فصلنامه زیست شناسی گیاهی ایران
سال یازدهم شماره 4 (پیاپی 42، زمستان 1398)

In order to investigate the effect of biofertilizers on biochemical properties of fenugreek plant under stress conditions, a factorial experiment was conducted in a randomized complete block design with three replications. Different levels of irrigation were considered at three levels (irrigation after 50, 100 and 150 mm evaporation from evaporation pan) as the first factor and application of biological fertilizers in four levels included as mycorrhizal + Azotobacter, mycorrhizal fungi, Azotobacter and control (no biofertilizer) as the second factor. The results revealed that the hydrogen peroxide, malondialdehyde and glycine betaine in mycorrhiza + Azotobacter treatment decreased significantly in different levels of irrigation. The highest content of ascorbic acid (7.23 mgkg-1 fw) and glutathione (36.20 mgkg-1 Fw) were observed in combined mycorrhizal fungi and Azotobacter treatment in optimum irrigation conditions. Water deficit stress reduced significantly soluble sugars, so Mycorrhizal+Azotobacter treatment increased the amount of soluble sugars in Fenugreek. The maximum amount of proline was observed in control (without biofertilizer) and irrigation treatment with 150 mm evaporation from the pan. So that the activity of catalase, ascorbate peroxidase and glutathione reductase in the inoculated plants with microorganisms under drought stress conditions of 100 and 150 mm evaporation from pan compared to 50 mm evaporation from pan was decreased. On this basis, the increase of enzymatic antioxidants activity and the enhancement of non-enzymatic antioxidants production in combined treatment of mycorrhiza+bacteria, can reduce the activated oxygen vulnerability, and could increase the tolerance to water stress.

Satureja avromanica Maroofi. is an endemic and endangered medicinal plant. In order to in vitro propagation of this plant, an experiment was performed in two phase. The first phase was performed as a factorial based on completely randomized design. The first factor included four concentrations of simvastatin (0, 5, 10 and 20 µmol) and second factor included four concentrations of salicylic acid (0, 0.1, 0.3 and 0.5 mmol). Shoot tips were used as micro explants and MS culture media was used as stock culture media for all treatments. After 45 days from culture of micro explants, viability of micro explants, percentage of dry weight, number and length of stem, leaf area, content of chlorophyll a, b and total chlorophyll, carotenoid, proline, total phenol and total soluble protein were evaluated. In the second phase, the effects of three levels of IBA (0, 0.5 and 1 μmol) on percentage of rooted sample, root length and number of roots were investigated. Results indicated that micro explants that were subjected under interaction of high concentrations of simvastatin and salicylic acid were burned. The most of studied traits were affected significantly by simvastatin and salicylic acid. Maximum mean of dry weight percentage, proline and total phenol were observed in explants treated with 0.3 mmol SA+ 5µmol SS. The highest of stem length was related to 10 µmol SS treatment and the maximum of chlorophyll, carotenoid and total soluble protein were observed in explants treated with 20 µmol SS. Among the applied treatments for stimulation of rooting, 0.5 μmol IBA was the most effective treatment.

Measuring plant characteristics is one of the essential requirements for calculating plant functional diversity. Therefore, in the present study, the plant characteristics of Capparis spinosa L. were measured at the locations of its distribution in Rouhkandi, Ghareh Darreh and Bileshwar rangelands. Vegetation sampling was carried out systematically in 30 two-by-two-meter plots that were 30 m apart along three transects of 300 m. At the same time, the plant characteristics (structural and biomass traits) of 10 C. spinosa rootstocks that were healthy and strong, and well grown in each location were measured. Diameter of crown and collar diameter of each stand, number of dams per stand, height of each ditch, number of branches per dune, length of each branch, number of fruits per dune, fruit health, fruit length and width of each dune, as structural traits and weight of fruit with peduncle, number flower or bud of each duck and fresh weight of each duck were considered as biomass traits. The results of traits comparison showed that the values of structural traits as well as the number of fruits per leaf and average weight of each fruit were not the same in different rangelands. Overall, there was a significant difference between the structural and biomass traits of C. spinosa in the distribution sites. However, structural and biomass traits appear to be correlated with one another and reinforce the other factor. Therefore, it is recommended that if management of C. spinosa species breeding, soil conservation and carbon sequestration is required, it should be developed in locations that increase its structural traits. If management of breeding is to be used as a medicinal plant, it needs to be developed in places where biomass traits are increased.

