Iranian Cultivars Research Articles

Comprehensive In Silico Analysis of the NHX (Na+/H+ Antiporter) Gene in Rice (Oryza sativa L.)

The Na+/H+ antiporter (NHX) gene family plays a pivotal role in plant salt tolerance in regulating intracellular Na+ and H+ homeostasis. In this study, seven candidate OsNHX genes (OsNHX1 to OsNHX7) were identified in the rice genome and classified into three phylogenetic clusters (Vac, Endo, and PM) based on their predicted subcellular localization. Five OsNHX gene pairs (OsNHX1/OsNHX2, OsNHX1/OsNHX3, OsNHX1/OsNHX4, OsNHX2/OsNHX6, and OsNHX5/OsNHX6) were found to have arisen from dispersed duplication events and exhibited purifying selection, indicating functional conservation. Analysis of cis-regulatory elements (CREs) revealed a diverse range of elements associated with tissue-specific expression, hormone signaling, and stress responses, particularly to dehydration and salinity. Notably, CREs associated with tissue/organelle-specific expression and stress responses were the most abundant, suggesting a potential role for OsNHX genes in regulating growth, development, and stress tolerance in rice. Importantly, expression profiling revealed that OsNHX1, OsNHX2, OsNHX3, and OsNHX5 were upregulated under salt stress, with significantly higher expression levels in the salt-tolerant rice cultivar Pokkali compared to the salt-sensitive cultivar IR64. Our findings provide a comprehensive analysis of the evolutionary, structural, and functional features of the OsNHX gene family and highlights their critical role in rice salt tolerance, offering insights into potential applications for crop improvement.

Unraveling the genetic basis of oil quality in olives: a comparative transcriptome analysis.

The balanced fatty acid profile of olive oil not only enhances its stability but also contributes to its positive effects on health, making it a valuable dietary choice. Olive oil's high content of unsaturated fatty acids and low content of saturated fatty acids contribute to its beneficial effects on cardiovascular diseases and cancer. The quantities of these fatty acids in olive oil may fluctuate due to various factors, with genotype being a crucial determinant of the oil's quality. This study investigated the genetic basis of oil quality by comparing the transcriptome of two Iranian cultivars with contrasting oil profiles: Mari, known for its high oleic acid content, and Shengeh, characterized by high linoleic acid at Jaén index four. Gas chromatography confirmed a significant difference in fatty acid composition between the two cultivars. Mari exhibited significantly higher oleic acid content (78.48%) compared to Shengeh (48.05%), while linoleic acid content was significantly lower in Mari (4.76%) than in Shengeh (26.69%). Using RNA sequencing at Jaén index four, we analyzed genes involved in fatty acid biosynthesis. Differential expression analysis identified 2775 genes showing statistically significant differences between the cultivars. Investigating these genes across nine fundamental pathways involved in oil quality led to the identification of 25 effective genes. Further analysis revealed 78 transcription factors and 95 transcription binding sites involved in oil quality, with BPC6 and RGA emerging as unique factors. This research provides a comprehensive understanding of the genetic and molecular mechanisms underlying oil quality in olive cultivars. The findings have practical implications for olive breeders and producers, potentially streamlining cultivar selection processes and contributing to the production of high-quality olive oil.

Characterization of quantitative trait loci from DJ123 (aus) independently affecting panicle structure traits in indica rice cultivar IR64.

The online version contains supplementary material available at 10.1007/s11032-024-01494-5.

Rice Big Grain1 improves grain yield in ectopically expressing rice and heterologously expressing tobacco plants.

