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Showing 26 results for Wheat
Reza Mir Drikvand, Goodarz Najafian, Mohammad Reza Bihamta, Asa Ebrahimi,
Volume 1, Issue 2 (2-2015)
Abstract
This study was conducted to identify markers associated with some kernel traits in bread wheat in two separate experiments under field and laboratory. One hundred wheat genotypes were evaluated in an alpha lattice experimental design with two replications. Grain hardness, seed length, seed width and thousand kernel weights were measured. Association mapping was performed based on 96 unlinked and 22 SSR QTL linked markers, using structure and Tassel software. Correction for population structure was performed using genome wide SSR markers so that genotypes were divided into six sub-populations. Totally, 35 SSR markers linked to traits were detected eight of them being QTL linked markers and other markers that were linked to traits, were used to investigate population structure. The QTLs linked markers were as follows: Chromosomes 5B, 5D and 6D had three QTL for grain hardness. Nine QTLs were detected on chromosomes 1A, 1B, 2A, 2B, 2D, 5B, 5D, 6D and 7B for kernel length, kernel width and thousand kernel weights. The results of this study demonstrate that association mapping is a useful approach to complement and enhance previous QTL information for marker-assisted selection in wheat.
Reza Mir Drikvand, Asma Khyrolahi, Asa Ebrahimi, Mohammad Rezvani,
Volume 2, Issue 1 (5-2015)
Abstract
In this study, genetic diversity of 25 rainfed bread and durum wheat genotypes were assessed using 20 SSR primers that all of them were generated scorable bands. Totally 69 alleles (ranged between 2 allele for Xcfd40 and Xgwm369, and 5 allele for Xbarc54 primers per each locus), were distinguished. Polymorphic information content (PIC) for all SSR primers was calculated. The highest (0.98) and the lowest (0.64) amount of PIC was pertained to Xcfd40 and Xgwm30 primers, respectively. Based on similarity matrix, the highest and lowest genetic similarity was belonged to Seri82 and Seri (0.86) and Sita/chil and Baviacora (0.14), respectively. Cluster analysis could distinct spring and winter wheat genotypes and as well as bread and durum wheat genotypes. It was concluded that SSR marker was suitable for evaluation of genetic diversity in rainfed wheat genotypes. This genetic diversity can be used in wheat breeding programs.
Davoud Sadeghzadeh-Ahari, Peyman Sharifi, Rahmatollah Karimizadeh, Mohtasham Mohammadi,
Volume 2, Issue 1 (5-2015)
Abstract
To estimate the genetic components and the mode of inheritance for some morphological traits, six rainfed durum wheat genotypes (Chehel daneh, Gerdish, Zardak, Syrian-1, Waha and Knd1149//68/ward) and their complete diallel progenies were grown in a randomized complete blocks design with two replications in 2005-06 cropping season in Maragheh Dryland Agricultural Research Station. Results of diallel analysis revealed that additive variance were important for inheritance of grain yield, number of grain per spike, spike length and number of fertile tiller than dominance variance. The positive value of ‘F’, indicated that there were excess of dominant alleles in comparison to recessive ones in the parents for all of the studied traits. The average degree of dominance (H1/D) 0.5 showed partial dominance for grain yield, number of grain per spike, spike length, 100 grains weight and number of fertile tiller and over-dominance for peduncle length. Graphic analysis indicated that increase of grain yield, number of grain per spike, spike length, 100 grains weight and number of fertile tiller were under the control of combination of recessive and dominance alleles. Predominance of additive effects for grain yield demonstrated that breeding methods based on selection may be advantageous in improving of this trait. The highest value of this trait relevant to Gerdish (10.33 g/plant), therefore this genotype can be used as cross parent in breeding programs for receiving to lines with high yield and yield components. The cross of Waha × Knd1149//68/ward with high value of GY and GCA for this trait can be used as a suitable cross for hybrid production.
Ali Darvishian, Ahmad Ismaili, Farhad Nazarian-Firouzabadi, Reza Mirdrikvand, Tahmasb Hosseinpour,
Volume 2, Issue 2 (3-2016)
Abstract
Plant breeding is selection of advanced genotypes and its progress depends on correct evaluation of genetic variation. Among different selection procedure, molecular markers have a good potential for evaluation of variation. In this research, RAPD molecular markers were used to evaluation of genetic diversity among 25 wheat cultivars and advanced breeding lines. Genomic DNA was extracted from leaves by Dellaporta method and 30 primers were used for PCR amplification. Results of Primers led to 200 storable electrophoretic bands which 130 of them (65%) were polymorphic. F4 and A18 primers produced the greatest and lowest band, respectively. Cluster analysis was performed based on band presence (1) and absence (0) using Jaccard coefficient similarity and UPGMA method. Similarity coefficient ranged from 0.22 to 0.87 with an average of 0.64. The highest similarity (0.87) was observed between Azar2 and Sardari and lowest similarity (0.22) was observed between Seimareh and BAVICORA. With cut of line on 0.72 in dendrogram, 6 main groups were clustered and other genotypes were clustered in different group. Regarding to the high similarity among these genotypes, it is necessary to develop the wheat germplasm in related research centers.
