Jointvetch (Aeschynomene spp., Fabaceae) is considered a problematic broadleaf weed for rice production in Brazil, the United States, and Asia. Seed dormancy is particularly important for the perpetuation of annual weeds, representing the only link between different generations and thus the source of all future weed infestations. Seed dynamics in annual species are complex and related to many biotic and abiotic factors. The objectives of this study were to determine whether dormancy occurs in Aeschynomene denticulata and Aeschynomene indica seeds, and, if so, what is the most efficient method to break it. In addition, the persistence of seeds in soil also was investigated for both species. Three experiments were conducted, two in lab conditions and one in field conditions. The first experiment consisted of germination tests conducted in controlled conditions to determine whether seeds have dormancy. The second experiment tested the effectiveness of preheating, precooling, potassium nitrate, gibberellic acid, water soaking, chemical scarification, and mechanical scarification as dormancy breaking methods. Finally, the third experiment evaluated seedbank longevity for 1-year period in the rice-cultivated soil during which seeds were buried and recovered every 3 months. Variations in physical dormancy are present at different levels in both species due to seed-coat impermeability to water absorption. Meanwhile, A. denticulata can persist over a year in soil seed bank but A. indica seeds only persisted for half a year.

中文翻译：

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Aeschynomene denticulata 和 Aeschynomene indica 的种子动态

在巴西、美国和亚洲，荆芥（Aeschynomene spp., Fabaceae）被认为是一种用于水稻生产的有问题的阔叶杂草。种子休眠对于一年生杂草的延续尤为重要，代表不同世代之间的唯一联系，因此是所有未来杂草侵染的根源。一年生物种的种子动态很复杂，与许多生物和非生物因素有关。本研究的目的是确定Aeschynomene denticulata和Aeschynomene indica是否发生休眠种子，如果是这样，打破它的最有效方法是什么。此外，还研究了两种物种的种子在土壤中的持久性。进行了三项实验，两项在实验室条件下，一项在现场条件下。第一个实验包括在受控条件下进行的发芽测试，以确定种子是否具有休眠状态。第二个实验测试了预热、预冷、硝酸钾、赤霉酸、水浸泡、化学松土和机械松土作为打破休眠方法的有效性。最后，第三个实验评估了水稻栽培土壤中种子库的寿命为 1 年，在此期间，每 3 个月埋藏一次种子并回收一次。由于种皮对吸水的不渗透性，两种物种在物理休眠方面存在不同程度的差异。同时，A. denticulata在土壤种子库中可以存留一年以上，而A. indica种子只能存留半年。