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Showing 28 results for Wheat
Soheila Shayan, Mohammad Moghaddam Vahed, Majid Norouzi, Seyed Abolghasem Mohammadi, Mahmoud Tourchi, Bafrin Molaei,
Volume 4, Issue 2 (3-2018)
Abstract
Drought stress is one of the factors that reduces yield in the world. Considering that wheat is grown mostly in semi-arid areas, much attention has been paid to develop drought tolerant varieties. This experiment was conducted during 2013-2014 in Tabriz University research farm, Iran. In this investigation the inheritance of some agronomic and physiological traits was studied in the field condition through generations mean analysis. The generations were produced from the cross of Arg (tolerant to drought) and Moghan3 (sensitive to drought) varieties. The experiment was a split plot design based on randomized complete blocks with two replications. The irrigation conditions were arranged in the main plots and generations in the subplots. In the stress condition, irrigation was withheld after pollination. Based on the analysis of variance, significant difference were observed among different generations in terms of plant height, peduncle length, flag leaf length, flag leaf width, number of fertile tillers, leaf chlorophyll content, leaf temperature, days to maturity, spike weight, straw weight, biomass, grain yield and harvest index. The interaction between generations and irrigation conditions was significant only for grain yield. The generation mean analysis in both normal and drought stress conditions showed that chi-square of three parameter model was significant for all of the studied characteristics, indicating the presence of non-allelic interactions in the inheritance of these traits. The broad sense and narrow sense heritabilities for the traits under study were estimated as 0.502-0.946 and 0.244-0.429 in the normal condition and 0.653-0.951 and 0.221-0.377 in the water stress condition, respectively. The average degree of dominance for all of the characters in both normal and water stress conditions was greater than one which indicated the existence of over-dominance gene action in controlling these traits. At both conditions, the dominance genetic variance was higher than the additive genetic variance for all of the traits. The results indicate the necessity of selection in advanced generation or exploiting dominance gene action in the breeding programs, if hybrid varieties are produced in the wheat plant.
Dr Mohammad Motamedi, Ms Parviz Safari,
Volume 4, Issue 2 (3-2018)
Abstract
Drought stress is one of the most important factors involved in reducing wheat production and identifying genetic structure and gene action type in controlling grain yield in water stress condition is essential for choosing appropriate breeding methods. In this study, 9×9 one way diallel crosses were used to study the genetic structure of wheat grain yield at stress and non- stress conditions. Combining ability analysis by the second Griffing method for both conditions resulted in significant GCA and SCA variances, representing grain yield may be controlled by additive and non- additive effects of genes. The results of applying combining ability analysis indicated that among the parents, genotypes Ghods and Bam had the highest GCA for grain yield and the best specific crosses were Arg × Ghods, Navid × Moghan, Bam × Alvand (for both irrigation regimes) and Bam × Ghods (in stress condition). Biplot analysis of diallel data was used to display GCA and SCA for parents and to determine heterotic groups and the best crosses. In general, according to the results, Bam, Ghods and Arg were tolerant cultivars and had the ability to maintain yield in drought stress condition as well as to transfer these properties to the hybrids. So these genotypes can be used to improve stress tolerance in breeding programs.
