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By identifying the factors that initiate seed dormancy release, we can reliably predict whether a seed will remain dormant within or exit the seed bank and become a seedling. With regard to annual weed species, assessing which factors efficiently break seed dormancy is critical for estimating the number of weed seeds that will develop into problematic weeds. To better understand dormancy breaking in Redroot pigweed (Amaranthus retroflexus), dormant seeds were treated with cold stratification (4°C for 30 days), application of gibberellic acid (at 500, 1000, 1500, and 2000 parts per million), ultrasound (for 10, 20, 30, and 40 min), soaking in hot water (90°C for 3, 5, 7, and 10 min), and 98% sulfuric acid (for 1, 2, and 3 min). The results showed that Redroot pigweed seed dormancy was effectively broken by cold stratification, gibberellic acid, and ultrasound. Short treatments with hot water had minimal effect while longer times or treatment with sulfuric acid stopped seed germination. In addition to germination percentage, germination rate, plumule length, radicle length, seedling length, seedling dry weight, and seed vigor index were also measured; similarly, application of gibberellic acid had the most significant effect on these parameters. The results of this study add to our knowledge of what processes effectively or ineffectively break Redroot pigweed seed dormancy and promote growth. [ABSTRACT FROM AUTHOR]

• The germination of cannabis treatments varied with landrace and treatments. • H 2 SO 4 , GA 3 , and KNO 3 enhanced the germination capacity of cannabis landraces. • Control produced vigorous seedlings compared dormancy-breaking pre-treatments. The current study evaluated the effectiveness of different pre-treatments for dormancy breaking and seed germination of five cannabis landraces. These landraces were collected from local growers in three regions of KwaZulu-Natal Province in South Africa, namely, Bergville (B), Hammersdale (H), and Ladysmith (L). Each genotype was assigned an alphabet and number based on where the seed material was collected. The five landraces were as follows, 'B1', 'K1', 'H1', 'L1', and 'L2'. The study was conducted using various pre-treatments, including potassium nitrate (KNO 3), hydrochloric acid (HCL), hot water (HW) at 70 °C, nitric acid (HNO 3), dry prechilling at 10 °C, gibberellic acid (GA 3), sulfuric acid (H 2 SO 4), and water, which served as the control. Before the germination test, the seed viability of cannabis landraces was assessed using the tetrazolium chloride (TCC) test. Afterward, the seeds were germinated in Petri dishes with cotton pads moistened with distilled water for five (5) days. The study was later validated under tunnel conditions. The parameters such as germination percentage, germination rate, seedling length, and seed vigour index of the germinated seeds were then measured. The landraces, dormancy breaking treatments, and their interactions showed significant differences (p < 0.001) in germination percentage, germination rate index, seedling length, and seed vigour index under both laboratory and tunnel conditions. In summary, GA 3 , KNO 3 and prechilling were the most effective pre-treatments to improve the germination and seedling growth of cannabis genotypes and breaking seed dormancy. Therefore, it was concluded that cannabis genotypes had physiological dormancy. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Seed germination in Melocactus and other cactus species is hampered by dormancy. However, most studies failed to achieve high seed-germination rates, suggesting a complex mechanism of dormancy in Cactaceae. Thus, the objective of this study was to evaluate whether factors such as light and phytoregulators overcome the dormancy in the seeds of the friar's crown cactus (Melocactus zehntneri). Two consecutive experimental sets were designed: one with seed germination under filter paper conditions and different wavelengths and Photosynthetically Photon Flux Densities (PPFDs); and one in vitro experiment using a culture medium to evaluate the influence of different phytoregulators, such as gibberellic acid (GA3), benzylaminopurine (BAP) and ethephon (ET), both in the germination of seeds of M. zehntneri. Seeds of M. zehntneri are positive photoblastic. Red light and gradual increases in PPFD resulted in the highest germination rates (60.8–61.7%) and germination speed index (4.4–4.5). In vitro seeding in culture media increased the germination percentage to 76% in control without phytoregulators. Ethephon showed a major effect in releasing the germination of dormant seeds of M. zehntneri, totaling 98% of seeds germinated under in vitro conditions, while GA3 and BAP showed minor or no effect on germination. The present study resulted in an efficient in vitro technique for germination and a better understanding of cacti seed dormancy. [ABSTRACT FROM AUTHOR]

