Showing 16 results for Triticum Aestivum
Volume 5, Issue 1 (1-2003)
Abstract
Current assimilation, as a source of carbon for grain filling in cereals, may be limited for normal grain filling under Mediterranean climate. In such conditions reserves accu-mulated before anthesis play an important role in grain growth, but the extent of their contribution depends on prevailing environmental conditions. The experiment described here was carried out to determine the effects of different levels of water stress on dry mat-ter and nitrogen accumulation and their remobilization from the shoot to the grain. The pot experiment was conducted in the glasshouse using two wheat cultivars (Sun 92A and Vasco) differing in yield and protein content. The plants were subjected to water stress at 10 days after anthesis (daa). The following treatments were established: not watered (se-vere stress), medium stress (-2 Mpa water potentional of the Flag leaf), mild stress (-1 Mpa water optional of the Flag leaf), divided root and control. Results indicated that the dry matter and N content of vegetative organs and its concentration were greater at 24 daa than at maturity under all conditions. Water stress during the post anthesis period was unfavorable to a high assimilation rate, so yield was determined to a great extent by the availability of water and the behavior of the cultivars related to shoot reserve remo-bilization during the grain filling period.
Volume 6, Issue 22 (10-2009)
Abstract
The aim of this research was to compare the benefits of wheat enrichment in the farm with flour fortification in the factories. Three experiments have been carried out in the early of third Millennium in 6 different provinces, i.e. East and West Azerbaijan, Kerman, Sistan and Balouchestan and Southern Khorasan. The first and second experiments (2000-02 and 2002-04), were designed based on t-distribution and included two treatments: The control plots were given nutrients based on Farmer's conventional fertilization practice (NP) and the treated plots received nutrients based on soil tests (balanced fertilization) in Meyaneh (3 wheat farms) and Naghadeh (1 wheat farm) in East and West Azerbaijan provinces. In the wheat fields, micronutrient-fertilizer solution with 0.5% was sprayed at three stages (stem elongation, heading, and a week after flowering). After harvesting, the grain yield, phytic acid, Zn and PA/Zn molar ratio were measured. Then, whole-wheat bread and regular bread prepared from these farms were fed for 4 and 6-month periods to different groups in Tajark, Khanghah and Kahriz villages in East and West Azerbaijan, respectively. Before and after feeding the village inhabitants, zinc (Zn) and iron (Fe) concentration were measured in their blood serum. In the third experiments, in the summer of 2003, a study on the effect of fortification and improvement of the quality of bread on the health of consumer subjects was carried out on the total personnel of Moghadam Mersad Military Station. A number of the drafted military service personnel of Moghadam Mersad Military Station and some personnel from Ravar Aboozar Military Station were selected for blood tests. During a 4-month test period, bread consumed at the Station and the associated units was fortified and the correct procedure of baking was taught to the bakers. The amount of Zn and Fe in the blood serum of the subjects was determined with an atomic absorption spectrometer. Fortification of the wheat flour was carried out at the Baghin Martyrs Station, by adding, 80 mg Zn; 50 mg Fe; 10 mg vitamin B1; 2.5 mg Vitamin B2; and 5 mg vitamin B6 per kg of flour. In the first and second experiments, the results demonstrated that there was a significant difference at one percent level for grain yield (α=0.01). Also, the statistical analysis revealed a significant difference for phytic acid, Zn and molar ratio of phytic acid to Zn (PA/Zn) in all wheat farms. Consumption of whole wheat bread in comparison with white bread for 4 and 6-month periods noticeably increased Zn and Fe concentration in blood serum especially in 6-month period. While the average Zn and Fe concentration in the blood serum in the second experiment for the control was 80 and 100, they were increased to 110 and 130 μg/deciliters after the intervention in Kahriz village. In the third experiment, in places where bread was not fortified, the average level of Zn in the blood serum of individuals was measured to be 72 μg/deciliters; whereas, the serum Zn of the test subjects consuming fortified bread for a three-month period averaged 89 μg/deciliters (P<0.01). For persons who fed on unfortified bread, 47% suffered from Zn deficiency but those who used the superior quality, fortified bread, only 10% suffered from this deficiency (P<0.01). While the number of people using stomach-problem-related-medicines at the Beghin Martyrs Station during a 4-month period before the experiment was figured to be 1615, it was reduced to 1375 cases after the test; or a 15% decrease during a 4-month period. In conclusion it can be mention that superiority of the enrichment in the farm over flour fortification in the factory has been proven. Enrichment is preferred to flour fortification and its most important benefits are at least 20% increase in wheat yield as well as grain quality and more than 10% increase in minerals concentration due to more uptake by human's digestion system.
