فهرست مطالب

Plant Physiology - Volume:11 Issue: 3, Spring 2021

Iranian Journal of Plant Physiology
Volume:11 Issue: 3, Spring 2021

  • تاریخ انتشار: 1400/04/14
  • تعداد عناوین: 8
|
  • Ameneh Zamani, Mojtaba Karimi *, Ali Abbasi-Surki, Fatemeh Direkvand-Moghadam Pages 3651-3658

    The soil water limitation is a relevant abiotic stress that affects the plants life. In this respect, adoption an efficient strategy may improve the plant growth during this stress. The present study was conducted in order to find the likely useful effect of the humic acid (HA) on Stevia (Stevia rebaudiana) in a pot trial, especially under drought stress condition. Therefore, five levels of humic acid (0, 1, 1.5, 2 and 2.5 mg.kg-1 of soil) were applied in the soil containing Stevia seedling under normal (well-watered) and drought stress condition (resulted from 10-days irrigation intervals), based on a factorial experiment with three replications. Drought stress significantly reduced the Stevia leaf production and steviol glycosides (SVglys) content and compositions. Stevioside (Stev) and Rebaudioside A (Reb A) contents were significantly decreased by drought stress and all concentrations of HA. On the other hand, HA (in concentration more than 1.5 mg.kg-1 of soil) strongly increased the leaf production in Stevia and resulted in a significant increase of the SVglys yield (44% in comparison with no HA). Results clearly demonstrated that although HA showed an inhibitory effect for SVglys content in Stevia leaf, it can increase the SVglys yield through a remarkable increase in leaf growth in Stevia, especially under drought stress condition.

    Keywords: Stevia, Stevioside, Rebaudioside A, Steviol glycosides, leaf yield
  • Saba Dashab, Heshmat Omidi * Pages 3659-3682

    Quinoa (Chenopodium quinoa Willd.) is a grain-like crop with a high-grown potential in Iran. Quinoa is a very nutritious plant because of its high nutritional value, therefore, compared to milk nutrition by the FAO. This study was conducted to evaluate quinoa seedlings' physiological and biochemical properties under the effects of priming and drought stress treatments. The experiment was factorial based on a completely randomized design in a greenhouse at the Agriculture Faculty of Shahed University, Tehran, Iran. Experimental factors included priming at two levels (hydro-priming and bio-priming) and drought stress at five levels (control (0), -0.5, -1, -1.5, and -2 MPa with polyethylene glycol). Analysis of variance showed that the effects of priming and drought stress were significant on most of the studied traits. The results showed a significant decrease in quinoa seedling indices (such as shoot and root dry weight) under high levels of drought stress. However, the application of bio-priming (growth-promoting bacteria) improved physiological indices, such as proline content and antioxidant enzyme activity. The interactions of priming and drought stress were significant on fructose, glucose, proline content. The highest seedling proline content was related to -2.0 MPa in bio-priming, and the lowest was to non-stress conditions in hydro- and bio-priming This study showed that the highest mean dry weight of shoots, protein content, enzymatic and non-enzymatic antioxidants was observed at the bio-priming level. The priming treatments (hydro and bio) leads to improvement characteristics such as root dry weight, proline content, superoxide dismutase activity, and anthocyanin content.

