جستجوی مقالات مرتبط با کلیدواژه "triticum aestivum" در نشریات گروه "کشاورزی"

The study of genetic diversity in crops is essential for breeding programs and conservation of heritage resources and is a key step in assessing the adaptation of the population to new environmental conditions and thus the selection of new cultivars. There are various methods for estimating genetic diversity in different plant species, including the use of morphological traits and DNA markers.

For this purpose, in this study, genetic diversity between 25 bread wheat accessions in terms of 23 agronomic traits and 20 SSR molecular markers was investigated. A field experiment was conducted in 2016-2017 in the form of a randomized complete block design with three replications in rainfed and irrigation at the end of the growing season conditions in the research farm and laboratories of the Faculty of Agriculture and Natural Resources of Razi University.

The results of analysis of variance showed that there was a significant difference between the accessions for most of the studied traits. Based on the results of cluster analysis, the accessions were divided into four groups. The results of comparing the mean and cluster analysis showed that accessions 2, 13, 6, 15, 18 and 10 were the best accessions based on agronomic characteristics, which can be suggested for breeding programs, and in contrast to accessions 3, 24, 11, 12 and 16 as the weakest accessions in terms of The studied agronomic traits were identified. In assessing the genetic diversity of the populations using 20 SSR markers, 16 primers with suitable polymorphisms were selected. The percentage of total polymorphism was estimated to be 93.75. XCFD168-2D, XGWM350-7D and XGWM136-1A primers with 100% polymorphism, maximum number of alleles, high amount of polymorphic information content indices, marker index, effective multiplex ratio index and resolving index due to the high proliferation of bands and the production of high polymorphic bands, they were introduced as the most suitable primers for wheat in subsequent studies. Molecular analysis of variance showed that the degree of diversity within the groups was greater than the diversity between the groups. The results of cluster analysis by UPGMA method based on Jaccard similarity coefficient led to the classification of 25 bread wheat accessions in four different groups, which showed high agreement with the results of analysis to the main coordinates, and finally accessions 1, 3 and 25 had the greatest genetic distance with accessions 13 , 7 and pioneer cultivars, so it is possible to suggest the selection of parents from these two groups for breeding programs.

Evaluation of agronomic characteristics showed that accessions 2, 13, 6, 15, 18 and 10 are superior accessions, among which, oxides of external and internal origin were observed. In evaluating the genetic diversity of the accessions, the primers XCFD168-2D, XGWM350-7D and XGWM136-1A were identified as the most suitable primers for wheat in subsequent studies. Markers with high polymorphism as well as markers and accessions with unique bands in the banding pattern are also of great value for breeding programs, for example, identifying genes useful for resistance to various biological and abiotic stresses in wheat and promoting its various cultivars.