Seeds establish dormancy to delay germination until the arrival of a favorable growing season. In this study, we identify a fate switch comprised of the MKK3–MPK7 kinase cascade and the ethylene response factor ERF4 that is responsible for the seed state transition from dormancy to germination. We show that dormancy-breaking factors activate the MKK3–MPK7 module, which affects the expression of some α-EXPANSIN (EXPA) genes to control seed dormancy. Furthermore, we identify a direct downstream substrate of this module, ERF4, which suppresses the expression of these EXPA s by directly binding to the GCC boxes in their exon regions. The activated MKK3–MPK7 module phosphorylates ERF4, leading to its rapid degradation and thereby releasing its inhibitory effect on the expression of these EXPA s. Collectively, our work identifies a signaling chain consisting of protein phosphorylation, degradation, and gene transcription , by which the germination promoters within the embryo sense and are activated by germination signals from ambient conditions. This study shows that the MKK3–MPK7 cascade positively regulates dormancy breaking by promoting the expression of some EXPA s, whereas ERF4 binds directly to the GCC boxes in the exons of EXPA s and suppresses their expression. During the dormancy-breaking process, the activated MKK3–MPK7 cascade phosphorylates ERF4 and promotes its rapid degradation, leading to release of its inhibitory effect on EXPA expression. [ABSTRACT FROM AUTHOR]

In order to study the dormancy characteristics of Osmanthus fragrans seeds and break dormancy to shorten the sowing and seedling raising cycle, in this study, Osmanthus fragrans var. thunbergii seeds were used as test materials to identify the dormancy types through the determination of water absorption and the effect of endogenous inhibitors on the germination of cabbage seeds. The dormancy breaking test was carried out by means of mechanical treatment, low-temperature sand storage, lanthanum nitrate, and GA3 soaking. The results showed that the water absorption of shelled seeds and scratched seeds were higher than that of intact seeds, indicating that the seed shell had a certain blocking effect on the water absorption of seeds. The germination rates of cabbage seeds cultured with seed shell and endosperm extract were significantly lower than that of the control. The extract had a significant inhibitory effect on the germination and elongation of cabbage seed roots, indicating that the seed shell and endosperm contained substances inhibiting the germination of cabbage seeds. In the single factor experiment, the seed shell scratching treatment, soaking seeds in 1 000 mg/L of GA3 and 30 mg/L of lanthanum nitrate solution for 48 h respectively, and low-temperature sand storage for 90 d had the most significant effect on breaking seed dormancy, and the seed germination rate was significantly higher than that of the control. In the comprehensive factor test, the germination rate(87.78%) was the highest in the treatment of GA3 1 000 mg/L + 50 mg/L of lanthanum nitrate + 5 ℃ sand storage for 60 d + seed scratching. The seed of Osmanthus fragrans var. thunbergii belonged to the type of compound dormancy. The main reason for dormancy was the physiological post ripening of embryos, which could be solved by GA3, lanthanum nitrate soaking and low-temperature stratification. The secondary reason was the mechanical obstruction of the seed shell, which could be solved by removing the seed shell and scratching the seed shell. [ABSTRACT FROM AUTHOR]

