جستجوی مقالات مرتبط با کلیدواژه « گندم دوروم » در نشریات گروه « بیوتکنولوژی و ژنتیک گیاهی »

It is important to evaluate and display the potential of new cultivars and promising lines in farmers' conditions in order to introduce new cultivars and lines and increment the spread of them in farm conditions. For this purpose, thirty-three selected varieties/breeding lines from Dry Agriculture Research Institute (DARI) wheat breeding program were evaluated on farmers' fields at Koohdasht, based on randomized complete block design. Results indicated that Paya and Kabir varieties and G17, G18 and G31 lines had the highest grain yield with an average of 5280, 3985, 4210, 4003 and 3950 kg/ha, respectively. Grain yield showed positive and significant correlation with biological yield (BY), number of grain per spike (NGS) and harvest index (HI), and negative correlation between yield and day to maturity. Therefore BY, NGS, HI and early maturity can be used as suitable selection index to identify high-yielding genotype in the rainfed wheat breeding program. Paya and Kabir cultivars and G31, G18, G29, G17 and G16 lines were the best genotype for SIIG index. Based on cluster analysis results, genotypes were classify in three groups including early maturity- high yield  genotypes (class 1), early maturity- low yield genotypes (class 2) and early maturity- low yield genotypes (class 3). According to the results of this research, with the aim of sustainable wheat production in the tropical region that generally faced with late-season drought, new varieties of Kabir and Paya with high yield and early maturity are recommended. In addition, durum wheat lines G17, G18 and G32 with high performance and desirable agronomic characteristics can be considered in the variety introduction program or as parents in a breeding program.

In order to investigate different lines of durum wheat for water stress tolerance, an experiment was carried out in the greenhouse in the form of a split plot design in a Randomized complete block design with three replications using 20 lines of durum wheat at two levels of water stress (40% and 70% of the amount of available water was completely drained in 0.4 and 0.7 levels of stress, respectively and re-irrigation was performed) and a control level (complete irrigation). Also, water-soluble and salt-soluble proteins were extracted and SDS-PAGE was done. Measured traits were photosynthetic pigments (chlorophyll a, chlorophyll b, chlorophyll a/b, total chlorophyll and carotenoids), soluble sugar and prolin content. The results of the analysis of variance showed that there was a significant difference between the studied lines at different levels of stress. The results of comparing the mean of the studied traits showed that in total, lines 16 and 5 have the highest value in most of the traits and lines 10 and 18 have the lowest value in most of the traits. Also, the results obtained from the cluster analysis indicated that due to the higher mean values compared to the other lines both in stress-free and stress conditions, lines 16 and 5 (Mra-1/4/Aus1/3/Scar/GdoVZ579//BitI, TRN//21563/AA/3/BD2080/4/BD2339/5/RASCON_37/TARRO_2//) have a higher performance stability in the different environmental conditions. Furthermore, the results of molecular analysis of the studied proteins showed that in water and salt soluble proteins based on matrix similarity and genetic distance of straw, the lowest genetic distance was between genotypes 18 and 19 (0.32) and the highest genetic distance was between genotypes 16 and 8 (0.98). Finally, it can be concluded that there is a significant genetic diversity between the studied cultivars and this diversity can be used in plant breeding.

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.

Durum wheat (Triticum turgidum) with an average annual production of 40 million tons, is the tenth most important and common crop grown worldwide. The aim of this study was to analysis the genetic diversity and population structure of durum wheat genotypes for knowledge and apply in future genomic studies using SilicoDArT markers generated by DarTseq.

The DNA of 94 durum wheat genotypes were extracted by CTAB method from fresh leaves. The quality and quantity of extracted DNA were measured using spectrophotometer and adjusted to 50 ng / μl. The DNA samples were processed at Diversity Array Technology Pty, Ltd, Australia (https://www.diversityarrays.com) for DArTseq analyses using genotyping by sequencing Platform. Genetic diversity and population structure analysis were performed on the remaining 7882 markers using: Power Markerv.3.25, DARwinver 5.0, STRUCTURE2.1., GenAlexv. 6.41 and Rv3.2.3 software.