Wheat (Triticum aestivum L.) is one of the most important crops and is grown nearly everywhere in the world. Wheat is the primary staple food in many countries. In light of the fact that wheat yield varies depending on environmental conditions, it is crucial to employ strategies that increase wheat yield. To investigate the effects of foliar application of cytokinin on the physiological traits and yield of wheat cultivars, a factorial experiment based on randomized complete block design with tree replications was conducted at the research farm of the Agriculture Faculty, University of Zanjan, during the 2016 cropping seasons. Six wheat cultivars (Azadi, Karaj 3, Roshan, Falat, Sardari and Yavarus) were treated with foliar applications of cytokinin (6-benzylaminopurine) at two levels (0 (control) and 50 µM). At the 50% stage of cluster emergence (code 55 Zadox growth stage), hormone foliar application was performed three times per week. Foliar spraying was done at sunset. To improve absorption, five ml of diluted Tween 20 (0.1%) was added to each 20-liter sprayer. 10 days after the third spraying, a sample was taken and the traits were measured in order to determine their value. The application of cytokinin significantly increased photosynthetic rate, leaf area index durability, weight per thousand grains, biological yield, and grain yield. The application of cytokinin had no significant impact on the greenness index of the Falat, Karaj 3, Roshan, and Yavarus cultivars, but increased the greenness index of the Sardari cultivar by 116.2% and decreased the greenness index of the Falat cultivar by 12.0%. The Karaj 3 cultivar had the highest photosynthesis with an average of 10.6 μmol.m-2.s-1 net CO2 assimilation rate, while the Falat cultivar had the lowest photosynthesis with 6.46 μmol.m-2.s-1 net CO2 assimilation rate. The application of cytokinin increased the leaf area index duration of the Falat, Karaj 3, and Yavarus cultivars while having no effect on the other cultivars. The foliar application of cytokinin had no effect on the number of seeds per plant, but there were significant differences in the number of seeds among the cultivars studied. The cultivars Karaj 3 and Yavarus had the highest and lowest seed yields per plant, with 172.6 and 83.7 seeds per plant, respectively. The foliar application of cytokinin increased the final grain dry weight of the Azadi, Roshan, and Yavarus cultivars by 5.6%, 14.8%, and 6.2%, respectively, but had no effect on the Karaj 3, Falat, and Sardari cultivars. The Azadi cultivar with an average of 1.08 mg/day and the Sardari cultivar with an average of 1.55 mg/day had the lowest and highest grain filling rates, respectively, among the cultivars studied. Except for the cultivar Roshan, the application of cytokinin increased during the grain filling period of all other cultivars. Compared to the control treatment, cytokinin increased the one-thousand seed weight by 5%. Cytokinin increased the weight of one-tousand seeds by 5% compared to the control treatment. The application of cytokinin increased the yield of the Yavarus, Karaj 3, and Sardari cultivars by 23.7%, 30.1%, and 65.5%, respectively, but had no effect on the yield of other cultivars. In the absence of cytokinin application, Azadi had the highest grain yield at 5700 kg/ha, while Roshan had the lowest at 3100 kg/ha. The application of cytokinin had no significant effect on the harvest index. The Sardari and Yavarus cultivars had the highest and lowest harvest indices (31.4% and 25.1%, respectively), whereas the harvest indices of the other cultivars did not differ significantly. Morphological, physiological, and yield-related traits differ among wheat cultivars, as demonstrated by the results of the present study. The results demonstrated that the response of wheat cultivars to cytokinin application was highly variable, and that hormone application may be ineffective or have a negative impact on certain traits.

To investigate the allelopathic effect of aqueous extract of Malva sylvestris weed on the germination characteristics of Triticum aestivum (hamoon cultivar), an experiment was conducted in 2019 in the Biotechnology Research Institute, University of Zabol. The experiment was conducted in a completely randomized design with three replications. The aqueous extracts concentrations of Mallow included 0, 25, 50, 75, and 100 ml/L. The experimental results show that the aqueous extract of Malva sylvestris had a significant effect on radicle length, hypocotyl length, germination percentage, chlorophyll b, and phenol. The results indicated that different concentrations of aqueous extract of Malva sylvestris have a different trend on the measured traits. Although with increasing the concentration of Malva sylvestris extract, the percentage of germination, radicle, and hypocotyl length has decreased, the synthesis of chlorophyll and phenol in wheat treated with 50 ml of aqueous extract of Malva sylvestris has reached its maximum. At a concentration of 100 ml of aqueous extract of cottage cheese, root length and germination percentage decreased by 65% and 85%, respectively, compared to the control. The results of this study showed that aqueous extract of cheese had a negative effect on the growth characteristics of wheat.

