Research paper
Leila Baghazadeh Daryaii; Davoud Samsampour; Abdoolnabi Bagheri; Jelveh Sohrabipour
Abstract
Bacterial endophytes grow symbiotically inside plants and improve the growth of their hosts. We evaluated the effects of inoculating macroalgae bacterial endophytes, introduced formerly by our group, Bacillus aquimaris strain OD14, B. megaterium strain AM25, B. zhangzhouensis strain Tv91C, individually ...
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Bacterial endophytes grow symbiotically inside plants and improve the growth of their hosts. We evaluated the effects of inoculating macroalgae bacterial endophytes, introduced formerly by our group, Bacillus aquimaris strain OD14, B. megaterium strain AM25, B. zhangzhouensis strain Tv91C, individually and in combination with each other on the reactive oxygen species (ROS) of scavenging and antioxidant functions, as well as growth characteristics of Mexican lime seedlings under salinity stress. Accordingly, Mexican lime (Citrus aurant-ifolia Swingle.) seedlings were subjected to four salinity levels, i.e. 0, 2000, 4000 and 6000 µs cm-1 in the presence or absence of bacterial endophytes. The results indicated that salinity stress significantly reduced growth, chlorophyll, and carotenoid content of plants lacking endophytes. Combinatory applications with bacterial endophytes significantly improved the above-mentioned parameters under salinity stress. Lipid peroxidation levels were significantly reduced in plants inoculated with bacterial endophytes. Salinity stress significantly increased the activities of ascorbate peroxidase (APX), superoxide dismutase (SOD), glutathione reductase (GR), peroxidase (POD), and catalase (CAT) in salinity conditions. Overall, the inoculation with bacterial endophytes improved salinity tolerance and reduced the accumulation of ROS by increasing their scavenging via an enhanced redox state of glutathione and more effective antioxidant enzyme activities.
Research paper
Mohammad Fazli; Nima Ahmadi
Abstract
Adverse conditions during pre- and postharvest stages affect the longevity and quality of horticultural crops. Thus, storage conditions should be considered in marketing management, especially for cut flowers. Methyl jasmonate is a well-known signaling molecule involved in plant defense responses. Applying ...
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Adverse conditions during pre- and postharvest stages affect the longevity and quality of horticultural crops. Thus, storage conditions should be considered in marketing management, especially for cut flowers. Methyl jasmonate is a well-known signaling molecule involved in plant defense responses. Applying it as a treatment can effectively prolong the vase life of horticultural crops. The expression of Laccase gene, acting downstream of the ethylene signal transduction, can be induced by exogenous ethylene. The PIP2 gene is a major group of plasma membrane proteins that are linked to aquaporin channels. This study explored the effect of methyl jasmonate on postharvest quality and expression LAC and PIP2 genes of cut rose, cv. ‘Red alert’. The results showed that methyl jasmonate improved the vase life of cut roses, although it was most effective at 0.2 µl L-1. An analysis of antioxidant enzymes indicated that the highest catalase activity and peroxidase activity occurred in response to 0.2 µl L-1 and 0.2-0.3 µl L-1 methyl jasmonate, respectively, although both enzymes showed a decreasing trend during the vase life period. Proline levels increased significantly in response to 0.2 and 0.3 μl L-1 methyl jasmonate concentr-ations. Quantitative PCR analysis showed that all concentrations of methyl jasmonate significantly reduced the expression of PIP2 and LAC genes. The lowest expression level of PIP2 and LAC genes occurred in response to 0.2 and 0.3 µl L-1 methyl jasmonate, respectively. Based on our findings, the expression pattern of the Laccase gene may be regarded as a marker in evaluating postharvest characteristics of cut roses.
Research paper
Ali Salehi Sardoei; Mehdi Sharifani; Mostafa Khoshhal Sarmast; Mahmoud Ghasemnejad
Abstract
Citrus species are comprised of susceptible plants that can barely tolerate freezing temperatures. To determine the relationship between cold stress tolerance (LT50) and some important physiological traits, four commercial citrus cultivars of citrus species were studied. These were Citrus unshiu, Citrus ...