The amount of polymorphic information content (PIC) of SilicoDArT markers ranged from 0.023 to 0.499 with an average of 0.38. The mean reproducibility and call rate of sequences in all linkage groups were above 0.98 and 0.92, respectively. The number of mapped SilicoDArT markers varied from 300 markers in the linkage group (Chr1A) to 853 markers in the linkage group (Chr7B). Chromosome size covered by SilicoDArT markers ranged from 829200 kbp in the linkage group (Chr3B) to 589293.786 kbp in the linkage group (Chr1A). The results of cluster analysis by Neighbor-Joining (NJ) method, population structure and discriminant analysis of principal components were highly consistent with each other and clearly divided the studied genotypes into four distinct groups. Genetic diversity among populations was primarily within the population (76.36 vs. 23.64%).

The relatively high number of subpopulations and the presence of high genetic diversity among and within populations were the characteristics of studied durum wheat genotypes in this study. Therefore, considering the loss of 84% genetic diversity of durum wheat during the early domestication processes, these populations can be used as a valuable resource in basic and applied research in breeding projects.

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.

Evaluation of genetic diversity in a gene pool contributes to the effective selection of genotypes and shortens the plant breeding programes time. Genetic diversity plays a very important role in reducing genetic vulnerability during breeding process. In the present study, 96 durum wheat breeding line was evaluated for genotypic diversity using 12 SCoT primers. Our results revealed that the SCoT primers generated 76 polymorphic bands, with an average of 5.42 fragments per primer. The values of marker index (MI) and polymorphism information content (PIC) indicated that SCoT markers were efficient for detection of genetic diversity in durum wheat germplasm. The average of PIC and MI values for the SCoT markers were 0.46 and 2.51, respectively. According to Shannon’s index (I), Nei’s genetic diversity (He), the observed (Na) and effective (Ne) number of alleles, the ICARDA population had a higher level of genetic diversity than the CIMMYT’s population. Genetic relationships inferred from a nighbour-joining’s dendrogram clustered all the investigated lines into seven main groups. This clustering was supported by a principal coordinate analysis (PCoA). Our Results indicated a desirable genetic diversity among studied lines and confirmed that the SCoT technique is a suitable tool for studying genetic diversity in durum wheat germplasm.

Genetic variation, population structure and linkage disequilibrium in 144 durum wheat genotypes, mainly belonged to different geographic regions of Iran, has been studied in this research. Genotyping of population carried out by Illumina Infinium 15K array, consisting of 13006 SNP markers. Polymorphism information content (PIC) ranged from 0.08 to 0.37, with a mean value of 0.26. Pairwise kinship coefficients among genotypes showed that 58.85% of the values were zero and only about one percent of the coefficients were larger than 0.5, indicating that there was a poor relatedness among the genotypes. We identified six main subgroups within the population inferred by STRUCTURE analysis. The subgroups were somewhat separated based on geographical origins. Principal coordinates analysis (PCoA) indicated that the first two principal coordinates explained 16.35 and 7.52% of the total genetic variance among the genotypes, respectively. The results of this research indicated that SNP markers are efficient tools for genetic variation characterization, and population structure studies of wheat genotypes and can be used in selection of genotypes as crossing parents and marker-assisted selection in breeding programs.

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.