Volume 7, Issue 3 (7-2005)
Abstract
Physiological traits are receiving increasing attention as screening tools for drought re-sistance. Two field experiments were conducted in 1998 at the Experimental Station of College of Agriculture, Shiraz University at Badjgah, to evaluate the effectiveness of leaf water potential, leaf osmotic potential and canopy temperature in screening resistant bread wheat (Triticum aestivum L.) genotypes. Nine wheat cultivars consisting of drought resistant, intermediate and susceptible genotypes were grown in two randomized com-plete block designs with three replications. The experiments only differed with respect to their irrigation regimes. Leaf water potentials and leaf osmotic potentials at three devel-opmental stages -stem elongation, booting and flowering - under water stress conditions, and canopy temperature in non-stress conditions could discriminate between resistant and susceptible cultivars. Although the drought susceptibility index could partly dis-criminate between resistant and susceptible cultivars, it was not evaluated as a reliable index. The linear regression of grain yield on each trait was determined. The linear re-gressions of grain yield on leaf water potential; leaf osmotic potential and canopy tem-perature confirmed the above results.
Volume 8, Issue 32 (10-2011)
Abstract
Paying a heavy subsidy just on N and P-fertilizers has caused farmers to overuse these fertilizers in the country and hence, more than 90% of the fertilizer use constitutes N and P-fertilizers on the irrigated wheat farms. Due to continuous imbalanced fertilization, especially the overuse of P-fertilizers and the absence of Zn-fertilizers in the farmers’ conventional fertilization practice, there has been an increase in the concentration of phytic acid (C6H18O24P6) in the wheat grains. Increased level of phytic acid (PA), would lead to a high molar ratio of phytic acid to zinc (PA/Zn) in wheat grains up to around 60. Phytic acid combines with metal cations in the digestive system and converts them to phytate complexes which do not get absorbed in the human body. Presence of higher PA has been mentioned as a reason for discarding the wheat bran. Removing bran from the wheat grains is the fastest and easiest way of discarding PA. According to the World Health Organization (WHO), for absorption of nutrients by digestive system in human body, PA/Zn index must be less than 25. Due to calcareous nature of the studied soils and continuous imbalanced fertilization, especially the overuse of P-fertilizers, PA/Zn molar ratio is around 60. Since the main part (70%) of mineral nutrients, vitamins and PA are accumulated in the wheat bran, the authorities; instead of scientifically solving the problem- i.e. reducing PA and increasing Zn concentration in wheat grains- have decided to take away bran from the wheat kernel in the process of flour preparation. By removing subsidies in the 5th Development Plan, since the price of bread will increase significantly, so it is necessary to increase the quality of the bread. To achieve high quality bread, concentrations of PA and Zn should decrease and increase, respectively. This is possible only through the enrichment of wheat in the farm by the use of balanced fertilization, eliminating subsidy on P-fertilizers and allocating subsidy to zinc, bio- and organic fertilizers in order to reduce PA/Zn index. Various studies in the past two decades have shown that if current imbalanced fertilization is continued, PA/Zn index will be well around 60, necessitating the removal of the bran. But, if balanced fertilization is adopted as a general practice by the country's farmers, this ratio will decrease and it will not be necessary to remove the bran in flour processing. It is suggested to remove the subsidy from N and P-fertilizers and allocate them to Zn, biological and organic fertilizers, as well as conducting soil and plant analysis to determine required fertilizer levels. Phosphate fertilizers must be given to the farmers only on the basis of soil tests. Imposing heavy penalties on the bakers who illegally use baking soda instead of yeast and implementing optimal fertilizer management practices will result in crop enrichment in wheat farms, which, in addition to achieving sustainable production of healthy crops, will contribute to upgrading Iranian society’s health-rating. By practicing balanced fertilization, applying zinc sulfate and bio-organic fertilizers, the country's nutrition will improve and the quality and quantity of whole wheat bread will be upgraded significantly, and hence the problem of malnutrition will be solved in the Iranian society.
