Drought stress and osmo-priming effects on physiological and biochemical characteristics of Ocimum basilicum

2016 ◽  
Vol 6 (1) ◽  
pp. 905-913
Author(s):  
Bahram Majd Nassiry ◽  
Neda Mohammadi

    One of the effects of reducing water content on soil is reduction of growth and development of seedlings and variation of field development. Seed priming technique has been known as a challenge to improve germination and seedling emergence under different environmental stresses. The objectives of this research were to evaluate the effects of osmo-priming on germination characteristics and changes of proline, protein and catalase activity of Ocimum basilicum seeds. Results showed that drought stress reduced the germination characteristics and drought stress in -8 bar was the critical stress.  Priming treatments were include KNO3, PEG and NaCl by 0, -4 and -8 bar concentrations. The seeds were primed with those materials for 8 and 16 hours. The highest germination characteristics were obtained from nitrate potassium in -8 bar for 16 hours priming. Therefore the best seed treatment under drought stress during germination was obtained from the osmo-primed with -8 bar nitrate potassium for 16 hours. The drought stress increased proline and catalase activity but reduced total protein. Priming treatment increases proline, total protein and catalase activity under drought and control conditions. It is concluded that priming results in improvement in germination components of Ocimum basilicum in drought stress conditions and increases the resistance to drought stress with improvement of proline, protein and catalase activity in germination phase.

2014 ◽  
Vol 47 (2) ◽  
pp. 41-48 ◽  
Author(s):  
M.A. Aghbolaghi ◽  
M. Sedghi

Abstract Low seed germination and seedling emergence is one of the main problems in saline areas. Seed priming technique has been known as a challenge to improve germination and seedling emergence under different environmental stresses. The objective of this research was to evaluate the effect of seed priming with NaCl and water on growth and seed reserve utilization of millet seeds under salinity stress. Treatments were combinations of four levels of salinity stress (0, ⊟4, ⊟8 and ⊟12 bar) and three levels of seed priming and control with three replicates. Results showed that with increase in salinity stress, germination components such as germination percentage, germination index, mean time to germination, normal seedling percentage, seedling length, seedling dry weight of utilized (mobilized) seed and seed reserve utilization efficiency decreased, but seed priming showed lower reduction. The highest germination characteristics and seed reserve utilization was obtained by halo-priming in control conditions. It is concluded that priming results in improvement in germination components of millet in salinity stress conditions.


2020 ◽  
Vol 53 (1) ◽  
pp. 1-18
Author(s):  
S A TABATABAEI ◽  
O ANSARI

Seed priming methods have been used to increase germination and seedling establishment under different abiotic stress conditions. Seed priming was used in barley to increase seed germination and tolerance on stress exposure. Barley seeds were treated with various priming agents for different time and temperatures. The effect of priming was assessed on germination characteristics on subsequent exposure to drought (PEG-12 bar) stress for 7 days. Seed priming treatments significantly (p≤ 0.01) affected germination percentage (GP), normality seedling percentage (NSP), germination Index (GI), germination uniformity (GU), means time to germination (MTG), coefficient of velocity of germination (CVG), seedling vigor index (SVI) and coefficient of allometry (AC). Seed priming with gibberelic acid (GA), salicylic acid (SA), ascorbic acid (ASc), hydropriming (HP), osmopriming (OP) and combined treatments (CT) significantly (p≤ 0.01) increased germination characteristics, compared to the unprimed. Seed priming with concentrations 25, 50 ppm of GA for 15 h at 10°C, 25 ppm of SA for 12 h at 10°C, 50 ppm of ASc for 12 h at 15°C, treatment 16 h hydropriming at 10°C and -15 bar PEG for 24 h for osmopriming may be considered as optimal treatment for priming of barley seeds in drought stress conditions. In some cases, combined treatments are better than the separate treatments. Seed priming with PEG (potential -l5 bar PEG for 24 h at 10°C) was more effective in drought stress than the other treatments.


2017 ◽  
Vol 155 (10) ◽  
pp. 1541-1552 ◽  
Author(s):  
M. A. ABOUTALEBIAN ◽  
S. NAZARI

SUMMARYLate sowing causes substantial yield reduction in canola. This yield reduction is principally due to lower emergence and poor crop establishment because of prevailing low temperatures. A field experiment was conducted using five sowing dates over two growing seasons (2014/15 and 2015/16). The effect of two seed-priming strategies (hydropriming and osmopriming with zinc sulphate, ZnSO4) was measured in three canola cultivars (Okapi, Zarfam and Talayeh). Results showed that both seed-priming treatments were effective in improving emergence percentage (EP) of canola cultivars. The highest EP occurred in the earlier sowing in both years. On 5 September, EP for the hydropriming, osmopriming and no-primed treatments were 89, 93 and 73% in Okapi, 83, 89 and 69% in Zarfam, and 81, 89 and 72% in Talayeh, respectively (data averaged across both years). Delay in sowing date compared with 5 September caused a sharp reduction in EP in primed seed and control conditions. Maximum seedling emergence rate and coefficient of uniformity of emergence were seen in early sowing for Okapi cultivar with ZnSO4 osmopriming. Experimental evidence showed that in canola cultivars the activities of superoxide dismutase, peroxidase and catalase were higher in the leaves of plants from seed primed with ZnSO4 compared with seed from hydroprimed plants. Cultivar analysis of total antioxidant content activities indicated, the maximum increase was observed in the Okapi and Talayeh cultivars.


