Purpose Juniper (Juniperus procera) is a common forest tree species in Saudi Arabia. The decline in many populations of J. procera in Saudi Arabia is mainly due to seed dormancy and loss of natural regeneration. This study assessed the effects of chemical and hormonal treatments on seed germination and seedling growth in juniper plants. Methods The seeds were subjected to either chemical scarification with 90% sulfuric acid and 20% acetic acid for 6 min or hormonal treatment by seed soaking in two concentrations (50 and 100 ppm) of three growth regulators, namely, indole acetic acid (IAA), gibberellins (GA3), and kinetin, for 72 h. A control group without any seed treatment was also prepared. The experiments were performed in an incubator maintained at room temperature and under a light and dark period of 12 h for 6 w. The germinated seeds for each treatment were counted and removed from the dishes. The selected germinated seeds from different treatments were planted in a greenhouse and irrigated with tap water for another 6 weeks. The hormone-treated seedlings were sprayed with their corresponding hormone concentrations 1 w after planting. Results The highest percentage of seed germination was significantly recorded after seed soaking in 50 ppm GA3, whereas treatment with IAA (100 ppm) resulted in the best seedling growth. Seedlings treated with the three phytohormones showed a significant increase in photosynthetic pigments, total soluble sugars, proteins, percentage of oil, IAA, GA3, and kinetin contents of juniper seedlings compared with the control value, whereas abscisic acid content was decreased compared with chemical treatments. Conclusion The investigated different treatments had an effective role in breaking seed dormancy and improving seedling growth of J. procera, which is facing a notable decline in its population worldwide. Moreover, such an effect was more pronounced in the three phytohormones that succeeded in breaking dormancy and growth of the Juniperus plant than in the other treatments.

中文翻译：

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化学和激素处理对改善杜松种子萌发和幼苗生长的影响。前恩迪

用途 杜松 (Juniperus procera) 是沙特阿拉伯常见的森林树种。沙特阿拉伯许多 J. procera 种群数量的下降主要是由于种子休眠和自然再生能力丧失所致。这项研究评估了化学和激素处理对杜松植物种子发芽和幼苗生长的影响。方法用 90% 硫酸和 20% 乙酸对种子进行化学松土 6 分钟，或用两种浓度（50 和 100 ppm）的三种生长调节剂（即吲哚乙酸 (IAA)）浸泡种子进行激素处理。 、赤霉素 (GA3) 和激动素，持续 72 小时。还制备了未进行任何种子处理的对照组。实验在室温、明暗时间为12小时的培养箱中进行6周。对每次处理的发芽种子进行计数并从培养皿中取出。将不同处理选出的发芽种子种植在温室中，并用自来水再灌溉6周。定植后1周，对激素处理过的幼苗喷洒相应浓度的激素。结果 用 50 ppm GA3 浸泡种子后，种子发芽率最高，而用 IAA (100 ppm) 处理后，幼苗生长最好。 3种植物激素处理的杜松幼苗光合色素、可溶性总糖、蛋白质、含油率、IAA、GA3、激动素含量较对照显着增加，而脱落酸含量较化学处理下降。 。结论 所调查的不同处理对于打破麻雀种子休眠和改善麻雀幼苗生长具有有效作用，麻雀在全球范围内种群数量显着下降。此外，与其他处理相比，这种效果在成功打破杜松植物休眠和生长的三种植物激素中更为明显。