• Senna macranthera seeds are adapted to fire. • The heat and the aqueous extract of the smoke influence the seed dormancy break. • The gaseous smoke is lethal for seed germination. • Early dormancy breaking can reduce the vigor of buried seeds. Fire can trigger the germination of several forest species, as heat and smoke can break the dormancy of seeds buried in the ground. In this study, we applied heat, smoke and pyroligneous acid (PA) to dormant seeds of Senna macranthera (Fabaceae), a Brazilian Cerrado native tree, in order to evaluate the effect of forest fire triggers on its germination. We used dormant seeds soaked in distilled water, without the application of fire and smoke, as a control treatment. The test lasted seven days and root protrusion was used as a germination criterion. After this period, a viability test based on the longitudinal section was performed on the non-germinated seeds. The control germination after seven days was 0%, but the viability test confirmed that they were alive (integument swelling and green color cotyledons). There was a positive effect of fire on the germination of burnt seeds buried at a depth of 5 cm soaked in PA (14.0%), followed by burnt seeds buried at a horizon of 2 cm (11.2%) and those that were not soaked in PA (10.0%). Smoked seeds showed swelling of the tegument by the viability test, but they were dead, indicating that there was a negative effect (0%) of the gaseous smoke on germination. We conclude that the strong promotional effect of heat and liquid smoke (using PA) on dormancy breaking and seed germination of S. macranthera suggests that this species is fire-adapted. However, the gaseous smoke was lethal, revealing that this species has different responses depending on the type of trigger (heat or smoke) and fire conditions. [ABSTRACT FROM AUTHOR]

Seed germination in Melocactus and other cactus species is hampered by dormancy. However, most studies failed to achieve high seed-germination rates, suggesting a complex mechanism of dormancy in Cactaceae. Thus, the objective of this study was to evaluate whether factors such as light and phytoregulators overcome the dormancy in the seeds of the friar’s crown cactus (Melocactus zehntneri). Two consecutive experimental sets were designed: one with seed germination under filter paper conditions and different wavelengths and Photosynthetically Photon Flux Densities (PPFDs); and one in vitro experiment using a culture medium to evaluate the influence of different phytoregulators, such as gibberellic acid (GA3), benzylaminopurine (BAP) and ethephon (ET), both in the germination of seeds of M. zehntneri. Seeds of M. zehntneri are positive photoblastic. Red light and gradual increases in PPFD resulted in the highest germination rates (60.8–61.7%) and germination speed index (4.4–4.5). In vitro seeding in culture media increased the germination percentage to 76% in control without phytoregulators. Ethephon showed a major effect in releasing the germination of dormant seeds of M. zehntneri, totaling 98% of seeds germinated under in vitro conditions, while GA3 and BAP showed minor or no effect on germination. The present study resulted in an efficient in vitro technique for germination and a better understanding of cacti seed dormancy.

This research was carried out to determine the effects of germination temperature and 12 dormancy breaking applications on the germination of the seeds of the gum tragacanth (Astragalus gummifer Labill.) bush. The research was carried out in the Field Crops Department laboratory, Iğdır University Faculty of Agriculture, in 2019. Gum tragacanth seeds were germinated for 28 days in the dark at constant temperatures of 10, 15, 20, and 25 °C and variable temperatures of 20/10 °C, 20/15 °C, 25/10 °C, and 25/15 °C. As a result of the research, the highest total germination rate was determined at 10.7% at 25/10 °C and 25/15 °C temperatures. It was determined that there was 89.3% dormancy in gum tragacanth seeds. Then, 12 dormancy breaking methods (matrix priming, hydro priming, gibberellic acid (GA3, potassium nitrate, cold, moist stratification, warm moist stratification, warm+cold moist stratification, cold+warm moist stratification, cold water, hot water, mechanical scarification, and chemical scarification) were applied. After dormancy breaking applications were made, the seeds were germinated again at 25/15 °C. At the end of the study, it was revealed that the highest total germination percentage with 50.7% was obtained from the application of hot water for 2 minutes. On the other hand, it was determined that matric priming, hydro priming, gibberellic acid, potassium nitrate, cold, moist stratification, warm moist stratification, cold+warm moist stratification, mechanical scarification, and chemical scarification applications did not have any effect on removing the dormancy status of gum tragacanth seeds.

