Seed and Plant Improvement Institute
  • Karaj, Ostan-e Alborz, Iran
Recent publications
In the present study, in vitro regenerated shoot tips of three apricot cultivars namely ˈQaysiˈ, ˈShamsˈ and ˈOrdubadˈ, already infected with Apple chlorotic leaf spot Trichovirus (ACLSV), Apple mosaic Ilarvirus (ApMV), and Tobacco ring spot Nepovirus (TRSV), were exposed to electrotherapy (0, 30, 40, 50, and 100 mA), thermotherapy (38°C for 7 days), chemotherapy (ribavirin at 0, 25, 50, 75, and 100 mg L − 1 ), or droplet-vitrification cryotherapy (40 min at 0°C prior to -20°C and − 80°C for 10 and 15 min, respectively) to achieve virus-free plants. Although electrotherapy with current intensities more than 40 mA led to drastic decrease in explants' viability, a 40–60% virus removal rate was noticed depending on the type of virus and the variety tested. Amongst various shoot tip sizes exicised, 1.0–2.0 mm explants exhibited by far more survival (60–80%) and virus eradication rate (90–100%) following thermotherapy. The explants' survival and proliferation rates also decreased with increment of ribivirin concentration in the culture medium as compared to the untreated cultures. The rate of virus elimination, however, inclined by 75–100% upon exposure to 25 mg L − 1 ribavirin. According to our results, production of virus-free regenerants would be feasible in Prunus armeniaca L. providing proper therapeutic methods are adopted as regards the type of infecting virus and the host variety.
Seed traits in bread wheat are valuable to breeders and farmers, thus it is important exploring putative QTLs responsible for key traits to be used in breeding programs. GWAS was carried out using 298 bread wheat landraces and cultivars from Iran to uncover the genetic basis of seed characteristics in both rain-fed and well-watered environments. The analyses of linkage disequilibrium (LD) between marker pairs showed that the largest number of significant LDs in landraces (427,017) and cultivars (370,359) was recorded in genome B, and the strongest LD was identified on chromosome 4A (0.318). LD decay was higher in the B and A genomes, compared to the D genome. Mapping by using mrMLM (LOD > 3) and MLM (0.05/m, Bonferroni) led to 246 and 67 marker-trait associations (MTAs) under rain-fed, as well as 257 and 74 MTAs under well-watered conditions, respectively. The study found that 3VmrMLM correctly detected all types of loci and estimated their effects in an unbiased manner, with high power and accuracy and a low false positive rate, which led to the identification of 140 MTAs (LOD > 3) in all environments. Gene ontology revealed that 10 and 10 MTAs were found in protein-coding regions for rain-fed and well-watered conditions, respectively. The findings suggest that landraces studied in Iranian bread wheat germplasm possess valuable alleles, which are responsive to water-limited conditions. MTAs uncovered in this study can be exploited in the genome-mediated development of novel wheat cultivars.
To find the best inoculation method for evaluation of the resistance in potato genotypes against bacterial blackleg caused by Pectobacterium atrosepticum under in vitro conditions, five inoculation methods were compared. In vitro grown explants of five potato genotypes were inoculated with different inoculation methods, then placed on MS solid medium and incubated at 23?C with 70% relative humidity under the light regime of 16 hours a day. After the appearance of symptoms, the efficiency of inoculation methods was then recorded based on the severity of disease symptoms in potato genotypes: Farmosa, Agria, Picaso, Marfona and a wild potato genotype ?Solanum phureja'. Plantlets inoculated by piercing the crown with sterile toothpick inoculated in bacterial suspension of 108 cfu/ml showed the most severe symptoms. Based on all experiments, cultivar Marfona showed higher resistance among all cultivars and, cultivar Agria was the most susceptible. Finally, after witnessing the reactions of different varieties to inoculation methods and comparing them with previous evaluations of resistance in greenhouse conditions, the crown treatment employing sterile toothpick after infection in 108 cfu/ml bacterial suspension was selected and introduced as the best evaluation method of in vitro potato explants against blackleg.