S. Hatami , A.a. Emamjomeh, M. Farshadfar , H. Safari , B. Fakheri ,
Volume 9, Issue 2 (9-2018)
Abstract
Aims: Wheat is one of the most important crops products in Iran. Considering the role of nanotechnology in the production of crops, the study of the effect of nanoparticles on its growth processes is very important. The aim of this study was to investigate the effect of silver nanoparticles on germination characteristics of wheat in in vitro situation.
Materials and Methods: In this experimental study, germination characteristics of 10 wheat cultivars were performed in 4 concentrations including silver nanoparticles, 10000, 5000, 1000, and zero (Control) with 4 replications in factorial design based on completely randomized design. Root and shoots length, root to shoot ratio, germination rate, percentage of germination, time average and index of germination, daily mean germination, seedling emergence and, vigor index were measured. Analysis of variance and Pearson correlation as well as SPSS 18 and Excel 2013 were used to analyze the data.
Findings: All traits had a significant correlation with each other (p<0.01). There was a significant difference between cultivars and also between different concentrations of nanosilver for all traits (p<0.01). Major decomposition and cluster analysis showed the highest level of germination at the control and further at 1000 ppm level. Also, with increasing nanoparticle concentration, the germination characteristics also showed a significant decrease (p<0.01). Orom and Parsi were the best cultivars because of the highest value of germination characteristics.
Conclusion: High concentrations of silver nanoparticles have an effect on germinating characteristics and reducing their amounts. There are variations between the wheat cultivars for the studied characteristics. Orom and Parsi cultivars are superior to other cultivars.
Volume 13, Issue 7 (12-2011)
Abstract
The short arm of rye (Secale cereale L.) chromosome 1 (1RS), besides being part of the rye genome, is present in many hundred wheat cultivars as either 1RS.1BL or 1RS.1DL wheat-rye translocation. In this study, the distribution of the wheat–rye translocation was examined in 33 Iranian winter and spring wheat cultivars, nine of which had a known donor of 1RS.1BL translocation and the other 24 were randomly selected cultivars without a known source of 1RS.1BL in their pedigree. The presence of the translocation was verified in 4 cultivars, using genomic in situ hybridization analysis. We also compared the Na+ exclusion and K+/Na+ ratios in leaf and root of the identified 1RS.1BL translocations and in eight randomly selected non-translocated (NT) control cultivars grown in hydroponic solutions, containing 0 and 200 mM NaCl. Mean comparisons showed that the 1RS.1BL cultivars (Atrak, Dez, Falat, Rasul) had significantly lower rates of whole plant dry weight and root dry weight in the presence of 200 mM NaCl compared with NT control cultivars. No significant difference was observed between translocated and NT cultivars for Na+ concentrations and K+/Na+ ratios in their leaves or roots. Although, there are many useful genes in 1RS arm, it has no substantial contribution to Na+ exclusion in comparison with NT controls at seedling stage.
Volume 15, Issue 5 (9-2013)
Abstract
Individual grain weight of wheat kernels differs with their positions on a spike. Cultivation practices (such as fertilizer nitrogen and plant growth regulators application) can be used to improve weight of basal and distal kernels. For this purpose, two experiments based on randomized complete block design were carried out with three replications. The aim of this research was to study the mechanisms related to sink strength as well as the regulatory factors affecting sink activity. One cultivar of a facultative wheat, cv Yangmai15, was used. Treatments of the experiments included application of nitrogen (two levels) and plant growth regulators [abscisic acid (ABA) and Fluridone (inhibitor ofABA synthesis)] in basal and distal kernels, respectively. Results showed that nitrogen application increased grain yield and its components. Grain filling in basal kernels started earlier and its rate was higher than that of the distal kernels. Nitrogen fertilizer increased the individual kernel weight both in basal and distal kernels, and the rate of increment was higher than the control, even in distal kernels. The application ofABA resulted in increase in grain weight, whereas a considerable decrease in grain weight was observed in response to Fluridone compared to the control. Nitrogen application together withABA application enhanced the activity of SuSase, AGPase, SSS, and SBE in basal and distal kernels and the increment in the activity was higher in distal kernels. It is concluded that simultaneous application of nitrogen andABA enhanced grain weight by regulating the activity of key enzymes involved in starch synthesis.
