Bhatt Arvind, Pérez-García Félix
Rev Biol Trop. 2016 Sep;64(3):965-74. doi: 10.15517/rbt.v64i3.19824.
Ochradenus baccatus is a perennial glycophyte growing in Middle East and it is one of the most important food sources for many animal species in desert regions. The aim of our study was to investigate the effects of seed storage, light, temperature and gibberellic acid (GA3) on germination of O. baccatus seeds. We also investigated the germination characteristics of O. baccatus seeds under different saline concentration and their capability to recover germination once they were transferred to distilled water. Seeds were stored at room temperature (20 ± 2 ºC) and at -18 ºC. Germination tests were conducted at alternating temperatures of 15/25, 20/30 and 25/35 ºC in either continuous darkness or photoperiod of 12-h dark/12-h light. To study the effect of GA3 on germination of O. baccatus seeds, freshly-collected seeds and stored seeds were soaked for 24 h in a GA3 water solution (1 g/L) before sowing. To assess the salinity tolerance during germination, seeds were germinated under different salinity levels (100, 200 and 400 mM NaCl). Stored seeds at room temperature and -18 ºC germinate equally well at different temperature regimes and light conditions. However, freshly matured seeds were not able to germinate even when they were treated with GA3. On the contrary, stored seeds at room temperature and -18 ºC treated with GA3 increase the final germination percentages. These results indicated that O. baccatus seeds have physiological dormancy and they need to be stored in order to break their dormancy. In the present study, one year of storage did not show a significant variation in germination between the two storage conditions assayed. Therefore, further research is needed to know about the maximum storage period for O. baccatus seeds under different storage conditions. Very few O. baccatus seeds (less than 5 %) germinated at the tested lowest concentration of NaCl. However, ungerminated seeds were able to germinate when salinity stress was alleviated. In conclusion, O. baccatus seeds have physiological dormancy, and seed storage (at room temperature and at -18 ºC) for one year is effective for breaking this dormancy. In addition, O. baccatus seeds present ability to remain viable in saline conditions and they will be able to germinate once the salinity level decrease.
巴卡 Ochradenus baccatus 是一种生长在中东地区的多年生甜土植物，是沙漠地区许多动物物种最重要的食物来源之一。我们研究的目的是调查种子储存、光照、温度和赤霉素（GA3）对巴卡 Ochradenus baccatus 种子萌发的影响。我们还研究了巴卡 Ochradenus baccatus 种子在不同盐浓度下的萌发特性，以及将它们转移到蒸馏水中后恢复萌发的能力。种子分别储存在室温（20±2℃）和-18℃下。在连续黑暗或12小时黑暗/12小时光照的光周期条件下，于15/25、20/30和25/35℃的交替温度下进行萌发试验。为了研究GA3对巴卡 Ochradenus baccatus 种子萌发的影响，将新采集的种子和储存的种子在播种前于GA3水溶液（1g/L）中浸泡24小时。为了评估萌发期间的耐盐性，种子在不同盐度水平（100、200和400mM NaCl）下萌发。在室温下和-18℃储存的种子在不同温度条件和光照条件下萌发情况相同。然而，即使经过GA3处理，刚成熟的种子也无法萌发。相反，在室温下和-18℃储存并经GA3处理的种子最终萌发率有所提高。这些结果表明，巴卡 Ochradenus baccatus 种子具有生理休眠特性，需要经过储存来打破休眠。在本研究中，两种储存条件下储存一年的种子萌发情况没有显著差异。因此，需要进一步研究以了解巴卡 Ochradenus baccatus 种子在不同储存条件下的最长储存期。在测试的最低NaCl浓度下，很少有巴卡 Ochradenus baccatus 种子（不到5%）萌发。然而，当盐胁迫缓解时，未萌发的种子能够萌发。总之，巴卡 Ochradenus baccatus 种子具有生理休眠特性，在室温下和-18℃储存一年对打破这种休眠是有效的。此外，巴卡 Ochradenus baccatus 种子在盐胁迫条件下具有保持活力的能力，一旦盐度降低它们就能萌发。
