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Showing 11 results for Rice
Peyman Sharifi, Hashem Aminpanah,
Volume 3, Issue 2 (3-2017)
Abstract
In order to investigate yield stability, genotype×environment interactions and estimation of a number of genetic parameters related to yield and yield components, seven promising rice lines together with Shirodi and line 843 (as control cultivars) were evaluated. The experiment was carried out base on randomized complete block design with three replications in three locations of Mazandaran province, Iran (Tonekabon, Amol and Sari) during three growing seasons from 2012 to 2014. Analysis of variance revealed that there were significant differences among genotypes for yield at almost all three locations. Combined analysis of variance indicated that there were no significant differences among locations and years, whereas year×location×genotype interaction was found significant for grain yield, plant height and thousand grain weight. Results of stability analysis by univariate methods showed that genotype number 6 was the most stable genotype over all three locations, having less variance within locations and smaller coefficients of variance and a high grain yield (6020.8 kg ha-1 ). The high coefficient of phenotypic and genotypic variation was indicative to genetic variability for all of the studied traits. The broad-sense heritability ranged from 49.06% (plant height) to 92.48%% (number of filled grain per panicle) and was 59.46% for grain yield. The highest phenotypic and genotypic coefficients of variation and genetic gain over total average obtained for the number of grains per panicle. Thus, it is possible to improve this trait by selection method and could be used as a selection index to improve grain yield. Overall, genotype number 6 could be considered as a superior genotype to achieve a dwarf cultivar with stable yield.
Halbibi Badirdast, Seyed Yahya Salehi-Lisar, Hossain Sabouri, Ali Movafeghi, Ebrahim Gholamalalipour Alamdari,
Volume 5, Issue 1 (9-2018)
Abstract
One of the main objectives of plant breeding is defining the relationship between genotype and phenotype. Nowadays, molecular markers provide powerful tools to evaluate this relationship for plant breeders. In this study, genetic diversity of 112 rice lines was evaluated by 20 pairs of SSR markers which linked to drought tolerant alleles. Totally, 77 polymorphic alleles with mean of 3.85 alleles per primer pairs were amplified. The minimum number of alleles was belonged to RM28199 and RM212 markers with 2 alleles, and the maximum number of alleles was belonged to RM72 marker with 6 alleles. The range of PIC for the examined markers was 0.30 to 0.72 and the mean of PIC was 0.58. The maximum amount of PIC was belonged to RM85 and RM20A markers and the minimum of PIC was belonged to RM28099 marker. Considering the gene diversity coeficient, RM28099 and RM 85 markers had minimum (0.33) and maximum (0.76) diversity, respectively. The stepwise regression analysis of the microsatellite data and morphologic traits identified 62 and 54 informative alleles for the evaluated traits in flooding and drought conditions, respectivly. Cluster analysis based on molecular data divided the genotypes into 7 groups. Considering the appropriate distribution of amplified DNA by the studied markers in this study, markers that have high separation power and high association with important agronomic traits in drought stress condition (if further experiments confirmed them), could be employed in plant breeding programs of drought stress.
Elham Nasiri, Atefeh Sabouri, Akbar Forghani, Masoud Esfahani,
Volume 5, Issue 2 (3-2019)
Abstract
In order to select the best parents for crossings, plant breeders seek varieties or genotypes with highest genetic dissimilarities. This can be achieved by measuring the similarities among genotypes, using multivariate analysis methods such as cluster analysis. This study aimed to group 50 aerobic and lowland rice genotypes based on biochemical characteristics including Iron, Zinc, Manganese and protein, and their linked DNA markers. According to the cluster analysis results using Ward method, the genotypes were assigned to four groups. The third group, as the smallest group including three genotypes (IR82635-B-B-82-2, Caiapo, and Gohar), had the highest value for these micronutrients. Their mean value for Iron, Zinc, Manganese, and protein were 32.39, 34.15, 25.66 mg/kg and 6.71%, respectively. Also, all genotypes were classified into two main groups based on microsatellite markers information, that according to QTL mapping studies these markers were identified as linked to elements. So, the most of non-local genotypes and aerobic rice cultivars were assigned in a separate group. The correlation between Euclidean distance of elements and protein matrix and genetic similarity matrix (Nie) using Mental correlation test was estimated significant (p<0.01) that can be evidence of a genetic relationship between the SSR markers and genome controlling regions of elements in this population.
