نشریه تحقیقات بذر
پیاپی 45 (زمستان 1401)

In order to investigate the effect of gibberellic, ascorbic, salicylic acid pretreatments on the germination of Lolium prenne L., Lolium rigidum Gaudin species. An experiment was designed in the laboratory of the Caspian Forest Seed Center. This research was conducted with the treatment of gibberellic acid with concentrations of 125, 250 parts per million for 24 hours and ascorbic acid with concentrations of 100, 200, 300 mg/liter and salicylic acid with concentrations of 200, 300, 400 mg/liter for a period of 24 hours. The time was 12 hours in the form of a completely random design with 3 repetitions. In addition, distilled water was considered as control treatment. In this experiment, traits such as germination percentage, germination speed, germination value and seed germination index were evaluated. The results of analysis of variance and mean comparison showed that there is a significant difference between the treatments in terms of germination percentage, germination speed, germination value and germination index at the level of 1% and priming increases the germination percentage and germination speed. , germination value and germination index. As a result, gibberellic, ascorbic, and salicylic acid treatments as suitable pretreatments significantly increased the seeds of Lolium rigidum Gaudin species. and Lolium prenne L. are in the germination stage, and ascorbic acid treatment at a concentration of 300 mg/liter caused better germination compared to other treatments.

Sunn hemp (Crotalaria juncea) is an allelopathic cover crop used for the physical control of weeds. In order to investigate the effect of Sunn hemp formulated extract with chitosan nanoparticles on the germination of some weeds, an experiment was carried out in 2021 at the Faculty of Agriculture and Natural Resources of Mohaghegh Ardabili University with three replications. The experimental treatments included weed species wild mustard (Sinapis arvensis L.) and pigweed (Amaranthus retroflexus) and extract concentration as zero (distilled water), 150 and 200 g/L. The results showed that Sunn hemp formulated extract with chitosan nanoparticles affected the germination percentage and related components in weed seeds. Also, the results indicated that with the increase in concentration (150 and 200 g/L respectively) the germination percentage of wild mustard seeds (20 and 44%, respectively) and pigweed seeds (6 and 12%, respectively) decreased compared to zero concentration. The results demonstrated that the wild mustard weed seed was more affected compared to the pigweed. Pearson's analysis showed a negative and significant effect of germination on time up to 25, 50 and 75%, mean germination time, and germination index. It also showed the positive and significant effect of germination on the coefficient of the velocity of germination, peak value, and germination value. The results emphasize the effect of Sunn hemp extract formulated with chitosan at a concentration of 200 g/L on the reduction of germination and its related components in wild mustard seeds.

The use of seed priming methods has been introduced today as one of the factors to increase the germination and establishment of seedlings and plant under adverse environmental conditions, especially salinity. Therefore, in this study, the effect of seed priming with gibberellic on germination and consumption of triticale seed storage materials under salt stress conditions was investigated. The experimental treatments in this study were 5 levels of salinity stress (zero, 40, 80, 120 and 160 mM) and 4 levels of seed priming (zero, 25 and 50 ppm gibberellic acid and control seed without prime) with 3 replications. The results showed that the highest percentage of germination (95.33%), germination index (41.65 seeds per day), seedling length (19.27 cm) and the percentage of normal seedling (95.33%) was related to seed priming with gibberellic acid 50 ppm. Also, the highest seed vigor index (1836) was related to seed pretreatment with 50 ppm gibberellic acid. In all the applied salinity levels, the highest weight of mobilized seed reserve was obtained from seed priming with 50 ppm gibberellic acid. The highest seed reserve utilization efficiency from control seeds at 160 mM potential and the highest seedling dry weight and seed reserve depletion percentage in nonstressed conditions were obtained from seed priming with 25 and 50 ppm gibberellic acid. Seed germination improves triticale germination components under salinity stress conditions and increases the plant's tolerance to salinity against salinity stress in the germination stage.

