Univrsity of Tehran Press Iranian Journal of Field Crop Science 2008-4811 56 4 2025 12 22 Response of Germination Characteristics in Different Cleavers (Galium tricornutum) Populations to Stratification Methods Response of Germination Characteristics in Different Cleavers (Galium tricornutum) Populations to Stratification Methods 121 132 105084 10.22059/ijfcs.2025.384809.655110 FA Pooran Fathi Dept. of Crop Production and Genetic Faculty of Agriculture, University of Kurdistan Sanandaj, Iran. 0009-0005-6861-1566 Iraj Tahmasebi Dep of crop protecture and genetic, factuly of agriculture, university of kurdestan, sanandaj, Iran. 0000-0002-1368-5788 Iraj Nosrati Dept. of Plant Production and Genetics, Razi University, Kermanshah Iran. 0000-0002-2703-8418 Sirwan Babaei Dept. of Crop Production and Genetic Faculty of Agriculture, University of Kurdistan Sanandaj, Iran. 0000-0001-5084-2140 Journal Article 2024 12 11 Introduction. Galium tricornutum is one of the most damaging weeds in wheat fields across the world. This plant reproduces through seeds, which are dormant and it has been proven that the degree of dormancy varies in different ecotypes collected from various environment. stratification is one of the common methods for overcoming seed dormancy in is G. tricornutum. Research has shown that G. tricornutum seeds have primary dormancy in which exposing seeds to low winter temperatures and favorable humidity in the spring may lead to breaking seed dormancy and germination. Hence, the aim of this study was to determine the efficacy stratification can be effective in removing the seed dormancy of G. tricornutum collected from western parts of Iran. Materials and Methods. Seeds of G. tricornutum were collected from infested fields of some areas located in three provinces, including Western Azerbaijan (Heydarlu, Nazlu, Silvaneh), Kurdistan (Zafaraabaad, Saral, Gazneh, Sou, Kamyaran, Najafabad), Kermanshah (Kuzaran, Ravansar, Gilane-Gharb, Kermanshah), and Ilam (Abdanan, Sheshdar, Chovar, Ilam, Sarabeleh, Eyvan). After harvesting seeds, the presence of dormancy was confirmed in all ecotypes. The minimum and maximum time required for stratification to mitigate seed dormancy was also determined. Cold stratification treatments were applied at 4°C at 24, 48, and 72 hours. To apply hot-cold stratification, the same procedure was followed as for cold stratification, except that first, hot water at 80 degrees was used for three minutes. Finally, germination percentage, germination rate, germination index, and average germination time were measured. Results and Discussion. The results of this study showed that the highest germination percentage was related to treatments of three minutes at 80 and immediately expose to 4 degrees Celsius for 72 hours in Gazneh from Kurdistan province (83%) and Abdanan from Ilam province (77%). Although Gazneh had the highest altitude among the studied areas, it was also one of the areas having the highest precipitation, and Abdanan was also one of the low-altitude areas with high temperature and rainfall, but its altitude was lower than other screened areas. Stratification had the greatest effect on the populations of Gilane-Gharb (60.48%), Gazneh (52.44%), and Abdanan (47.43%), respectively. Although the altitude of Gazneh is different from that of Gilane-Gharb and Abdanan, all three regions had an average rainfall of 320-530 mm and a temperature of 15-30 degrees Celsius higher than the other studied regions. The lowest germination percentage was observed in the Kuzran (9%) and Najafabad (11.71%) populations, which had the lowest average rainfall (160-220 mm) and average temperature (10-15°C). The populations of Kamyaran, Zafarabad, and Ivan did not differ significantly from each other. This is despite the fact that the altitude of Kamyaran and Ivan regions is close to each other, but Zafarabad is higher. These regions were also similar in terms of temperature and rainfall during the growing season. The highest germination rate was related to treatments of three minutes at 80 and immediately at 4 degrees Celsius for 72 hours in Gazneh from Kurdistan (20.23) and the lowest germination rate was achieved in the Najafabad seed population. There was significant difference in germination index among stratification treatments. The highest germination index was for Gazneh (9.38) and the lowest was for control treatment of Najafabad and Silvaneh (0). The highest means germination time was check of Silvaneh (non-treated) (12.86) and the lowest rate was related to treatments of three minutes at 80 and immediately at 4°C for 72 hours in Silvaneh (0.03) and control treatment in Njafabad (0.04). Conclusion. Appropriate timing is necessary to control this weed without chemical methods. Chilling generally increased the germination of this species; therefore, the appropriate timing for controlling this plant species is early spring because natural chilling occurs in the fall and winter, and germination will occur in the spring with moisture. By stimulating seed germination using weed control methods, newly germinated G. tricornutum seeds can be removed from the field before they compete with the crop using low-cost methods such as shallow plowing. The success rate of this