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Citrus species are comprised of susceptible plants that can barely tolerate freezing temperatures. To determine the relationship between cold stress tolerance (LT50) and some important physiological traits, four commercial citrus cultivars of citrus species were studied. These were Citrus unshiu, Citrus sinensis var. ‘Thomson navel’, Citrus paradisi var. ‘Star Ru by’ and Citrus limon var. ‘Lisbon’. Assessments of cold-stress tolerance were carried out at 4, -4 and -8 °C. Ultimately, the results showed that the Japanese mandarin and ‘Thomson navel’ had the highest stress tolerance (LT50). Citrus unshiu tolerated cold stress up to -8.4 LT50. The correlation coefficient demonstrated that significant, positive correlations were observed between several pairs of attributes, i.e. LT50 and total flavonoids, chlorophyll a and chlorophyll b, carotenoids and chlorophyll a, chlorophyll b and total chlorophyll, relative moisture content and malondialdehyde, as well as glycine betaine and catalase. According to the regression coefficient, a change of one unit in lipid peroxidation caused a decrease of 1.9238 units and 5.9615 units in LT50 at +4 and -4 °C, respectively. While commercial citrus cultivars were selected for cold-tolerance and other traits, the efficiency of cold-tolerance correlated more with carotenoid content, chlorophyll content and lipid peroxidation, considering the assessments at particular temperatures.
Research paper
Babak ValizadehKaji; Saied Maleki; Ahmadreza Abbasifar
Abstract
Table grape is a non-climacteric fruit with a short shelf-life. The current study aimed at applying specific treatments to prolong its shelf-life and maintain qualitative characteristics during storage. In a factorial arrangement and a completely randomized design, the first factor was the storage period ...
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Table grape is a non-climacteric fruit with a short shelf-life. The current study aimed at applying specific treatments to prolong its shelf-life and maintain qualitative characteristics during storage. In a factorial arrangement and a completely randomized design, the first factor was the storage period and the second factor was the combination of warm water treatments and gum arabic (GA). The fruits were stored at 5 °C and 80% relative humidity in permanent darkness. On days 0, 20, 40, and 60 of the storage period, seven berries from each replicate were randomly sampled and analyzed for physicochemical and qualitative parameters. The storage time negatively affected the qualities of ‘Bidane-h Ghermez’ table grape fruits. This deterioration in quality was countered by the application of warm water treatments and GA coating, especially by the 45 °C+GA 5% treatment. Compared to the uncoated control group, the application of 45 °C+GA 5% caused a better maintenance of vitamin C (30.43–160.00%), TSS/TA (19.76–21.57%), anthocyanin (37.40–57.75%), antioxidant activity (7.35–36.40%), total phenol (12.01–24.49%), and sensory attributes (66.66–248.50%) in the fruits during storage. Also, this treatment caused lower levels of weight loss (53.27–45.48%), H2O2 (9.90–26.55%), and malondialdehyde (8.84–27.92%). Therefore, the application of warm water treatments and GA coating, particularly at 45 °C+GA 5%, had a remarkable role in extending the shelf-life of table grape fruits. In addition to their effective role in storage, warm water and GA are especially recommended because of their low costs.
Research paper
Seyed Mohammad Mahdi Mortazavian; Mahdieh Arshadi Bidgoli
Abstract
Cumin (Cuminum cyminum L.) is an annual, outcross plant with medicinal properties. It is adapted to arid and semi-arid regions of the world. This research aimed to evaluate genetic parameters such as GCA and genetic distance based on molecular markers and important traits for parent selection among diverse ...
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Cumin (Cuminum cyminum L.) is an annual, outcross plant with medicinal properties. It is adapted to arid and semi-arid regions of the world. This research aimed to evaluate genetic parameters such as GCA and genetic distance based on molecular markers and important traits for parent selection among diverse genotypes of cumin. For this purpose, ISSR markers and a polycross assay were conducted. Forty-nine half-sib families were obtained from the polycross test and were evaluated for two years under normal and drought stress conditions. The measurements were aimed at 1000-seed weight, mechanized harvest height, and seed yield. The statistical analysis guided a selection of elite parents due to the high genetic diversity among half-sib families. An estimation of narrow sense heritability and general combining ability of the studied traits revealed the contribution of both additive and non-additive effects in genetically controlling the evaluated traits. According to the general combining ability, drought tolerance indices and genetic distance of 49 genotypes, the top 10 candidates were selected for the production of drought-tolerant seeds. From a molecular perspective, the banding patterns obtained from ISSR markers showed significant genetic diversity among all genotypes and indicated a proper distance among ten selected parents. The findings of this experiment provided a starting point for cumin breeding. It is likely that a breeding program would proceed with random pollinations among the ten select genotypes under controlled conditions to produce high-yield drought-tolerant varieties.