Seyede Minoo Mirarab Razi, Reza Shirzadian-Khorramabad2, Hossein Sabouri, Babak Rabiei, Hossein Hosseini Moghadam5,
Volume 6, Issue 1 (9-2019)
Abstract
Salinity is an important limiting factor in the production of more plants, including rice. Due to the limited amount of cultivated area, identification of tolerant genotypes to environmental stresses and especially salinity is very important. The aim of this study was to investigate the genetic diversity among 114 recombinant lines derived from the intersection of local Tarom × Khazar cultivars under non stress conditions and salinity levels of 8 dS/m in reproductive stage in a completely randomized design. Combined analysis of variance showed that the differences between lines was significant for all traits. Genotypic variation coefficients also showed that the highest genetic variation among the evaluated recombinant lines was related to the number of panicles per plant. In contrast, days to 50% flowering showed the least genetic variation among these lines. In non stress and stress conditions, the highest genotypic and phenotypic correlation coefficient was observed between grain yield and number of fill grain in seedlings. Based on the cluster analysis of grain yield, the lines were classified into four groups under normal conditions and were classified into three groups under salinity conditions. The third-party lines in both cases had a higher average than the overall average. In general, the results of this study showed that there is a significant genetic variation between the studied lines in terms of salt tolerance and this variety can be used in subsequent corrective programs. Accordingly, lines 83, 81, 56, 39, 37 and 89 were the most sensitive lines and lines 107, 101, 16, 100, 84, 98, 47, 32, 14, 29, 95, 63, 5, 49, 92 and 10 were the most tolerant lines to salinity stresses of 8 dS/m and they also had higher yields and yield components. Strained lines are proposed directly for cultivating saline or for transferring salt tolerance to commercial cultivars through future breeding programs.
Atefeh Khakpour, Maryam Zolfaghari, Karim Sorkheh,
Volume 6, Issue 1 (9-2019)
Abstract
Glycyrrhiza is one of the important medicinal plants that is in danger of extinction. Search for finding accessions that have a higher glycyrrhizic acid is very important in breeding programs. Functional genomics methods such as EST sequencing prepare the ability to identify consensus gene families among studied species and interpretation of the genome. In this research, 55960 EST sequences of two different species of this plant along with the protein sequences were analyzed in order to identify the molecular aspects and functional analysis of the genome and the gene network involved in the biosynthesis of glycyrrhizin. Also, in order to validation of results, relative expression of four important genes in the pathway of glycyrrhizin biosynthesis including squalene synthase (SQS), β-amyrin synthase (BAS), β –amyrin 11-oxidase (CYP88D6) and UDP-glucuronyl transferase (UGT) were evaluated. After trimming and qualitative evaluation the sequences, 6427 contig sequences and 30895 singleton (37322 unigene) were generated, which covered a total of 26884666 bp (7.06%) of the licorice genome. Genome functional activity showed that most genes play a role in the catalytic activity and cellular and metabolic processes in which these genes interact within cells and intracellular organels. Locating this group of genes showed that the genes involved in glycyrrhizin biosynthesis pathway were localized in endoplasmic reticulum. Results of validation using qRT-PCR showed that in the autumn and in the rhizome tissue, the genes of BAS, CYP88D6, UGT and SQS were up-regulated. The results of this study can be valuable for genomic sequencing, functional groups, genetic diversity and functional genomics of this plant.