Ali Akbar Asadi, Mostafa Valizadeh, Seyed Abolghasem Mohammadi, Manochehr Khodarahmi,
Volume 6, Issue 2 (3-2020)
Abstract
Dehydration is the most important limiting factor in agricultural production in arid and semi-arid regions, and water shortages (especially at the reproductive stages) due to lack of precipitation and unequal distribution are inappropriate for limiting the yield. In this research, cross between the Gasspard cultivar (dehydrated susceptible parent) and DN11 line (resistant parent) was performed. F1, F2, F3, BC1 and BC2 generations along with parents, were planted in a randomized complete blocks design with three replications in normal and water deficit conditions for two consecutive years. Physiological traits were measured for single plant samples. Weighted analysis of variance showed that water deficit stress caused significant decrease in flag leaf area and unsignificant decrease in stomatal conductance. Generation mean analysis for Chlorophyll index was accompanied by different results in terms of regression fitted models for each environment, but for stomatal conductance, the results of the generation mean analysis were the same in both environments. In addition to additive and dominant effects, epistatic interaction effects also played role in the inheritance of all studied traits. Most of these effects were double-effects. In flag leaf area, additive, additive × dominant and dominant × dominant effects were involved in inheritance. In water relative content, in addition to these effects, dominant effect was also involved in inheritance. Generations variance analysis showed that the gene action was additive for relative water content, dominant for flag leaf area and over dominant (in both conditions) for stomatal conductance. The gene action for Chlorophyll index under stress and normal conditions were over dominant and additive respectively.
Mehrnoosh Rafeie, Mohammad Reza Amerian, Behzad Sorkhi, Parviz Heidari, Hamid Reza Asghari,
Volume 6, Issue 2 (3-2020)
Abstract
To investigate the effect of exogenous brassinosteroid application on grain yield, catalase, chlorophyll content, membrane mtability index and gene expression of some genes involving in brassinosteroid signaling pathway (BES1 and BRI1) under drought stress, a split-split plot on randomized complete block design with three replications was conducted at the experimental field of Seed and Plant Improvement Institute, Karaj, Iran in 2019. The main factor was two irrigation treatments (normal irrigation and water holding after 50% flowering stage), the subplots were four concentrations of brassinosteroid (0, 0.25, 0.625 and 1 mg/l) and seven genotypes (Mehregan, Paris, 2858, 3505, 3737, 4228 and 4056) were considered as sub-sub plots. Samples were taken at 30 days after 50% flowering stage (zadoks 89) from flag leaves. The results showed that drought stress significantly reduced grain yield, chlorophyll content, membrane stability index and increased catalase in all genotypes. Genotype 4228 was identified as the most tolerant genotype among unknown wheat genotypes based on grian yield, chlorophyll content, membrane stability index and catalase. Also, the result revealed that applied epibrassinolide could reduce the destructive effects of drought stress on wheat thus grain yield was enhanced under drought stress in all genotypes by increasing the aforementioned traits. Forethermore, grain yield was increased by rising the epibrasinolide concentration. Gene expression pattern of TaBES1 and TaBRI1 using real-time PCR showed that although brassinosteroid enhances drought tolerance in wheat but its signaling pathway is different from the BRI1 signaling pathway.
Saman Valizadeh, Ahmad Ismaili, Hadi Ahmadi, Omid Ali Akbarpour, Bijan Bajalan, Ashkboos Amini,
Volume 6, Issue 2 (3-2020)
Abstract
Wheat is mostly cultivated at rainfed condition in Iran, so, water deficit stress has much effect on yield reduction. Hence, breeding activities are necessary for introduction of wheat tolerant genotypes to water deficit stress. In order to estimate the heritability and genetic correlation between traits of 36 wheat genotypes, an experiment was conducted in two separate conditions (water stress and non-stress) based on a randomized complete blocks design with three replications. Studied traits in wheat genotypes under water stress and normal condition showed significant differences for environment, genotype and genotype× environment interaction at 1 and 5% level of probability. The results of the factor analysis showed that the 6 first factor in normal condition explained 81.13% of total variance, and the 5 first factor in stress condition explained 74.96% of total variance. Estimation of genetic correlations based on REML approach revealed that biological yield, harvest index and number of grains per spike had the highest correlation with grain yield and these characteristics are of important for selecting the varieties with high yield under non-stress and stress conditions. Estimation of heritability based on REML approach showed that number of days to heading had the highest amount of heritability in both normal and stress conditions.