Background Pre-harvest sprouting (PHS) refers to a phenomenon, in which the physiologically mature seeds are germinated on the spike before or during the harvesting practice owing to high humidity or prolonged period of rainfall. Pre-harvest sprouting (PHS) remarkably decreases seed quality and yield in wheat; hence it is imperative to uncover genomic regions responsible for PHS tolerance to be used in wheat breeding. A genome-wide association study (GWAS) was carried out using 298 bread wheat landraces and varieties from Iran to dissect the genomic regions of PHS tolerance in a well-irrigated environment. Three different approaches (RRBLUP, GBLUP and BRR) were followed to estimate prediction accuracies in wheat genomic selection. Results Genomes B, A, and D harbored the largest number of significant marker pairs (MPs) in both landraces (427,017, 328,006, 92,702 MPs) and varieties (370,359, 266,708, 63,924 MPs), respectively. However, the LD levels were found the opposite, i.e., genomes D, A, and B have the highest LD, respectively. Association mapping by using GLM and MLM models resulted in 572 and 598 marker-trait associations (MTAs) for imputed SNPs (− log10 P > 3), respectively. Gene ontology exhibited that the pleitropic MPs located on 1A control seed color, α-Amy activity, and PHS. RRBLUP model indicated genetic effects better than GBLUP and BRR, offering a favorable tool for wheat genomic selection. Conclusions Gene ontology exhibited that the pleitropic MPs located on 1A can control seed color, α-Amy activity, and PHS. The verified markers in the current work can provide an opportunity to clone the underlying QTLs/genes, fine mapping, and genome-assisted selection.Our observations uncovered key MTAs related to seed color, α-Amy activity, and PHS that can be exploited in the genome-mediated development of novel varieties in wheat.
Meeting nutritional needs and removing restrictions of nutrient uptake ensures quinoa production. This research has been conducted over a two year (2018–2020) in Khuzestan Agriculture and Natural Resources Research Center to appraisal the role of P and Zn elements on changing quinoa genotypes performance by modifying photosynthetic processes and nutrients uptake. This experiment was run as factorial based on a randomized complete block design with three factors and three replicates. In this study, four levels of P2O5 fertilizer (0, 50, 100, 150 kg ha⁻¹), three rates of ZnSO4 (0, 4 and 8 kg ha⁻¹), and three genotypes of quinoa (Giza 1, Q26, Titicaca) were examined. Regarding results, the desirable performance of Giza 1 and Titicaca genotypes was observed in 100 kg ha⁻¹of P2O5 fertilizer and 4 kg ha⁻¹ ZnSO4 treatment. An eight kg ha⁻¹ of ZnSO4 had a negative effect on the quinoa physiological indices. The number of grains per plant was identified as the essential feature, with 94.75% justification of grain yield changes. Nutrient’s analysis exhibited the highest grain quality in top levels of P2O5 and ZnSO4 application, which differed with control mode. Pearson correlation results were implied that grain yield correlated positively and significantly (p ≤ 0.01) with chlorophyll index (CI), number of panicles per plant (NPP), number of grains per plant (NGP), and 1000-grain weight. Upmost photosynthetic power and nutrients efficiency were allocated to Q26 genotype at 150 kg ha⁻¹ level of P2O5 accompanied by 4 kg ha⁻¹ ZnSO4 foliar application, which led to higher grain production.
Foliar application of amino acids and nutrients is an effective practice to improve plant yield in agriculture and horticulture. The hydroponic experiment was carried out to find the changes in physiological attributes, antioxidant enzymes activity, minerals, and flower number and longevity of gerbera (Gerbera jamesonii) plants under foliar application of L-glutamic acid (GA), potassium (K), and nitrogen (N). Plant fresh weight under 4 and 8 g L⁻¹ GA was higher than other experimental treatments. The main improvement of flower number was related to 5 g L⁻¹ K. Lignification in plants treated with non-GA/N and 5 g L⁻¹ K was higher compared to other experimental treatments. Relative water content (RWC) and total soluble sugar (TSS) in plants sprayed with 8 g L⁻¹ GA and 5 g L⁻¹ N and K were greater than other experiment plans. The activities of phenylalanine ammonia-lyase (PAL), catalase (CAT), superoxide dismutase (SOD) increased by progressing GA, N, and K application. The highest leaf P was observed in 4 g L⁻¹ GA with no foliar-applied K and N. Leaf N increased with enhancing GA and N, in which its highest amount was found in plants experiencing 8 g L⁻¹, 4 g L⁻¹ N, and 5 g L⁻¹. Besides, the concentration of K increased by advancing the foliar-applied GA, N, and K, particularly K levels. The maximum flower longevity, as an important trait, increased with 8 g L⁻¹, 10 g L⁻¹ N, and 5 g L⁻¹ K. The present study suggests high concentration of GA in combination with high N and medium K to achieve the optimum plant quantity and quality in gerbera. Heat map analysis showed two distinguished clusters by GA and N through an effective role of SOD, TSS, PAL, and CAT in distinguishing the GA-based clusters and TSS, flower number, and P for N-based clusters.