Functional genomics through transgenesis has provided faster and more reliable methods for identifying, characterizing, and utilizing genes or quantitative trait loci linked to agronomic traits to target yield. The present study explored the role of Big Grain1 (BG1) gene of rice (Oryza sativa L.) in yield improvement of crop plants. We aimed to identify the genetic variation of OsBG1 in various indica rice cultivars by studying the allelic polymorphism of the gene, while also investigating the gene's potential to increase crop yield through the transgenic approach. Our study reports the presence of an extra 393bp sequence having two 6bp enhancer elements in the 3' regulatory sequence of OsBG1 in the large-grain cultivar IR64 but not in the small-grain cultivar Badshahbhog. A single copy of the OsBG1 gene in both the cultivars and a 4.1-fold higher expression of OsBG1 in IR64 than in Badshahbhog imply that the grain size is positively correlated with the level of OsBG1 expression in rice. The ectopic expression of OsBG1 under the endosperm-specific glutelin C promoter in Badshahbhog enhanced the flag leaf length, panicle weight, and panicle length by an average of 33.2%, 33.7%, and 30.5%, respectively. The length of anthers, spikelet fertility, and grain yield per plant increased in transgenic rice lines by an average of 27.5%, 8.3%, and 54.4%, respectively. Heterologous expression of OsBG1 under the constitutive 2xCaMV35S promoter improved the number of seed pods per plant and seed yield per plant in transgenic tobacco lines by an average of 2.2-fold and 2.6-fold, respectively. Improving crop yield is crucial to ensure food security and socio-economic stability, and identifying suitable genetic factor is the essential step towards this endeavor. Our findings suggest that the OsBG1 gene is a promising candidate for improving the grain yield of monocot and dicot plant systems by molecular breeding and genetic engineering.

Co-overexpression of chitinase and β-1,3-glucanase significantly enhanced the resistance of Iranian wheat cultivars to Fusarium

Fusarium head blight (FHB) is a devastating fungal disease affecting different cereals, particularly wheat, and poses a serious threat to global wheat production. Chitinases and β-glucanases are two important proteins involved in lysing fungal cell walls by targeting essential macromolecular components, including chitin and β-glucan micro fibrils. In our experiment, a transgenic wheat (Triticum aestivum) was generated by introducing chitinase and glucanase genes using Biolistic technique and Recombinant pBI121 plasmid (pBI-ChiGlu (-)). This plasmid contained chitinase and glucanase genes as well as nptII gene as a selectable marker. The expression of chitinase and glucanase was individually controlled by CaMV35S promoter and Nos terminator. Immature embryo explants from five Iranian cultivars (Arta, Moghan, Sisun, Gascogen and A-Line) were excised from seeds and cultured on callus induction medium to generate embryonic calluses. Embryogenic calluses with light cream color and brittle texture were selected and bombarded using gold nanoparticles coated with the recombinant pBI-ChiGlu plasmid. Bombarded calluses initially were transferred to selective callus induction medium, and later, they were transfferd to selective regeneration medium. The selective agent was kanamycin at a concentration of 25 mg/l in both media. Among five studied cultivars, A-Line showed the highest transformation percentage (4.8%), followed by the Sisun, Gascogen and Arta in descending order. PCR and Southern blot analysis confirmed the integration of genes into the genome of wheat cultivars. Furthermore, in an in-vitro assay, the growth of Fusarium graminearum was significantly inhibited by using 200 μg of leaf protein extract from transgenic plants. According to our results, the transgenic plants (T1) showed the resistance against Fusarium when were compared to the non-transgenic plants. All transgenic plants showed normal fertility and no abnormal response was observed in their growth and development.

The first draft genome sequence of Russian olive (Elaeagnus angustifolia L.) in Iran

Russian olive (Elaeagnus angustifolia L.) is a native tree species of Iran and the Caucasus region growing in both wild habitats and cultivated settings. The area under cultivation of this tree has been increasing in recent years due to its ability to withstand drought and soil salinity. Revealing the complete genome of this tree holds great importance. To achieve this, a local cultivar of Russian olive was sampled from the northwest region of Iran for whole genome sequencing using the Illumina platform resulting in approximately 6GB of raw data. A quality check of the raw data indicated that approximately 45,011,388 read pairs were obtained from sequences totalling around 6.7×109bp with CG content of 31%. To assemble the genome of the Russian olive tree, the raw data was aligned to a reference sequence of the jujube (Ziziphus jujuba) genome, which is the taxonomically closest plant to the Russian olive. Assembly of alignments yielded a genome size of 553,696,299bp consisting of 339,701 contigs. The N50 value was 5,300 with an L50 value of 24,921 and GC content of the Russian olive genome was 31.5%. This research represents the first report on the genome of the Iranian cultivar of the Russian olive tree.