Volume 16, Issue 2 (3-2014)
Abstract
A consortium of biofertilizers (Azotobacter chroococcum and Bacillus subtilis) was applied in conventional as well as organic matrix entrapped granular forms as sole nutrient source in two different doses for cultivation of wheat (Triticum aestivum L. cv. PBW-343). A double dose of conventional biofertilizers increased the growth of wheat plants as measured on 30, 60, 90, and 120 Days After Sowing (DAS) in terms of root and shoot length, number of roots and leaves, as well as fresh and dry weight of roots and leaves over the recommended dose (0.6 kg ha-1) of the same biofertilizers. The entrapment of biofertilizers in an organic matrix further increased the efficacy of these biofertilizers over the non-entrapped conventional forms. An increase in the plant growth of wheat by application of higher dose of biofertilizers and entrapped biofertilizers was correlated to the availability of NO3-, NO2- and NH4+ in the plant’s rhizosphere (0-15 cm) and its transport from soil to the plant leaves as well as productivity and yield of wheat in these experimental fields. The increase of 63.47 and 32.17% in wheat yield was recorded in 120-days old plants by the application of organic matrix entrapped biofertilizers in double dose over no fertilizers and un-entrapped biofertilizers in single dose. The results indicate that efficacy of biofertilizers can be enhanced by increasing the dose of biofertilizers and by providing suitable carriers to replace chemical fertilizers load for wheat cultivation with eco-friendly and organic nutrient technologies.
Volume 17, Issue 6 (11-2015)
Abstract
The studies carried out over 2010-13 involved a static field experiment initiated in 1999 at Brody Research Station of the Poznan University of Life Science, Poland. The soil tillage systems for winter wheat were compared on a soil classified as Albic Luvisols. The aim of experiments was to evaluate impact of ploughless soil tillage on some soil physical, chemical, biological properties and winter wheat productivity parameters. Tillage systems included: Conventional Tillage based on moulboard ploughing (CT), Reduced Tillage with a stubble cultivator (RT), and No-Tillage (NT). The soil tilled under RT and NT recorded higher values of water content and soil bulk density, especially in the top layer. On the other hand, in the 10-20 cm layer, soil bulk density was significantly higher under CT than under RT and NT. Soil penetration resistance was lower under CT than under RT and NT from 0 to 20 cm depth. However, soil penetration resistance was consistently higher under CT than under RT and NT from 21 cm to 30 cm depth. Organic C and nutrient elements tended to accumulate in the surface horizons under RT and NT compared with CT. Enzymatic activities were found in the more superficial layers of soil under RT and NT than under CT. The grain yield decreased by 6.9% under NT compared to CT, and ranged over a similar level under RT and CT. The decreased yield in NT probably resulted primarily from a lower number of ears per unit area. In our opinion, in the future, more research is needed to determine the role of changing soil properties over time in crop yields, and no-tillage system needs to be improved to secure plant establishment and crop yield.
Volume 17, Issue 7 (12-2015)
Abstract
Pasting is one of the most important properties of wheat starch determining the flour quality and functionality. Twenty three New Plant Type (NPT) wheat derivatives along with three checks (PBW 343, HD 2329, and Raj 3765) have been studied in multi-location trials to assess the variation and environment induced fluctuations for their starch pasting properties. Although all flour pasting characteristics varied, Breakdown Viscosity (BV) and Setback Viscosity (SV) exhibited greater variability across environments. Additive Main effects and Multiplicative Interaction (AMMI) analysis indicated significant interactions between Genotypes and Environments Interaction (GEI) in starch pasting properties. Genotypes accounted largest proportion (39.78%) of the Sum of squares (SQ) for peak viscosity (PV) followed by environments (33.30%) and GEI (33.30%). Trough Viscosity (TV), GEI accounted for the largest proportion (40.44%) of the SQ followed by environments (31.76%) and genotypes (27.80%). Genotypes accounted for the largest proportion (44.0%) of the SQ for (BV) followed by environments (33.30%) and GEI (21.59%). With respect to FV, environments accounted for the largest proportion (43.07%) of the SQ followed by GEI (30.84%) and genotypes (26.09%). Environments accounted for the largest proportion (52.48%) of the SQ followed by genotypes (23.89%) and GEI (23.65%) for SV. The interactions between genotype and locations differed greatly; however, some genotypes apparently found to be specifically adaptable to growth location. Correlation among starch pasting characteristics revealed that significant positive correlations were found between PV and BV, FV and TV, as well as SV and FV in all the individual environments tested that can be utilized in selection and simultaneous improvement in for starch quality improvement.
