Ex Vitro Rooting and Survival of Regenerated Shoots ‎from three Fig (Ficus carica L.) Genotypes

The aim of this study was to optimize the rooting of regenerated shoots from nodal segments of three genotypes of fig named: ‘Bargchenari’, ‘Dehdez’ and ‘Runu’. For that purpose, the bottom of shoots (about 5 mm) was dipped in Indole-3-butyric acid (IBA) solution of different concentrations: 500, 1000, 1500, 2000 mg L-1 and control for 5 seconds and then cultured in sand medium. The test was performed in a completely randomized design with at least 5 replications. In ‘Runu’, the highest rooting percentage and the number of roots per shoot (100% and 15.67, respectively) were observed in concentration of 2000 mg L-1 ‎IBA, whereas, ‘Bargchenari’ and ‘Dehdez’ produced the highest rooting percentage and the root number per shoot at concentrations of 1000 and 1500 mg L-1 IBA respectively. Three months after transferring rooted shoots to soil mixtures, ‘Bargchenari’ genotype showed the highest survival rate (80%), shoot length (2.5 cm) and leaf number (4.65 leaves per shoot). In relation to survival percentage, the best medium was perlite, but plantlets showed better growth on perlite + peat medium

Influence of Gibberellin on Increasing of Sodium Chloride Tolerance via Some Morpho-Physiological Changes in Two Olive Cultivars

Cultivars of Olive (Olea europaea L.) have different ability for adaption to saline environments. Salinity is one of the major factors limiting plant growth and development. The aim of this research was to study the salinity status tolerance of two olive cultivars: ‘Zard’ and ‘Shiraz’ and also the possibility of using gibberellin to increase plant salt tolerance. Treatments were different concentrations of sodium chloride: 0, 50, 100 and 200 mg L-1, which were added to the pots via irrigation water, and foliage application of gibberellin (GA3) at 0, 10 and 100 mg L-1, which were applied one month after salinity treatments on plants. The results showed that increasing salinity declined leaf area; shoots and roots length; leafs, shoots and roots fresh and dry weights, and increased the amount of leaf proline, and leaf and roots Na+ and Cl-. Application of gibberellin reduced sodium and chloride concentrations in plants, but increased the amount of potassium and chlorophyll. The rate of Na+ accumulation in leaves and roots was lower in ‘Shiraz’ than in ‘Zard’. In different levels of sodium chloride, gibberellin increased the synthesis and accumulation of proline in two cultivars, but this increase was more pronounced in ‘Shiraz’. ‘Shiraz’ showed more vegetative growth than ‘Zard’

Growth and physiological responses of grafted and non-grafted cultivars of Ziziphus spina-christi to salinity

Two grafted cultivars of Z. spina-christi (‘Danehgird’ and ‘Danehboland’ were grafted on wild seedlings) and non-grafted seedlings were grown in soil and perlite mixture (1:1 v/v) and treated with 0 (0 dS m-1), 3.2 (5 dS m-1), 6.4 (10 dS m-1) and 12.8 (20 dS m-1) g/l NaCl. After 16 weeks, salt stress resulted in a substantial decrease in root length, stem, leaf surface, lateral root number, root, stem and leaf fresh and dry weight in both grafted cultivars and seedling rootstock. These reductions were predominance in seedling rootstock than in grafted cultivars. In all organs (leaf, stem and root) of grafted ‘Danehboland’ cultivar, the K+/Na+ ratio was significantly higher than non-grafted wild seedling in saline and non-saline conditions. The proline and soluble sugar also was significantly higher in the leaves of ‘Danehboland’ cultivar than non-grafted control. The results imply the predominance of the scion genotype in determining salt tolerance in comparison with rootstock seedling

Effect of 24-epibrassinolide on salinity-induced changes in loquat (Eriobotrya japonica Lindl)

This study was carried out to investigate the role of 24-epibrassinolide (24-EBL) in inducing loquat plant salt tolerance. Plants were treated with five levels of salt, so that the electrical conductivity (EC) of 0.5 (control), 2, 4, 6 and 8 dS m-1 was established in pots. Then, the plants were sprayed with different concentrations of 24-EBL (0, 0.25, 0.5 and 0.75 mg l-1). Under salt stress, the plant growth parameters and chlorophyll content decreased, while the total soluble sugars and proline contents considerably increased. However, the application of 24-EBL significantly ameliorated the plant growth by reducing the adverse effects of salinity on the examined parameters. The ion concentrations showed an increase in accumulation of Na+ and Cl- coupled with a decrease in K+ with increasing salinity in medium. Exogenous application of 24-EBL had a significant effect on leaf Na+, K+, Cl- contents. Out of different 24-EBL concentrations, the effects of 0.5 mg l-1 proved the best under stress conditions.