The most popular Iranian cantaloupe ‘Samsoori’ is highly susceptible to devastating viruses transmitted by Aphis gossypii . A dominant gene ( Vat ) causing resistance to the aphid and viruses was detected in ‘Ginsen Makuwa’ in spite of its low fruit quality. They were crossed and the segregating offspring were assessed for combining favorable traits with Vat gene. In the F 2 population, moderate to high broad-sense heritability estimates were found for measured traits including, fruit weight (0.78) and soluble solid content (SSC) (0.7). The F 3 families were significantly different from each other for earliness, fruit shape indices, cavity, flesh thickness, SSC, and fruit numbers per plant. Resistant and susceptible plants were determined by genotyping 210 plants in F 4 generation using a dominant DNA marker for the resistant allele of Vat gene. Out of 15 selected F 3 families, four were susceptible, three were homozygote resistant and six showed segregation in their progeny for the Vat gene. Selection assisted by Vat gene marker was a very useful and applied approach for the identification of healthy plants along with phenotypic selection.
Salinity stress is one of the major limiting abiotic stresses that decrease crop production worldwide. To recommend genotypes for cultivation under saline stress conditions, comprehensive understanding of genetic basis and plant responses to this stress is need. In the present study, a total of 20 barley genotypes were investigated to isolate potential salt-tolerant genotypes at the early growth stage using hydroponic system, and adult plant under field conditions. Different growth and physiological traits including root fresh and dry weights (RFW and RDW), shoot fresh and dry weights (SFW and SDW), relative water content (RWC), membrane stability index (MSI), relative chlorophyll content (SPAD index), root and shoot Na ⁺ (RN and SN), root and shoot K ⁺ (RK and SK), root and shoot K ⁺ :Na ⁺ ratios (RKN and SKN), root-to-shoot Na ⁺ translocation (RTSN), root-to-shoot K ⁺ translocation (RTSK), stomatal conductance ( G S ), transpiration rate ( T E ), and photosynthesis rate ( P N ) were measured. Barley seedling were treated with two salinity levels (0 mM NaCl (as control conditions) and 200 mM NaCl (as stress conditions)) for 30 days. Moreover, the yield performance and stability of investigated barley genotypes were evaluated across five environments during the 2018–2020 cropping seasons. Salinity stress significantly decreased growth and physiological traits in all seedling plants; however, some salt-tolerant genotypes showed the lowest reduction in measured traits. Multivariate analysis grouped measured traits and tested genotypes into different clusters. The multi-trait genotype–ideotype distance index (MGIDI) selected genotypes G12, G14, G6, G7, and G16 as the salt-tolerant barley genotypes. Considering the results of the AMMI analysis showed that grain yields of tested barley genotypes were influenced by environment (E), genotype (G) and GE interaction effects. Based on the weighted average of absolute scores of the genotype index ( WAASB ) and other stability statistics, G7, G8, G14, and G16 were selected as superior genotypes. Considering the outputs of MGIDI and WAASB indices revealed that three genotypes G7, G14 and G16 can be recommended as new genetic resources for improving and stabilizing grain yield in barley programs for the moderate climate and saline regions of Iran. In conclusion, our results suggest that the using MGIDI index in the early growth stage can accelerate screening nurseries in barley breeding programs.