2019 ◽  
Vol 4 (1) ◽  
pp. 39
Author(s):  
Renu Agarwal ◽  
SK Gupta ◽  
Sushma Srivastava ◽  
Rohit Saxena

Introduction: Ocimum basilicum (OB), a herb known for its antihypertensive, anticholinesterase and antioxidant properties was investigated for possible intraocular pressure (IOP) lowering effects in rabbits with ocular hypertension (OHT). Methods: The IOP lowering effect of a single drop of OB extract (OBE) was evaluated in oculonormotensive rabbits using three concentrations (0.25, 0.5 and 1% w/v). The concentration showing maximum IOP reduction was further evaluated in rabbits with water-loading and steroid-induced OHT. Results: IOP lowering effect of OBE 0.5% in oculonormotensive rabbit eyes was significantly greater compared to OBE 0.25% (p<0.05) but was comparable (p>0.05) to OBE 1%. Therefore, 0.5% concentration was selected for further evaluation. Pretreatment with OBE (0.5%) caused significantly lower increase in IOP after water loading amounting to 23.39% above baseline as compared to 54.00% in control eye, 15 minutes post water loading. At 60 minutes, post water loading, mean IOP rise was 95.12% and 63.58% in control and test eyes, respectively. Significant difference between the mean IOP of two eyes persisted during the 2nd hr. In rabbits with steroid induced OHT, OBE 0.5% produced a mean IOP reduction of 24.73% at the end of first hr and the mean peak IOP reduction of 31.63% was observed at the end of 2 hr. A significant difference between the IOP of test and control eyes persisted from 1 to 6 hr. Conclusions: Ocimum basilicum seed extract showed significant IOP lowering effect in rabbits with water loading and steroid induced OHT, however, its utility as an effective antiglaucoma medication needs further investigations.


2021 ◽  
Vol 280 ◽  
pp. 109904
Author(s):  
Remi Chakma ◽  
Arindam Biswas ◽  
Pantamit Saekong ◽  
Hayat Ullah ◽  
Avishek Datta

2021 ◽  
Author(s):  
Dmitry Moiseevich Olenchikov

Abstract Recently, more and more reservoir flow models are being extended to integrated ones to consider the influence of the surface network on the field development. A serious numerical problem is the handling of constraints in the form of inequalities. It is especially difficult in combination with optimization and automatic control of well and surface equipment. Traditional numerical methods solve the problem iteratively, choosing the operation modes for network elements. Sometimes solution may violate constraints or not be an optimal. The paper proposes a new flexible and relatively efficient method that allows to reliably handle constraints. The idea is to work with entire set of all possible operation modes according to constraints and control capabilities. Let's call this set an operation modes domain (OMD). The problem is solved in two stages. On the first stage (direct course) the OMD are calculated for all network elements from wells to terminal. Constraints are handled by narrowing the OMD. On the second stage (backward course) the optimal solution is chosen from OMD.


2002 ◽  
Vol 50 (2) ◽  
pp. 197 ◽  
Author(s):  
Timothy J. Wills ◽  
Jennifer Read

Various fire-related agents, including heat, smoke, ash and charred wood, have been shown to break dormancy and promote germination of soil-stored seed in a broad range of species in mediterranean-type systems. However, relatively little work has been conducted in south-eastern Australian heathlands. This study examined the effects of heat and smoked water on germination of the soil seed bank in a mature sand heathland within the Gippsland Lakes Coastal Park, in south-eastern Australia. Heat was clearly the most successful treatment for promoting seed germination, followed by smoked water, then controls, with 55% of species present in the germinable soil seed bank requiring a heat or smoke stimulus to promote seed germination. Mean species richness of the germinable soil seed bank was found to be significantly higher in heat-treated soil than in smoke and control treatments. Seedling density of heat-treated soil was almost 10 times that of controls, while smoke-treated soil was almost five times that of controls. Seedling emergence was fastest in heat-treated soil, followed by smoke and control soils. Of the species found in the soil seed bank, 25% were absent from the extant vegetation, suggesting the existence of post-fire colonisers in the soil seed bank. The results have implications for the design of soil seed bank experiments and the use of fire as a tool in vegetation management.


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