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The objective of this study was to study the seed quality aspects of wheat (Triticum aestivum L.) and the extent of weed seed contamination present in wheat seeds produced in different regions of Iran. Four districts (cities), each including 12 fields (six certified seed fields and six farm-saved seed fields), were selected in each regions (provinces). One kilogram of the wheat seed sample was collected from each field for analysis in the laboratory. Wheat seeding was commonly done by farm-saved seed sourced from within the farm due to the high costs of certified seeds purchased from outside sources, followed by the low seed quality. The use of a farm-saved seed resulted in a higher germination rate and a lower mean time to germination compared with another system. The more positive temperatures experienced by mother plants could decrease the number of normal seedling and seedling length vigor index. Generally there was virtually no difference about physiological quality between certified seed and farm-saved seed sector that is related to lower quality of certified seed. The certified produced seeds had the lower number of weed seed, species and genus before and after cleaning. The highest seed purity and 1000 seed weight was obtained from the certified seed production system. The need for cleaning the farm-saved seed samples before sowing is one of the important findings of this survey. [ABSTRACT FROM AUTHOR]

Information regarding the evaluation of priming treatments on germination traits of Dracocephalum moldavica L. varieties is not available. Therefore, this assay was conducted during 2013 in Islamic Azad University of Sanandaj located in Kurdistan province of Iran. Twelve treatments resulted from a factorial combination of six priming method (factor A) and two varieties of moldavian dragonhead (factor B), arranged in a completely randomized design replicated three times. Factor A included 50 mg L-1 Salicylic acid (SA), 100 mg L-1 SA, 50 mg L-1 Ascorbic acid (AsA), 100 mg L-1 AsA, hydro-priming and control. Factor B included Kurdish landrace and SZK1 cultivar. Results showed that the highest and lowest emergence percentages were 90.1% in Kurdish SA50 and 52.8% in SZK1 AsA100 treatments, respectively. Hydro priming treatment increased the emergence rate index more than 100 mg L-1 SA, 100 mg L-1 AsA and control treatments. The highest shoot weight was 9.41 mg for Kurdish SA50 treatment and the lowest length, 1.24 mg was attributed to SZK1 control treatment. The highest (6.56 mg) and lowest (1.74 mg) radicle weight were observed in Kurdish-hydro-priming and SZK1-AsA100 treatments. The Kurdish landrace showed a favorable germination condition compared to SZK1 cultivar. [ABSTRACT FROM AUTHOR]

Salinity and water-deficit stress reduce yield in agricultural crops. On the other hand, seed germination is critical in seedling establishment and subsequent plant growth. Therefore, the present investigation was carried out to evaluate the effects of chitosan (Ch) concentrations (0% [control], 0.05%, 0.1%, 0.2%, 0.4%, 0.5%, 1%, 2%, and 3%) on the tolerance of safflower (Carthamus tinctorius L.) to different osmotic potentials (0, −0.4, −0.8, and −1.2 MPa). Induced osmotic potential significantly decreased germination percentage, germination index and rate, length and weight of root and shoot, and protein content. Proline content, malondialdehyde content (MDA), and catalase (CAT) and peroxidase (POX) activity increased when osmotic potential was increased to −0.8 MPa. Under unstressed conditions (0 MPa), there were no significant differences in germination percentage among different concentrations of chitosan, whereas MDA content, CAT, and POX activity were increased by low concentrations of chitosan (0.05%–0.4%). With increasing water-deficit stress, low concentrations of chitosan increased germination percentage but decreased MDA and proline contents and CAT and POX activity. Thus, it could be concluded that low concentrations of chitosan exhibited positive effects on water-deficit alleviation through the reduction of enzyme activity. Therefore, chitosan should be an effective biostimulator to enhance seedling growth and plant tolerance to oxidative stress conditions, especially under conditions of drought stress. [ABSTRACT FROM PUBLISHER]