Due to the slow growth of the yew tree and importance of its metabolites, today, the paclitaxel producing endophytes have been found to be of great research interest. To that extent, in no presence of endophyte, the production of taxol in plant is not possible. In the present study, it has been tried beside the investigation of the qualitative changes of callus from the point of paclitaxel, the endophytic situation of it also be studied. For this purpose, an experiment was conducted with three levels of 1, 2 and 3 mg/L of 2, 4-D, and two levels of 0.5 and 0.2 mg/L of Kinetin in two species of T.baccata and T.brevifolia. Finally, the amount of paclitaxel and the endophytic status in callus were studied. After 3 months of cultivation, 9 colonies of the endophytic fungi appeared in the callus of both species and leaves of T.baccata. The isolated fungi were identified based on their morphology and reproductive organs, such as the formation of spores. Although molecular and biochemical studies of isolated endophytes did not show the ability to produce taxol in them, endophytic fungi in the yew callus, which was first reported, could be a turning point in a better understanding of host and endophytic fungi in the production of valuable metabolites of paclitaxel, especially in cell and hairy root cultures.

Salinity stress is recognized as one of the most important factors limiting plant growth. Auxin and gibberellin are one of the most important plant hormones, with the smallest variation in their levels causing extensive responses throughout the plant. It has been shown that these two hormones are introduced to environmental stresses in tandem with other hormones in order to adapt the plant to new conditions. The aim of this study was to evaluate the changes in auxin and gibberellin hormones and its relationship with changes in the physiology, anatomy and morphology of okra plant under the influence of salt stress. In this study, okra plants were exposed to salinity treatments (0, 50, 100 and 150 mM NaCl) for 7 days. After treatment, root and stem length, fresh and dry weight, auxin and gibberellin levels were measured. The results showed that the levels of auxin and gibberellin hormone decreased significantly under salinity stress. In addition, the activity of the enzyme auxin oxidase increased. In this study, the Na+/K+ ratios and electrical conductivity increased while potassium and relative water content decreased. Structural studies showed that the thickness of different organs (root, stem and leaf) and the stomatal index decreased. The study showed that the length of the spongy and palisade mesophilic cells decreased under salinity stress, and the reduction in leaf thickness is more related to the reduction in palisade mesophilic. This research enhanced our understanding about the commercial use of hormones in oredr to reduce environmental stresses.

 Removal of undesirable pollutants from aquatic ecosystems, which is caused by discharge of large amounts of industrial and urban pollutants into water resources, requires efficient, cost-effective and environmentally friendly technologies, such as phycoremediation. In this biological process, the physiological ability of some algal and cyanobacterial species in detoxifying pollutants such as textile dyes is used. In the present study, the ability of eukaryotic green alga Chlorella vulgaris and prokaryotic cyanobacter Spirulina platensis for decolorization of Direct Blue 129 (DB129) dye at zero (control), 20 and 60 mg. L-1 was studied during one week. Evaluations of physiological indices were performed on 1, 3 and 7 days of growth. C. vulgaris showed a higher percentage in removal efficiency than S. platensis. Dye treatment increased growth indices; Xm (maximum cell concentration), Px (cell productivity) and µm (maximum specific growth rate) and decreased td (doubling time) in C. vulgaris, compared to the control, but astaxanthin showed a higher increase in S. platensis. Chl a, Chl b and total carotenoid contents were increased in C. vulgaris alga at both concentrations of dye, and at 20 mg. L-1 in S. platensis, compared to control. Phycobilins were also increased in treated S. platensis. The highest concentration of dye (60 mg. L-1) caused the highest soluble carbohydrate production in both microorganisms. Along with an increase in dye concentration (unlike S. platensis) protein content was also increased in C. vulgaris. In general, it seems that C. vulgaris has a higher ability in decolrization and is more tolerant to DB129 dye stress than S. platensis.