JOURNAL OF PLANT ENVIRONMENTAL PHYSIOLOGY
Year:2013 | Volume:8 | Issue:2 (30)|Papers Count:8

The full text of this article is the Persian language, please for the view full text, refer to Persian Please click here to view the full text of this article

The full text of this article is the Persian language, please for the view full text, refer to Persian Please click here to view the full text of this article

Interactions between two plants affect their survival and establishment, therefore, the knowledge of these interactions can be useful for maintenance of the species, and rangelands management improvement. Since nurse species can be important factor to the rangeland plants population, they can be used in exploited areas. Thus, the role of nurse species was studied on palatable species of Sar-Aliabad (Gorgan province) rangeland, under three grazing conditions (overgrazing, open grazing and exclosure sites). In the first stage, in order to determine different grazing area around the grazing zone, 1´1m2 plots were systematically used in the four main directions. Then in each site, 40 plots have been systematic-randomly established and basal number of species per plots was recorded. The nurse species and related species were determined in each grazing areas and relationship between species have been measured in each site. Results indicated that Festuca ovina in all three grazing areas had positive and significant correlation with Astragalus verus. The correlation in overgrazing area was higher than exclosure and open-grazed areas. Therefore regarding that all rangelands in Iran have poor to medium condition, determination of nurse species and depended species can be useful for rangeland improvement programs and ecological management.

To investigate the effect of nitrogen, zinc and calcium on the vegetative and reproductive growth of strawberry (var. Selva), a factorial experiment was conducted based on completely randomized blocks with 27 treatments and three replications, at strawberry garden of Gorgan. Treatments were zinc sulfate at 0, 1000 and 2000ppm, calcium chloride at 0, 1000 and 1500ppm and at 0, 100 and 200ppm concentrations. Vegetative and reproductive growth indices including LAI, number of crown, yield and shelf life of fruit were measured. Results showed that the maximum LAI was related to 200ppm urea, 1000ppm calcium chloride and 2000ppm zinc sulfate. Concentrations of 100ppm urea, 1000ppm zinc sulfate and 1000ppm calcium chloride showed the greatest effect on the shelf life of the fruit. Results indicated that the maximum number of crown was related to 200ppm urea, 1500ppm calcium chloride and 1000ppm zinc sulfate groups. Concentrations of 200ppm urea, 1500ppm zinc sulfate and 1000ppm calcium chloride had the greatest effect on the fruit number. Concentration of 100ppm urea, calcium 1000ppm chloride and 1000ppm zinc sulfate have the greatest effect on fruit weight.

Considering the expansion of salty soils in Iran, identification and achievement of salt resistant species is led to increase in the crop yield and production. In this research, the saplings of Mentha pulegium L. were transferred from Chahardeh, Lahijan to Tehran and planted into vases under drip irrigation of 20-90 mM sodium chloride. Morphological and developmental characteristics of the plants' vegetation organs were examined. Results showed that increase in salt concentration resulted in the rim chlorose, leaves necrosis and growth suppression. In the plants received 65 mM NaCl, an adaptation was observed and the growth was return to the normal condition (similar to the control plants). Microscopic comparative observations showed that increase in the salt concentration, the thickness of the root metaxylem elements increased. Along with the salt concentration increase, the root secondary structure was raised sooner and the generative layer activity and the number of cell layers increased. Hydration was observed in the leaves as a result of increase in osmotic pressure. The thickness of phloem elements decreased at the higher salt concentrations; however, the thickness of phloem elements was approximately normal 65 mM salt concentration.

Increase in soil salinity is a major problem for fertility and growth of the plants in many regions of the world. cyanobacterium Anabaena sp. FS76 seems to be a potent strain regarding viability and nitrogen fixation ability under environmental fluctuations. Soil samples were collected from Golestan Province paddy-fields during one year. The soil samples were incubated and the bacteria were identified and isolated and placed into BG110 medium under light intensity of 2mE.m-2.s-1, 2oC and continuous white irradiation. A wide range of sodium chloride salinity (0, 5, 10, 15, 20, 25 and 30%) was tested. EC value was determined with EC meter to balance the salinities. Growth was measured using optical density. Chlorophyll and phycobiliproteins were extracted and measured using methanol and glycerol. Results showed that growth rate reached the maximum levels at 5% salinity, which was higher at the control (without salt) medium. Although, it can survive less than normal condition, under other salinities. Also, pigmentation showed higher values under these salinities. It seems that the salinity amelioration ability of this strain is significant specially under 0-5% salinity. The EC values showed a significant decrease during the experiment, in different salinity groups. The results of growth, pigmentation and salinity amelioration ability coincident with the other characteristics of this specimen show a potent candidate for future possible agricultural biotechnological purposes.

In this study, the effect of plant growth regulators was investigated on shoot and root explants of Polygonium bistorta terminal buds. The experiment was conducted as a completely randomized design using 1, 2 and 3 mg/L kinetin, 0.1, 0.2 and 0.3 mg/L BA and combination of BA (0.2, 0.3 and 0.4 mg/L) + NAA (0.1 and 0.2 mg/L), in MS culture medium with three replications. The plantlets were planted using the terminal buds growing method in the MS medium under appropriate light and temperature conditions. After one month, the plantlets reached a sufficient growth and were ready for rooting. In the second experiment, the propagated plantlets were subjected to 0.5, 1, 1.5 and 2 mg/L IBA for rooting based on a completely randomized design with 3 replications. After 45 days, the fully-rooted plantlets were transferred to a green house and planted in the vases and, thereafter, cultivation operations including irrigation, fertilization and spraying were carried out. Results showed that the use of growth regulators at different concentrations led to branch, root and leaf production in different sizes. 0.1 mg/L BA had the greatest effect on the production of shootings and leaves, while, the combination of BA+NAA had approximately the lowest effect. 0.5 and 1 mg/L IBA resulted in an increase in the root length, while 0.5 mg/L IBA affected the number of roots.

The full text of this article is the Persian language, please for the view full text, refer to Persian Please click here to view the full text of this article