Phytate, the highest inorganic phosphorus in cereal grains, is an anti-nutritional factor that reduces the bioavailability of iron (Fe) and zinc (Zn). The whole grains of 109 hexaploid landraces and modern bread wheat cultivars (Triticum aestivum L.) were used to determine Fe, Zn, and phytate concentrations and their bioavailability using phytate:mineral molar ratios. In addition, some morphological and physiological features were identified as contributory factors for the screening process. In the field experiment, the concentrations of Fe and Zn, ranged between 0.036-0.255 mg/g and 0.030-0.085 mg/g, respectively. There were no significant differences in Fe and Zn concentration between the bread wheat cultivars and landraces. Therefore, efforts made by breeders for developing high-yielding wheat didn’t have detrimental effects on Fe and Zn concentrations. The modern bread wheat cultivars showed a significantly higher phytate concentration than landraces. Grain phytate ranged from 15.07-28.77 mg/g resulting in a variation in phytate:Fe of 6.24-58.14 and phytate:Zn of 32.20-77.22, indicating poor bioavailability of these minerals. The identified drawbacks were due to relatively high phytate concentration which in turn could be due to a high level of soil phosphorus concentration, suggesting increasing mineral bioavailability by the breeding methods to reduce the phytate and phytate:mineral ratio. In the solution culture experiment, the role of root length, root dry weight, and root nutrient concentration in distinguishing cultivars’ Fe uptake was demonstrated. The study also revealed that lower values of root length, root dry weight, and leaf dry weight led to lesser leaf Fe which in turn caused reduced contents of photosynthetic pigments and chlorophyll fluorescence. Due to high Zn and Fe concentration, and low concentration of phytate and phytate:mineral molar ratio, some of the current landraces such as Khoram Abad (1), Sarouq (4), Eskan Arak (2), and Hoseinabad Arak could be exploited by breeding strategies in biofortification programs.

Abstract Application of defense-inducing compounds such as microbial volatiles is a new strategy for suppression of plant diseases based on plant intrinsic genetic potential. In this study, effect of defense inducing compounds including, benzothiazole, methyl salicylate, methyl jasmonate, butanediol, indole and acetoin were investigated on Gaeumannomyces graminis var. tritici mycelial growthin vitro and on suppression of wheat take-allat greenhouse situation as a completely randomized design. Seeds of wheat cultivar Pishgam were surface sterilized and placed in 100 μM solution of benzothiazole, methyl salicylate, methyl jasmonate, butanediol, indole, acetoin or control (distilled water) for 30 minutes. Seeds were sown in the pots containing pathogen inoculated soil in the greenhouse for 30 days. In vitro experiment showed that indole, butanediol and acetoin as best treatment reduced pathogen mycelial growth only 14.29, 14.29 and 8.27% compared to untreated control. Analysis of plant growth factors showed that defence inducers treatment had no significant effect on root dry weight compared to infected control. In contrast, benzothiazole, acetoin and methyl salicylate significantly increased aerial part dry weight. Moreover, all of the chemical inducers were able to reduce disease severity, significantly. The highest disease suppression were achieved in the case of benzothiazole and acetoin decreasing disease severity by 60.9 and 57.4 %, respectively. Exploitation of plant defense inducers seems to be promising strategy in management of wheat take-all disease.

The wheat is one of the most important sources of human food. In production of this product abiotic stresses such as drought, salinity, temperature, etc., involved in cultivation. Therefore, identification and evaluation of genes involved in stress resistance in this plant is very importance. Aim of this study was identifying responsive genes to drought and their expression variation in, resistant and susceptible wheat.

 The data available on the NCBI GEO microarray data were collected in 2018. The libraries were belonging to drought resistant and drought susceptible wheat under stress and control conditions. Using meta-analysis, altered genes expressed under stress conditions were identified for each group of cultivars. Significantly expressed altered genes were identified, the aci-reductone-dioxygenase-like protein (ARD) gene was evaluated for laboratory confirmation. Leaf sampling was performed in 4-leaf stage at three times 2, 4 and 7 days after stress with a control sample with three biological replications. RNA extraction from leaf samples was performed using RNx ™ -plus extraction solution and Real time PCR reaction using specific primers of d ARD gene.