Interaction of wheat-Parastagonospora nodorum isolates: Exploring host susceptibility and fungal virulence

The fungus Parastagonospora nodorum causes substantial economic losses in wheat worldwide. P. nodorum secretes multiple proteinaceous necrotrophic effectors (NEs) that induce compatible interactions with hosts possessing corresponding dominant susceptibility (S) genes. This study focused on unraveling the virulence pattern and presence of NEs secreted by 33 isolates of P. nodorum in the context of its interaction with 40 wheat genotypes. Wheat genotypes were classified into six groups based on their variable responses to P. nodorum isolates. The S gene Tsn1 was present in 70 % of the highly susceptible cultivars and completely absent in all resistant cultivars. Cultivars possessing all three S genes, Tsn1, Snn1, and Snn3, were susceptible to all P. nodorum isolates. The S gene Snn3 was detected in all Iranian wheat cultivars, whereas its proportion in the world's cultivars was 62.5 %. SnTox1-Snn1 was the most abundant NE-S gene (100 %) in the Iranian P. nodorum and Iranian cultivars. Furthermore, SnToxA was produced in Pichia pastoris, and infiltration of SnToxA resulted in necrosis response exclusively in wheat genotypes harboring the S gene Tsn1. Overall, these findings extend our substantial knowledge of P. nodorum-wheat interactions and their underlying molecular basis in Iran, a country in the Fertile Crescent where both wheat and its pathogens coevolved.

Enhancement of genetic transformation efficiency in indica rice cultivar IR64 by vacuum infiltration and exogenous application of polyamines

Enhancement of genetic transformation efficiency in indica rice cultivar IR64 by vacuum infiltration and exogenous application of polyamines

Seed Halopriming: A Promising Strategy to Induce Salt Tolerance in Indonesian Pigmented Rice.

Unfavorable environmental conditions and climate change impose stress on plants, causing yield losses worldwide. The Indonesian pigmented rice (Oryza sativa L.) cultivars Cempo Ireng Pendek (black rice) and Merah Kalimantan Selatan (red rice) are becoming popular functional foods due to their high anthocyanin contents and have great potential for widespread cultivation. However, their ability to grow on marginal, high-salinity lands is limited. In this study, we investigated whether seed halopriming enhances salt tolerance in the two pigmented rice cultivars. The non-pigmented cultivars IR64, a salt-stress-sensitive cultivar, and INPARI 35, a salt tolerant, were used as control. We pre-treated seeds with a halopriming solution before germination and then exposed the plants to a salt stress of 150 mM NaCl at 21 days after germination using a hydroponic system in a greenhouse. Halopriming was able to mitigate the negative effects of salinity on plant growth, including suppressing reactive oxygen species accumulation, increasing the membrane stability index (up to two-fold), and maintaining photosynthetic pigment contents. Halopriming had different effects on the accumulation of proline, in different rice varieties: the proline content increased in IR64 and Cempo Ireng Pendek but decreased in INPARI 35 and Merah Kalimantan Selatan. Halopriming also had disparate effects in the expression of stress-related genes: OsMYB91 expression was positively correlated with salt treatment, whereas OsWRKY42 and OsWRKY70 expression was negatively correlated with this treatment. These findings highlighted the potential benefits of halopriming in salt-affected agro-ecosystems.

Physiological resistance responses of rice plant (Oryza sativa) provided with silicate fertilizer to sheath blight disease (Rhizoctonia solani)

