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Stevia rebaudiana Bert. is a medicinal plant used as a calorie-free sweetener due to the presence of steviol glycosides in its leaves. The present study evaluated morphological, biochemical, and molecular changes of stevia under salicylic acid (SA) elicitors (0, 25, 50, 75 and 100 µM) and yeast extract (YE) (0, 1, 2, 3 and 5 g/L) under in vitro conditions. The results showed significant effects of elicitors on morphological traits and photosynthetic pigments of stevia. The highest morphological traits were observed at 25 µM and control treatments of SA and YE respectively. On the other hand, increasing the concentrations of both elicitors resulted in lowered morphological traits. In general, plants treated with YE showed lowered growth, with the concentration rise lowering the growth further. HPLC results showed an increase in steviol glycosides content in 50 µM SA and 2 g/L YE treatments and then the highest amount of stevioside and rebaudioside A was at concentrations of 25 µM and 3 g/L. Investigation of expression levels of four genes (KA13H, UGT74G1, UGT76G1, and UGT85C2) indicated that the highest rate of expression occurred at the concentrations of 50 µM SA and 2 g/L of YE. While, control treatment had the lowest levels expression of the studied genes in both elicitors, which indicates the significant effect of elicitors compared to the control. These results demonstrate the significant effect of SA and YE at medium concentrations on levels of expression of key genes of biosynthetic pathway as well as the production of stevioside and rebaudioside A. Thus, this approach could be employed to elevate the steviol glycosides' levels under in vitro conditions. [ABSTRACT FROM AUTHOR]

In recent years, cultures of algae were developed for both wastewater treatment and bio-fuel production. In this research, green microalgae Chlorella vulgaris were applied for bioremediation of an Iranian petrochemical wastewater samples. The efficiency of C. vulgaris and nonionic surfactants were examined in laboratory scale for elimination of COD, BOD, Total Nitrogen (TN), Total Phosphors (TP), and total petroleum hydrocarbons (TPH). In the preliminary study, the growth of the algae were monitored in pure as well as 25%, 50% and 75% diluted wastewater samples The effectiveness of two surfactants of Tween 20 and Tween 60 were investigated in 15 day experiments. Removal of all parameters was significantly increased using surfactants. Nitrogen and Phosphors removal were observed in all experiment up to 100%. Maximum TPH degradation of 27% was observed by Tween 60 compare to 10% for control sample. Hence, using Chlorella vulgaris and surfactants can be recommended for treatment of wastewaters from petroleum industries. [ABSTRACT FROM AUTHOR]

Tan spot is a destructive foliar disease of wheat caused by the fungal pathogen Pyrenophora tritici-repentis. Recently, tan spot has become a serious problem in the northern parts of Iran, where it causes severe yield losses. The objective of this study was to identify the physiological races of P. tritici-repentis in Iran, and to test isolates from this country for the presence of the toxin-encoding genes ToxA and ToxB. In total, 184 isolates were collected from two provinces, Golestan and Mazandaran, near the Caspian Sea. The virulence of 48 of these isolates was evaluated on four differential wheat genotypes. Race 1 was predominant and represented 90% of the tested isolates, while the remaining 10% were classified as race 2. No other races were identified. ToxA- and ToxB-specific primers were used in a PCR-based analysis to detect the presence of these genes in the Iranian isolates. The ToxA gene was amplified from all of the isolates evaluated, while no amplicon was obtained from any of the isolates with the ToxB-specific primers. The presence of ToxA and absence of ToxB is consistent with the race designation of the isolates. The ToxA sequence from 10 isolates selected, based on geographical origin, was found to be identical, and also shared 100% identity with other ToxA sequences from P. tritici-repentis in GenBank. This is the first study of the race structure of P. tritici-repentis in Iran. [ABSTRACT FROM AUTHOR]

Sunflower is one of the major annual world crops grown for edible oil and its meal is a potential source of protein for human consumption. It contains tocopherol that decreases potential risk of chronic diseases in human. The objectives of the current research are to assess the genetic variability and to identify AFLP markers and candidate genes associated with seed-quality traits under well-irrigated and water-stressed conditions in gamma-induced mutants of sunflower. Two mutant lines, M8-826-2-1 and M8-39-2-1, with significant increased level of oleic acid were identified that can be used in breeding programs for quality increase high oxidative stability and heart-healthy properties. The significant increased level of tocopherol in mutant lines, M8-862-1N1 and M8-641-2-1, is justified by observed polymorphism for tocopherol pathway-related gene; MCT. The most important marker for total tocopherol content is E33M50_16 which explains 33.9% of phenotypic variance. One of the most important candidate genes involving fatty acid biosynthesis, FAD2 ( FAD2- 1), is linked to oleic and linoleic acids content and explained more than 53% of phenotypic variance. Common markers associated with different seed-quality traits in well-irrigated and water-stressed conditions could be used for marker-assisted selection (MAS) in both conditions. Other markers, which are specific for one condition whereas linked to different traits or specific for a trait, could be useful for a given water treatment. [ABSTRACT FROM AUTHOR]

The article reports on the study which investigates the variations in essential oil content and composition of Ferula gummosa collected from different parts of Iran. The study showed that the samples from tropical regions showed better percentage and type of flavoring combinations than samples from cold regions. It is indicated that the samples from different regions but the same altitude showed different compositions, reflecting the genetic variability.