Among differential expressed genes of resistant cultivars, transcription factors genes were Myb3, ethylene responsive 5a, MIKC-type MADS-box WM24B and salinity inducible ERF4 and in sensitive cultivars, transcription factors such as WRKY15, MADS-box TaAGL8, WRKY39 and Myb have increased expression. By identifying the genes and transcription factors mentioned and changing their expression, wheat cultivars can tolerate drought stress. Real time PCR results of ARD Gene for 6o4 and Sundor, drought resistant and drought susceptible wheat varieties was consistent with the results of the meta-analysis and it confirmed the result.

 According to gene expression results and other outcomes of metanalysis in this study, an effective step can be taken in predicting drought resistance and susceptibility in different wheat cultivars.

To evaluate genetic diversity between Sistan common wheat cultivars, it was used 10 SSRs primers associated to stem, leaf and yellow rusts resistance genes. The lowest (3) and highest (7) allele number were generated by 12C, SCS719 and Xgdm116 primers and Xgwm443 primer, respectively (4.55 allele per each primer). The highest genetic diversity (0.39) and MI (2.29) was related to Xgdm116 and Xgwm533 primers, respectively; also, the lowest genetic diversity (0.1) and MI (0.33) was related to Xcfd36 primer. Xgdm36 primer showed the highest Ne, Shannon diversity and Nei diversity (1.45, 0.63 and 0.44, respectively); on the other hand, Xcfd36 primer the lowest Ne, Shannon diversity and Nei diversity (1.18, 0.19 and 0.11, respectively). The highest polymorphic bands between wheat cultivars were related to Arg. Arg and Aflak showed the least diversity for resistance to yellow rust and leaf rust, respectively. Also, Arg had the highest diversity for three types of rusts. The Xgdm116, Xwmc810 and SCS719 primers had more effect on identification of wheat cultivars. Finally, Arg cultivar can be recommended as a donor parent in wheat breeding programs for rust resistance. To gain the highest heterosis, it can be suggested hybridization between Arg and Hirmand cultivars.

Salt stress is considered as one of the most important constraints in wheat production worldwide, thus for, research toward development of tolerant varieties is of great importance. Discovering genes and molecular mechanisms involved in salt tolerance are the primary steps in molecular breeding for salinity. In this study, taking advantage of the data deposited in NCBI Gene Bank, two salinity-related microarray data sets of bread wheat were analyzed to identify salt responsive genes. Bioinformatics’ analyses indicated that 3096 and 2060 genes were salt responsive genes in root and shoot, respectively. Gene ontology analysis of salt responsive genes showed that these genes were enriched for response to chemical stimulus, response to oxidative stress, transport, regulation of transcription and carbohydrate metabolic process in biological process category in both tissues. Furthermore, the differentially expressed genes in metabolic process category were enriched for catalytic activity, binding and oxidoreductase activity in both tissues. In order to determine the key genes involved in salt tolerance, hub analysis was performed on the salt responsive genes identified in the root. Based on the achieved results, the role of regulatory genes including protein kinases, protein phosphatases and transcription factors such as MYB and WRKY, was highlighted in inducing salt tolerance.

Plant lipid transfer proteins, also known as plant LTPs, are a group of highly-conserved proteins of about 8-10kDa found in higher plant tissues. As its name implies, lipid transfer proteins are responsible for the shuttling of phospholipids and other fatty acid groups between cell membranes. Here we study the expression pattern of Lipid transfer protein gene from wheat (Triticum aestivum) responding to Septoria tritici Blotch (STB) by semi quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). This method is used to qualitatively detect gene expression in different cells. level of LTP2 gene expression was measured over time, from 0h to 6 days after inoculation in Wangshuibai as a resistant wheat cultivar and Falat as a sensitive one. The results showed that inoculation of wheat by M. graminicola (asexual stage: Septoria tritici) cause different level of LTP2 gene expression in both resistant and susceptible cultivars over time. The pattern of gene expression indicated that LTP2 gene is an early expression gene in resistant cultivar and induced at 24h after inoculation and in sensitive cultivare the high level expression have been seen at 6 days after inoculation. Thus, according this results can be concluded that these genes, along the main genes, increase and maintain resistance to Septoria tritici blotch in wheat. In this study we cloned LTP2 genes from both cultivars and after sequencing the blast protein was studied. Blast results confirmed that these proteins contain eight cysteines that are conserved in all LTP peptides.