Abstract. Azizah R, Rachmawati D. 2023. Physiological resistance responses of rice plant (Oryza sativa) provided with silicate fertilizer to sheath blight disease (Rhizoctonia solani). Biodiversitas 24: 3785-3795. Sheath blight disease that is caused by the fungus Rhizoctonia solani Kühn generally leads to the reduction of rice yields. The application of silicate fertilizers can increase the resistance to pathogens. This research aimed to determine the effect of silicate fertilizer application on the physiological resistance responses of rice plants to R. solani, the primary pathogen responsible for rice sheath blight. This study used three rice cultivars with different resistance levels to sheath blight, including Pandan Wangi (resistant), Cisadane (susceptible), and IR64 (moderately resistant), which were treated with three doses of silicate fertilizer 0 kg ha-1, 200 kg ha-1 and 400 kg ha-1 with sheath blight inoculation and without inoculation. The results showed that Pandan Wangi provided with 200 kg ha-1 silicate fertilizer produced the highest reduction in the percentage of relative lesion height (RLH), and the application of 400 kg ha-1 silicate fertilizer had a greater positive effect of reducing the lesion in Cisadane and IR64. In susceptible and moderately resistant cultivars, Cisadane and IR64, higher doses of silicate fertilizer have a better effect on strengthening plant tissue during inoculation treatments. The application of 400 kg ha-1 silicate fertilizer without inoculation significantly affected relative water content. In the moderately resistant cultivar IR64, the silicate fertilizer played a role in the physiological response by strengthening the plant tissue, as indicated by the increasing lignin content, sclerenchyma and cuticle thickness.

Rice-Magnaporthe transcriptomics reveals host defense activation induced by red seaweed-biostimulant in rice plants.

Red seaweed extracts have been shown to trigger the biotic stress tolerance in several crops. However, reports on transcriptional modifications in plants treated with seaweed biostimulant are limited. To understand the specific response of rice to blast disease in seaweed-biostimulant-primed and non-primed plants, transcriptomics of a susceptible rice cultivar IR-64 was carried out at zero and 48h post inoculation with Magnaporthe oryzae (strain MG-01). A total of 3498 differentially expressed genes (DEGs) were identified; 1116 DEGs were explicitly regulated in pathogen-inoculated treatments. Functional analysis showed that most DEGs were involved in metabolism, transport, signaling, and defense. In a glass house, artificial inoculation of MG-01 on seaweed-primed plants resulted in the restricted spread of the pathogen leading to the confined blast disease lesions, primarily attributed to reactive oxygen species (ROS) accumulation. The DEGs in the primed plants were defense-related transcription factors, kinases, pathogenesis-related genes, peroxidases, and growth-related genes. The beta-D-xylosidase, a putative gene that helps in secondary cell wall reinforcement, was downregulated in non-primed plants, whereas it upregulated in the primed plants indicating its role in the host defense. Additionally, Phenylalanine ammonia-lyase, pathogenesis-related Bet-v-I family protein, chalcone synthase, chitinases, WRKY, AP2/ERF, and MYB families were upregulated in seaweed and challenge inoculated rice plants. Thus, our study shows that priming rice plants with seaweed bio-stimulants resulted in the induction of the defense in rice against blast disease. This phenomenon is contributed to early protection through ROS, protein kinase, accumulation of secondary metabolites, and cell wall strengthening.

Detection of novel loci involved in non-seed-shattering behaviour of an indica rice cultivar, Oryza sativa IR36

Asian rice (Oryza sativa) was domesticated from O. rufipogon, and reduced seed-shattering behaviour was selected to increase yields. Two seed-shattering loci, qSH3 and sh4, are involved in reducing seed shattering in both japonica and indica rice cultivars, while qSH1 and qCSS3 are likely specific to japonica cultivars. In indica cultivars, qSH3 and sh4 fail to explain the degree of seed shattering, as an introgression line (IL) of O. rufipogon W630 carrying domesticated alleles at qSH3 and sh4 still showed seed shattering. Here we analysed differences in seed-shattering degree between the IL and the indica cultivar IR36. The values for grain detachment in the segregating population between the IL and IR36 were continuous. Based on QTL-seq analysis using the BC1F2 population between the IL and IR36, we detected two novel loci, qCSS2 and qCSS7 (QTLs for the Control of Seed Shattering in rice on chromosomes 2 and 7), which contributed to the reduced seed shattering in IR36. We further investigated the genetic interaction of qCSS2 and qCSS7 under the presence of qSH3 and sh4 mutations in O. rufipogon W630 and found that IL carrying IR36 chromosomal segments covering all four loci are required to explain seed-shattering degree in IR36. Since qCSS2 and qCSS7 were not detected in previous studies on seed shattering in japonica, their control may be specific to indica cultivars. Therefore, they are important to understanding the history of rice domestication as well as to adjusting the seed-shattering degree of indica cultivars to maximise their yield.

