Germination timing is highly regulated in short-lived plant species since it strongly influences recruitment success of vegetation. In deserts, the spatiotemporal distribution of plant-available water is highly episodic and unpredictable, making winter months more favorable for seed germination when other abiotic conditions co-occur. We hypothesized that changes in photoperiod and thermoperiod would impact germination more in seeds that had undergone in situ storage. We assessed 21 annual and short-lived perennial species in the Arabian Desert to find (1) if seeds were dormant at maturity, (2) if in situ seed storage increased germination percentage compared with no storage, (3) if photoperiod and thermoperiod germination requirements were influenced by in situ storage, and (4) if a phylogenetic association in seed germination could be observed. Seeds of each species collected in early 2017 were divided into two batches. One was tested for germination within one week (fresh seeds). The other was stored in situ at the maternal location (stored seeds) until October 2017 and tested for seed germination in the first week of November. Seed germination was conducted in incubators at two thermoperiods (15°C/20°C and 20°C/30°C; 12 h/12 h), and two photoperiods (12 and 0 h light per day). Results indicated that seed germination percentages of 13 species were significantly enhanced by in situ storage. A thermoperiod response was exhibited by stored, but not fresh seeds. Light exposure increased germination of fresh seeds but had only a minimal effect on stored seeds. Germination traits exhibited no phylogenetic correlation. This result indicated that selection pressure for germination strategy was stronger than that for taxonomic traits of these desert species.

短时植物物种的发芽时间受到高度调节，因为它会严重影响植被的募集成功。在沙漠中，植物可用水的时空分布是高度偶发性且不可预测的，因此当其他非生物条件同时发生时，冬季更有利于种子发芽。我们假设光周期和热周期的变化会对原位贮藏的种子发芽产生更大影响。我们评估了阿拉伯沙漠中的21个一年生和短命多年生物种，以发现（1）种子是否在成熟时处于休眠状态;（2）如果原地种子存储与没有存储相比增加了发芽率，（3）如果光周期和热周期萌发了需求受原地影响（4）是否可以观察到种子发芽中的系统发育关联。2017年初收集的每种物种的种子分为两批。测试一个在一周内的发芽率（新鲜种子）。另一种在母体位置原地储存（储存种子），直到2017年10月，并在11月的第一周进行种子发芽测试。在培养箱中在两个热周期（15°C / 20°C和20°C / 30°C； 12小时/ 12小时）和两个光周期（每天光照12和0小时）下进行种子萌发。结果表明，原位显着提高了13种种子的发芽率。存储。储存的种子表现出热周期反应，但没有新鲜的种子。光照增加了新鲜种子的发芽率，但对储存的种子影响很小。萌发性状没有显示系统发育相关性。该结果表明，发芽策略的选择压力强于这些荒漠物种的分类性状。