Research paper
Hamidreza Roosta; Fatemeh Nili; Ali Pourkhaloee; Naser Askari
Abstract
Photosynthetic parameters and stem strength of Gerbera jamesonii ‘Bayadere’ plants were studied after foliar application with calcium chloride (0, 0.5, 1, and 1.5 g L-1) under natural light (NL), red light LEDs (R), blue light LEDs (B) and red + blue light LEDs (RB). Chlorophyll content increased ...
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Photosynthetic parameters and stem strength of Gerbera jamesonii ‘Bayadere’ plants were studied after foliar application with calcium chloride (0, 0.5, 1, and 1.5 g L-1) under natural light (NL), red light LEDs (R), blue light LEDs (B) and red + blue light LEDs (RB). Chlorophyll content increased under LED lights and foliar application with calcium chloride. The maximal quantum yield of PSII efficiency (Fv/Fm) and performance index (PI) reached the lowest value under NL conditions. The highest values of photosynthesis rate, stomatal conductance, and transpiration rate (E) were achieved by RB lighting. Under the RB light and calcium chloride spraying, the plants showed the lowest leaf nitrate content, compared to NL conditions. This resulted in the highest leaf nitrate content. The higher the nitrate content, the lower the stem strength. However, the leaf calcium content showed an opposite trend. Sprays of 1.5 g L-1 calcium chloride in combination with RB lighting significantly in creased the flower stem strength and reduced stem bending, compared to non-treated plants. In summary, the RB lighting and foliar application with calcium chloride enhanced the growth and flower stem firmness of cut gerbera.
Research paper
Bahman Jafari; Mojtaba Kordrostami; Ali Akbar Ghasemi-Soloklui
Abstract
Seed germination is a crucial stage in the life cycle of plants. It determines their growth and reproduction success. Temperature is one of the most important environmental factors that affect seed germination. This research aimed to estimate the cardinal temperatures and the thermal time requirement ...
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Seed germination is a crucial stage in the life cycle of plants. It determines their growth and reproduction success. Temperature is one of the most important environmental factors that affect seed germination. This research aimed to estimate the cardinal temperatures and the thermal time requirement for seed germination. The effects of different temperature levels were evaluated on the germination characteristics of tomatoes (Lycopersicon esculentum cv. ‘Early CH’). An experiment was conducted using a completely randomized design with four replications and seven temperature levels, i.e. 5, 10, 15, 20, 25, 30, and 35 ° C. The relationship between germination rate and temperature was described and the cardinal temperatures for the seed germination of tomato (cv. ‘Early CH’) were calculated. Four regression models were used: segmented, dent-like, original beta, and modified beta. The highest germination percentage (81-86%) and vigor index (4.04-5.47 cm) were similarly obtained in the 20-30 °C range. The highest germination rate (5/7 seeds per day) was observed at 25 °C. The lowest mean germination time (4.5-4.84 days) occurred in the 20-25 °C range. Germination characteristics were significantly different when the temperature increased above 30 °C. While measuring the regression models, the segmented model was best for estimating the cardinal temperature of this cultivar. In general, cardinal temperatures for seed germination were estimated using a superior regression model for minimum (0.5-3 °C), optimal (25-26 °C), and maximum (35.4-40 °C) temperatures. Additionally, the thermal time model accurately predicted the seed germination process (R2 = 0.90). The amount of thermal time to achieve 50% germination in this cultivar was estimated at 1848.29 degree-hours.
Research paper
Shadab Panahi; Azizolah Khandan-Mirkohi; Gail Taylor; Seyed Alireza Salami
Abstract
In this study, we investigated important morphological traits of select populations of Iranian fiber hemp. The analysis of variance showed significant diversity among the populations. Four of the eight genotypes showed a large biomass suitable for the fiber industry. Kerman, Sirjan, Dezful, and Arak ...