Exploring genomic regions involved in bread wheat resistance to leaf rust at seedling/adult stages by using GWAS analysis

BackgroundGlobal wheat productivity is seriously challenged by a range of rust pathogens, especially leaf rust derived from Puccinia triticina. Since the most efficient approach to control leaf rust is genetic resistance, many efforts have been made to uncover resistance genes; however, it demands an ongoing exploration for effective resistance sources because of the advent of novel virulent races. Thus, the current study was focused on detecting leaf rust resistance-related genomic loci against the P. triticina prevalent races by GWAS in a set of Iranian cultivars and landraces.ResultsEvaluation of 320 Iranian bread wheat cultivars and landraces against four prevalent rust pathotypes of P. triticina (LR-99–2, LR-98–12, LR-98–22, and LR-97–12) indicated the diversity in wheat accessions responses to P. triticina. From GWAS results, 80 leaf rust resistance QTLs were located in the surrounding known QTLs/genes on almost chromosomes, except for 1D, 3D, 4D, and 7D. Of these, six MTAs (rs20781/rs20782 associated with resistance to LR-97–12; rs49543/rs52026 for LR-98–22; rs44885/rs44886 for LR-98–22/LR-98–1/LR-99–2) were found on genomic regions where no resistance genes previously reported, suggesting new loci conferring resistance to leaf rust. The GBLUP genomic prediction model appeared better than RR-BLUP and BRR, reflecting that GBLUP is a potent model for genomic selection in wheat accessions.ConclusionsOverall, the newly identified MTAs as well as the highly resistant accessions in the recent work provide an opportunity towards improving leaf rust resistance.

Brassinosteroids Mediate Endogenous Phytohormone Metabolism to Alleviate High Temperature Injury at Panicle Initiation Stage in Rice

High temperatures cause physiological and biochemical changes and significantly affect young panicle development of rice (Oryza sativa L.). Brassinosteroids play important roles in enhancing crop stress resistance. In this study, we subjected rice cultivars Huanghuazhan (heat-resistant) and IR36 (heat-sensitive) to high temperature (HT, 40 ºC) or normal temperature (NT, 33 ºC) for 7 d at the panicle initiation stage, in conjunction with application of 24-epibrassinolide [EBR, a synthetic brassinolide (BR)] or brassinazole (BRZ, a BR biosynthesis inhibitor) at the beginning of the treatments. HT exacerbated spikelet degeneration and inhibited young panicle growth, which were partially prevented by EBR application, while BRZ application aggravated the reduction in spikelet number. HT decreased the contents of BR, active cytokinins (aCTK), active gibberellins (aGA) and indole-3-acetic acid (IAA), but increased the content of abscisic acid (ABA) in young panicles. The activities of key enzymes involved in sucrose hydrolysis, glycolysis and the tricarboxylic acid cycle in young panicles were decreased with the change of endogenous hormone levels under HT. In addition, the contents of H2O2 and malondialdehyde (MDA) were increased and the activities of antioxidant enzymes were decreased in young panicles. Exogenous application of EBR induced the expression of phytohormone biosynthesis-related genes and down-regulated the expression of phytohormone catabolism-related genes to increase the contents of endogenous BR, aCTK, aGA and ABA, thus promoting the decomposition and utilization of sucrose in young panicles, enhancing the activities of superoxide dismutase, catalase and peroxidase, and reducing the accumulation of H2O2 and MDA in young panicles, whereas application of BRZ had the opposite physiological effects. These results showed that brassinosteroids mediate endogenous phytohormone metabolism to alleviate HT injury at the panicle initiation stage in rice.

Wheat breeding for early heading: Does it improve grain yield under drought stress and well-watered conditions?

