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Showing 27 results for Wheat
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.
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