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Development of in vitro propagation system for Atriplex halimus L.
123-129.Views:229Explants excised from adult shrubs were surface sterilized and cultured on Murashige and Skoog (MS) basal medium in the presence of plant growth regulators (PGRs) at different concentrations. A high multiplication rate of 7.2-fold was achieved every four weeks on MS medium supplemented with 4.44 μM BA, 0.49 μM IBA and 0.58 μM GA3. Rooting was achieved with 73% efficiency within 2-4 weeks on agar-gelled MS basal medium free of PGRs. Rooted plantlets were gradually acclimatized to field conditions over 5-6 weeks with 65% efficiency. For in vitro selection for salt tolerance, MS medium was supplemented with increasing concentrations of NaCl ranging between 25 and 1000 mM. This study has demonstrated that in vitro shoots could tolerate up to 600 mM NaCl with optimal growth at 200 mM, while higher concentrations of NaCl affected growth negatively. Growth and shoot number decreased with increasing NaCl concentration with all plantlets died at 1000 mM NaCl.
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Effects of different levels of NaCl and CaCl2 on seed germination characteristics of Melissa officinalis L. and Ocimum basilicum L.
21-25.Views:325More than 15 million hectares of Iran’s land areas are suffering from salinity.We investigated the effects of two types of salt (NaCl, CaCl2) in different levels on the germination and initial growth of two medicinal and aromatic plants, Melissa officinalis L. and Ocimum basilicum L. The experiment was carried out in Qazvin Agriculture and Natural Resource Research Center based on a randomized complete block design, for 14 days in a germinator. Sweet basil germinated above 50% in each saline treatment (EC=10 dSm-1), in alkali treatment (CaCl2=18800 mg/L) and in sodic-saline treatment (Ec=10 dSm-1; SAR=5.6), however at the highest concentrations germination was slowed down. Lemon balm showed a higher sensitivity: except the lowest NaCl treatment, each other ones inhibited germination and its rate to some extent. The combined treatments of both salts increased the stress reactions. However, seedling growth was less effected. The results showed a stimulating effect of NaCl treatment in 2500 mg/L (EC<5 dSm-1) for both species concerning germination and seedling growth.
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Boistimulator effect of stress tolerant rhizobacteria on horticultural models
83-87.Views:226The tolerant bacteria for abiotic stresses such salinity, drought, and different pH have been used as a good tool to improve plant growth in sustainable agriculture. A pot experiment was conducted to evaluate the potential of isolated stresstolerant bacteria for red mud-polluted soil on growth performance of giant reed plants with increasing concentrations of NaCl 0.0; 0.1; 0.2; 0.3; 0.5; 1.0% under gnotobiotic conditions. At the same time biostimulator potential of isolated bacteria was observed in case of radish in vitro germination experiment under salt stress. It was found that the observed bacterial strain can tolerate the salt and pH moderately however it is resistant against hydrogen-peroxide caused oxidative stress in high concentration (up to 2640 mM). Molecular identification, basis on 16S rDNA showed 98% similarity to the Bacillus aryabhattai bacterial strain. The isolated strain alleviated the negative effect of salt (0.05%) for the radish seed germination. However in higher salt concentration (≥0.1%) the bacterial mitigating effect vanished. The inhibition of increasing salt concentration for giant reed plantlets was also alleviated by halotolerant bacteria treatment (≥0.5%).
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The salt tolerance of vegetable paprika varieties
39-45.Views:176In our experiments, we have chiefly tested the salt sensitivity of sweet pepper varieties. In cold forcing, 0.3 1/plant nutrient solutions of different NaCI content were given twice weekly. EC of the nutrient solutions containing 0.25% Volldünger Linz complex fertilizer was made up to 6, 10, 14 and 18 mS/cm, respectively, by 2.51/9.17/17.97/26.76 g/m2 doses of pharmacopeal NaCI every week. The solution used for the control treatment contained Volldünger only (EC 4.4 mS/cm). Irrigation was made with pure water (EC 0.6 mS/cm) when necessary.
The varieties chosen for the experiments were the following: Feherözön, HRF F1, Syn. Cecei (of white, conical fruit), Boni (of white, blunt, infolded fruit), Titan F1 (of pointed, hot fruit) and Pritavit F1 (of tomato shaped fruit).
In general, the symptoms caused by NaCI treatments (with doses higher than 10 g/m2 weekly) have been the following:
- They have reduced the leaf area, the height of the plants, the total and the early yield, the number of fruit set per square meter, the average weight of the fruit (and, in some measure, fruit length, too) and the thousand seed weight.
- They have increased the calcium and the chlorine content of the leaves and fruits and the dry matter content of the fruits.
- They haven't affected the dry matter content of the leaves, the nitrogen, phosphorus and potassium content of the leaves and fruits, and the germinating ability of the seed.
- The effect on stem diameter and on seed production per fruit has been contradictory in some cases.
The effects of the intermediate treatments haven't been explicit in several cases.
The results of the examination of cuticular secretion have indicated the increase of the sodium and chlorine content of the leaves. This can be important in field growing where the rainwater may wash out a part of sodium and chlorine from paprika leaves.
The hot, pointed variety and the tomato shaped paprika haven't shown clearly higher salt tolerance than the varieties of white fruit colour.