Showing 8 results for Seed
Roya Ghaffarri, Fariba Meighani, Homeira Salimi,
Volume 1, Issue 1 (12-2014)
Abstract
Mesquite is an invasive and problematic weed in warm and dry areas and so its management is very important. In order to study the effective factors on mesquite seed germination, the following studies were conducted to investigate: 1- seed viability; 2- the effect of constant temperatures on seed germination including 5, 10, 15, 20, 25, 30, 35 and 40°C independent dark and independent light conditions; 3- Effect of temperature fluctuations on seed germination including 10/0, 20/10 and 30/20°C; 4- the effect of scarification with concentrated sulphuric acid and physiacal scarification on seed germination; 5- the effect of planting depth seed on seedling emergence; 6- the effect of drought stress including 0, 100, 200, 300, 400, 500, and 600 Mm PEG on seed germination; and finally 7- the effect of salt stress including 0, 100, 200, 300, 400, 500, 600, and 700 mM NaCl on seed germination. All experiments were performed as completely randomized designs with 4 replications. The results showed that seed viability of mesquite was 81%. The optimum temperature for seed germination was a constant temperature- 30°C. In general, constant temperature was more suitable than temperature fluctuations for seed germination. The best seed planting depth for seedling emergence was 2 cm. The most seed germination was observed under the effect of 20 min scarification with concentrated sulphuric acid. Physical scarification had no significant effect on seed germination. While the study of salt and drought stresses effect showed that the most seed germination (after control without NaCl and PEG), was due to concentrations of 100 and 200 mM, seed germination decreased with the increase of NaCl and PEG concentrations. Based on the present results, light did not play a crucial role on seed germination. Therefore, mesquite seeds were not photoblastic. These characteristics are very important in making mesquite an invasive weed. Having precise information of these traits, enables us to have a better control over the management of this troublesome weed.
Kobra Gholipoor, Parto Roshandel,
Volume 5, Issue 4 (3-2019)
Abstract
In order to study the diverse effects of seed priming with 24-epibrassinolide (EBL) (0, 0.1, 1 mg/l) to increase tolerance of tomato plants (Lycopersicon esculentum Mill.) to salinity (0, 70 and 140 mM NaCl), the experiments were conducted as factorial based on completely randomized design at greenhouse condition. Results showed that salt stress significantly decreased the growth of tomato plants. However, priming with EBL (1 mg/l) significantly decreased the negative effects of NaCl (particularly at 140 mM). At this case, EBL increased the fresh and dry weights (<2 folds), total chlorophyll (+72%), carotenoids (+ 2 folds), free proline (+3 folds), electrolyte leakage (-18.6%), Na+/K+ in the roots (-57.5%) and shoots (-62%) compared to salinity control. Generally, it could be concluded that priming with epibrassinolide resulted in enhanced salt tolerance in tomato plants via increment in free proline, photosynthetic pigments and decrease in electrolyte leakage and Na+/K+ ratio in the tissues.
Rezvan Mohammadi, Parto Roshandel, ,
Volume 6, Issue 1 (5-2019)
Abstract
In order to study the effects of magnetopriming on the physiological and phytochemical characteristics of Hyssopus officinalis plants, this research was conducted as a factorial experiment in a completely randomized design. Results showed that magnetopriming (particularly at 200mT/5 min) increased the level of shoot dry weight (82.6 percent), root dry weight (86.5 percent), total chlorophyll (32.8 percent), carotenoids concentration (32.4 percent) and polyphenols content (2 folds) in 60-day-old Hyssopus officinalis. Also, electrolyte leakage and lipid peroxidation decreased by 27.6 and 45 percent, respectively. In addition, reducing power, DPPH and superoxide anion scavenging activities significantly augmented. However, higher activities of superoxide dismutase (76 percent), catalase (4.2 folds), ascorbate peroxidase (2.4 folds) and guaiacol peroxidase (48 percent) were found at 90 mT. Results suggested that the application of magnetopriming promoted growth in H. officinalis through augmentation of cellular membrane integrity as well as biomass and photosynthetic pigments content. Furthermore, it was found to enhance the antioxidative system. Magnetopriming might apparently improve the medicinal properties via increasing the level of polyphenols and antioxidant capacity in H. officinalis.
Tahereh Naeemi, , Baratali Fakheri,
Volume 6, Issue 2 (8-2019)
Abstract
Plant growth is greatly influenced by environmental stresses including water deficit, salinity and extreme temperatures. Therefore, the identification of genes, especially regulatory ones whose expression enables plants to adapt to or to tolerate these abiotic stresses, is very essential. MYB proteins, a superfamily of transcription factors, play regulatory roles in developmental processes and in defense responses in plants. Members are characterized by a structurally conserved DNA-binding domain, i.e., the MYB domain. Thus, a factorial experiment in a randomized complete block design with three replications was carried out to investigate the effect of different levels of drought stress on the relative expression of TaMYB73 transcription factor gene using Real Time PCR method at Biotechnology Research Institute of Zabol University. The experimental treatments included durum wheat genotypes (Shabrang, Behrang, Karkheh, Aria and Dena) and drought levels (5, 10, 15, 20 and 25% of field capacity). Seedlings of genotypes
were cultured in pots and drought stress was exerted after 45 days (four to five leaves). Data analysis was performed using Ratio =2 -ΔΔCT and SAS software version 9.1. The results of the 2-way ANOVA for the effect of genotype, drought stress and cross-effects of drought stress on the relative expression of TaMYB73 gene and the amount of osmotic regulators (Proline and Carbohydrate) at different stress levels (20, 15, and 5% of field capacity) were significant in comparison with the normal condition (25% of field capacity) at 1% probability level. With the increase of drought stress level from 5 to 20% of crop capacity, relative to the normal level (25% crop capacity), the relative expression of TaMYB73 gene and osmotic regulators of proline and carbohydrates increased in Beharang, Karkheh and Dena genotypes. Therefore, Karkheh and Dena genotypes showed greater resistance to drought stress among the 5 genotypes studied.
