Molecular biology and (trans) gene expression technology in plant breeding
Abolfazl Mazandarani; Saeid Navabpour; Ahad Yamchi
Abstract
The main source of protein and micronutrients in wheat grains is the flag leaf and to a lesser extent the lower leaves. As healthy leaves reach the final stage of growth, senescence, they remobilize the nutrients necessary before tissue destruction and death. This experiment was carried out in Golestan ...
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The main source of protein and micronutrients in wheat grains is the flag leaf and to a lesser extent the lower leaves. As healthy leaves reach the final stage of growth, senescence, they remobilize the nutrients necessary before tissue destruction and death. This experiment was carried out in Golestan province, and the Wheat cultivars studied were included Euclide and Antonius. Sampling was carried out from flag leaf, other leaves, stem, and grain at 7 stages, Anthesis, 7, 11, 15, 19, 23, and 27 Day After Anthesis (DAA). The total chlorophyll content in the Antonius cultivar was higher in both flag leaf and other leaves than Euclide cultivar. The expression of TaNAM-B1 and TaSAG12 genes, which have been identified as signaling genes for senescence in wheat, showed results consistent with the results of chlorophyll content in leaves. Increased expression of both genes after anthesis was observed earlier in Euclide cultivar than the Antonius cultivar and had higher expression in most stages. In light of the results, the change in concentrations of Cu, Zn, and Fe in the Euclid cultivar was more in all organs than in Antonius one. Also, given the importance of minerals in the food basket, it can be noted that Euclid cultivar, in which leaf senescence begins earlier and more minerals are stored, can produce grains with higher nutritional value than Antonius cultivar.
Germplasm genetic diversity & plant breeding
Mohsen Saeidi; Majid Abdoli
Abstract
To evaluate the genetic diversity and the effect of drought stress on grain yield of wheat, 56 wheat genotypes were evaluated for terminal drought stress tolerance in field environments in the Kermanshah of Iran during the 2010-2011 cropping season. The experiments were conducted at the Campus of Agriculture ...
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To evaluate the genetic diversity and the effect of drought stress on grain yield of wheat, 56 wheat genotypes were evaluated for terminal drought stress tolerance in field environments in the Kermanshah of Iran during the 2010-2011 cropping season. The experiments were conducted at the Campus of Agriculture and Natural Resources, Razi University using alpha-lattice design with two replicates under two different water regimes included non-stress (normal irrigation at all stages of growth) and drought stress (end-season after flowering stage) conditions. Several new stress tolerance indices were evaluated. So that, ten drought tolerance indices including stress tolerance index (STI), relative drought index (RDI), yield index (YI), yield stability index (YSI), drought resistance index (DI), abiotic tolerance index (ATI), stress susceptibility percentage index (SSPI), sensitive drought index (SDI), modified stress tolerance index in normal irrigation (K1STI), and modified stress tolerance index in stress irrigation (K2STI) were calculated based on grain yield under drought (GYs) and irrigated (GYp) conditions. The result of analysis of variance indicated high significant differences among genotypes for grain yield trait. In general, terminal drought stress reduced 27.2% of grain yield. The Shiroudi, Rassoul, Darab-2, Marvdasht, Argh, and Shiraz genotypes which are high reduction of grain yield (61.1, 51.3, 48.4, 44.1, 43.1, and 43.0%, respectively) and also genotypes 318, Ghohar, 330, Mahdavi, and Alamout which are low reduction of grain yield with drought stress (4.1, 4.7, 7.0, 7.5, and 10.2%, respectively). Furthermore, results showed that wheat genotypes can be classified as normal and stress situations using cluster analysis. The correlation analysis among grain yield under non-stress and drought stress conditions with different drought tolerance indices showed that STI, YI, K1STI, and K2STI indices were appropriate indicators to identify the high grain yield genotypes. Based on these indicators, Mughan-1, Golestan, Navid, 330, Darab-2, and Bahar genotypes had the highest grain yield under both experimental conditions. Therefore, these wheat genotypes are suitable for cultivation in Mediterranean regions that are constantly exposed to drought stress at the end of the growing season, and areas with similar climatic conditions. Also, they are recommended to be used as parents for the improvement of drought tolerance in other wheat genotypes.
Molecular markers & plant breeding
Elham Mehrazar; Ali Izadi-Darbandi; Mohsen Mohammadi; Goodarz Najafian
Abstract
Marker assisted selection (MAS) is a tool for breeding, screening, and genetic characterization of germplasm. Allelic variation of both high and low molecular weight glutenin subunits (HMW/LMW-GS) is associated with the rheological properties of wheat flour. In this study, we investigated glutenin pattern ...