Amir Mohammad Mahdavi, Nadali Babaeian Jelodar, Ezatollah Farshadfar, Nadali Bagheri,
Volume 7, Issue 1 (9-2020)
Abstract
In order to determine yield stability of 23 bread wheat genotypes and two commercial cultivars as check, an experiment was conducted based on a randomized complete block design with three replications in the experimental field of faculty of Agriculture, Razi University Kermanshah (Iran), during three cropping seasons (2015-2018). The results of combined ANOVA showed that the effect of environment, genotype and genotype × environment interactions on grain yield were significant (P<0.01). Stability was evaluated using environmental variance statistics, coefficient of variation, Wrick´s ecovalence, Shukla’s stability variance, Regression slope, deviation from regression slope, Plaisted and Peterson method and AMMI model. Variance analysis of additive main effects and multiplicative (AMMI) showed that three IPCAs were significant at 1% probability level. The first three principal components justified a round 85.7% of the sum of square of the interaction. Also, AMMI stability value (ASV) was used for simultaneously using information obtained from two significant components of AMMI. According to ASV index, genotypes Pishgam, Wc-4958 and Pishtaaz had the lowest ASV value and were known as the most stable genotypes. Genotypes Wc-4987, Wc-47615, Wc-47399 and Wc-47638 had the highest ASV value and distance from the center of Bi-plot. Therefore, Pishtaaz is one of the most stable genotypes due to having the first rank in terms of studied parameters as well as proper bakery properties and desirable drought resistance. In general, regarding to the climate change in the country, especially in the rainfed conditions and based on the above statistics and the biplots derived from AMMI analysis, the Wc-4958 line, with pishtaaz and Pishgam cultivars as stable and adaptable genotypes, are suggested to rainfed conditions on the studied area.
Fatemeh Darvishnia, Mohammadhadi Pahlevani, Khalil Zaynali Nezhad, Khosro Azizi, Saied Bagherikia,
Volume 7, Issue 1 (9-2020)
Abstract
In order to determine the most effective indices for quantifying drought tolerance and identify genotypes that are tolerant to water stress in bread wheat, 50 bread wheat genotypes were compared in a randomized complete block design with three replications under both the non-stress dry farming with two complementary irrigation and the water stress dry farming conditions in Khorramabad, Iran. Analysis of variance showed that there was a significant difference among the genotypes in terms of all of the traits except the number of spike per area. In this study, eight indices including: Stress Tolerance Index (STI), Geometric Mean Productivity (GMP), Mean Productivity (MP), Yield Index (YI), Harmonic Mean (HM), Yield Stability Index (YSI), Stress Susceptibility Index (SSI), and Tolerance index (TOL) were calculated by using of seed yield of the genotypes under both conditions. Indices that selection based on them will improve the yield in both conditions, are considered as suitable index. STI, GMP, MP and HM were introduced as suitable index for drought resistance selection. Genotypes Shiroodi and S-90-5 were determined as the most appropriate based on 3D plot. Based on positive correlation between water stress resistance indices and yield under stress and non-stress environments, STI and GMP were the best indices. By using the Biplot method, Shiroodi, S-90-5 and Oroum genotypes were considered as high yielding potential genotypes under the both conditions. According to the results of cluster analysis, genotypes were classified into three groups based on drought tolerance indices. Graphical analysis of genotypes also showed that genotypes Shiroodi and S-90-5 were more profitable than others under both drought stress and non-drought stress conditions. These genotypes could also be used as parents caring desirable genes in the crossing programs and selection of tolerate genotypes.
