Iranian Journal of Plant Physiology
Volume:7 Issue: 1, Autumn 2016

Seeds of medicinal plant Artemisia sieberi were pretreated with H2O2 (0, 10, 50, 90, and 140 μM) and grown in saline condition (0 and 150 mM NaCl) for one month. Phytochemical properties such as antioxidant capacity and also salt tolerance in the plans arising from H2O2 pretreated seeds under salt stress were examined. Results showed a decrease in H2O2 and malondialdehyde concentrations in the shoots of pretreated A. sieberi. Furthermore, seed pretreatment with H2O2 (particularly at 50 μM) increased photosynthetic pigments content, antioxidant capacity and dry and fresh weights of shoots in the pretreated plants under both normal and saline conditions. The activity of the antioxidant enzymes increased in all pretreated A. sieberi plants particularly at 50 μM H2O2. Data indicated H2O2pretreatment can induce salt tolerance in A. sieberi by supporting physiological and phytochemical processes such as photosynthesis, reactive oxygen species scavenging and detoxification, and also membrane stability in this species. Additionally, hydrogen peroxide pretreatment enhanced reducing power and antioxidant activity in A. sieberi suggesting an increase in its medicinal properties.

Cucurbita pepo var. styriaca is known as a medicinal crop among other cucurbits and has been cultivated around many decades in some parts of Iran by local farmers. The present study was conducted on 8 accessions of C. pepo seed from various planting zones. All collected seeds were planted in Horticultural Science Research Field of University of Tehran in three replications with two observations in each replicate based on randomized complete block design. Seed characteristics and phytochemical composition were analyzed after fruit ripening. The result of variance analysis showed that all of the studied characteristics had significant differences among accessions. Gorgan accession (193 gr) and Mashhad accession (102 gr) had the highest and lowest seed weight, respectively which had seed coat in comparison with naked seed types. Among naked seeds, Shahroud accession revealed higher seed weight (148 g). Maximum oleic acid content, an unsaturated fatty acid (vital and important fatty acids), was for Esfahan accession as naked seed. The results showed that maximum total phenolic compound was related to Qom accession with 4 mg GAE/kg and Khomein accession as naked seed type had maximum antioxidant content. Although naked seed is known as medicinal cucurbits because of high amount of un-saturated fatty acid, this study demonstrated that other cucurbits like Chalous accession with normal seeds also had high amount of unsaturated fatty acid.

Little seed canary grass (Phalaris minor L.) is a major weed in wheat fields in some parts of Iran. To evaluate the efficacy of molecular and greenhouse methods in detecting the resistance of 49 biotypes of canary grass(Phalaris. Spp) to acetyl-CoA carboxylase-inhibiting herbicides, two methods including whole plant screening and PCR-based molecular methods were applied. Results showed that there were resistant biotypes (ile-1781-Leu) among the studied weed populationand the similarity between greenhouse and molecular methods was 67%. According to the molecular method, an isoleucine (ile) 1781 to leucine (leu) mutation in plastidicACCase enzyme of 30 biotypes (67% of biotypes) was identifiedas a mutation endowing to the clodinafop-propargyl resistance. The partial differences of about 33% between greenhouse and molecular methods can be explained by mutation in another location or through another metabolism –based mechanism.

One of the methods for achieving more yields is to use seed priming technique correctly. When it comes to using seed priming, practically important issues should be taken into account including interval between priming to planting and conditions for storage of primed seeds. Thus, it is very crucial to be informed of duration and temperature for storage of primed seeds. This research seeks to compare the effect of temperature and duration of hydroprimed wheat seeds (var Kouhdasht) on growth indices and grain yield. This test was carried out with three replications in Research Farm of Agricultural Faculty of Lorestan University, as completely randomized block design. The relevant factors include storage temperature (15, 20 and 25° C) and storage duration of hydroprimed seed (0, 2, 4, 6, and 8 days). The results showed that hydropriming increased number of productive spike and grain yield. Nevertheless, delay (8 days storage) in planting and storage seeds at high temperature (25° C) could decrease benefits of priming. Storage temperature and duration of hydroprimed seeds affect morpho-physiological characteristics as well as yield. Seeds stored at 15 and 20° C showed a better yield than those stored at 25° C. Primed seeds stored at 20° C for 2 days showed a better performance than the other applied treatments.