Mohtasham Mohammadi, Mozafar Roustaie,
Volume 2, Issue 2 (3-2016)
Abstract
For development of high yield wheat cultivars, this study was conducted to estimate the general combining ability (GCA) of parents, specific combining ability (SCA) of hybrid progenies, heritability and heterosis of grain yield and some agronomic traits. A partial diallel crosses which obtained in a set of six wheat genotypes were sown in randomized complete block design at Gachsarann agricultural research station in 2013-14 growing season under dryland condition. The results of this study revealed a significant difference among the genotypes for all of the traits that indicating considerable genetic variation. Significant effects of GCA and SCA indicated role of additive and non-additive gene action in the control of all considered traits. The mean square ratio of GCA to SCA and Baker genetic ratio showed a preponderance of non-additive gene action for all of the studied traits. Broad-sense heritability was high (0.67-0.99) for all of them, which indicated the role of genetic factors compared with non-genetic factors for controlling of these traits. Narrow-sense heritability was low to moderate (0.06–0.37). Among the parents, Koohdasht was the best general combiners for early growth vigor, days to maturity, spike length, peduncle length, flag leaf extrusion and grain yield. The Koohdasht × DAMARA-6 hybrid showed the best specific cross for days to heading, days to maturity, grain filling period, plant height, chlorophyll content, canopy temperature, grain length and grain yield. These hybrids showed positive and significant heterosis for grain yield, chlorophyll content and grain length and negative heterosis for plant height. It is expected to produce desirable segregants and could be exploited successfully in wheat improvement programs. In addition, because of preponderance of non-additive gene action for studied traits, particularly in the early generations, efficiency of genetic selection was low and selection for genetic improvement of these traits must be retraced in advanced generations.
Reza Nikooseresh, Goodarz Najafian,
Volume 3, Issue 1 (9-2016)
Abstract
In order to study genetic diversity, heritability and relation of some important traits with grain yield in bread wheat, 20 bread wheat irrigated lines evaluated using a randomized complete block design with three replications during two cropping cycles/years. Based on combined analysis results, there were a significant difference between genotypes. Also, in all traits, coefficient of phenotypic variation was greater than coefficient of genetical variation, indicating the effect of environment on investigated traits. The significant correlation between grain yield and number of days to maturity, spikes per m2 and the grains per spike. number of days to heading and number of days to maturity had highest heritability among traits, with 87 and 69%, respectively. Results of this showed that selection of early heading or shorter no. of days to heading and early maturing or shorter number of days to maturity is recommended to breeders for selection materials favorable for terminal warm condition and water shortage, preventing grain yield reduction. Results of cluster analysis showed that genotypes are divided in six groups. Totally, six superior genotypes from the fourth cluster were selected as superior lines. Based on bi-plot analysis, genotypes 14 and 5 showed the lowest genotype × trait interaction, but genotypes 16 and 8 showed the highest genotype × trait interaction.
Bafrin Molaei, Mohammad Moghaddam, Seyed Siamak Alvaikia, Ali Bandeh-Hagh,
Volume 3, Issue 2 (3-2017)
Abstract
This experiment was conducted during 2013-2014 in Tabriz University research farm, Iran. In this research, the inheritance of some agronomic and physiological traits in different generations of Bam (tolerant to drought) and Artha (sensitive to drought) cross was studied in field conditions by generation mean analysis. The experiment was a split plot design using randomized complete blocks with two replications with the irrigation conditions in the main plots and generations in the sub-plots. The interaction between generations and irrigation conditions was significant only for grain yield. Based on the result of generation means analysis for the spike length and straw weight, the threeparameter model was found fitting the analysis. For the thousand-seed weight in the water stress condition and for the plant weight in the irrigation condition, a non-significant chi-square suggesting that the six-parameter model for these traits is suitable. For the other traits, the chi-square was significant in both conditions. For spike length and leaf area, the degree of dominance was greater than one (2.3 and 1.53, respectively) which showed the existence of over-dominance gene action in controlling these traits. Straw weight in normal condition, leaf area and thousand seed weight in the stress condition had a high broad-sense heritability. The narrow-sense heritability for all other traits was low, suggesting the need for exploiting dominance gene action in the breeding programs if hybrid varieties are produced in the bread wheat.
Mohsen Barajehfard, Mohammad Reza Siahpoosh, Mohammad Modarresi,
Volume 3, Issue 2 (3-2017)
Abstract
In order to identify QTLs associated with stemlet and rootlet growth in the early stages of germination of wheat, 144 recombinant inbred lines derived from the cross of Kaz and Mantana were evaluated in a completely randomized design. The linkage map using composite interval by 234 microsatellite (SSR) primers and 267 AFLP loci have been already prepared in this population which covered 20 chromosomes of wheat. For root length, 1, 2 and 2 QTLs were located on 4D, 4B and 2D chromosomes, respectively. Two QTLs of rootlet length was located on 6B and 3D chromosomes. The QTLs of rootlet number were identified on 4A, 5A and 3B chromosomes. For each of stemlet dry weight (SDW) and rootlet dry weight (RDW) traits only one QTL identified on 4A and 3D chromosomes, respectively. Overall, for SDW to RDW ratio on 2D and 3D chromosomes, three QTLs were located. The QTLs of stemlet wet weight (SWW) were detected on 6B and 2B chromosomes. On 1B, 2D and 6B chromosoms, three QTLs were recognized for SWW to RWW ratio. For all traits, the range of LOD = 2.04-6.34 and R2 =5.11-19.58 were calculated. The highest amount of LOD and R2 (5.11 and 19.58, respectively) were obtained for rootlet length QTL (QSL-chpgu-4D). The least distance to the nearest adjacent marker (AFgcCGb marker) was 0.005 Centi-Morgan which belonged to rootlet length QTL (QRL-chpgu-3D) on 3D chromosome.
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.
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