timing varies due to the different sensitivity of seeds in each region to chilling, but it will have a positive effect in all regions studied. Research on this species are usually time-consuming due to seed dormancy, and researchers may not be very interested in studying this species for this reason. Therefore, a low-cost method that can break seed dormancy in a short period of time would be of great help to researchers. Introduction. Galium tricornutum is one of the most damaging weeds in wheat fields across the world. This plant reproduces through seeds, which are dormant and it has been proven that the degree of dormancy varies in different ecotypes collected from various environment. stratification is one of the common methods for overcoming seed dormancy in is G. tricornutum. Research has shown that G. tricornutum seeds have primary dormancy in which exposing seeds to low winter temperatures and favorable humidity in the spring may lead to breaking seed dormancy and germination. Hence, the aim of this study was to determine the efficacy stratification can be effective in removing the seed dormancy of G. tricornutum collected from western parts of Iran. Materials and Methods. Seeds of G. tricornutum were collected from infested fields of some areas located in three provinces, including Western Azerbaijan (Heydarlu, Nazlu, Silvaneh), Kurdistan (Zafaraabaad, Saral, Gazneh, Sou, Kamyaran, Najafabad), Kermanshah (Kuzaran, Ravansar, Gilane-Gharb, Kermanshah), and Ilam (Abdanan, Sheshdar, Chovar, Ilam, Sarabeleh, Eyvan). After harvesting seeds, the presence of dormancy was confirmed in all ecotypes. The minimum and maximum time required for stratification to mitigate seed dormancy was also determined. Cold stratification treatments were applied at 4°C at 24, 48, and 72 hours. To apply hot-cold stratification, the same procedure was followed as for cold stratification, except that first, hot water at 80 degrees was used for three minutes. Finally, germination percentage, germination rate, germination index, and average germination time were measured. Results and Discussion. The results of this study showed that the highest germination percentage was related to treatments of three minutes at 80 and immediately expose to 4 degrees Celsius for 72 hours in Gazneh from Kurdistan province (83%) and Abdanan from Ilam province (77%). Although Gazneh had the highest altitude among the studied areas, it was also one of the areas having the highest precipitation, and Abdanan was also one of the low-altitude areas with high temperature and rainfall, but its altitude was lower than other screened areas. Stratification had the greatest effect on the populations of Gilane-Gharb (60.48%), Gazneh (52.44%), and Abdanan (47.43%), respectively. Although the altitude of Gazneh is different from that of Gilane-Gharb and Abdanan, all three regions had an average rainfall of 320-530 mm and a temperature of 15-30 degrees Celsius higher than the other studied regions. The lowest germination percentage was observed in the Kuzran (9%) and Najafabad (11.71%) populations, which had the lowest average rainfall (160-220 mm) and average temperature (10-15°C). The populations of Kamyaran, Zafarabad, and Ivan did not differ significantly from each other. This is despite the fact that the altitude of Kamyaran and Ivan regions is close to each other, but Zafarabad is higher. These regions were also similar in terms of temperature and rainfall during the growing season. The highest germination rate was related to treatments of three minutes at 80 and immediately at 4 degrees Celsius for 72 hours in Gazneh from Kurdistan (20.23) and the lowest germination rate was achieved in the Najafabad seed population. There was significant difference in germination index among stratification treatments. The highest germination index was for Gazneh (9.38) and the lowest was for control treatment of Najafabad and Silvaneh (0). The highest means germination time was check of Silvaneh (non-treated) (12.86) and the lowest rate was related to treatments of three minutes at 80 and immediately at 4°C for 72 hours in Silvaneh (0.03) and control treatment in Njafabad (0.04). Conclusion. Appropriate timing is necessary to control this weed without chemical methods. Chilling generally increased the germination of this species; therefore, the appropriate timing for controlling this plant species is early spring because natural chilling occurs in the fall and winter, and germination will occur in the spring with moisture. By stimulating seed germination using weed control methods, newly germinated G. tricornutum seeds can be removed from the field before they compete with the crop using low-cost methods such as shallow plowing. The success rate of this timing varies due to the different sensitivity of seeds in each region to chilling, but it will have a positive effect in all regions studied. Research on this species are usually time-consuming due to seed dormancy, and researchers may not be very interested in studying this species for this reason. Therefore, a low-cost method that can break seed dormancy in a short period of time would be of great help to researchers.

https://ijfcs.ut.ac.ir/article_105084_14058c8dd61969906eee6ecedc7769fb.pdf