    Keywords: antioxidant activity, growth-promoting bacteria, Polyethylene glycol, Proline content, shoot, root dry weight
  • Ali Ashraf Jafari *, Soheila Afkar, Meysam Faraji Pages 3671-3682
    This study was conducted to analyze genetic diversity in 15 natural populations of Iranian Agropyron pectiniforme using morphological traits and RAPDs (Random Amplification of Polymorphic DNA) molecular markers. Five primers out of the 10 were highly polymorphic and produced 128 polymorphic bands ranging in length of 500 to 2200 bp. According to AMOVA (Analysis of Molecular Variance) results, there was higher genetic variation between populations (53%) than within (47%) them. Cluster analysis based on RAPD data categorized the populations into five clusters. PCoA (Principal Coordinates Analysis) results showed the first four coordinates accounted for 95% of the total variation. The scatter of genotypes based on the first two components was agreement with cluster analysis results. There was non-significant mantel correlation coefficient between molecular and geographical data indicating classification of A. pectiniforme based on RAPD marker was not in accord with geographical distribution. With regard to morphological traits, characters including plant height and the number of stems per plants are suitable parameters for selection of potential parents in the breeding programs. The non-significant mantel correlation coefficient between molecular and morphological marker was observed, then suggested that the two marker systems give different estimates of genetic relations among populations. Finally, our findings demonstrate the feasibility of the RAPD technique for quantifying genetic distances among A. pectiniforme populations. It was concluded that, there is sufficient genetic variation between Iranian populations of Agropyron pectiniforme which these genotypes can be useful for germplasm improvement and cultivar development.
    Keywords: Agropyron pectiniforme, AMOVA, Geographic data, Molecular marker, Morphological marker
  • Hadis Zaremanesh, Hamid Reza Eisvand *, Naser Akbari, Ahmad Ismaili, Mohammad Feizian Pages 3683-3700
    Salinity stress is a limiting factor for plant growth and production. To reduce the salinity effects, humic acid was applied in soil, and its mitigation effect was studied on Satureja khuzistanica Jamzad. The research was conducted as a factorial experiment based on a completely randomized block design with four replications at Lorestan University. The factors included salinity stress (0, 25, 50, 75, and 100 mM NaCl) and humic acid (0, 10, 20, 30, and 40 mg/kg soil). Results showed that salinity stress decreased plant height, dry weight, leaf number, root length, chlorophyll, and carotenoids. However, it significantly increased flavonoid contents and SOD, CAT, and GR activities. Essential oil (EO) quantity and quality were affected by salinity. The EO percentage and yield decreased by salinity. Forty-three constituents were identified, among which carvacrol, γ-terpinene, α-terpinene, myrcene, p-cymene, α-thujene, citronellol, and α-pinene were the major compounds according to their contents and formed more than 94% of the EO. The percentage of some of the other constituents decreased to zero under specific salinity and humic acid treatments. The application of humic acid could mitigate salinity effects on growth and EO production. However, there was an interaction between salinity and humic acid on EO yield and quality. It seems that the application of humic acid is useful for improvement EO yield of S. khuzestani, but the amount of its application depends on the EO consumers’ favorite.
    Keywords: Antioxidant, Medicinal Plants, Organic essential oil, environmental stress, Secondary metabolites
  • Yasaman Azimi, Seyyedeh Mahdokht Maddah, Golaleh Mostafavi * Pages 3701-3708
    Rhabdosciadium aucheri (Apiaceae) is a perennial herbaceous species, which is endemic to W, S and C Iran. In the present study aqueous, ethanolic and methanolic extracts were obtained from aerial parts of the specimens collected from Hamadan province, using both Maceration and Soxhlet methods. Due to the direct relationship between total phenolic and flavonoid contents and the plant antioxidant activity, the aim of the present investigation was the comparative study of total amount of each parameter extracted by aqueous and hydroalcoholic solvents. The results demonstrated that, the highest amount of phenolic and flavonoid compounds extracted by ethanolic solvents using Maceration technique were 37.28 ± 1.03 mg GAE/gr GW and 22.68 ± 0.63 mg QE/gr DW respectively. These results were significant at p < 0.05. Moreover, 72.17 ± 17.10 % was the highest free radical inhibition percentage for methanolic extracts. However, the differences were not considered as significant. The results also showed that using hydroalcoholic solvents are more powerful compared to aqueous solvents in the extraction of phenolic and flavonoid contents and consequently their antioxidant activity.
    Keywords: antioxidants, Ethanol extract, methanol extract, Total phenol, Total flavonoid
  • Banhishikha Singh, Rajeshwari Chatterjee, Niniva Datta, Soma Banerjee * Pages 3709-3718
    Iron toxicity is an abiotic stress comes with high concentrations of Fe2+ in the soil solution which is a well-recognized problem of rice (Oryza sativa L.) cultivation in lowland. Rice varieties differ widely in their ability to tolerate excess iron. The present study was undertaken with four rice varieties viz. Dhruba, Sampriti, Dhiren and Puspa. The objective is to study the influence of high applied Fe2+ concentrations on the growth, chlorophyll content, and antioxidant enzyme activities. The spectral reflectivity and absorption of different chemical bonding through Fourier-transform infrared spectroscopy (FTIR) of four rice varieties was also analyzed. The seven days old rice seedlings were treated with Ferrous sulphate subjected to 100 ppm to 750 ppm for further 14 days iron stress was used to analyse the morphological and biochemical responses. Besides, Fourier transform infrared spectral reflection was attributed in root and shoot part. The results indicated shoot growth and chlorophyll content decreased in 750 ppm in all the selected rice varieties of interest. On the contrary the catalase activity, protein content and lipid peroxidation increased in these varieties. However, the expression of high amount of CAT activity in Sampriti variety and high amount of SOD activity in Dhruba variety leads to tolerance in iron stress in comparison to other two varieties of interest. FTIR revealed steep band stretching of various functional groups of different compounds in both the root and shoot part of all the varieties.
    Keywords: Rice, Iron stress, Chlorophyll, Antioxidant, Fourier transform infrared spectroscopy
  • Mojtaba Fateh *, Hamdollah Kazemi Arbat, Soleyman Mohammadi, Farhad Farahvash, Eskandar Zand Pages 3719-3730