Mohammad Reza Jafarzadeh Razmi, Saeid Navabpour, Hossein Sabouri, Seyedeh Sanaz Ramezanpour,
Volume 6, Issue 2 (3-2020)
Abstract
In order to analyze the genetic components of agronomic traits among 116 F9 recombinant lines derived from crosses of Ahlamitarom × Sepidroud rice cultivars, an experiment was conducted as a randomized complete block design in research farm of Gonbad Kavous University of Agriculture with three replications in 2016 and 2017. Genetic linkage map provided with 80 SSR markers, 28 iPBS Markers (79 polymorphic alleles), 7 IRAP markers (17 polymorphic alleles) and 26 ISSR markers (70 polymorphic alleles), which covered 1275.4 cM of the rice genome. QTL analysis was performed by Composite Interval Mapping. In two years, 15 QTLs detected for the studied traits. The additive effected varied from 6.725 g for grain weight up to -85.626 g for grain weight. Also, R2 for the detected QTLs explained from 11.3% to 20% of the total variation. The highest R2 was related to grain weight in the first year of experiment. Among the detected QTLs, qGWs on chromosome 1, were found to be stable and large effector QTLs for rice (Oryza sativa L.) grain weight, and can be used in marker-assisted breeding and selection programs after validation.
Alireza Haghighi Hasanalideh, Ezatollah Farshadfar, Mehrzad Allahgholipour,
Volume 6, Issue 2 (3-2020)
Abstract
This study was conducted to evaluate the gene effects, heritability, heterosis and identification of appropriate breeding methods for improving rice viscosity parameters, during 2014-2016 at Rice Research Institute of Iran. The progeny obtained from the North Carolina III mating design with their parents were planted in a randomized complete block design with three replications. Analysis of variance for viscosity parameters revealed that the effect of females, male effect and interaction between males and females effect were significant for all parameters with the exception for peak viscosity. Evaluating of genetic parameters indicated that viscosity characters are affected by additive and non-additive effects of gene action. The share of non-additive effects in genetic control of peak viscosity had beyond additive gene action, while, the contribution of additive effects was greater for the breakdown viscosity, final viscosity and setback viscosity. High estimates of broad sense heritability revealed that the expression of viscosity parameters is more influenced by genetic effects. With regard to non-additive gene actions and low narrow sense heritability estimation in peak viscosity, using hybrid based programs would be promising to improve this trait. For other viscosity parameters, narrow sense heritability estimates were high. Therefore, the use of selection based programs to improve these traits is encouraging. Assessing of relative heterosis through mid-parents showed that heterosis ranged from -3.73 to 1.93%, 5.51 to 21.33%, -4.57 to 1.26% and -26.04 to 9.36%, for the peak viscosity, breakdown viscosity, final viscosity and setback viscosity, respectively.
Kobra Arab, Rudabeh Ravash, Behrouz Shiran,
Volume 6, Issue 2 (3-2020)
Abstract
Increasing drought tolerance, especially in rice, which is one of the most important crops in Asia, is necessary. Transcription factors are specific sequence DNA-binding proteins that are capable of activating or suppressing transcription. These proteins regulate gene expression levels by binding to cis regulatory elements in the promoter of target genes to control various biological processes such as growth, cell division and response to environmental stresses. In this study, MAD8 and MYB93 genes that were involved in drought stress in rice were considered in two leaf and anther tissues at 0, 24, 48, 72 h and one week after stopping irrigation. The results of q-PCR analysis showed significant expression changes of these transcription factor genes under drought stress conditions. In this study, a significant increase in the expression of these genes at 24 h after drought stress in transgenic plants (Promoter region with accession: NC_029264.1 and GUS gene have transformed) compared to non-transgenic plants showed a relationship between these transcription factors and higher expression of transported promoter in transgenic plants.