The salinity tolerance of 17 breeding wheat genotypes along with three local varieties was evaluated under control and salinity stress (160 mM NaCl) conditions. At the seedling stage, shoot and root dry weights, relative water content (RWC), membrane stability index (MSI), relative chlorophyll content (SPAD index), root and shoot Na ⁺ (RN and SN), root and shoot K ⁺ (RK and SK), root and shoot K ⁺ /Na ⁺ ratios (RKN and SKN), root-to-shoot Na ⁺ translocation (RTSN), root-to-shoot K ⁺ translocation (RTSK), stomatal conductance ( G S ), transpiration rate ( T E ), and photosynthesis rate ( P N ) were measured. Moreover, the investigated genotypes were assessed in terms of grain yield across four saline regions during the 2018–2019 cropping seasons. Salinity stress caused a significant reduction in the RDW, SDW, PN, G S , T E , SK, RKN, SKN, RTSN, and RTSK, but resulted in increased RN, RK, and SN. The results of AMMI analysis of variance also indicated significant differences among test locations, genotypes, and their interaction effects. The PCA-based biplot revealed that grain yield strongly correlated with RKN and RK. Furthermore, the correlation among P N , G S , and T E traits was strong and positive and had a positive correlation with RWC, MSI, RDW, and SPAD index. Considering our results, RK and RKN were identified as useful physiological tools to screen salt tolerance at the early-growth stage. According to the ranking patterns obtained by the average sum of ranks method (ASR) and grain yield, we observed that genotype number G5 had considerable physiological potential at the early-growth stage and also responded well to soil salinity at the farm; thus this genotype can be promoted for commercial production.
Stem rust is one of the most important diseases, threatening global wheat production. Identifying genomic regions associated with resistance to stem rust at the seedling stage may contribute wheat breeders to introduce durably resistant varieties. Genome-wide association study (GWAS) approach was applied to detect stem rust (Sr) resistance genes/QTLs in a set of 282 Iranian bread wheat varieties and landraces. Germplasms evaluated for infection type and latent period in four races of Puccinia graminis f. sp. tritici (Pgt). A total of 3 QTLs for infection type (R2 values from 9.54% to 10.76%) and 4 QTLs for the latent period (R2 values from 8.97% to 12.24%) of studied Pgt races were identified in the original dataset. However, using the imputed SNPs dataset, the number of QTLs for infection type increased to 10 QTLs (R2 values from 8.12% to 11.19%), and for the latent period increased to 44 QTLs (R2 values from 9.47% to 26.70%). According to the results, the Iranian wheat germplasms are a valuable source of resistance to stem rust which can be used in wheat breeding programs. Furthermore, new information for the selection of resistant genotypes against the disease through improving marker-assisted selection efficiency has been suggested.
Wax accumulation on the sorghum surface plays an important role in drought tolerance by preventing non-stomatal water loss. Thereby, the effects of post-flowering drought stress (PFDS) on the chemical compositions of epicuticular wax (EW), relative water content (RWC), chlorophyll, and grain yield in sorghum drought contrasting genotypes were investigated. The experiment was conducted as a split-plot based on randomized complete block design (RCBD) with two water treatments (normal watering and water holding after 50% flowering stage), and three genotypes (Kimia and KGS23 as drought-tolerant and Sepideh as drought-susceptible). Scanning electron microscopy and GC-MS analyses were used to determine the wax crystals density and its compositions, respectively. Finally, based on literature reviews and publicly available datasets, six wax biosynthesis drought stress-responsive genes were chosen for expression analysis. The results showed that the EW and wax crystals density were increased in Kimia and Sepideh genotypes and no changed in KGS23 genotype under drought stress. Chemical compositions of wax were classified into six major groups including alkanes, fatty acids, aldehydes, esters, alcohols, and cyclic compounds. Alkanes increment in drought-tolerant genotypes led to make an effective barrier against the drought stress to control water losses. In addition, the drought-tolerant genotypes had higher levels of RWC compared to the drought- susceptible ones, resulted in higher yield produced under drought condition. According to the results, SbWINL1, FATB, and CER1 genes play important roles in drought-induced wax biosynthesis. The results of the present study revealed a comprehensive view of the wax and its compositions and some involved genes in sorghum under drought stress.
