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Thank you for visiting nature. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser or turn off compatibility mode in Internet Explorer. In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript. Scarcity of water and the small area of the agricultural land are considered as the crucial environmental issues challenged the Arabian Gulf countries. In this study, experiments were conducted to identify the salt tolerance during the germination and the seedling stages of some native halophytes in the State of Qatar. Seeds of eight native species Salsola setifera, Halopeplis perfoliata, Caroxylon imbricatum , Suaeda aegyptiaca , Acacia tortilis , Limonium axillare , Tetraena qatarensis and Aeluropus lagopoides were investigated. Five halophytes were investigated for seedling growth under saline irrigation ranged from 0 to mM NaCl. No significant differences obtained in growth biomass of seedlings of each of Caroxylon imbricatum, Suaeda aegyptiaca and Tetraena qatarensis between saline and non-saline treatments. Halophytes are plants that have the ability to complete its life cycle in salt concentrations of not less than mM NaCl 1 , 2. Halophytes have been regarded as a rich source of potential new crops forage, oilseed and vegetable crops because of their diversity 3 , 4. The oilseed halophyte, Salicornia bigelovii , yields an average biomass of Halophytes could also be good sources of livestock feeds 7. In Qatar the uses of wild plants have been recoded for long period of time 8 , 9. Some plants used as food for camel and other animals like Salsola setifera , Caroxylon imbricatum , Acacia tortilis and Aeluropus lagopoides. In addition, some plant species showed pharmacological properties including anti-inflammatory Salsola setifera and Caroxylon imbricatum , treating tooth from gum infection Suaeda aegyptiaca 8 , The demands on natural resources such as, fresh water and suitable land for agriculture have been increasing progressively worldwide. Concerns about food and water security in the arid land of Middle East countries in general and in the Gulf countries in particular have been raised For water and food security purposes, scientists were looking for innovation practices to deal with unutilized saline areas by growing salt tolerant plants that can germinate and survive in such conditions In arid environments, the scarcity of water and the sudden increase of population have increased the demand on using natural plants that can cope with the drought and saline conditions The high yield of such plants in arid environments without exhausting freshwater resources is the major objective for increasing the governmental and the scientific research efforts on the halophytes in Qatar. According to literature, few studies have been conducted about eco-physiological aspects of halophytes in Qatar 14 , 15 , 16 , 17 , 18 , Most of the previous work was mainly aimed to describe the saline vegetation based on saline soil habitats or plant communities 8 , 10 , 14 , 20 without much consideration for their ecological and economical potential for the purpose of halophytic crop establishment. To survive in a saline environment, halophytes need first to achieve the seed germination, which represents the most critical stage in the life cycle followed by the seedling survival stage 21 , The difference in response to germination among halophytes in a saline environment determine the distribution and abundance of halophyte populations 23 , 24 , Scientists indicated that seeds of halophytes remain viable for a prolonged period of exposure to salt stress and germinate when conditions are favorable 26 , Additionally, beyond the tolerance limits of the species, the high salinity can completely inhibit seed germination According to Khan and Gul , the physiological response of seed germination has perhaps evolved to make the particular halophyte adapt to specific environmental conditions The plant species, included in this study characterized to survive under harsh environmental condition of high temperature, limited annual rainfall, which in turn increases the salinity of soil and scarcity of available fresh water for irrigation. Sodium and chloride ions are the main elements that aid in increasing soil salinity 9. The present study is kind of the first in screening for local halophytes to serve future research in investigating their economical values and the utilization of the salt affected lands in coastal and in inland areas. The goal of this research is to provide quantitative data about degree of tolerance of halophytes from Qatar to saline irrigation during the two critical initial stages, seed germination and seedling survival. The results of this study may possibly contribute to a better understanding of the performance of these species, and they will allow us to recommend the best halophyte s for future use in vegetation restoration. It is a peninsula occupying an area of 11, km 2 and a coastline of km in length with a very shallow, semi-enclosed sea characterized by hyper-salinity 39—41 psu practical salinity unit for surface water. The main landforms of Qatar are stony desert Hamads and rocky ridges together forming As a subtropical desert, Qatar is hot and has dry weather, the annual rainfall is about 81 mm. The daily average temperature ranges from Seeds of eight plant species Salsola setifera Moq. Akhani, Halopeplis perfoliata Forssk. Bunge ex Schweinf. Zohary, Acacia tortilis Forssk. