaction between lines and Salinity shows a lines specific adaptation to different salinity. Therefore, this diversity can successfully be used for improvement of barley yield. However, the correct selection of doubled haploid lines can be considered as one of the crucial factors in farm management and economic barley production. Generally, salinity was decreased root length and cumulative root length. In four lines did not decrease the root length under salt stress and in three lines didn’t show reduced cumulative root length under salt stress. The root angle, in all lines except the six lines, under Stress-free conditions was greater than the stress condition. Root area showed a downtrend in stress conditions than under normal condition those five lines are not obeyed of the law. The effect of salinity on root diameter did not show similar results among the lines. Using cluster analysis and Arunachalam and Bandyopadhyay (1984) method, barley doubled haploid lines were divided two groups based on studied traits both normal and salinity conditions. Genotypes with 2, 29 and 69 code were selected as superior genotypes in both of conditions.
ConclusionThe results of experiment showed that the root traits are affected by salt stress. Since, it is necessary, we know about the relationship between root traits such as, area and length of root and their relationship with salt stress. Salt stress decreased amount of root area, cumulative length, length of longest root and root angle. Tolerance to salinity is related to all of traits involved in salt tolerance. The root absorbs water and nutrients to the extensive role that it can play a major role in salinity tolerance. Cluster analysis based on the studied traits in both conditions (normal and stress) divided genotypes in two groups and multivariate analysis of variance confirmed these results. Arunachalam and Bandyopadhyay showed genotypes number 2, 29 and 62 were superior genotypes in both conditions. Therefore, these genotypes can be used in both of condition.