To identify the optimum intercropping system of sorghum and clover in terms of quantity and quality of forage yield, a two-year experiment was conducted in a semi-arid region of Iran, during the 2016 and 2017 growing seasons. Treatments consisted of eight cropping systems: S75C25 (75% sorghum + 25% clover), S50C50 and S25C75, as replacement series; S100C50, S50C100, and S100C100 as additive series; and sole cultures of sorghum and clover. The highest and lowest dry matter (DM) yield (29.17 and 10.71 Mg·ha-1) were found in the S100C100 and clover monoculture systems, respectively. Although the highest content of crude protein (CP) and digestible dry matter (DDM) were recorded from clover monoculture, the maximum yield of CP and DDM were obtained from the S100C100. Increasing the proportion of clover in intercropping decreased the acid detergent fiber and neutral detergent fiber, increased the relative feed value, net energy for lactation and dry matter intake. Increasing the proportion of sorghum in intercropping improved the yield of DM, CP and DDM. The land equivalent ratio for DM yield was higher than one in all intercropping treatments but were significantly higher in the additive intercropping systems. Overall, it could be concluded that sorghum and clover additive intercropping systems increased forage yield and quality, however if simultaneous increase of the quantity and quality of forage is the interest of this study then the S100C100 system had a significant advantage over other treatments and can be a suitable alternative for sorghum and clover monoculture systems in semi-arid regions.
This study attempted to address molecular, developmental, and physiological responses of tomato plants to foliar applications of selenium nanoparticles (nSe) at 0, 3, and 10 mgl ⁻¹ or corresponding doses of sodium selenate (BSe). The BSe/nSe treatment at 3 mgl ⁻¹ increased shoot and root biomass, while at 10 mgl ⁻¹ moderately reduced biomass accumulation. Foliar application of BSe/nSe, especially the latter, at the lower dose enhanced fruit production, and postharvest longevity, while at the higher dose induced moderate toxicity and restricted fruit production. In leaves, the BSe/nSe treatments transcriptionally upregulated miR172 (mean = 3.5-folds). The Se treatments stimulated the expression of the bZIP transcription factor (mean = 9.7-folds). Carotene isomerase ( CRTISO ) gene was transcriptionally induced in both leaves and fruits of the nSe-treated seedlings by an average of 5.5 folds. Both BSe or nSe at the higher concentration increased proline concentrations, H 2 O 2 accumulation, and lipid peroxidation levels, suggesting oxidative stress and impaired membrane integrity. Both BSe or nSe treatments also led to the induction of enzymatic antioxidants (catalase and peroxidase), an increase in concentrations of ascorbate, non-protein thiols, and soluble phenols, as well as a rise in the activity of phenylalanine ammonia-lyase enzyme. Supplementation at 3 mgl ⁻¹ improved the concentration of mineral nutrients (Mg, Fe, and Zn) in fruits. The bioaccumulated Se contents in the nSe-treated plants were much higher than the corresponding concentration of selenate, implying a higher efficacy of the nanoform towards biofortification programs. Se at 10 mgl ⁻¹ , especially in selenate form, reduced both size and density of pollen grains, indicating its potential toxicity at the higher doses. This study provides novel molecular and physiological insights into the nSe efficacy for improving plant productivity, fruit quality, and fruit post-harvest longevity.
The genotype + genotype × environment (GGE) biplot methodology has the potential to determine combining ability effects, identify efficient testers, and distinct heterotic groups in a line × tester study. However, it has not been adequately applied for such analysis. Therefore, this study was done to assess the combining ability of some maize inbred lines and testers for grain yield, identify most efficient testers and classify inbred lines into heterotic groups using GGE biplot. Fifteen experimental single cross hybrids, generated from a 5 x 3 line by line × tester crosses procedure, were evaluated across seven sites in Iran in 2018 using a randomized complete block design with three replicates per entry at each site. According to the pooled analysis of variance, crosses showed significant differences for grain yield. Also, the differences observed among the testers, inbred lines, and interactions for the line × tester, crosses × environments, line x tester x environment was significant. The inbred line L4 was recognized as outstanding for its general combining ability (GCA) effect and the tester K18 was highly efficient based on its discriminating power. It can be concluded that the crosses of L4 x K47/3 and L4 x B73 are suggested to release high grain yield hybrids. Results of the GGE biplot analyses were close to the conventional line × tester method in combining ability and heterotic patterns of the yield of lines, grouping, and identification of testers.