Physiological and Biochemical Changes of Some Grapevine Cultivars under Different Irrigation Regimes

In this research, the responses of six grapevine cultivars to irrigation regimes were investigated using some physiological and biochemical traits in order to determine the water deficit tolerant cultivars and to select them as a rootstock. The potted plants were subjected to different irrigation treatments: well-watered (100% FC or Full Irrigation, FI), mild (75 % FI), moderate (50% FI) and severe water deficit (25% FI) for a period of 60 days. A factorial experiment (6 cultivars × 4 irrigation levels) was conducted in a completely randomized design (RCD) under greenhouse conditions. The results showed that ‘Rotabi’ cultivar had the highest quantum efficiency of photosystem II (Fv/Fm) and relative water content (RWC %) under severe water stress deficit and cultivar ‘Thompson Seedless’ had the lowest amount of these two above mentioned traits. The lowest total chlorophyll (TCh) occurred in ‘Yaghouti’ and ‘Flame Seedless’ and the highest one in ‘Rotabi’ and ‘Thompson Seedless’. The highest amount of starch, proline and protein was observed in ‘Rotabi’ in response to different irrigation levels. ‘Perlette’ had the highest activity of POD, SOD and protein content as well as total chlorophyll content under 25% FI. ‘Siah Samarghandi’ and ‘Thompson Seedless’ cultivars indicated the same activity of superoxide dismutase (SOD) in different irrigation levels. In conclusion, it seems that ‘Rotabi’ and ‘Perlette’ are the most tolerant grapevine cultivars in response to progressive water deficit

Tissue Culture of Rubus sp. by Different Methods and Assessment of Genetic Fidelity of Regenerated Plants Using RAPD

Different methods employed in plant tissue culture can provide a valuable source of plants for the horticultural industry and novel germplasm for breeding programs, but the genetic fidelity and lack of somaclonal variation of regenerated plants needs to be verified. In this study, the genetic fidelity of blackberry (Rubus hirtus Waldst. & Kit.) plants regenerated in vitro was assessed with 11 randomly amplified polymorphic DNA (RAPD) markers. Three routes were assessed: callus induction on Yasuda medium with 6-benzyladenine (BA, 8.88 μM), 1-naphthaleneacetic acid (NAA, 10.84 μM) and glycerol (2%, v/v), somatic embryogenesis on Murashige and Skoog (MS) supplemented with 7.57 μM abscisic acid (ABA), and micropropagation from single nodes on MS basal medium containing NAA (0 and 2.86 μM) and BA (0, 4.44, 8.88 and 17.76 μM). MS medium with 2.86 μM NAA and 8.88 or 17,76 μM BA was the most effective medium for axillary shoot multiplication of R. hirtus and Rubus sanctus Schreb. from nodal segments. A total of 618 fragments were successfully generated by RAPD and the maximum of loci was observed in primer 1204-209 that show 10 and 69 bands. Genetic similarity exceeded 86% when regenerated plants were compared to mother plants. Based on the RAPD data profile, almost true-to-type plants were produced by different methods of plant regeneration (direct shoot regeneration, somatic embryogenesis and organogenesis)

Embryogenesis in Valerian (Valeriana officinalis L.) using leaf segments

Abstract:A simple procedure for direct embryogenesis without an intervening callus production was developed in valerian (Valeriana officinalis L.) using the leaf segments. Direct somatic embryogenesis were induced using by half-strength MS medium supplemented with 2,4-D (0.5 mg·l-1), glutamic acid (100 mg·l-1), 4% sucrose and 8 g·l-1 agar. Germinated embryo to form plantlets enhanced on MS medium supplemented with NAA (0.1 mg·l-1) and Kin (2 mg·l-1). Regenerated plants with well-developed root and shoot systems were successfully (72%) transferred to greenhouse

Antioxidant and carbohydrate changes of two pomegranate cultivars under deficit irrigation stress

The purpose of this study was to evaluate the biochemical responses to water stress tolerance of two pomegranate cultivars, ‘Rabbab’ and ‘Shishehgap’. After the establishment of rooted stem cuttings of both cultivars under greenhouse conditions, they were treated with four levels of deficit irrigations (100%, 75%, 50% and 25% of field capacity) in a completely randomized design with four replications. The results showed a significant difference between the two cultivars regarding antioxidant enzymes activities. In both cultivars, the water stress increased the activity of superoxide dismutase, catalase and ascorbate peroxidase. However, at high water deficit (25% field capacity, FC), ‘Rabbab’ showed significantly higher enzyme activity than ‘Shishehgap’. In each level of irrigation, there were not considerable differences in peroxidase activity between the two cultivars. An increment of 162% and 65.5% in soluble sugar was gained at 50% FC in ‘Rabbab’ and ‘Shishehgap’, respectively. ‘Rabbab’ showed better growth performance in each level of irrigation than ‘Shishehgap’. Therefore, it can be concluded that 'Rabbab', with lesser decline in leaf relative water content (RWC), a strong antioxidant system and accumulation of more soluble carbohydrates, can resist higher water stress than 'Shishehgap'