ABSTRACT
Background: The post-harvesting process of medicinal plants such as drying operation and storage conditions has great influence on their quality and quantity of the active ingredients
Objective: The aim of this experiment was to investigate the effect of pre-drying operation and also storage conditions and duration on the essential oil content and composition of Thymus daenensis
Methods: A factorial experiment was conducted based on randomized complete block design with three replications. The first factor include drying operations [including pre-drying and without pre-drying], the second factor include storage method [shade storage and storage in a refrigerator at 4 degree C], and the third factor was storage duration [storing the plants organs for 60, 120 and 180 days]. The essential oil was extracted by clevenger apparatus and its components were identified using GC and GC/Mass
Results: The highest amounts of essential oil, linalool, borneol, terpinene-4-ol, thymol methyl ether, e-anethol, thymol and carvacrol were observed in plants stored for 60 days. Also, the highest amounts of a-pinene, camphen, Beta pinene, myrcene, a-phellandrene, a-terpinene, limonene, cis-sabinene hydrate and trans-sabinene hydrate were observed in the plants dried in the shade after pre-drying operation and stored in the refrigerator for 120 days
Conclusion: Drying of T. daenensis plants under shade without pre-drying operation and storing in 4 degree C was the best way to obtain the highest amounts of essential oil and its main components [thymol and carvacrol]
ABSTRACT
Background: The composition of the planting beds and its microorganisms has a very important role on the establishment, growth and phytochemical performance of medicinal plants
Objective: The aim of this study was to determine the effect of different planting beds and inoculation of mycorrhizal fungus on the changes of stevioside, rebaudioside, and morpho-physiological traits of stevia
Methods: This study was conducted in a factorial experiment based on randomized complete blocks design [RCBD] with 10 treatments and 4 replications. The first factor consisted of inoculum and non-inoculum treatment of Glomus intraradices, and the second factor was the different combination of peat moss, coco peat, perlite and soil as planting beds
Results: Mycorrhizal fungi inoculation significantly increased the plant height, number of lateral branches, stem and root diameter, number of leaves, leaf fresh/dry weight, shoot dry weight, root dry weight, and content of stevioside, rebaudioside A and C. Also, different combination of planting beds had a significant effect on the plant height, stem dry/fresh weight, leaf fresh weight, root dry/fresh weight, and content of stevioside, rebaudioside A and C
Conclusion: The results of this study showed that the combination of peat moss + coco peat + soil [2:1:1] with mycorrhizal fungi inoculation among the treatments had the highest positive effect on leaf dry weight and glycoside carbohydrates in stevia plants
ABSTRACT
Background: According to the importance of Stevia rebaudiana that it's sweetener steviol glycosides, has been introduced in recent year as a natural alternative for saccharose, the evaluation of bio-fertilizers effects on growth and development of stevia is necessary
Objective: In this research the effect of vermicompost and mycorrhiza on growth traits and steviosid [ST] content in Stevia rebaudiana was studied
Methods: This research was conducted in faculty of agriculture of Tarbiat Modarres University, Tehran, Iran, through a factorial experiment based on randomized complete block design with 12 treatments and 3 replications. The first factor was different levels of vermicompost [0, 10% and 20%] in basal medium including garden soil + 15% by weight Cow manure and also garden soil alone as a control treatment. Second factor was mycorrhiza fungi including inoculation Glomus mosseae and Piriformospora indica and treatment of non-inoculated plants.
