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Showing 24 results for Stress
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.
Seyedeh Zahra Hosseini, Ahmad Ismaili, Seyed Sajad Sohrabi,
Volume 5, Issue 2 (3-2019)
Abstract
Drought is a threaded factor in the world production and application of breeding methods could improve the tolerant and adapted cultivators under drought stress condition. In order to evaluate and determine the stress tolerance indices and identifion of tolerant genotypes to drought stress, 15 safflower genotypes were evaluated in a randomized complete block design with three replications in two conditions (stress and non-stress). Analysis of variance showed significant differences among genotypes for all traits, stress tolerance indices and yield in both conditions. Significant positive correlation was found between grain yield in the stress condition with indicators stress tolerance index, harmonic mean and geometric mean productivity indicating that these indices are suitable criteria for screening drought tolerant genotypes. No significant correlation was observed between Ys with tolerance index and mean productivity, hence they can be discarded as the desirable markers for identifying drought tolerant genotypes. In conclusion, using a graphical approach of three dimensional scatter plots, Principal component analysis and biplot analysis, two tolerant genotype (Syrian and Kino-76) were selected for future programs in stress and non-stress condition.
Sara Motallebinia, Omid Sofalian, Ali Asghari, Ali Rasoulzadeh, Bahram Fathi,
Volume 6, Issue 1 (9-2019)
Abstract
In the present study, in order to evaluate the drought tolerance indices and their relationship with ISSR markers, 12 rapeseed genotypes were studied using a factorial experiment based on completely randomized block design under the three irrigation treatments (control and irrigation after drainage of 60 and 85% moisture content) in the greenhouse of Mohaghegh Ardabili University, Iran. Drought tolerance genotypes were evaluated by quantitative indices including MP, GMP, SSI, STI and TOL. Cultivars in all five of indices at two levels of stress exhibited significant differences. Regarding the results of the mean comparison at both levels of stress, SLMO46 was identified as the most resistant cultivar with the highest amount of MP and STI, and Karun was the most sensitive one with the highest amount of SSI index. According to the results of factor analysis, in the first level of stress, Sarigol32 and Karun were sensitive, and in the second level of stress, Talaye and Sarigol32 were sensitive as well. SLMO46 was known to be resistant to stress in both levels of stress. Phenotypic correlation of grain yield under stress and non-stress conditions was investigated in two levels of stress with 5 drought indices. In first level of stress condition, grain yield had a positive and significant correlation with mean productivity, geometric mean of productivity and stress tolerance index. In the second level of stress condition, the same correlation was observed with the difference that there was no significant correlation between drought tolerance and tolerance indices. Canonical correlation analysis was performed between drought indices and molecular markers. Five ISSR primers (5, 9, 11, 14 and 19) with the highest polymorphic percentages were used for calculation using the first factor coefficients. ISSR-PCR was used to identify some of the molecular markers associated with drought tolerance indices. A total of 106 clear and score-able loci were amplified by 18 ISSR primers, of which 60 bands (56.6%) were polymorphic. Finally, according to the results, these markers can be used in rapeseed breeding programs for drought tolerance.
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.
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.
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.
Shaghayegh Mehravi, Gholam Ali Ranjbar, Hamid Najafi-Zarrini, Ghader Mirzaghaderi,
Volume 7, Issue 1 (9-2020)
Abstract
Anise is an annual plant belonging to Apiaceae family and fruit essential oil of this herb is used in various pharmaceutical, cosmetic and beverage industries. Drought stress is one of the most critical limiting factors for anise production in worldwide. In this research, to finding interrelationships among different traits and performance, some anise genotypes were evaluated using the biplot method. In this study, 18 anise genotypes were evaluated in normal irrigation regime and drought stress conditions according to a randomized complete block design with three replications at the field of the Western Australia University (UWA), Australia. Fifteen phonological, morphological and physiological traits were measured. Results indicated the positive and significant correlations between yield and fruit number and fruit thousand weight in both conditions. Due to the negative correlation between phonological features with fruit yield in two different irrigation conditions, it could be concluded that to have genotypes with high fruit yield, selection for early ripening genotypes should be done in anise. In this study, a significant correlation was observed between fruit yield and relative water content in the stress condition. Therefore, this trait can be used as a physiological index to evaluate drought tolerance in anise. According to cluster analysis based on the measured traits, genotypes were divided into 3 groups in both non-stress and stress conditions. According to the results of the comparison of the means of the groups in non-stress and drought stress conditions, genotypes No. 1, 5, 6, 11, 12, 14, 15 and 16 were identified as the most drought-tolerant genotypes. These genotypes could be utilized in breeding programs for further improvement of drought tolerance in anise germplasm.
