فهرست مطالب mohammad modaresi

The milkweed shrub, in addition to ecological functions, has special industrial and medicinal values. This plant is widely planted for afforestation in arid lands in the south of Iran. Regard to scarcity of fresh water, using of seawater as a vital and alternative source of water for irrigating of halophyte plants was suggested. Thus, the current research was carried out to investigate the efficiency of diluted seawater on seed germination, growth and physiology parameters of milkweed seedling. For this purpose, an experiment was conducted in completely randomized design with three replications in two separate experiments; in vitro and nursery, with different levels of diluted seawater i.e. 0, 12.5, 25 and 50% using saline meter. The results of seed germination test showed that germination parameters and seed vigor index significantly decreased by increasing seawater concentration to more than 12.5%. The results of nursery experiment revealed that concentrations of more than 25% of seawater significantly reduced growth performance and gas exchange of seedling. The survival rate 55%, height 19.9 cm, specific leaf area 190.7 g/cm2 and root length 22.54 cm as well as photosynthesis rate 2.83 µmol, transpiration rate 0.42 mmol, chlorophyll 20.45% and relative water content 43.95% were observed in 25% seawater treatments. It is recommended that researchers conduct a broader study of the salinity-tolerant physiology of this valuable medicinal plant to obtain more comprehensive information for afforestation programs.

Present study was conducted to find out the effect of arbuscular mycorrhizal fungi Glomus intraradices and the plant growth promotion rhizobacterium Pseudomonas putida inoculant on the concentration of macro and micro elements and seedling quality indices of Calotropis procera seedlings in a completely randomized design with three replications. The results of one way ANOVA showed that measured parameters of nutrients and seedlings quality index have been significantly influenced by the inoculation fungi and bacteria. The Duncan’s comparison of mycorrhizal inoculum than control in total root nitrogen concentration was 26%, iron concentration in leaves and root were 70% and 52% as well as potassium and zinc concentration in the leaf as of 5% and 45%, respectively that compared to the control has increased. Mean comparison of Rhizobacterial inoculation with control showed that total nitrogen, iron and manganese concentrations in the leaf were 57%, 450% and 225% respectively, and iron and zinc concentrations in the root increased 58% and 84%, respectively. According to thehe mean comparison of Duncan’s, mycorrhizal treatment with Rhizobacterial had increase in total nitrogen, potassium, iron and zinc concentrations in leaf by 51%, 48%, 450% and 31%. Nitrogen and potassium in the root were observed at 48% and 300%, respectively. Comparing seedlings quality indices, inoculated seedlings of the Rhizobacteria with the index of 0.85 were highest rate, which was 66% higher than the control. The results of this study indicated that inoculation of mycorrhizal and Rhizobacterial has increased in nutrient content and quality of seedlings. Despite the slight differences between inoculations, it is recommended to use both types of mycorrhizal and Rhizobacterial inoculum in order to replace the fertilization in the culture media in nursery.

Cyanobacteria have been considered due to producuction of types of secondary metabolites and antimicrobial compounds. This research designated for optimization of BG11 culture medium to increase the antifungal activity of Cyanobacterium sp. PGU1 against the plant pathogenic fungi, Fusarium oxysporum f. sp lycopersici and Rhizoctonia solaniAG2-2-IIIB. Cyanobacterium was isolated from the Persian Gulf and identified as Cyanobacterium sp. using morphological characteristics and 16S rRNA sequencing. Optimization was done by changing the amount of nitrogen (NaNO3) (0.75, 1.5 and 3 g/l) and phosphate (K2HPO4) (0.02, 0.04 and 0.08 g/l) and then the antifungal activity of cyanobacterium was investigated. Antifungal effects of pure culture methanol extract of cyanobacterium were investigated under in vitro conditions by mixing the extract derived from pure culture before and after optimization to the pathogen culture medium. Growth inhibition percentage for F. oxysporum f. sp. lycopersici and R. solani AG2-2-IIIB increased from 79.33 to 87.43, and from 82.47 to 90.62 percent, respectively.