In order to evaluate dry matter remobilization to seeds in the winter type rapeseed cultivars grown under drought stress conditions, an experiment was carried out using a randomized complete block design arranged in a split plot with three replicates in Shahre-Qods, Iran, in the 2011-2012 growing season. Irrigation treatments including control (irrigation after 80 mm evaporation from evaporation pan class A) and drought stress (irrigation withholding starting from stem elongation, flowering and silique formation stages) were allocated to the main plots and three winter type rapeseed cultivars (GKH2005, Opera and SLM046) were considered as the subplots. The results showed that drought stress increased dry matter remobilization and remobilization efficiency. By contrast, agronomic traits such as the number of siliques on the main stem and secondary branches, number of seeds per silique, 1000 seed weight, oil yield, harvest index and productivity effort (silique dry weight/biomass ratio) were decreased. The GKH2005 cultivar showed the maximum seed yield, which was 1058, 1409 and 2099 kg ha-1, when irrigation withholding started from stem elongation, flowering stage, and silique formation stages, respectively; this was due to the higher amount of remobilization and the efficiency of remobilization and maximum number of silique in the secondary branches. In general, the results suggest that higher remobilization and remobilization efficiency are among the most important drought stress tolerance mechanisms in the oilseed rape.
Background Stem rust caused by Puccinia graminis f. sp. tritici (Pgt) is an important disease of wheat in the world. Pgt pathogen is constantly evolving and creating more virulent races that break down stem rust (Sr) resistance genes. As a result, many of Sr genes have become ineffective against new Pgt races. Exploring new sources of resistance to detect new Sr genes/QTLs is very important in order to introducing them into wheat breeding programs and developing resistant wheat cultivars. The objective of the present study was to evaluate 297 Iranian wheat genotypes for resistance to stem rust at seedling stage and to detect Sr resistance genes/QTLs through association mapping (AM). Results A set of 297 Iran bread wheat cultivars and landraces were evaluated for infection type and latent period in four race of Pgt. Genotypic data of 282 genotypes were available, so AM was performed based on 282 genotypes. The results of population structure analysis showed that 277 genotypes clearly were distinguished in the three subpopulations and the other five genotypes were classified in the mixed group. The mean linkage disequilibrium decreased with increasing genetic distance. The markers did not have a uniform distribution on the genomes, so the share of each of the A, B and D genomes in commercial cultivars and landraces was approximately 37, 46 and 17%, respectively. Collectively, 69 QTLs for infection type and 62 QTLs for latent period of studied Pgt races were identified in the original dataset (P ≤ 0.001). In the imputed SNPs dataset, the number of QTLs for infection type increased to 504 QTL and for latent period increased to 454 QTLs (P ≤ 0.001). Conclusion Based on the results of this study, it can be concluded that the Iranian wheat genotypes are valuable source resistance to stem rust. By incorporating these genotypes into wheat breeding programs and optimizing effective resistance genes, an important step can be taken to prevent the threat of and the disease to ensure food security. This study provides additional useful information for selection of resistant genotypes against the disease by improving marker-assisted selection efficiency.
Introduction. More attention has been paid in recent decades to extracts and essential oils from various plants as natural antioxidant sources due to their positive effects on food oxidation reactions. Our study aimed to compare the antioxidant activity of aqueous and alcoholic extracts from Salvia leriifolia L. and Linum usitalissmum L.The extracts were subjected to a pulsed electric field with intensities of zero (without pretreatment), 3 and 6 kV·cm–1, and a constant pulse number of 30. For this purpose, parameters such as total phenolic compounds and antioxidant activity were investigated by DPPH and TEAC methods. Results and discussion. Our results showed that a higher intensity of a pulsed electric field pretreatment and the use of an alcoholic solvent significantly raised total phenolic compounds in the extracts and their antioxidant activity at a 95% confidence level. We found significant effects of the plant source (Linum usitalissmum and Salvia leriifolia), pretreatment (pulse electric field at intensities of 0.3 and 6 kV·cm–1), and a solvent (aqueous and alcohol) on the extracts’ antioxidant activity (P < 0.05). In addition, there was a significant correlation between the results of the DPPH and the TEAC antioxidant activities (P < 0.01 and r = 0.932). Conclusion. The total antioxidant activity (based on both TEAC and DPPH methods) and total phenolic compounds extracted from Salvia leriifolia were higher than those from Linum usitalissmum (P < 0.05). Based on the results, the extract obtained from Salvia leriifolia with an alcoholic solvent and a pulsed electric field pretreatment (at 6 kV·cm–1 and 30 pulses) was selected as possessing desired antioxidant properties.