Vahide Payamenoor, Akram Hasani Satehi, Sadegh Atashi, Abbas Rezaii Asl,
Volume 7, Issue 1 (4-2020)
Abstract
The present study aimed to increase the seed germination and the initial performance of pistachio seeds by investigating the effects of the magnetic field and osmopriming treatments simultaneously. 10 treatment levels of 10, 20 and 30 mT for 5, 15, 25 minutes and 1 control treatment (without exposure to a magnetic field) were performed in three replicates and the best level of magnetic surface was selected. The results showed that seeds subjected to the magnetic field showed an increase in plumule length, radicle length, total length of seedlings, fresh and dry weight of plumule as well as radicle and germination speed compared with the control treatment. However, there was no significant difference in the germination percentage and uniformity of seeds. Magnetized seeds, with the superior selective treatment (10 mT for 15 minutes), were primed with solutions of potassium nitrate, humic acid and salicylic acid at levels of 10, 25 and 40 mM and a control level (the best level of magnetism) in three replicates. The best result was obtained from humic acid (25 mM). With regard to the low cost of the purchase or construction of magnetic devices and their positive effects, their application could be recommended (10 mT for 15 minutes) combined with the humic acid (25 mM)) so that the quality of pistachio seedlings production would be increased.
Marzieh Beygom Faghir, Zahra Ghandharizadeh, Golnoush Shamshiri,
Volume 7, Issue 2 (7-2020)
Abstract
The present study was aimed to investigate foliar anatomy and flower, fruit and seed morphology of three subspecies of Agrimonia eupatoria (i.e. A. eupatoria subsp. eupatoria, A. eupatoria subsp. grandis and A. eupatoria subsp. asiatica) and the species of Aremonia agrimonioides, belonging to the subtribe Agrimoniiae (Rosaceae) in Iran. Firstly, plant specimens were collected and then identified on the basis of relevant references. For anatomical analysis, the cross sections of basal leaves of each taxon were prepared, studied by light microscopy and then photographed by means of a digital camera. For morphological analysis, the flower, achene and seed characters were carefully examined using digital microscopy. To determine the relationships among the taxa, 57 characters were included in the Principal Component Analysis (PCA). The results supported the classification proposed by Flora Iranica and showed the importance of leaf anatomical, flower, achene and seed morphological characters in separating inter-generic, intraspecific and interspecific relationships among the representatives of subtribe Agrimoniinea in Iran.
Fatemeh Nejadhabibvash, Mohammad Bagher Rezaee,
Volume 7, Issue 4 (2-2021)
Abstract
Beta vulgaris belongs to the family Amaranthaceae and was found to have halophytic ancestors. The objective of this study was to investigate the effect of sodium chloride on seed germination, therefore the early stages of seedling growth of Beta vulgaris grown under different salinity levels (0, 100, 150 and 200 mM of NaCl) were studied. The experiment was laid out in a completely randomized design (CRD) with four replications. It was revealed that as concentration of NaCl increases, the rate and percentage of germination, length and fresh weight of radicle & plumule and seedling vigour index decrease. In conclusion, our results indicated that salt stress decreased Beta vulgaris seed germination and early seedling growth while induced changes in the anatomical characteristics such as increased level of cutin synthesis on epidermal leaves cells and altered the thickness of vascular system, epidermis and parenchyma in leaves, roots and petioles.
Farshad Darvishi, Armin Kheirollahi Meidani,
Volume 8, Issue 3 (10-2021)
Abstract
Gamma-decalactone, an intramolecular 4-hydroxydecanoic acid ester, has a peach-like aroma and is widely used in the food and cosmetics industries. The biotechnological production of this compound is possible via biotransformation of castor seed oil by the yeast Yarrowia lipolytica. This study aimed to compare the production of gamma-decalactone by wild-type strain with that in a mutant strain producing lipase in high amounts. It was found that cells with yeast-like morphology produce more gamma-decalactone than hyphae-like cells. The maximum production of gamma-decalactone by wild-type and mutant strains was 65 mg/L after 24h of inoculation and 90 mg/L after 72h of inoculation, respectively. The mutant strain converts 38% more substrate into gamma-decalactone than the wild-type strain, therefore, it could significantly increase the productivity of industrial-scale production of gamma-decalactone.