Rahmatollah Karimizadeh, Tahmasb Hosseinpour, Jabbar Alt Jafarby, Kamal Shahbazi Homonlo, Mohammad Armion,
Volume 7, Issue 2 (3-2021)
Abstract
There are different methods for study the genotype × environment interactions and determining stable genotypes such as parametric, non-parametric and multivariate methods. In this research, 19 selective genotypes from advanced trials of durum wheat at 2011-2012 agronomic year, have been cultivated with Dehdasht check cultivar for three growing years (2012-2015) in five locations (including Gachsaran, Gonbad, Khorramabad, Moghan and Ilam) in a randomized complete block design with four replications in each location. Combined analysis of variance indicated significant effects of genotype, environment and interactions of genotype × environment. In parametric uni-variate methods, genotypes 7, 12, 18 and 20 were determined as stable genotypes. In non-parametric uni-variate methods, genotypes 2, 7, 12, 13, 18, 19 and 20 had the lowest genotype × environment interaction and they were determined as stable genotypes. In AMMI method, genotypes 2, 7, 12, 19 and 20 had the lowest rank in different environments and highest grain yield, and these genotypes seems more stable genotypes. It can be concluded that genotypes 7, 12, 18 and 20 could be considered as promising genotypes and candidate for introducing new durum cultivar.
Seyede Yalda Raeesi Sadati, Sodabeh Jahanbakhsh Godehkahriz, Ali Ebadi, Mohammad Sedghi,
Volume 7, Issue 2 (3-2021)
Abstract
Under drought stress condition, the signaling system induces expression of certain genes to counteract the deleterious effects of environmental stress. Among the essential micronutrients for plant growth and development, zinc has an important role in many plant metabolic processes including gene expression and stress tolerance. In order to investigate the effect of drought stress and ZnO on relative expression pattern of some genes involved in abiotic stresses (including WRKY1, HMA2 and ZIP1 genes) in wheat cultivars, a factorial experimental was conducted in pot condition based on a completely randomized design with three replications. In this experiment, the first factor was three levels of drought stress (35, 60 and 85% of field capacity), the second factor was three wheat cultivars (including Heidari, Meihan and Sysons), and the third factor was three levels of ZnO (0, 0.5 and 1 g/l-1). According to the results, with increasing the level of drought stress, the relative expression of WRKY1 and ZIP1 genes in drought tolerant cultivar (Meihan), and also with increasing nanoparticle concentration over stress time, the expression of ZIP1 gene in drought sensitive cultivar (Sysons) increased. The highest relative expression of HMA2 gene was observed in Heidari cultivar under mild drought stress. Generally, the expression of all three genes studied in tolerant cultivar (Meihan) increased under drought stress. Increasing the expression level of HMA2 and ZIP1 genes could be related to the transfer of zinc to consuming tissues and also, to increase the consumption of zinc in current metabolism of plant, which is important in tolerance of wheat to drought stress.
Esmaeil Dasturani, Khalil Zaynali Nezhad, Masood Soltani Najafabadi, Mohammadhadi Pahlevani, Hassan Soltanlo, Saeed Bagherikia,
Volume 8, Issue 1 (8-2021)
Abstract
The aim of this study was to determine the haplotype groups and identify the specific alleles associated with desirable agronomic characteristics in bread wheat. For this purpose, 42 local bread wheat genotypes belong to Iran region and nine commercial cultivars along with Chinese Spring variety (reference genotype) were cultivated in the format of augmented design and evaluated based on their 13 phenotypic traits. The results of descriptive statistics showed that awn length and day to flowering had the highest and lowest phenotypic coefficient of variation, respectively. Eight microsatellite markers were used to investigate the haplotype variation of QTLs associated with phenotypic traits located on wheat chromosomes 4B and 7D. The result showed that the genotypes were classified into 13 and 6 haplotype groups according to the allelic comparison with the reference genotype on chromosome 4B and 7D, respectively. In order to investigate the relationship between traits and markers, analysis of variance was performed based on completely randomized design with unequal numbers of replications for each marker. In general, of the 13 traits studied, there was a statistically significant linkage for eight traits and for the three traits, an allele-specific was introduced simultaneously. If the breeders are interested in genotype selection that simultaneously have three desirable characteristics such as early anthesis, semi-dwarfing and a greater number of grains per spike, they can use an allele-specific (153 bp) of Xgwm149-4B marker.