Volume 19, Issue 2 (3-2017)
Abstract
This study was aimed to assess the effects of excess boron on 59 genetically divergent wheat accessions and to identify those with high and stable yields under a range of soil boron concentrations. The second aim was to test the applicability of a laboratory technique performed at juvenile stages of development in estimating field boron tolerance. The study comprised a control and three boron treatments, applied as 50, 100 and 150 mg boric acid L-1 in laboratory, and 33.0, 67.0 and 133.0 kg boric acid ha-1 in field trial. Yield performance and stability were evaluated using biplots from sites regression model, while interrelationships among analyzed parameters were assessed using path coefficient analysis. Parameters were mostly decreased by excess boron when compared to the control (seedling root length, seedling dry weight, grain number per spike, grain yield, flag leaf area, leaf area duration and grain weight). Significant increase was noted for seedling boron concentration and content, percentage of sterile spikelets per spike and number of spikes per m2. Spike length, number of spikelets per spike, and anthesis date remained unaffected. The majority of accessions with high and stable yields were of local origin, so, we conclude that adaptation to environmental factors other than elevated soil boron plays an important role in overall field boron tolerance. The effects of excessive external boron on boron accumulation noted at the seedling stage in laboratory studies corresponded to its effects on yield in field.
Volume 20, Issue 7 (12-2018)
Abstract
The objective of this study was to evaluate the adaptability and stability of wheat genotypes simultaneously in unbalanced Multi-Environment Trials (MET) in four different regions of Brazil, using the method of harmonic means of the relative performance of genetic values. Mixed model was applied to the analysis of Genotype- Environment Interaction (GEI) in wheat. Grain yield data were obtained from a network of MET carried out at seven locations from 2008 to 2010. A joint of experiments in complete randomized blocks design with some common treatments was used in all 21 experiments. Adaptability and stability parameters were obtained by several different methodologies, based on prediction, Harmonic Mean, and of the Relative Performance of Genotypic Values (HMRPGV). These methodologies ranked in a very similar way the studied genotypes and indicated the genotypes CD0950, CD0857, CD0667, CD0915, CD0914, CD0669, CD0859, and CD0851 as the superior ones for grain yield, adaptability, and stability in all environments. Dourados-MS (2010) was the worst environment with lowest mean (1,560.26 kg ha-1) and São Gotardo–MG (2008) was the best environment with highest mean (5,687.08 kg ha-1). The genotype more stable by HMRPGV across 21 environments tested was CD085; in the best environment, it was ranked the sixth (6,319.30 kg ha-1), but changed your values in the worst environment and was ranked the fifth (2,051.53 kg ha-1). The HMRPGV proved to be a practical and useful statistical tool in the determination of the Value for Cultivation and Use (VCU), particularly in the selection of genotypes’ reliability when genotypes are selected for the environments evaluated. This method has the advantage of providing results that are directly interpreted as breeding values for yield, stability, and adaptability.
Volume 21, Issue 5 (9-2019)
Abstract
In recent years, spelt (Triticum aestivum (L.) ssp. Spelta) has become an added-value alternative crop to modern wheat. Spanish spelt constitutes a unique separate gene pool from central European germplasm. The availability of spelt Doubled Haploid (DH) production protocol is a great advantage to speed up breeding programs. This is the first study evaluating the ability of DH plant production, by anther culture, of five Spanish spelt landraces and three F5 lines derived from Spanish spelt x bread wheat crosses. Two central European commercial varieties were also included in the analysis. DH plants were obtained from all material with the exception of one F5 line. The Spanish spelt landraces produced more embryos/100 anthers (73-166.3) than the two European varieties (8.6-22.2). The main bottleneck in the Spanish germplasm was the high number of albino plants regenerated, with percentage of green plants lower than 13% in three of the landraces. Nevertheless, up to 15.6 and 1.8 green plants/100 anthers were obtained from the Spanish and the central European germplasm, respectively. A great variation in the percentage of spontaneous chromosome doubling was obtained, with 4 lines producing around 80% and 2 lines less than 15%. The ovary genotype used for anther co-culture is a critical factor to increase the efficiency of the system. Bread wheat ‘Caramba’ ovaries increased almost 6 times the number of green plants as compared to spelt landrace ‘BG-1987’ ovaries. This study shows that DH plants can be produced efficiently from Spanish spelt to be used in breeding programs.
