جستجوی مقالات مرتبط با کلیدواژه "seed dormancy" در نشریات گروه "اکولوژی"

Parkinsonia aculeata is a valuable medicinal plant in traditional medicine that is more adapted to tropical and subtropical arid regions and planted as an ornamental plant. Since, seed germination of P. aculeata does not occur easily, the current research was performed to test different dormancy breaking treatments on germination characteristics of P. aculeata.

The studied treatments included scarification with sandpaper, H2SO4 (98%), KNO3 (0.2%), soaking the seeds in 90 °C hot water for 15 minutes, Gibberellic acid (250, 500 and 100 ppm), leaching (placing the seeds in running water for 48 hours), combination of leaching treatment with KNO3, and combination of leaching treatment with Gibberellic acid (250, 500 and 100 ppm). To compare the results, distilled water was considered as control treatment. A Completely Randomized Design (CRD) was made with 13 treatments and 4 replications.

Results showed that there were significant differences between treatments on germination percent, germination speed, length of root, length of shoot and length of seedling and index of seed vigor (p<0.01). The seeds had more than 85% dormancy and applying leaching (germination percent, 75%) and scarification treatments (70%) as well as boiling water (57.5%) had the highest effect on releasing the seed dormancy compared to control (15%).

Since, one of the establishment problems of this plant is the seed dormancy period, using leaching for 48 hours will help in germination improvement of P. aculeata.

Germination is a critical stage in the life cycle of plants and often controls population dynamics, with major practical implications. Salsola arbusculiformis is one of the most important plants used to prevent soil erosion and a good fodder resource for sheep and goat in the rangelands of Iran. However, the species seems to have low seed germination, so the purpose of this study was to investigate the effects of different treatments to improve its seed germination. Three concentrations of gibberellic acid (100, 500 and 1000 ppm), mechanical scarification with sandpaper, concentrated sulphuric acid (H2SO4 (98%)), potassium nitrate (KNO3 (0.2%)), thiourea one Molar, four prechilling periods (10, 20, 30 and 150 days at 2 °C) were used as study treatments and distilled water as control. The results showed that there were significant differences (p<0.05) among and within the treatments in their effects on seed germination. The effective treatments to stimulate seed germination were prechilling for 150 and 30 days; sulphuric acid and sandpaper scarification. Prechilling for 150 and 30 days increased germination by 88.4% and 85.65%, respectively, while sulphuric acid and sandpaper scarification both increased germination by 76.1% compared to the control. The results also showed that gibberellic acid, potassium nitrate and thiourea did not promote seed germination. It was inferred that the most effective treatments among the methods used for breaking seed dormancy of Salsola arbusculiformis were prechilling for 150 days and mechanical scarification by hand with sandpaper.