In order to investigate the germination of Rye weed (Secale cereale L.) under the influence of Russian knapweed (Acroptilon repens L.) aqueous and formulated extracts with chitosan, an experiment was conducted as a factorial based on a completely randomized design with three replications in the Agricultural and Natural Resources Faculty laboratory of the University of Mohaghegh Ardabili in 2017. Experimental treatments included the type of extract (Russian knapweed aqueous extract and its formulated extract with chitosan) and seven concentrations of zero (Control), 0.625, 1.25, 2.5, 5, 10, and 20%. The results indicated that rye germination and its related components were significant at the (P≤1%). The formulated Russian knapweed extract at a concentration of 0.625 caused a 15.17% increase in plumule length compared to the control treatment, and the concentrations of 5 and 10% of the formulated extract caused 100% control of the plumule and radicle length compared to the control treatment. The concentration of 0.625 of Russian knapweed aqueous extract was the lowest (10 %) and the concentration of 5 and 10 of the extract formulated with chitosan was the highest (100 %) showed a decrease in the plumule, radicle, and seedling fresh weight compared to the control treatment. Also, the concentrations of 5 and 10 formulated extracts of Russian knapweed reduced 100% plumule, radicle, and seedling dry weight. Increasing the concentration of both types of extract increased the inhibition potential of germination so that in concentrations of 10 and 20% Russian knapweed extract, and formulated extract with chitosan, a significant reduction in rye germination was recorded. Aqueous and formulated extracts of Russian Knapweed with chitosan in concentrations of 10 and 20% are recommended for controlling Rye weed germination in laboratory conditions.

water deficit stress during growth and flowering is one of the most major environmental constraints, which influences seed grain filling and consequential germination and early growth stages of plants. In this study, the impact of foliar application of micronutrients (control, Fe, Zn, Fe + Zn, nano- Fe, nano- Zn, nano- Fe + nano- Zn) on quinoa at 2 reproductive stages (50% and 100% of flowering stage) were evaluated under 2 levels of water deficit stress, control (-0.03±0.045) bar and water deficit stress (-9±0.045) bar. The results showed that germination traits including percentage, rate, mean germination time, germination uniformity, seedling length and weight index as well as chlorophyll and carotenoid content were significantly affected by micronutrient foliar application, foliar application time and water deficit stress. water deficit stress decreased the percentage and rate of germination and seedling indices, but foliar application of micronutrients reduced the adverse effects of foliar application of micronutrients. Foliar application of micronutrients also increase the amount of photosynthetic pigments. The findings of this research show that foliar spraying with nutrients, especially nano-iron + nano-zinc, increases the germination indices to improve the germination and growth of quinoa seedlings under water stress conditions.

To investigate the effect of spermidine on the cold tolerance of cucumber cultivar ‘Rashid’ in completing germination stage, an experiment was conducted using a completely randomized design with 4 replications and 4 treatments consist of different concentrations of spermidine (0, 0.1, 0.5 and 1 mM) in Incubator of College of Agriculture, Isfahan University of Technology. So seeds were exposed to 20°C for two days and then treated with spermidine, the remaining 13 days they were kept at 15, 13, 11 or 9°C. To compare the effects of temperature and its interactions with the hormone, data of four experiments analyzed as a split-plot experiment (four different temperatures as four main plots and four spermidine concentrations as four subplots). At the end of each experiment characteristics consist of length of shoot and root, fresh and dry weight of shoot and root and ion leakage of shoot and root were measured. The findings of this study showed that the application of spermidine in low concentrations was more effective than high concentrations for controlling chilling injury. Also in most cases, concentrations of more than 0.5 mM spermidine demonstrated inhibitory effect on measured characteristics. By reducing the temperature in this stage, most of the growth characteristics reduced, significantly. Significant interactions between hormone concentrations and temperatures were observed on shoot and root length, and root fresh weight. Overall, 0.5 mM spermidine is recommended to reduce the negative effects of chilling injury on the germination of cucumber seeds.