Journal of Plant Biological Sciences
Year:2019 | Volume:11 | Issue:39 |Papers Count:6

In order to evaluate the effects of various concentrations of Jasmonic acid and nano-titanium dioxide (NTD), as two elicitors, on the activity of antioxidant defensive system (enzymatic and non-enzymatic) and physiological traits of sage, a factorial experiment in a completely randomized design with three replications was conducted at the University of Zabol. Trial treatments consisted of three concentrations of Jasmonic acid (0 as control, 75 and 150 mg/L) and titanium dioxide (0 as control, 50 and 100 mg/L), respectively. Comparing the mean values showed that increasing the concentration of NTD would result in a significant increase of the concentrations of traits examined so that with increasing the concentration of NDT (treatment with 100 mg/L), traits such as essential oil, chlorophyll a, chlorophyll b and total chlorophyll, relative water content, proline, phenol, peroxidase, ascorbate peroxidase, guaiacol peroxidase, superoxide dismutase and catalase would also have an increasing trend compared to the control treatment. Also, with increasing the concentration of Jasmonic acid (treatment with 150 mg/L), traits such as relative water content, chlorophyll a, chlorophyll b and chlorophyll total, proline, essential oil, phenol, peroxidase, ascorbate peroxidase, guaiacol peroxidase, superoxide dismutase and catalase would have an increasing trend compared to the control treatment. The results of correlation showed a significant positive correlation (P<0. 01) between the concentration of essential oil and phenolic compounds with that of total chlorophyll and also among antioxidant enzymes. According to the results, using Jasmunic acid and titanium dioxide individually, would have positive effects on the activity of antioxidant system and physiological traits of Sage.

In order to investigate the effect of hormones and hydro-priming on seed germination, growth and biochemical characteristics of borage seedlings under cadmium stress, a factorial experiment based on a completely randomized design was carried out with three replications. The experimental factors were cadmium stress (zero as a control, 10, 50 and 100 mg/L) and seed priming (hydro-priming for 48 hours, hormone priming with 150 ppm gibberellin for 48 hours, 4 mM salicylic acid concentration for 60 hours and control (no priming)). The results showed that the percentage and rate of seed germination, seedling length and dry weight and peroxidase and catalase enzymes activity of seedling were decreased under cadmium stress, which indicates the negative effect of cadmium on seed germination, growth and antioxidant enzymes activity of borage seedling. Also, cadmium stress was led to significantly increase of proline and percentage of abnormal seedlings. Hormone and hydro-priming significantly increased the germination, growth and biochemical characteristics of borage seedlings under cadmium stress conditions. Among the primed seeds, the highest germination rate, seedling length and dry weight and proline were obtained from seeds primed with 4 mM salicylic acid for 60 hours, which was significantly higher than those of the control. Furthermore, at all levels of cadmium stresses, seed priming with 150 ppm gibberellin for 48 hours, caused increase about 2. 25 to14. 3 and 1. 6 to1. 85 fold in the activity of catalase and peroxidase enzymes respectively as compared to control. Generally, seed priming was reduced the negative effects of cadmium stress through increasing seed vigor and improving the biochemical properties of seedlings, and led to improve the seed germination and seedling growth under favorable and cadmium stress conditions.

To evaluate somatic embryogenesis (SE) induction, mature, immature cotyledon and endosperm explants of Natanzi, Ghosi, Dar Gazi, and Williams cultivars obtained from 40-100 days after pollination, were cultured into the White, SH, and MS media containing 2. 3, 9 and 18 μ M of 2, 4-D. Then, to enhance the efficiency of direct SE, Ghosi cultivar endosperm as the preferable explant from previous experiment, was cultured in MS medium containing 0 to 2 μ M of 2, 4-D and 0 to 9 μ M of TDZ. To germinate and plant recovery, MS medium with different treatments consisted of control, 150 mg/L Fe-EDDHA, 2 mg/L AgNO3, and 1mg/L GA3 were used. Finally, for plant adaptation, two successive experiments consisted of using mycorrhizae (Glomus mosseae) treatment at 0 and 0. 25 g/Kg levels, and then applying two fertigation procedures, were separately carried out. The results revealed, the only endosperm of Ghosi cultivar in MS medium produced direct somatic embryos. 0. 5 μ M of 2, 4-D had the highest frequency of somatic embryos production (12. 66%). The highest frequency of normal embryo obtained in 0. 5 μ M 2, 4-D (71%) and 0. 5 μ M 2, 4-D + 4. 5 μ M TDZ (70%). The highest germination (9. 66%) and plant recovery (12%) obtained in Fe-EDDHA. In the adaptation phase, the usage of mycorrhizae and the second procedure of fertigation were known preferable. Overall, the method presented in this study can be used in molecular studies of this cultivar.