Mahmood Aslanparviz, Varahram Rashidi, Mansour Omidi, Alireza Etminan, Alireza Ahmadzadeh,
Volume 8, Issue 2 (3-2022)
Abstract
Evaluation of genetic diversity is the key principal for plant breeding, providing an opportunity to discover novel characters and alleles for breeders. In the present study, 69 durum wheat genotypes were investigated for genetic diversity using several inter-simple sequence repeat (ISSR) markers. Sixteen ISSR primers amplified a total of 163 fragments, which out 160 fragments were polymorphic. The mean values of polymorphic information content (PIC), resolving power (Rp) and marker index (MI) indicated that the used ISSR primers could be exploited for further assessing relationships among investigated genotypes and population structure analysis. The results of the molecular analysis of variance showed that the genetic variation within populations is more than between them. Based on genetic variation parameters, the highest number of observed alleles (Na), Shannon’s information index (I) and the percentage of polymorphic loci (PPL) were found in Iranian landraces. Cluster analysis and population structure grouped all investigated genotypes into three main clusters and six subpopulations, respectively. In conclusion, our results revealed the high rate of genetic diversity within Iranian landraces, so this germplasm can be used as a valuable gene source for the selection of parent lines and use of them in durum wheat breeding programs.
Elina Nazari Khakshoor, Amin Azadi, Peyman Fourozesh, Alireza Etminan, Eslam Majidi Hervan,
Volume 9, Issue 1 (9-2022)
Abstract
Salinity stress falls into the major environmental factors that limit the production of various crops, including wheat. An effective approach to reducing the impacts of stress is the production of new salinity-tolerant cultivars. Accordingly, identifying effective genes and molecular mechanisms responsible for salinity tolerance is an essential step for breeding programs. In this investigation, a population of F12 recombinant inbred lines (RIL) comprising 186 genotypes was studied to identify the loci that control some physiological traits and element concentrations in the wheat seedling stage under salinity stress. Totally, 12 quantitative traits loci (QTLs) were identified for wet weight, dry weight, length, and sodium and potassium contents using the composite interval mapping (CIM) analysis. Most of the identified QTLs were located on chromosomes B and D. A gene ontology (GO) analysis specified candidate genes in QTL regions. However, it is noteworthy that candidate genes need confirmation using marker-assisted identification. The prioritization of genes resulted in determining 3486 candidate genes in 19 GO phrases (including eight biological processes). These genes are involved in the processes of glutathione metabolism, L-phenylalanine catabolism, cytoplasmic translation, auxin-activated signaling pathway, transcriptional regulation, DNA-patterning, protoporphyrinogen IX, cell wall organization and genesis, xyloglucan tRNA metabolism, protein glycosylation, pigment biosynthesis, etc. GO may be introduced for identifying novel CGs in which the associated QTL is responsible for complicated traits.
Razieh Ghorbani, Raheleh Ghasemzadeh, Hadi Alipour,
Volume 9, Issue 1 (9-2022)
Abstract
In order to identify loci controlling seedling morpho-physiologic characteristics in 88 bread wheat cultivars, a greenhouse experiment based on simple alpha lattice was conducted under both normal and 120 mM (12 ds/m) salt stress condition of the Faculty of Agriculture, Urmia University in 2020-2021 cropping season. Chlorophyll a, b and carotenoid content, proline, plant fresh and dry weight, plant height and leaf relative water content (RWC), Na+, K+ and K+/Na+ concentrations were measured. After genotyping by sequencing with Ion Torrent technology and removal of SNPs with more than 20% of missing data and minor allele frequency less than 5%, a total of 5869 SNP markers were identified. Based on association mapping with the mixed linear model (MLM) method, a total of 25 marker-trait associations were detected under normal conditions. The A and D genomes had the highest and lowest number of significant marker-trait associations (MTAs). Among the studied traits under normal conditions, chlorophyll a had the highest number of MTAs on 1A, 3B, 3D, 5B, 7A chromosomes with eight MTAs. A total of 21 MTAs were identified under salt stress conditions which the genome B and D had the highest and lowest number of MTAs, respectively. Five MTAs were identified for plant fresh weight, which were located on chromosomes 4A and 6B. The results of this study provide valuable information about the loci associated with the studied traits, which can be used in marker assisted selection in wheat breeding programs after confirmation in biparental populations and additional experiments.