Abbas Saberi Kuchesfahani, Atefeh Sabouri, Amin Abedi, Ali Aalami, Teimour Razavipour,
Volume 7, Issue 1 (9-2020)
Abstract
water stress and, in this regard, it is necessary to improve rice cultivars to tolerance to environmental stresses. In this research 154 recombinant inbred lines (F9) derived from a cross between Shah-Pasand and IR28 in three conditions (non-stress, osmotic stress -0.3 and -0.6 Mpa induced through polyethylene glycol-6000) were evaluated as a factorial experiment in randomized complete block design. In addition, for molecular polymorphism experiment, 110 SSR and EST-SSR markers were assessed on parents of population and among them, 41 markers identified which had proper polymorphism between two parents. The regression analysis between germination components and molecular markers revealed the most coefficient of determination were found in RM211 for allometric coefficient (17%) under non-stress, RMES10-1 for Plumule dry weight (18%) under -0.3 MPa; and RM273 for germination uniformity (22.7%) under -0.6 MPa. RM3496, RM452, and RMES6-1 in three conditions had the most number of significant relationships with six, three and eight traits, respectively, and they can be a suitable candidate for simultaneous improvement of several traits in breeding programs of marker-assisted selection. In addition, after the identification of significant markers associated with germination components, the closest genes to these markers were identified using bioinformatic analysis, and the analysis of their expression were performed by rice transcriptome database. According to the results, the maximum gene expression pattern under drought stress and under non-stress conditions were related to loci LOC_Os01g57220 and LOC_Os01g26039, respectively and this information could be applied in breeding programs.
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.
Maryam Rasoulzadeh Aghdam, Reza Darvishzadeh, Ebrahim Sepehr, Hadi Alipour,
Volume 8, Issue 1 (8-2021)
Abstract
Nutrient deficiencies are important abiotic stresses that can affect plant growth and development. In this study, 76 sunflower pour lines collected from different regions of the world were evaluated in pot using some physiological traits with combined analysis of completely randomized design with three replications under optimal and phosphorus deficit conditions. Phosphorus deficiency decreased the means of all studied traits except canopy temperature. Oilseed sunflower lines were grouped into five and four clusters in each one of optimum and phosphorus deficient conditions, respectively. However, in both optimum and phosphorus deficient conditions, lines 19, 21, 27, 44 and 71 were classified into desirable cluster with high yield and yield components. Multivariate tolerance index (MFVD) for each genotype was calculated using the ratio and productivity matrices of the studied traits under optimal and phosphorus deficit conditions using principal component analysis on the resulting matrices. Based on the resulting biplot, lines 71, 74, 65, 21, 39, 7, 18 and 11 were introduced as desirable and phosphorus deficit tolerant lines.
Reza Mir Derikvand, Seyede Sajad Sohrabi, Seyyed Mohsen Sohrabi, Kamran Samiei,
Volume 8, Issue 2 (3-2022)
Abstract
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.
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.
Khadijeh Abbaszadeh, Reza Shirzadian-Khorramabad, Mohammad Mahdi Sohani, Zahra Hajiahmadi,
Volume 9, Issue 2 (3-2023)
Abstract
Salinity stress affects morpho-physiological and biochemical traits of plants. The transgenic Bt plants play a significant role in pest control, but their response and ability to cope with environmental stresses still need to be evaluated. Therefore, effect of salinity stress at 0, 50, 100, 150, and 200 mM on morphological, physiological, and molecular traits of T3 transgenic tomato plants containing cry1Ab gene (CH-Falat-Bt) was investigated and compared with that of the non-transgenic control (CH-Falat). Evaluation of the morphological traits (leaf area, root length, fresh and dry weight of roots) at different salinity levels revealed that CH-Falat-Bt transgenic plants are more tolerant to salinity stress compared to CH-Falat non-transgenic plants. The chlorophyll content at 150 and 200 mM salinity levels was 12 and 9% plants, respectively. Moreover, the amount of RWC, carotenoids, proline and soluble sugars increased significantly in transgenic plants as salinity levels increased. The relative expression of SOS1 and SOS2 genes showed a significant increase in all salinity levels in CH-Falat-Bt transgenic plants compared to CH-Falat non-transgenic plants. The amount of electrolyte leakage in the transgenic plants was significantly reduced compared to the non-transgenic plants. The results of morphological, physiological, and molecular investigations of CH-Falat-Bt transgenic plants confirmed that the undesirable effects of salinity stress on transgenic plants is much less than non-transgenic ones. in general CH-Falat-Bt transgenic plants are more tolerant to different applied salinity levels than the wild variety.