Thymus daenensis is a perennial plant belonging to Lamiaceae family that is a species endemic to Iran. Due to the indiscriminate use of this plant which possesses medicinal values, T. daenensis tissue culture is suggested to increase the quality and quantity of its effective compounds. Callus cultures using leaf and stem explants were subjected to different hormonal treatments. Ten-millimeter explants of leaves and stems were cut up from sterile seedlings. MS medium was used with different concentrations of naphthalene acetic acid, benzyl amino purine, kinetin and 2,4-D (mg per liter) in which callus formation was observed. The highest level of thymol (28/1335 micrograms per gram) was recorded in calluses derived from leaf explants whereas the lowest level was observed in calluses obtained from stem explants. Also the highest levels of thymol, i.e. 65/1313 and 30/1322 micrograms, were observed in treatments of 0.4 NAA BAP and 0.8 NAA BAP mg per liter, respectively. Moreover, the interaction of effects of different treatments of calluses and different concentrations of hormones showed that the highest level of thymol (38/1345 micrograms per gram) was obtained from the treatment of NAA.5 BAP 0.2 mg per liter in the calluses derived from leaf explants. In addition, the maximum callus weight (22.1 grams) was related to the treatment of 0.8 NAA BAP milligrams per liter. Results of the callus culture of T. daenensis to enhance the quality and quantity of its active ingredients showed that different explants and hormones with different concentrations and as well as their interactions had a significant effect on the level of thymol and callus weight (p≤0.01).

Phytoremediation is one of the most widely used methods for removing soil contaminants. In this research, the function of Vetiveria zizianoides to remove cadmium from four different treatments with varying amounts of cadmium chloride contamination (including 0, 20, 40, and 60 mg per liter) was investigated and physiological changes caused by the accumulation of this metal in the plant were monitored. According to the obtained results, cadmium accumulation in roots was higher as compared to the shoots. Based on factors such as the amount of biomass and the length of organs, the growth rate was reduced in plants accumulating more cadmium. Our findings also showed that increased concentrations of cadmium chloride in the experimental units caused a significant reduction of photosynthetic pigments compared to control. However, phenolic compounds and malondialdehyde showed a significant increase with increasing concentrations of cadmium chloride. In addition, the cadmium uptake by the plant was increased with increasing concentration of cadmium chloride. Our results clearly showed the high capability of Vetiveria zizianoides for biological removal of cadmium from contaminated soil.

Salinity is one of the most severe abiotic stresses in one-half of all irrigated lands, causing negative effects on physiological, biochemical, and molecular responses in plants. Application of chemical fertilizers, particularly phosphorus (P) fertilizers, may reduce harmful effects of salinity. In this study, an investigation was performed on the effects of exogenous application of different levels of phosphorous (0, 40, and 80 mg/kg soil as CaHPO4) on hydrogen peroxide (H2O2) and malondialdehyde (MDA) generation, the content of soluble proteins, and activities of antioxidant enzymes like superoxide dismutase (SOD) and peroxidase (POD), in shoots of two different cultivars of Capsicum annuum L. (cv DS 77-172 and cv Sera) under different concentrations of NaCl (0, 50, and 150 mM). Treatment of salt stressed grown seedling with CaHPO4 increased activity of POD. Under salinity conditions, phosphorous treatment decreased contents of H2O2 and MDA. These results indicate salt-induced deleterious effects in both pepper cultivars alleviated by phosphorous treatment.

Gerbera is one of the most popular cut flowers in the world. Several experiments have been done on the effect of different chemical compounds on longevity and quality of cut flowers. In the present study, two experiments based on a completely random design with two treatments and three replications were conducted on gerbera cut flower cv. Sorbet. The first experiment examined the effect of BA, GA3, and SA at 2 concentrations (50 and 100 ppm) as a pulse treatment and then holding vase life solution containing 3 ppm silver nanoparticle with 3% sucrose. The second experiment investigated the effect spray application of BA, GA3, and SA at 2 concentrations (25 and 50 ppm) and then holding vase life solution containing 3 ppm silver nanoparticle with 3% sucrose. Distillated water and 3 ppm silver nanoparticle with 3% sucrose were used as control. During the experiments traits such as vase life, relative fresh weight, anthocyanin content, PAL activity, and SOD activity were measured. Results showed that there was significant difference between treatments and control. As for different concentrations of BA, GA3, and SA followed by NSP and sucrose treatment in the first excrement, SA 100 ppm with 8.9 day longevity compared with control (5.6 day) and in second experiment, SA 50 ppm with 9.8 day longevity compared with control (5.9 day) had better result than other treatments in quantity and quality of enzymatic traits and vase life, respectively. Results revealed that there was significant difference between treatment and control (p≤0.01) in postharvest life in gerbera cut flowers.