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Marker assisted selection (MAS) is a tool for breeding, screening, and genetic characterization of germplasm. Allelic variation of both high and low molecular weight glutenin subunits (HMW/LMW-GS) is associated with the rheological properties of wheat flour. In this study, we investigated glutenin pattern using SDS-PAGE and their PCR based on DNA markers in 60 advanced wheat lines and cultivars with different origins. Specific DNA markers regarding to Glu-1 loci, such as 1319 bp, 669 bp and 450 bp fragments were respectively validated for 2*, 17+18, 5+10 alleles. These alleles showed the highest allelic percentage in Glu-1 loci in studied cultivars. However the Null, 7+8 and 5+10 alleles showed the highest allelic percentage in advanced lines. In this study, 23%, 40% and 37% of cultivars respectively, got good (10), moderate (8-9) and weak (4-7) quality scores. In advanced lines, 18%, 44% and 38% got good, moderate and weak quality scores respectively. Ten specific DNA PCR markers were also detected for genotyping Glu-B3 alleles. The most frequent Glu-B3 alleles in wheat cultivars were i, a, b and d with 24%, 21%, 20% and 12%, respectively.Specific PCR markers regarding to the reported Glu-B3 alleles were produced as 621bp, 1095bp, 1570 bp and 662bp consequently. The most frequent Glu-B3 alleles in advanced lines belonged to a, i and d alleles with 35%, 26% and 21% respectively. The results provided useful information for breeding program to improve breadmaking quality and develop new cultivars.
Molecular markers & plant breeding
Namdar Moradi; Hedieh Badakhshan; Hadi Mohammadzadeh; Mohammadreza Zakeri; Ghader Mirzaghaderi
Abstract
Iron is one of the most important nutrients in the human diet. According to the high consumption of staple foods such as wheat, the deficiency of iron in these crops would lead to nutritional disorders and related complications. To identify microsatellite markers associated with wheat grain iron content,38Iranian ...
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Iron is one of the most important nutrients in the human diet. According to the high consumption of staple foods such as wheat, the deficiency of iron in these crops would lead to nutritional disorders and related complications. To identify microsatellite markers associated with wheat grain iron content,38Iranian prevalent wheat genotypes were assessed using 30 pairs of genomic and EST microsatellite markers. Based on field experiments, significant difference was observed among studied genotypes for grain iron content which ranged from 34-53 mg/Kg. in the molecular experiment, the range of alleles per SSR locus was 2-9 with a mean of 4.5 and the mean of polymorphism information content (PIC) was 0.55. The stepwise regression analysis has been used for estimating the relationship between microsatellite markers and grain iron content. The results indicated that Xwmc617 (4A, 4B, 4D), Xgwm160 (4A) and Xbarc146 (6D,6B,6A) were significantly correlated with wheat grain iron content. The results of this research can be used in further studies and marker assisted breeding of wheat to increase grain iron content.
Advanced breeding technologies
Fahime Moloudi; Saeid Navabpour; Hassan Soltanloo; Seyedeh Sanaz Ramazanpour; Hamidreza Sadeghipour
Abstract
Drought stress is one of the serious problems that restricted agronomic plant production worldwide. In molecular level, the harmful effect of drought stress is mostly caused by producing of large amount of reactive oxygen species (ROS). Catalase and Metallothionein genes have a crucial role to mope the ...
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Drought stress is one of the serious problems that restricted agronomic plant production worldwide. In molecular level, the harmful effect of drought stress is mostly caused by producing of large amount of reactive oxygen species (ROS). Catalase and Metallothionein genes have a crucial role to mope the hydrogen peroxide (H2O2) resulting reducing oxidative damage. In this research the gene expression pattern of Catalase and Metallothionein was studied in response to drought stress treatments. The treatments included - 0.3 bar, - 0.9 bar, - 8 bar and -12 bar and wheat varieties included Zagros (drought tolerant), Moghan (semi- tolerant) and Tajan (drought sensitive). The amount of cellular oxidative levels (TBARM) increased steady by intensify of drought stress levels. Real time PCR analysis showed different expression pattern for catalase and metallothionein encoded genes. Catalase gene expression was increased during drought stress up to -8 bar and reduced in -12 bar treatment, in all cultivars specially in Tajan cultivar. Metallothionein gene expression was linearly reduced during different levels of drought treatments especially in Zagros and Tajan cultivars. The most activity for both genes has observed in Zagros cultivar at -0.9 bar treatment. Whereas, Moghan cultivar showed most transcription for both genes at -8 bar treatment. Overall gene activities, content of chlorophyll (a, b) and whole plants appearance declined by high level of drought stress e.g. -12 bar treatment in all cultivars particularly in Tajan variety. Whereas, the moderate levels of drought stress treatments induced genes activitiy.