Leila Khazaie, Reza Shirzadian Khoramabad, Ali-Akbar Ebadi, Ali Moumeni,
Volume 7, Issue 1 (9-2020)
Abstract
Mutagenesis has been one of the important sources of genetic diversity and Plant mutants can be important bio-resources for crop breeding and functional genomics studies. Breeding conventional methods for generating of genetic variability are of low efficiency. We showed that treatment of seeds of rice(Hashemi cultivar) with 0.8% EMS for 8 h caused visible phenotypic variations on M2 rice mutant genotypes including flowering date, plant height, number of fertile tiller, panicle length, number of filled and unfilled grains per panicle, grain width and length, 100 grain weight and grain yield. The phenotypic variation coefficients of most traits found to be more than the genetic variation coefficients. The number of filled grains per panicle and seed length had the highest and lowest general heritability, respectivly. The seed yield had also high heritability. Analysis of correlation between different characteristics in the mutant genotypes showed that the number of fertile tillers and the number of unfilled grains per panicle had positive correlation with yield. Also, grain yield exhibited positive and significant correlation with panicle length, number of tillers and number of filled grains at genotypic level. In multiple regression analysis by stepwise method, number of tillers, number of filled grains per panicle, 100-grain weight, and grain width entered into the model, respectively, that explained 96 percent of grain yield variations. Results of grain yield and its components path coefficient analysis showed that the number of tiller had the highest direct effect (0.77) through than other traits on grain yield and, therefore it can be considered as major trait in grain yield improvement in rice. Also, based on results of this research and by using optimal selection index, mutant genotypes EM 18-17-5 and EM 15-14-1 were selected as superior mutant genotypes. This mutant population is expected to be serves as a genetical resource for understanding rice biology as well as for use in genetic improvement of quantitative traits.
Mahnaz Katouzi, Saeid Navabpour, Hossein Sabouri , Ali Akbar Ebadi,
Volume 7, Issue 2 (3-2021)
Abstract
In order to identify QTLs controlling agronomically traits, landrace Tarom and rice Tarom mutant were crossed. SSR, ISSR, iPBS and IRAP markers were amplified in 250 F2 individuals to prepare the linkage map. Number of tillers, 100 grain weight, number of filled grains, number of unfilled grains, plant height, panicle length, number of branches, stem diameter, grain length, grain width, grain shape, straw weight, days to maturity, flag leaf length and flag leaf width were measured for 250 individuals. The linkage map covered 970.9 cM of rice genome. The distance between two adjacent markers was calculated to be 12.77 cM. Based on the results, a total of 13 QTLs were identified for the evaluated traits. For all studied traits, alleles transferred from the parents to the QTLs detected increased grain yield. Most QTLs were detected for days to flowering. Three QTLs were located on chromosomes 10 and 4 (two QTLs) for days to flowering. qLDF-4a and qLDF-4b had a negative additive effect and the parent alleles of the mutant landrace Tarom reduced the number of days to flowering. These QTLs explained 11.6% of the phenotypic variance. Since the population under study was derived from a cross between landrace and mutant Tarom cultivars and the resulting population varied only in the mutated genes; so, the QTLs detected in this study were more accurate in location and expression levels, and after validation of them, they could be recommended for marker assistant selection breeding programs.
Ahmad Kaab Omeyr, Payam Pourmohammadi, Abdolali Gilani, Khalil Alami-Saeid, Mohammad Fakhari,
Volume 8, Issue 2 (3-2022)
Abstract
Various strategies have been developed to reduce water consumption in rice cultivation, including rice cultivation in water-saturated soil, drying and wetting of the soil (periodic irrigation), and aerobic rice cultivation. In this study, in order to identify and grouping rice cultivars suitable for aerobic cultivation, 34 cultivars of native and improved rice cultivars were selected and evaluated. Factor analysis based on principal components analysis based on all traits showed that 6 factors were extracted with special values of more than one. These 6 factors, after the Varimax rotation, justify the 6 main and independent factors, justifying 78.08% of the total variation. In the first harvest, cluster analysis using WARD method, cultivars were grouped into 4 groups, which cluster 3 being the largest cluster. Discriminant analysis of first harvest, showed that all cultivars were grouped correctly. In canonical discriminant the first two canonical functions with eigenvalues greater than one explained a total of 88.9% of the variance. In cluster analysis based on the average of the data obtained from Raton product, genotypes were divided into two different groups. The genotypes of the first group were higher than the genotypes of the second group in terms of yield and yield components and were introduced as superior genotypes. Heritability with genetic improvement for leaf area duration, number of seedling (grown plants), number of spikes per unit area, number of full seeds and degree of maturity showed that these traits can be transferred to hybrid offspring and selections based on these traits are effective.
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