Saeid Navabpour, Horeyeh Najafi,
Volume 9, Issue 2 (3-2023)
Abstract
Environmental stress is one of the main factors that reduce the growth and performance of crops and threatening human food security. This study was conducted in order to investigate the effect of drought stress on the changes in biochemical traits and the level of expression of a MYB transcription factor gene in two wheat cultivars (Tajan and Zagros), under drought stress. The experiment was conducted as a factorial based on a completely randomized design with 3 replications. Drought treatments were applied at three levels of 40, 70 and 100% of field capacity 4 weeks after germination. Twenty days after the application of stress, leaves and roots were sampled in order to investigate the expression of MYB genes and measuring some biochemical traits. The results of examining the chlorophyll content under stress showed that the content of chlorophyll a and b decreased with increasing of stress intensity in different genotypes. The rate of reduction of chlorophyll a and b in Tajan genotype under severe stress was higher than Zagros genotype. Also, TBARM content under severe drought stress was significantly higher than moderate stress condition and this increase was seen in Tajen genotype more than Zagros genotype. qRT-PCR analysis showed that the MYB genes showed an increase in expression under drought stress. Furthermore, Zagros genotype, which is considered as a tolerant cultivar to drought stress, had a higher MYB expression level than Tajan cultivar for both genes, suggesting this cultivar for future breeding programs, also considering the importance MYB family genes during drought stress, the results can be used in molecular breeding and pyramiding breeding projects.
Hossein Abdi, Hadi Alipour, Iraj Bernousi, Jafar Jafarzadeh,
Volume 10, Issue 1 (9-2023)
Abstract
Evaluating the population structure is essential for understanding diversity patterns, choosing proper parents for crossing, accurate identification of genomic regions controlling traits, and evolutionary and kinship relationship studies. In this research, the genetic structure of a wheat population was studied in a panel consisting of 383 Iranian wheat genotypes of hexaploid (cultivars and landraces) and tetraploid species based on distance-based methods (principal component analysis and discriminant analysis of principal component). For this purpose, 16270 single nucleotide polymorphism (SNP) markers obtained by the GBS technique were used. According to the results, almost a quarter of the total variance was belonged to the diversity between populations, and the Fst coefficient between cultivars and landraces was equal to 0.15. In contrast, the above coefficient between tetraploid samples and hexaploid landraces was high and equal to 0.44. Genome D had the lowest value of Fst index and chromosome 4B showed the highest Fst coefficient, and other genetic diversity indices. Although the PCA biplot distinguished hexaploid wheat cultivars from landraces, it was unable to distinctly separate tetraploid genotypes from other genotypes. Accurate evaluation of the population structure with the DAPC method was able to identify and separate the predetermined successfully groups, suggesting that the DAPC approach maximizes the differentiation between groups and minimizes the changes within the group. Partial admixture between cultivars and landraces of hexaploid wheat can be related to gene exchange between these two groups or perhaps their wrong labeling at the time of collection. In general, the results of this study provided valuable information about the genetic differentiation of Iranian tetraploid and hexaploid wheat, which can be used in future wheat breeding programs. Further, protecting these genotypes in gene banks is necessary for different strategies.