    In order to investigate the effect of plant density and different amounts of nitrogen fertilizer on yield components, leaf area, chlorophyll and grain protein content of Zea mays cultivars and Amaranthus retroflexus biomass. The experiment was conducted in two crop years (2012-2013) in the form of a split plot based on a randomized complete block design with four replications. The main factors included maize cultivars (single cross hybrids of 370 and 704) and sub factors included different levels of maize densities (60000, 70000, 80000 and 90000 plant ha-1) and different levels of nitrogen fertilizer including 200, 300, 400 and 500 kg ha-1. The effect of density on all traits was significant, but the effect of cultivar on chlorophyll and leaf area index and nitrogen effect on number of ear per square meter were not significant. Maize cultivar of 704 had significantly higher number of grain per ear, weight of one thousand grains and grain protein compared to cultivar 370 but the number of ear was significantly lower than that of cultivar 370 and there was no significant difference in chlorophyll content and leaf area index between the two cultivars. The highest grain protein was obtained at densities of 80000 plant ha-1 and application of 400 kg ha-1 N. Also, cultivar 704 significantly decreased redroot biomass compared to cultivar 370. According to the results, recommended to farmers in Miandoab region to use cultivar 704 with a density of 80,000 plant ha-1 along with 400 kg N ha-1.

    Keywords: Fertilizer, leaf, Maize, Protein, weed
  • Mozhgan Farzamisepehr *, Mahlagha Ghorbanli, Zahra Tadji Pages 3731-3740

    For considering the effect of drought stress on some morphological and biochemical changes in two pumpkin species, Cucurbita maxima L. and Cucurbita pepo L. a kind of experiment was done by field culture in three water dispersal levels with field capacity, 2/3 field capacity, and 1/3 field capacity, based on the factorial design in random block form with four replications. The results indicated that increasing the stress level, leaves water potential under drought stress decreased in comparison to the control sample in both species. But with increasing drought stress, root length increased too. Also during drought stress, root soluble carbohydrates content, ascorbic acid content, dehydroascorbic acid, catalase, polyphenol oxidase, and peroxidase enzymes activity increased significantly in 5% level, according to the results with increasing the stress, soluble carbohydrates content decreased in leaf.

    Keywords: antioxidant enzymes, drought stress, growth parameters, pumpkin