Terminal drought stress strongly affects wheat grain yield under Mediterranean conditions. Therefore, developing early-heading bread wheat cultivars in these conditions is an important breeding strategy. In the present research, earliness was transferred from the Australian cultivar, Excalibur, to three Iranian cultivars, Roshan, Kalheydari and Mahdavi, in separate backcross (BC) breeding programs from 2012 to 2018. The earliest and latest heading genotypes of each BC 3 population, were selected as near-isogenic lines (NILs). NILs and their parents were assessed under diverse field conditions including rain-fed, moderate drought stress and well-watered conditions in three locations, Kerman, Sepidan and Semirom, during two growing seasons, 2018–2019 and 2019–2020. Breeding for early heading significantly improved earliness in all genetic backgrounds and increased grain yield by 36.4% and 9.6%, in the rain-fed and moderate drought stress conditions, respectively. Whereas, grain yield was not significantly affected by early heading under well-watered conditions. Results showed that breeding for early heading, a highly heritable trait, is an appropriate method to increase grain yield and reduce water consumption under drought stress and well-watered conditions, respectively. Based on these findings, we recommend transferring early heading to high yield late heading commercial cultivars using backcrossing. • For the first time, near isogenic lines of early heading were developed. • Breeding for early heading increased grain yield by 36.4% in rain-fed conditions. • Early heading increased grain yield by 9.6% in moderate drought stress conditions. • Early heading did not affect grain yield under well-watered conditions in Kerman.

Comparative transcriptome analysis reveals a rapid response to phosphorus deficiency in a phosphorus-efficient rice genotype.

Phosphorus (P) is an essential plant nutrient. Most rice growing lands lack adequate P, requiring multiple P fertiliser applications to obtain expected yields. However, P fertiliser is environmentally damaging, and already unaffordable to the marginal farmers. This warrants developing P-efficient rice varieties that require less P to produce the expected yield. However, genetic factors underlying P-use efficiency (PUE) in rice remain elusive. Here, we conducted comparative transcriptome analysis using two rice varieties with contrasting PUE; a P-efficient landrace DJ123 and a P-inefficient modern cultivar IR64. We aimed to understand the transcriptomic responses in DJ123 that allow it to achieve a high PUE under low P conditions. Our results showed that both DJ123 and IR64 had replete tissue P concentrations after 48 h of P deprivation. Yet, DJ123 strongly responded to the external low P availability by inducing P starvation-inducible genes that included SPX2, PHO1, PAPs and SQDs, while these genes were not significantly induced in IR64. We envisage that the ability of DJ123 to rapidly respond to low P conditions might be the key to its high PUE. Our findings lay a valuable foundation in elucidating PUE mechanism in rice, thus will potentially contribute to developing P-efficient modern rice variety.

Near-isogenic lines for resistance to blast disease, in the genetic background of the Indica Group rice (Oryza sativa L.) cultivar IR64

We developed 21 near-isogenic lines (NILs) in the genetic background of the Indica Group rice ( Oryza sativa L.) cultivar IR64, with each containing one of the 11 blast resistance genes: Pish , Piz , Piz-5 , Pi9 (t), Pii , Pi3 , Pik , Pik-h , Pik-p , Pi1 , and Pi7 (t). The NILs were confirmed to harbor these genes by their reaction patterns to standard differential blast isolates and by analyses for graphical genotypes using DNA markers located on the same chromosome regions as the target resistance genes. The agronomic traits of these NILs, such as days to heading and yield components, were also investigated and found to be very similar to those of IR64, even when grown under the dramatically different environmental conditions of the temperate and subtropical regions of Japan. These NILs and their genetic information will be used as gene sources for Indica Group rice breeding programs, to improve resistance to blast disease, and as a multiline variety that will also be useful as an alternative approach to the development of the durability of rice resistance to blast disease in tropical areas, especially in irrigated lowland ecosystems.

Integrated root phenotypes for improved rice performance under low nitrogen availability.