Seyedeh Somayeh Mousavi, Omidali Akbarpour, Dr Tahmasb Hosseinpour,
Volume 10, Issue 1 (9-2023)
Abstract
In this research, 15 bread wheat genotypes along with Aftab variety as a control variety were implemented with 4 replications in the form of randomized complete block design for 3 crop years (2016-2019) at Sarab Chengai Station in Khorramabad. The likelihood ratio test (LRT) showed that the genotype-year interaction effect was significant for grain yield. Based on this, singular value analysis (SVD) was performed on the matrix of best linear unbiased predictions (BLUP) of genotype × year interaction to evaluate the stability of genotypes. The scree plot showed that the first principal component accounted for 71.7% and the second principal component accounted for 28.3% of the matrix changes resulting from the best unbiased predictions of the genotype interaction per year. The biplot of the first principal component of the environment against the nominal yield also showed that genotypes No. 9, 12 and 13 had a negligible contribution to the genotype × year interaction and had higher general stability. Also, the biplot of grain yield against the weighted average of absolute scores (WAASB) placed the genotypes in four regions, so that genotypes No. 15, 16, 12, 11, and 10 are in the fourth region due to high stability (low values WAASB) and magnitude of response variable (high performance) were identified as superior genotypes. The WAASBY index (weighted average of WAASB stability and performance) identified genotypes No. 15, 16, 12, 10, 11, 14, 9 and 4 as stable and high yielding genotypes. In general, based on WAASB and WAASBY indices and their comparison, genotypes 15, 16, 12, 11 and 10 were selected as the best genotypes that can be recommended for cultivation in similar climates.
Fariba Ranjbar, Babak Abdollahi Mandoulakani, Raheleh Ghasemzadeh,
Volume 10, Issue 1 (9-2023)
Abstract
To evaluate the expression pattern of genes encoding antioxidant enzymes catalase, ascorbate peroxidase and polyphenol oxidase under iron deficiency conditions in Fe- efficient (Pishtaz) and -inefficient (Falat) bread wheat cultivars, a CRD (completely randomized design) based factorial experiment was conducted with three replications. The cultivars were grown under iron deficiency (Less than 1.5 mg Fe/kg soil) and compared with normal conditions (10 mg Fe/kg soil). The relative expression levels of the above-mentioned genes were measured using Real-time PCR technique in the leaves and roots of the cultivars at two growth stages: vegetative (one month after germination) and reproductive (30% of heading). The results revealed a remarkable enhancement in calatalse expression in the roots of both cultivars in the vegetatative stage but it was higher in Fe-efficient cultivar than -inefficient one. The expression of this gene was decreased in leaves at the same stage as well as in the roots of both cultivars in the vegetative stage. The expression level of ascorbate peroxidase gene in the reproductive stage in the roots of Fe-inefficient cultivar was higher than that of -efficient one. In the vegetative stage, the expression of this gene increased in the leaves and roots of Fe-efficient cultivar, but it was decresed in Fe-inefficient cultivar. The relative expression level of polyphenol oxidase gene in the vegetative stage under iron deficiency conditions in the leaf increased almost three times, compared to the roots, while the expression of this gene decreased in the reproductive stage in both leaves and roots. By increasing the expression of both catalase and ascorbate peroxidase genes in the roots of both cultivars in the reproductive stage under iron deficiency conditions, it seems that bread wheat cultivars might reduce the deletrious effects of stress and maintain yield through transferring much iron to the seeds in the seed filling stage. The findings of the present study may increase our understanding of the important role of genes encoding antioxidant enzymes in Fe deficiency stress conditions.