Nanoparticles (NPs) are atomic or molecular with dimension 1-100 nm that can modify their physico-chemical properties compared to the bulk material. In present investigation, Ag nanoparticles were synthesized from AgNO3 (20mM concentration) using leaves extracts of Aloe vera and effects of these biologically Ag nanoparticles and Ag at different concentrations (0, 40, 80ppm) were studied on growth characteristics and leaf flavonoid contents of Wheat. Formation of Ag nanoparticles was identified using UV–visible spectroscopy and X-ray diffraction (XRD). Synthesized Ag nanoparticles were confirmed by the absorption maxima at the wavelength of 460 nm. X-ray diffraction (XRD) analysis showed that the size of synthesized silver nanoparticles had 25nm. The result of treatments biologically Ag nanoparticles and Ag at different concentrations on Wheat showed that at 40 80 ppm of Ag nanoparticle and at 80 ppm of Ag increased root and shoot fresh weight. Application of 40, 80ppm of both Ag nanoparticles and Ag increased flavonoid contents at 300, 330nm wavelengths but had no effect flavonoid contents at 270nm wavelength.

Considering the importance of agricultural issues in adjacent lands to normal saline watersheds and its effect on plant growth and production, the present study was carried out in order to investigate the interaction effect of arbuscular mycorrhizal fungi and plant growth regulator of brassinolide on the possible reduction of adverse effect of salinity on wheat Pishtaz cultivar. The present research in a factorial randomized complete blocks design was conducted with four replications. Thus, mycorrhizal plants with Glomus mice (after ensuring mycorrhizal roots) and non-mycorrhizal 14 days by 24-epibrassinolide with zero and five micro molar concentration were foliar spray three times every other day. Then, they were irrigated by saline water originated from Urmia Lake and the electrical conductivity (EC) zero and 15 ds m per meter one time every three days. Finally, the 26-day-old plants were harvested and transported to the laboratory in order to perform some physiological measures. Findings showed an improvement in leaf area and reducing membrane leakage in separate fungal and brassinolide treatments. While the interaction effect of these two treatments only in the leaf area at the level of P

Wheat (Triticum aestivum L.) is a member of the Poaceae family، an annual and self-pollinated crop which has three groups of 14، 28 and 42 chromosomes with genome formula AA، AABB، AABBDD that the chromosomes are located in three homeologous genomes A، B and D. Wheat has an extremely large genome of 16 × 109 base pairs with more than 80% repetitive DNA and an average of 810 mega base pairs in each chromosome with 10 µm length. Wheat is the most important crop in universe and in Iran، known as strategic and basic commodities. This crop plays an important role in both aspects of production and consumption with a lot of genotypes that requires efficient and accurate means of identifying their relationships and determining their genetic diversity levels. Present study aims to determine the genetic diversity and genetic distances of 91 doubled haploid lines of wheat and their parents using SSR markers and assess the ability of microsatellite markers for detecting polymorphisms based on the variants among their germplasm. Results showed that the number of alleles per locus ranged from 2 to 8 and the allelic value of polymorphism information content (PIC) ranged from 0. 12 for Xgwm46 to 0. 87 for Xgwm186 with an average of 0. 5. A total of 39 alleles were detected. Diversity and genetic relationships of the samples were analyzed using Nei and Li and UPGMA statistical methods and the studied lines were classified into three common groups.