Greater nitrogen efficiency would substantially reduce the economic, energy and environmental costs of rice production. We hypothesized that synergistic balancing of the costs and benefits for soil exploration among root architectural phenes is beneficial under suboptimal nitrogen availability. An enhanced implementation of the functional–structural model OpenSimRoot for rice integrated with the ORYZA_v3 crop model was used to evaluate the utility of combinations of root architectural phenes, namely nodal root angle, the proportion of smaller diameter nodal roots, nodal root number; and L‐type and S‐type lateral branching densities, for plant growth under low nitrogen. Multiple integrated root phenotypes were identified with greater shoot biomass under low nitrogen than the reference cultivar IR64. The superiority of these phenotypes was due to synergism among root phenes rather than the expected additive effects of phene states. Representative optimal phenotypes were predicted to have up to 80% greater grain yield with low N supply in the rainfed dry direct‐seeded agroecosystem over future weather conditions, compared to IR64. These phenotypes merit consideration as root ideotypes for breeding rice cultivars with improved yield under rainfed dry direct‐seeded conditions with limited nitrogen availability. The importance of phene synergism for the performance of integrated phenotypes has implications for crop breeding.

Evaluation of drought tolerance in three commercial pomegranate cultivars using photosynthetic pigments, yield parameters and biochemical traits as biomarkers

Drought stress during the ripening phenological period has adverse effects on pomegranate (Punica granatum L.) fruit productivity, characteristics and composition, depending on the drought severity and specific cultivar. This fact underlines the importance of understanding the physiological and biochemical responses of pomegranate under drought stress to improve the quality of fruits. The responses of three commercial Iranian cultivars (‘Malase Saveh’, ‘Mikhosh’ and ‘Rabab-Neyriz’) to slight, moderate or intense drought stress were evaluated, considering yield-related (fruit yield, number of fruits per tree, fruit weight and fruit cracking), metabolite [glucose, fructose, total soluble solids (TSS), titratable acidity, total phenolics (TPC), ellagic acid, total anthocyanins (TAC), abscisic acid (ABA), indole acetic acid (IAA), proline, ascorbic (Asc) and carboxylic acids], and physiological parameters (oxidative stress indexes and activities of key antioxidant enzymes in leaves). Significant decreases in fruit yield (58–68%), number of fruits per tree (39–44%), fruit weight (30–41%), and leaf photosynthetic pigments (23–39%) were observed among cultivars in response to intense drought. On the other hand, significant increases in the levels of ABA, IAA, proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2), as well as the activities of catalase (CAT), peroxidase (POD), superoxide dismutase (SOD) and ascorbate peroxidase (APX) antioxidant enzymes were observed in the leaves of all cultivars under intense drought stress. With respect to fruit juice quality, intense drought caused a considerable decrease in the contents of sugars, TAC, TPC, ellagic acid, Asc, TSS, and TA relative to control conditions, while carboxylic acids increased. Slight drought caused small increases in the concentrations of sugars, TPC and ellagic acid in juice. The ‘Malase Saveh’ cultivar showed a better adaptive response to drought stress than the ‘Rabab-e-Neyriz’ and ‘Mikhosh’ ones, suggesting that this pomegranate cultivar could be used in breeding programs to develop new ones with beneficial water stress-adaptive traits and better fruit quality.

Evaluation of nuts morphology and composition of fatty acids in certain Iranian Pistacia vera L. (Anacardiaceae) cultivars

Fruits of various Pistachio (Pistacia vera L.) cultivars are widely used in food industries for its inimitable color, taste and nutrient value. We elevated fruit morphology and kernel fatty acids composition of eleven Iranian cultivars of pistachio. Oils of kernels were extracted using cold press method, and composition of the oil fatty acids in the methyl ester form was detected using gas chromatography (GC). For morphological study, nine qualitative and quantitative traits were evaluated. The quantitative ones widely differed among the studied cultivars, and ANOVA test revealed the significant variations (p = 0.00) for all of them. Moreover, the qualitative traits varied among the cultivars. We characterized 11 fatty acid components representing about 99.56 to 100 % of the total oil composition. The principal fatty acids for all the cultivars were: oleic, linoleic and palmitic acids, while their amounts differed among the cultivars. In this regard, unsaturated fatty acids comprised the major oil part, 87.46 to 88.89 %. Oleic acid (53.11-70.99 %) and palmitic acid (9.09 to 10.55 %) were detected as the unsaturated and saturated fatty acids in all the evaluated cultivars. The quality index of oils were determined according to oleic/ linoleic acids ratio, which highly varied among the cultivars. According to UPGMA tree and PCO plot, we divided the investigated cultivars into four chemotypes, and each of them was characterized by the certain oil composition.