Mohammad Nader Ebrahimi, Hadi Ahmadi, Mostafa Darvishnia, Daryoush Ghoudarzi,
Volume 10, Issue 2 (2-2024)
Abstract
Hexaploid winter wheat (Triticum aestivum L., 2n= 6x= 42, AABBDD) is an important small-grain cereal crop grown for food and feed. In Iran, wheat is the most cultivated cereal crop where winter wheat is ranked 1st in terms of production. Wheat fusarium head blight (FHB) is one of the most important diseases of wheat in humid and hot regions of the world, which causes a decrease in yield and grain quality. Fusarium head blight is caused by Fusarium graminearum. In order to investigate the resistance of some wheat traits against HBF, 27 varieties and lines of bread wheat were sown at the farm of Faculty of Agriculture, Lorestan University. The spikes were infected at the first flowering stage by spray inoculation. The results showed that there was a great diversity among the 27 varieties of bread wheat tested in terms of growth traits, yield components, and grain yield. The results of The Duncan's test for comparing means showed that cultivars Ghods, Shiraz, Morvarid 2, and Pishtaz had a significant superiority in terms of grain yield compared to other cultivars. The results of simple correlation and also stepwise regression analysis showed that the traits of 1000 seed weight, plant height, number of seeds per spike, number of spikes, spike length and plant height are very important traits for grain yield. According to values of broad sense heritability and genetic gain for plant height and high correlation of this trait and seed yield, plant height can be used as a suitable trait for improving seed yield by selection. The overall results showed that Shiraz, Pishtaz, Quds and Morwarid-2 cultivars are suitable for transferring resistance to wheat spike blight disease in breeding programs.
Nasrin Akbari, Siamak Alavi Kia, Mostafa Valizadeh,
Volume 10, Issue 2 (2-2024)
Abstract
Due to world population incline and the increasing wheat consumption as human main staple food, as well as high amount of waste of bread which is mainly due to its low quality, the wheat breeding programs to improve bread quality are of great importance. Therefore, evaluating the wheat grains quality and the genetic variation of bread-making quality traits among lines derived from crosses becomes imperative. To this end, the gliadin protein banding pattern of 28 recombinant inbred lines, their corresponding parents and 10 other commercial cultivars were examined via A-PAGE method. The variation between and within the lines and cultivars was determined using AMOVA according to the protein bands. The results of this study revealed high variation for gliadins coding loci with total mean of 73.96%. The percentage of polymorphism was estimated to be 91.67 and 56.25 for lines and commercial cultivars, respectively. The minimum and maximum number of gliadin bands were 12 and 25 bands, respectively. Also, based on PhiPT statistics, the significant difference was observed (P<0.05) between commercial cultivars and recombinant inbred lines in terms of gliadin banding patterns. Cluster analysis and PCoA via banding pattern of gliadins led to formation of three and four distinct groups, respectively. The highest variation was observed in ω-gliadins, suggesting that they may have a role in observed variation among genotypes and their bread making-quality traits.
Fatemeh Asadzadeh, Babak Abdollahi Mandoulakani,
Volume 11, Issue 1 (9-2024)
Abstract
To investigate the effect of iron deficiency stress on the expression of genes encoding bZIP4, bZIP79, and bZIP97 transcription factors in iron-efficient and -inefficient bread wheat cultivars, a factorial experiment was conducted in a completely randomized design with three replications in the research greenhouse of Urmia University. Falat (iron-inefficient) and Pishtaz (iron-efficient) cultivars were grown in iron deficiency and sufficiency conditions. The expression levels of genes mentioned above were measured using real time PCR technique in the leaves and roots of the cultivars at two growth stages: one month after germination (vegetative) and 30% of spiking (reproductive). The results revealed the highest increase in the relative expression of bZIP79 (more than 14-fold change) and bZIP97 (more than 3-fold change) in the leaves of iron-inefficient (Falat) and -efficient (Pishtaz) cultivars, respectively, at vegetative stage. The highest relative expression of bZIP4 was observed in the roots of iron-inefficient cultivars in the vegetative stage. This probably shows that bZIP4 might activate the transcription of the genes responsible for iron uptake from the soil. Increased expression of bZIP79 in the leaves of iron-efficient cultivar in the vegetative stage under iron deficiency conditions, indicates the involvement of this transcription factor in the activation of genes responsible for iron transfer from the leaves to the grain and other tissues. In general, this research helps understand the mechanism of plants coping with iron deficiency stress. Also, the identification of key bZIP transcription factors involved in the activation of genes responsible for iron absorption and transport in bread wheat plants provides the possibility of genetic manipulation of bread wheat cultivars to produce cultivars with a higher amount of iron in the grain.
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