In order to assess the genotype by environment interaction (GE) and select genotypes to exploit narrow and broad adaptations, twenty-two spring oilseed rape genotypes were subjected to field surveys at five experimental sites in the 2015-16 and 2016-17 growing seasons. Plant materials were sown in the form of a randomized complete block design with three replicates. The additive main effects and multiplicative interaction (AMMI) model was used to determine the genotype, environment, and GE effects. The sum of squares (SS) for the first three interaction principal components was very close to the SS for the GE signal; therefore, AMMI3 was diagnosed as the most accurate model to optimize predictive accuracy. Hyola 401 had the highest broad adaptability. In total, the chances of increasing yield were 55.80% from broad adaptations, 26.73% from narrow adaptations with 4 mega-environments, and an additional 17.47% from narrow adaptations with 5 mega-environments.
Fusarium verticillioides , which causes ear, kernel and stem rots, has been reported as the most prevalent species on maize worldwide. Kernel infection by F. verticillioides results in reduced seed yield and quality as well as fumonisin contamination, and may affect seedling traits like germination rate, entire plant seedling length and weight. Maize resistance to Fusarium is a quantitative and complex trait controlled by numerous genes with small effects. In the present work, a Genome Wide Association Study (GWAS) of traits related to Fusarium seedling rot was carried out in 230 lines of a maize association population using 226,446 SNP markers. Phenotypes were scored on artificially infected kernels applying the rolled towel assay screening method and three traits related to disease response were measured in inoculated and not-inoculated seedlings: plant seedling length (PL), plant seedling weight (PW) and germination rate (GERM). Overall, GWAS resulted in 42 SNPs significantly associated with the examined traits. Two and eleven SNPs were associated with PL in inoculated and not-inoculated samples, respectively. Additionally, six and one SNPs were associated with PW and GERM traits in not-inoculated kernels, and further nine and thirteen SNPs were associated to the same traits in inoculated kernels. Five genes containing the significant SNPs or physically closed to them were proposed for Fusarium resistance, and 18 out of 25 genes containing or adjacent to significant SNPs identified by GWAS in the current research co-localized within QTL regions previously reported for resistance to Fusarium seed rot, Fusarium ear rot and fumonisin accumulation. Furthermore, linkage disequilibrium analysis revealed an additional gene not directly observed by GWAS analysis. These findings could aid to better understand the complex interaction between maize and F. verticillioides .
Water stress is one of the main abiotic factors that reduces plant growth, mainly due to high evaporative demand and low water availability. In order to evaluate the effects of drought stress on certain morphological and physiological characteristics of two canola cultivars, we conducted a factorial experiment based on a completely randomized design. The findings show that drought stress exacerbations result in the plant's response to stress due to increased canola resistance caused by changes in plant pigments, proline, catalase, ascorbate peroxidase, peroxidase, superoxide dismutase and malondialdehyde, glucose, galactose, rhamnose and xylose. These in turn ultimately influence the morphological characteristics of canola. Drought stress reduces the concentration of carotenoids, chlorophyll a, chlorophyll b, total chlorophylls; however, glucose, galactose, rhamnose, xylose, proline, catalase, ascorbate peroxidase, peroxidase, superoxide dismutase, malondialdehyde (in leaves and roots) and the chlorophyll a and b ratios were increased. Reduction of plant height, stem height, root length, fresh and dry weight of canola treated with 300 g/l PEG compared to non‐treatment were 0.264, 0.236, 0.394, 0.183 and 0.395, respectively. From the two canola cultivars, the morphological characteristics of the NIMA increased compared to the Ks7 cultivar. Interaction effects of cultivar and drought stress showed that NIMA cultivar without treatment had the highest number of morphological characteristics such as carotenoid concentration, chlorophyll a, chlorophyll b, total chlorophylls a and b, whereas the cultivar with 300 g/l PEG (drought stress) had the highest amount of proline, malondialdehyde, soluble sugars and enzymes in leaves and roots. Increasing activity of oxidative enzymes and soluble sugars in canola under drought stress could be a sign of their relative tolerance to drought stress.
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88 members
Saeed Khavari khorasani
  • saeed khavari khorasani
Mehdi Ghaffari
  • Oil Crops Research Department
Ali Malihipour
  • Cereal Research Department
Farid Golzardi
  • Maize and Forage Crops Research Department
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Address
Shahid Fahmideh Blv., 31585-4119, Karaj, Ostan-e Alborz, Iran
Head of institution
Dr. Goodarz Najfian (Associate Prof.)
Website
www.spii.ir
Phone
026-32700043
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