Copyright of Research in Agricultural Sciences is the property of Ataturk University Coordinatorship of Scientific Journals and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This research was carried out to determine the effects of germination temperature and 12 dormancy breaking applications on the germination of the seeds of the gum tragacanth (Astragalus gummifer Labill.) bush. The research was carried out in the Field Crops Department laboratory, Iğdır University Faculty of Agriculture, in 2019. Gum tragacanth seeds were germinated for 28 days in the dark at constant temperatures of 10, 15, 20, and 25 °C and variable temperatures of 20/10 °C, 20/15 °C, 25/10 °C, and 25/15 °C. As a result of the research, the highest total germination rate was determined at 10.7% at 25/10 °C and 25/15 °C temperatures. It was determined that there was 89.3% dormancy in gum tragacanth seeds. Then, 12 dormancy breaking methods (matrix priming, hydro priming, gibberellic acid (GA3, potassium nitrate, cold, moist stratification, warm moist stratification, warm+cold moist stratification, cold+warm moist stratification, cold water, hot water, mechanical scarification, and chemical scarification) were applied. After dormancy breaking applications were made, the seeds were germinated again at 25/15 °C. At the end of the study, it was revealed that the highest total germination percentage with 50.7% was obtained from the application of hot water for 2 minutes. On the other hand, it was determined that matric priming, hydro priming, gibberellic acid, potassium nitrate, cold, moist stratification, warm moist stratification, cold+warm moist stratification, mechanical scarification, and chemical scarification applications did not have any effect on removing the dormancy status of gum tragacanth seeds. [ABSTRACT FROM AUTHOR]

Field bindweed (Convolvulus arvensis L.) is one of the most harmful weeds in the world. It is a common and problematic perennial weed in many crops such as corn, sunflower, cotton, vegetables and orchards in Turkey. Field bindweed has strong seed dormancy and its germination is delayed. A good understanding of the mechanism of seed dormancy is important for plant reproduction and control of field bindweed. This study was carried out in laboratories in order to determine the dormancy breaking methods (sulfuric acid, gibberellic acid, hydrochloric acid, microwave, cold-hot applications) 20°C and 27°C seeds from the Malatya Province and germination temperatures of seeds from different ecological regions where are the Adana, Ankara, Canakkale, Denizli, Erzurum, Hatay, Karaman, Kayseri, Konya, Malatya, Samsun, Sanliurfa, Tekirdag and Usak Provinces. The highest dormancy breaking happened in sulfuric acid 60 or 120 min (20°C) and keeping seeds 5 s in 90°C hot water (27°C). It has been determined that at germination temperature is between 10-40°C depending on the provinces where it was collected. The highest germination rate (96.3%) was observed in seeds of Erzurum province at 20°C. While there was no germination at 2 and 45°C, the highest germination rate (80%) at 40°C was also observed in the seeds of Erzurum province. [ABSTRACT FROM AUTHOR]

By identifying the factors that initiate seed dormancy release, we can reliably predict whether a seed will remain dormant within or exit the seed bank and become a seedling. With regard to annual weed species, assessing which factors efficiently break seed dormancy is critical for estimating the number of weed seeds that will develop into problematic weeds. To better understand dormancy breaking in Redroot pigweed ( Amaranthus retroflexus ), dormant seeds were treated with cold stratification (4°C for 30 days), application of gibberellic acid (at 500, 1000, 1500, and 2000 parts per million), ultrasound (for 10, 20, 30, and 40 min), soaking in hot water (90°C for 3, 5, 7, and 10 min), and 98% sulfuric acid (for 1, 2, and 3 min). The results showed that Redroot pigweed seed dormancy was effectively broken by cold stratification, gibberellic acid, and ultrasound. Short treatments with hot water had minimal effect while longer times or treatment with sulfuric acid stopped seed germination. In addition to germination percentage, germination rate, plumule length, radicle length, seedling length, seedling dry weight, and seed vigor index were also measured; similarly, application of gibberellic acid had the most significant effect on these parameters. The results of this study add to our knowledge of what processes effectively or ineffectively break Redroot pigweed seed dormancy and promote growth., Competing Interests: The authors declare that they have no competing interests., (© 2023 The Authors. Food Science & Nutrition published by Wiley Periodicals LLC.)