Eco-physiological studies on desert plants: germination of Halothamnus iraqensis Botsch. seeds under different conditions

Abstract

With the aim to investigate if the halophyte Halothamnus iraqensis Botsch. can be suitable for re-vegetation and remediation of salt-affected lands, this study evaluated (1) the effects of photoperiod, thermoperiod, storage period and wings' presence on its seed germination, and (2) the ability of its seeds to have successful germination recovery after salt stress. Germination tests in different photoperiods (12 h light/12 h darkness and total darkness) and thermoperiods (15°C/20°C and 20°C/25°C) were conducted for seeds collected in 2012, 2013, 2014, 2015 and 2016. The seeds collected in 2016 were sown under different salinity levels (0, 100, 200, 400 and 600 mM NaCl) to assess the salinity tolerance during the germination. Wings' presence highly inhibited seed germination of this species in both photoperiods and thermoperiods under all salinity level treatments. In addition, the germination recovery occurred well when seeds were deprived of their wings. The photoperiod of 12 h light/12 h darkness and the thermoperiod of 15°C/20°C were the best conditions for seed germination. Germination percentages of H. iraqensis seeds decreased with the increasing storage duration, especially after three years of the collection. In addition, H. iraqensis seeds were able to germinate under different salinity levels, and their germination percentages decreased with increasing salinity levels. H. iraqensis seeds have the ability to recover their germination after alleviating the salt stress, irrespective of photoperiod, highlighting the halophilous character of this species.

Seed mass, dormancy and germinability variation among maternal plants of four Arabian halophytes

“…Overall, freshly collected seeds of all the selected species showed high germination percentages and showed similar germination patterns. Higher germination response of freshly collected seeds have been reported previously for these species, believed to be an adaptation strategy that coincides with the rainfall patterns in the Arabian desert (Bhatt et al, 2019a,b,c). In the Arabian desert, most halophytes mature during November–December when temperature is low, and the chances of rainfall are high.…”

Evaluating germinability of eight desert halophytes under long-term seed storage: Implications for conservation

“…Wind-dispersal allows seeds to increase their chances of finding a suitable location for germination. Several studies on wind-dispersed seeds have indicated that the wings play an important role in controlling seed dormancy and germination requirements, such as light, temperatures and salinity (e.g., El-Keblawy, 2014, Bhatt and Santo, 2018, Bhatt et al., 2019). In our study, seeds of three species ( S .…”

Effects of Salt Stress on Growth, Proline and Mineral Content in Native Desert Species

“…Salinity tolerance strategies not only vary among species, but also among the different stages of plant growth [7,23]. In general, salinity either hinders the germination of salt-sensitive species (i.e., glycophyte) or delays the germination of salt-tolerant species (i.e., halophyte species) [24][25][26][27][28][29]. Similarly, the seedling stage is also reported to be highly sensitive to salinity stress [30,31].…”