In this study, the induced responses of acclimated and non-acclimated genotypes of bread wheat (Triticum aestivum L.) (Norstar) and durum wheat (Triticum turgidum L.) (Gerdish and SRN) to cold stress have been assayed by detecting electrolyte leakage index (ELI), malondialdehyde content (MDA) and the activity of antioxidant enzymes (superoxide dismutase, catalase, ascorbate peroxidase and guiacol peroxidase). Wheat genotypes showed different responses to thermal treatments (23 and -5°C). After exposing plants into cold stress, along with decreasing of damage indices the antioxidative activities increased particularly in acclimated plants so that the maximum and minimum activity of enzymes belonged to Norstar and SRN plants. Acclimated plants showed more readiness in facing up cold stress in Norstar plants compared to durum wheat so that the minimum damage indices and the maximum enzyme activities were observed. The results have shown a potent variety in the level and speed of cell responses in these genotypes. Simultaneous changes of damage indices (ELI and MDA results) and antioxidative activities showed that these enzymes accompanied with other defense mechanisms increased cold tolerance and/ or enhance plant survive in wheat and can cause plant recovery even after sever cold stress. The short-term cold acclimation increased genetic capacity in wheat genotypes so that the degree of tolerance in Norstar was higher than that of durum genotypes. Such defense and damage indices may be used as cold tolerance marker in evaluation of genotypes in a short-term cold stress profitably in a short time and low cost.

Genetic diversity assessment is a feasible approach and useful for germplasm. In this study، 30 genotypes of durum wheat were evaluated for GLU-B1 loci with three specific primer pairs. Nine alleles were present at the GLU-B1 locus. The b (BY8) allele was observed more frequently at the GLU-B1 locus. The amount of genetic variation for each primer that initiates B1. 2 (0. 85) primer were able to identify polymorphisms more than other primers. Cluster analysis was performed using UPGMA method and the similarity coefficient of 0. 62 based on jaccard subdivided the genotypes into eight subgroups. The results revealed that the HMW subunits in durum wheat genotypes are valuable sources and they can be used in breeding program to improve the quality of wheat products.

Different methods for determining the effect of genotype × environment interaction, there are parametric, nonparametric and multivariate methods. Nineteen selective advanced genotypes of durum wheat from 2004-2005 advanced yield trial by cv. Saimareh with the control variety for three agronomic years (2005-2008) in five locations (i.e: Gachsaran, Gonbad, Koohdasht, Moghan and Ilam) planted by using randomized complete block design with 4 replicates. In this study, four multivariate cluster analysis methods of Lin and Butler and AMMI method for analyzing of Genotype × environment interactions were used. In methods one and three of cluster analysis genotype 14, in methods two and four of cluster analysis genotype 12 were placed in individual group and these genotypes were selected as most stable genotypes with higher yield than total mean yield. The genotypes of 2, 4 and 14 have lowest SIPC1 in AMMI method and higher average grain yield than total mean yield determined for most stable genotypes. By attention to the result, genotypes 12 and 14 with average yield of 3218 and 2970 kg/ha respectively selected as promising genotypes for introduce cultivar. Also genotypes 2, 9 and 13 can use for excel and adaptable parents in crossing block projects.

Yield of six dryland durum and eleven dryland bread wheat lines was evaluated in a randomized complete block design with three replications in Tark and Alengareg vilages of Kandowan region of Miyaneh in 007. In harvest stage, some traits such as yield, plant height, ripening time, tolerance to dry and cold conditions, thousand seed weight, and tiller numbers were recorded. There was significant difference between durum genotypes in plant height and thousand seed weight at both studied regions. Also, genotypes were significantly different in dry tolerance and fertile tiller numbers, but not regions. Interaction of region in genotype was significant in yield, tiller numbers and dry tolerance but in plant height and thousand seed weight. Among durum lines, Gardish was the highest one. The highest yield belonged to PI000 with significant difference with the rest of the lines. Dry tolerance in Haurani and tiller number in Haurani, G-5, Dipper and PI000 was in the highest level, significantly. Plant height was also significantly different among beard wheat genotypes in both regions. Regions and genotypes were significantly different in yield and thousand seed weight. Among bread wheat lines, plant hight in Sardari was significantly higher than others. As a whole, thousand seed weight and yield in Unknown- was significantly higher than other bread wheat genotypes.