Volume 22, Issue 3 (4-2020)
Abstract
Among gliadins, α-gliadins are important active proteins in triggering celiac disease in human beings owing to the presence of toxic epitopes. A set of 177 α-gliadin gene sequences and the corresponding proteins were analyzed. Twenty accessions of hexaploids including 1, 14, and 5, respectively representing A, B, and D, with no intact CD-epitopes in α-gliadins, were identified. Twenty-two and 13 conserved motifs in non-repetitive domains NR1 and NR2, respectively, of α-gliadins differentiated all the amino acid sequences encoded by A genome of both diploids and hexaploids. Most of the amino acid sequences encoded by D genome (70 of 75 in hexaploids and 13 of 16 in diploids) could be identified by 22 amino acid motif. Large variations and lesser number of intact CD-epitopes was observed for α-gliadins belonging to B genome. As compared to diploids, repeat length of polyglutamine repetitive domain QII of B genome was lower in hexaploids indicating loss of Q residues during evolution of hexaploid wheat. The information can be used in assigning any α-gliadin sequences onto A, B, and D genomes and identifying wheat accessions with lesser CD-epitopes. The result presented here will be useful for the wheat improvement programs aiming for the management of celiac disease in human beings.
Volume 22, Issue 3 (4-2020)
Abstract
The influence of seed priming on the growth, amino and fatty acids contents of two wheat (Triticum aestivum L.) cvs. Keumkang and Backjung were evaluated through pot experiments in greenhouse and at field conditions. Four priming treatments involving three soaking media: 2.5% potassium Chloride (KCl), 1% potassium Sulfate (K2SO4), distilled water (H2O) and unprimed (dry seeds) as the control were laid out in a randomized complete block design with four replications for each experimental condition. Under greenhouse condition, 1% K2SO4 priming enhanced growth and yield of wheat, while 2.5% KCl reduced the dry matter yield in Keumkang, but not in Backjung. In field condition, 1% K2SO4 improved the growth of both cultivars and increased the yield of Backjung, while 2.5% KCl in Keumkang had the lowest yield. Overall, this study showed that seed priming with 2.5% KCl and 1% K2SO4 triggered specific changes in the Amino Acids (AA) and Fatty Acids (FA) compositions in grain and had carry-over effects on the plant’s metabolic adjustments, which were specific to the cultivar and the growing environmental conditions. The compositional changes in AA and FA induced by seed priming have a profound impact on grain and flour quality of wheat.
Volume 24, Issue 6 (11-2022)
Abstract
Wheat floret primordia develop in a rather narrow window of time, mostly coinciding with stem elongation. That is why the stem elongation phase is considerd a critical period for grain number and yield determination. Under controlled conditions, floral primordia development of 10 mostly adopted bread wheat cultivars including Bayat, Azadi, Falat, Navid, Chamran, Marvdasht, Pishtaz, Shiraz, Sirvan, and Baharan, which were released during the last five decades, was studied in detail at Shiraz University, Shiraz, Iran. Floral primordia monitoring showed that visible floral degradation among wheat cultivars occurred at several floral developmental stages from green anther (GA) to anthesis (AN). Floral degradation period started from yellow anther stage and was longer in cultivars with lower grain number per spike (Bayat, Navid, Shiraz and Azadi cultivars). Also, cultivars that started stem elongation earlier, such as Sirvan, Baharan, Chamran, and Falat, had extended period for stem elongation and produced higher grain number per spike. Overall, it appeared that under short growing seasons of semi-arid regions, in which delay in flowering usually results in more floral mortality during GA to AN, cultivars with earlier stem elongation could be more efficient in production of grains.