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In this study, we investigated important morphological traits of select populations of Iranian fiber hemp. The analysis of variance showed significant diversity among the populations. Four of the eight genotypes showed a large biomass suitable for the fiber industry. Kerman, Sirjan, Dezful, and Arak genotypes had the highest plant height and the largest stem diameter. These populations had late-flowering habits with a short inflorescence length. Our classification revealed that of the four high-fibrous candidates, three were classified in one group, comprising Kerman, Sirjan, and Dezful genotypes. The fourth one, Arak, was placed in the second group. Significantly positive correlations were observed between final plant height, footstalk diameter, and number of days to first-flower emergence. A strong correlation occurred between morphological traits and geographical data pertaining to the genotypes. Our findings indicated that a high elevation and a low average annual temperature are suitable for the growth of medicinal cannabis. Warmer weather made the plants taller with thicker stems and late blooming habits, which are more relevant for use in the fiber industry.
Research paper
Mohammad Taheri; Mousa Mousavi; Seyed Mohammad Hassan Mortazavi
Abstract
Olive shoots have a hard-rooting nature that causes significant problems associated with olive micro-propagation under in vitro conditions. Several factors may contribute to alleviating this problem, in cluding zinc and its derivatives. The current research involved the application of zinc oxide nanoparticles ...
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Olive shoots have a hard-rooting nature that causes significant problems associated with olive micro-propagation under in vitro conditions. Several factors may contribute to alleviating this problem, in cluding zinc and its derivatives. The current research involved the application of zinc oxide nanoparticles and zinc sulfate on olive explants ‘Caillette’, ‘Beldi’ and ‘Dezfoli’ cultivars. FT-IR spectroscopy, UV-Vis spectroscopy, FESEM, EDS, and DLS techniques characterized the zinc oxide nanoparticles. Then, micro cuttings containing two buds were cultured on a half-strength MS medium containing 1.5 mg L-1 of BAP hormone and 1 mg L-1 of GA3 hormone. The treatments led to olive shoots, 3 cm in length that were transferred to a 1/2 MS medium containing 3 mg L-1 of IBA. The olive shoots were treated with two types of zinc compounds, including zinc sulfate (0.0, 2.43, and 4.86 mg L-1) and zinc oxide nanoparticles (0.0, 2.43, 4.86, and 7.29 mg L-1). The results showed that zinc oxide nanoparticles induced callus growth in response to all concentrations but prevented root growth. Alternatively, zinc sulfate at all concentrations induced root and callus growth, although to a smaller extent than nanoparticles. The ‘Caillette’ cultivar had the highest rooting percentage and heaviest fresh and dry root weight. The ‘Beldi’ cultivar had the lowest of these values. Several factors potentially contributed to these results, such as hormonal (auxin biosynthesis), biochemical (enzyme and other proteins), and molecular factors (bZIP TFs), which changed by zinc application. A complementary bioinformatics study was conducted as well.
Research paper
Zahra Shirazi; Mahsa Rostami; Abozar Ghorbani
Abstract
Here, we evaluated how GolS and RfS gene families can potentially assist with grapevine drought tolerance. Through comprehensive bioinformatics analysis, we identified a set of putative genes associated with drought response in grapes. The analysis revealed the conservation of key functional domains ...
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Here, we evaluated how GolS and RfS gene families can potentially assist with grapevine drought tolerance. Through comprehensive bioinformatics analysis, we identified a set of putative genes associated with drought response in grapes. The analysis revealed the conservation of key functional domains and conserved motifs within the gene sequences, suggesting their potential involvement in stress adaptation. Additionally, we performed expression analysis of the identified genes under drought stress conditions. Accordingly, the results indicated substantial up-regulation levels in several genes, suggesting their potential importance in how grapevines respond to water scarcity. We explored the co expression network of these genes and identified possible interactions and regulatory relationships. The findings provided valuable information on complex regulatory mechanisms underlying drought-response in grapevines. The results bear implications for the genetic improvement of grape varieties, particularly in enhancing drought tolerance. By understanding the genetic basis of the droughtresponse mechanism, we can develop targeted strategies to improve crop management and assist in future attempts to breed grape varieties, emphasizing an enhanced tolerance to water deficits. This study sheds light on the potential roles of the GolS and RfS gene families in grapevine drought tolerance. The findings underscore the importance of genetic adaptation in grapevines to drought stress conditions. The knowledge herein can guide future research and breeding efforts to develop drought-tolerant grape varieties, ultimately contributing to the sustainability of grape production and the agricultural industry.