Results: The bio-fertilizers had significant effect [P and le;0.01] on the studied parameters. The maximum amount of growth parameters [chlorophyll content, and fresh and dry weight of aerial parts and root] was obtained treatment of 20% of vermicompost and Glomus mosseae inoculation. The highest content of steviosid was obtained in end of vegetative growth stage and control treatment
Conclusion: Application of vermicompost significantly improved the chlorophyll content and growth traits and also the highest their amounts were obtained in combination treatment of vermicompost and mycorrhizal inoculation
ABSTRACT
Thymus daenensis is on e of the endemic aromatic species in Iran that its essential oil is used in food and pharmaceutical industries. In this study, the effects of plant growth stages and distillation methods on essential oil content and thymol percentage of this species were evaluated. The aerial parts of Th. daenensis were collected in three stages of plant growth from Tehran province of Iran. The plant materials were dried in shade and their essential oils were isolated by hydro-distillation in three replications. In addition, the essential oils of plant materials at full flowering stage were obtained by hydro-distillation, water and steam distillation and steam distillation. The essential oils were analyzed by capillary GC and GC/MS. The result showed that the different plant growth stages and distillation methods had significant effect on essential oil content. The highest essential oil content was obtained at full flowering stage [2.28% w/w]. Among distillation methods, the highest essential oil content was obtained by hydro-distillation [2.27%] that was significant difference with other distillation method. There was no significant difference between essential oil composition at different plant growth stages. Also, thymol, p-cymene and y-terpinene were the main components. The highest percentage of thymol was obtained by hydro-distillation. Generally, it can be concluded that harvesting of Th. daenensis at full flowering stage and extraction of its essential oil by hydro-distillation were more suitable for obtaining the higher oil content and thymol percentage
ABSTRACT
Taxol is used to treatment of variety cancers including ovarian, breast, lung, head and neck carcinomas and the AIDS-related Karposi's carcinoma, and was originally obtained from bark of taxus brevifolia. However the amount of extracted taxol from taxus is extremely low and cannot be considered as a suitable commercial source and it has led to studies for finding new sources of Taxol. In 1998, Angela Hoffman and her team reported that hazel could be as a taxol-producing species and it has been confirmed by recent studies. On the other hand, the genes and enzymes involved in taxol biosynthesis pathway in taxus sp. have been identified and characterized but because of very slow growth and difficult somatic embryogenesis, manipulation of taxus is restricted. Instead, hazel with widely contribution in the world, easy invitro culture and characterization of some genes involved in the pathways of MVA and DXP [such as HMGR, IPI and GGPP], makes possibility of manipulation of taxol biosynthesis pathway. In this paper we reviewed a summary of genetic and biotechnology studies on hazel
ABSTRACT
As application of chemical fertilizers has been recognized to cause pollution soil, water and agricultural products, today bio-fertilizers are an alternative to mineral fertilizers for increasing soil productivity and plant growth in sustainable agriculture. To determine the effects of biological and chemical fertilizers on qualitative and quantitative yield of Shirazian Babooneh [Matricaria recutita L.]. This study was done in a randomized complete block design with three replications and six treatments along 2009-2010. The treatments were A [Control or no applying fertilizer], B [Bio-fertilizer as Nitroxin+ 53 Kg/ha chemical fertilizer], C [Bio-Super nitro plus and Nitroxin + 35 Kg/ha chemical fertilizer], E [Bio-fertilizer as Bio-sulfur] and F [106 Kg/ha chemical fertilizer]. The fertilizer treatments had significant effects on plant height [p<0.05], plant dry weight [p<0.05], capitol diameter [p<0.01], fresh weight of capitol per ha [p<0.01], dry weight of capitol per ha [p<0.05], essential oil yield per ha [p<0.01], chamazulene content [p<0.01] and total flavonoid content [p<0.01]. The chemical fertilizer had not significant effect on qualitative and quantitative yield of Shirzian Babooneh and the lowest qualitative and quantitative yield of Shirazian Babooneh was related to control [A] and chemical fertilizer [F] treatments. Although, the application of bio-fertilizers significantly increased the yield in respect of all studied parameters, the highest dry weight of capitol and content of essential oil were observed in biosulfur [E] treatment. The application of the bio-fertilizers increased qualitative and quantitative yield of Shirazian Babooneh and Bio-sulfur treatment was the best treatment. Also, the application of the bio-fertilizers can be in order to reduction in application of chemical fertilizers in agro-ecosystem which is attitude toward minimize of environmental pollution and sustainable agriculture
ABSTRACT
The study of allelopathic properties of plants is one of up-to-date biological and ecological methods, which can lead to discover the bio-herbicides and growth inhibitors. In order to study the allelopathic effects of harmal [Peganum harmala L] on seed germination and seedling growth on purslan [Portulaca oleracea L.] and black weed [Chenopodium album L.], these experiments were conducted. The aqueous extracts of harmal different organs including capsule, leaf, stem and root were applied at five concentration levels [0 as control, 1, 5, 10 and 15%] through a factorial experiment based on a completely randomized design with three replications. The results showed that different organ extracts had different negative effects on seed germination and seedling growth of the two species in such a way that capsules extracts had the highest inhibitory effect. With increasing extract concentrations of harmal, the seed germination and seedling growth of the two species was reduced significantly. The minimum amount of seed germination and growth of the seedlings were observed at 15% extracts concentration of capsules. Also, purslan seedlings appeared to be more sensitive to harmal extracts than black weed seedlings. The aqueous extracts of harmal different organs had inhibitory effects on seed germination and seedlings growth of purslan and black weed. Also, the highest inhibitory effects were related to capsule extracts