Salinity is one of the environmental stresses with negatively impact on growth and development process which can leads in oxidative stress induction in plants. Nitric oxide is a relatively stable gas radical and at low concentrations, prevents the production of active oxygen species. The phytochemical changes were investigated in response to application of nitric oxide (0 and 100 μ M) in Bidaneh Sefid grapevine plants under different concentrations of sodium chloride (0, 25, 50 and 100 mM). The experiment was done in a factorial experiment based on a completely randomized design with three replications in greenhouse conditions. According to the results, Nitric oxide application increased the chlorophyll, proline, total soluble sugar, total phenol, total flavonoid, soluble protein concentration and likewise significantly increased the activity of antioxidant enzymes of grapevine leaves. Nitric oxide increased the tolerance of grapevine plants under salinity stress conditions with effect on compatible osmolytes, antioxidant enzymes, potassium and magnesium. Consequently, 100 μ M of nitric oxide is recommended for increasing salinity stress tolerance (up to100 mM of NaCl).

West Loodab region with an area around 20000 hectares is located in Zagros mountain in 120 Km northwest of Yasouj of Kohgilooyeh and Booyerahmad province between 30º 50′ and 31º 08′ north latitudes and 50º 40′ and 50º 59′ east longitudes. Due to having extreme difference in elevation, this region has different climates and outstanding biodiversity. Collection of specimens was performed from February of 2014 to August 2016. 249 species belonging to 164 genera and 60 families were identified. The largest families were Asteraceae (37 taxa), Fabaceae (28 taxa) and Lamiaceae (22 taxa) and the most diverse genera included Euphorbia with 8 species, Astragalus with 7 species and Salvia with 6 species respectavily. According to Raunkiaer’ s classification, plants in this region were hemicryptophytes (41. 78%), therophytes (27. 71%), phanerophytes (12. 85%), geophytes (12. 45%), chamaephyts (4. 41%) and parasites (0. 81%) were life forms in this area. A considerable number of species (53%) belonged to Irano-Toranian phytogeographycal region. For this region 49 poisonous, 38 rare, 56 medicinal and 45 endemic speices identified.

Micro-propagation of olive has a long history but strong apical dominance at the shoot regeneration stage always affects its proliferation such that even with cytokinin treatments it is not controllable. This problem limits olive micropropagation. In the present study, we attempted to determine suitable concentrations of sodium dikegulac to reduce apical dominance and concomitantly increase lateral buds growth and shoot regeneration rate under two light qualities (red LED and white fluorescent). A factorial experiment was used with a complete randomized design with 4 replications and 4 explants per replication. The maximum number of regenerated shoots (3. 10 ± 0. 22 per bud) was observed at 5 mg/L of sodium dikegulac under the white fluorescent lamps, during 21 days of post sub culture. Based on the number of generated shoots, red light had a negative effect on shoot regeneration when accompanied by sodium dikegulac. Even though longitudinal growth of buds revealed a downtrend pattern by increasing concentrations of sodium dikegulac, but the longitudinal growth of buds was significantly higher under the red light compared to the white fluorescent in the same sodium dikegulac concentrations. Based on the results, it seems that sodium dikegulac and red light have antagonistic effects on each other and sodium dikegulac is only efficient on proliferation when it is used under the white light.