Razieh Khadivar, Ahmad Ismaili, Seyed Sajad Sohrabi, Hasan Torabi Podeh,
Volume 9, Issue 2 (3-2023)
Abstract
Drought stress is one of the main environmental factors that affects growth and productivity of crop plants, including lentil. In the course of evolution evolution, crucial genetic regulations mediated by non-coding RNAs (ncRNAs) have emerged in plant in response to drought and other abiotic stresses. In the present study, after identifying lncRNAs within the expression profile of lentil, RNA-seq data and real-time PCR analyses were employed to examine the expression pattern of some of the identified lncRNAs under drought stress. Additionally, psych R package was used to generate the lncRNAs-DEGs co-expression network. A total of 3590 lncRNA sequences were identified in lentils transcriptome. Numerous lncRNAs were co-expressed with genes involved in circadian rhythm regulation, zinc ion response, photosynthetic photoreaction, and ion homeostasis. The LCUL_evgLocus_104392, LCUL_evgLocus_99066 and LCUL_evgLocus_61876 sequences were differentially expressed in response to drought stress. Examining the co-expression of these sequences with differentially expressed genes in response to drought stress, led to the identification of metabolic pathways associated with these sequences. In this study, lncRNA sequences were identified for the first time in lentil, and provided useful insights into the function of lncRNA in plant resistance to drought stress. The lncRNAs-DEGs co-expression network can lead to a better understanding of drought response mechanisms in lentil.
Mozhgan Shirinpour, Ehsan Atazadeh, Ahmad Bybordi, Saeid Aharizad, Ali Asghari, Ashkboos Amini,
Volume 10, Issue 1 (9-2023)
Abstract
Considering the importance of maize production and the impact of water deficit stress on reducing the yield of maize, estimating the genetic components and heritability of traits for determine the breeding method under water deficit stress is essential in breeding programs. The generations drived from a cross between two inbred lines of maize including B73 (maternal line) and MO17 (paternal line), SC704 (F1) as well as F2, BC1, BC2 and F3 generations in order to estimate the genetic effects and heritability of yield, yield components and morphological traits were studied. Seven maize generations using the generations mean analysis under the full irrigation, mild and severe water deficit conditions were evaluated. The experiment was conducted in the form of randomized complete block design with 20 replications per experimental unit during two cropping seasons (2018-2019) at the Agricultural Research Station of University of Tabriz. The results of two-year combined analysis of variance and mean comparisons under three different irrigation regimes showed that water deficit stress significantly reduced all of the studied traits (except root/shoot ratio). The generations mean analysis showed the high contribution of non-additive gene effects for the genetic control of grain yield, ear diameter, number of kernel row, ear weight (in full irrigation conditions), 100 grain weight, plant height, fresh shoot weight and biological yield traits. According to these results, selection in the advanced generations and the breeding method based on hybridization can be effective to improve these traits. Also, the significant contribution of additive gene effects in controlling the inheritance of ear length, ear weight (in both stress conditions) and root/shoot ratio traits indicated that selection in early segregating generations and inbred parents can be effective for breeding of these traits and taking advantage of additive variance. Hybrid SC704 and inbred MO17 compared with the inbred B73 showed the lowest variation percentage under the water deficit stress conditions, which indicated their high yield potential and stability in the stress conditions.
Maryam Ebrahimi, Reza Darvishzadeh, Amir Fayaz Moghaddam,
Volume 10, Issue 1 (9-2023)
Abstract
Protection of food security is one of the basic priorities of any country, which is achieved through the development and introduction of new, high-yielding and stress-resistant crop varieties. Considering the wide range of usage; human nutrition, livestock and poultry nutrition as well as use in industrial products production, maize is of special importance in agricultural development programs. To improve a trait with complex behavior and low heritability, indirect selection by other traits or a suitable index developed based on several traits can be used. In this research, 86 maize genotypes were cultivated in the form of randomized complete block design with three replications in the field in the Faculty of Agriculture, Urmia University under two normal and salt stress conditions. The measurement of the traits was done from the tassel appearance to kernel physiological maturity. In order to speed up genotype selection and increase the acuracy of selecting high yielding genotypes, four selection indices including Smith- Hazel, Pasek- Baker, Brim and Robinson were used and calculated. The results of present study revealed that selection based on the Smith- Hazel index with the highest selection efficiency (∆H) will increase the grain yield in normal and grain yield and plant height in salt stress conditions. This index, with its high correlation with the breeding value is introduced as a superior index. Based on this index, R59 and 6*/88 genotypes were introduced as the superior genotypes under normal and salt stress conditions, respectively. Nonetheless, these genotypes were recognized as the best genotypes considering the results of all other investigated indices. Identifying and introducing genotypes tolerant to salinity stress is of particular importance due to the expansion of saline lands and the limitation of access to water suitable for irrigation. Based on the above results, 6*/88 genotype is recommended for the development of promising hybrids for cultivation in areas with water or saline soil.
Seyede Maryam Seyed Seyed Hassan Pour, Leila Nejadsadeghi, Zahra Sadat Shobbar, Danial Kahrizi,
Volume 10, Issue 2 (2-2024)
Abstract
Camelina )Camelina sativa (is an annual, self-pollinating, allohexaploid plant with diploid inheritance belonging to the Brassicaceae family. Camelina exhibits a remarkable degree of similarity to the model plant Arabidopsis thaliana. WRKY transcription factors are among important gene families in plants that play crucial roles in regulating growth and development and in response to diverse stresses. In this research, using bioinformatics analysis and databases, members of the WRKY gene family were identified and their various characteristics were investigated. Overall, the genome of the Camelina plant was found to harbor 214 members of the WRKY gene family. All 214 WRKY genes were found to possess the conserved WRKY functional domain, along with a variety of motifs within their structural composition. Phylogenetic analysis divided the identified members of Camelina WRKY genes into four main groups. Examination of the chromosomal positions revealed that the 214 identified WRKY genes exhibited an uneven distribution across the chromosomes. In order to validate the identified genes, the expression of two genes (Csa11g065620 and Csa07g035970) orthologs of two genes involved in drought stress in Arabidopsis (WRKY8 and WRKY57), were investigated in a drought tolerant (DH 91) and a drought sensitive (DH 101) lines. The results of the gene expression analysis showed that both genes had high expression in drought stress conditions in tolerant line in comparison to normal conditions, whereas no significant expression was found in drought sensitive line. The findings of the present study offer valuable insights for evolutionary investigations and enhance our understanding of the functional roles of the WRKY gene family in Camelina, thereby laying a foundation for future research endeavors in this field.
Nasrin Akbari, Reza Darvishzadeh,
Volume 11, Issue 1 (9-2024)
Abstract
Sunflower, one of the important oilseed plants, is affected by drought stress, consequently leading to yield decreases. Direct selection for improving seed yield, as the end result of multiple traits, is often ineffective due to the significant impact of environmental conditions. For many years, indirect selection through other traits or selection indices has been proposed to improve seed yield. In the present experiment, 100 oilseed sunflower genotypes were evaluated in terms of some agro-morphological traits using a simple 10 × 10 lattice design under normal and drought stress conditions during two consecutive croping seasons. In drought stress conditions, irrigation was done after 180 mm of evaporation from class A evaporation pan, compared to 90 mm in normal irrigation conditions. Brim, Smith-Hazel, Robinson and Pesek-Baker selection indices were calculated to select genotypes under two environmental conditions. In order to evaluate and compare the efficiency of selection indices and select the best index, the genetic gain of traits (∆G), expected gain (∆H) and relative efficiency of selection index (RE) were calculated. The results of this study showed that the direct response to selection for the traits including seed oil content, days to maturity and leaf length under both environmental conditions was more favorable compared to the correlated response. However, for head and stem diameter traits, the lowest efficiency of direct selection was observed under both environmental conditions compared to other investigated traits. Considering the two criteria; the genetic gain of traits (∆G) and expected gain (∆H) under normal and drought stress conditions, the two indexes of Brim and Smith-Hazel were introduced as the best index and the genotype ENSAT-254 was introduced as the superior genotype. The selected ENSAT-254 genotype can be considered in developing hybrid cultivars for cultivation under drought stress conditions, provided it is validated at the molecular level by analyzing the expression of genes related to water deficit stress tolerance.
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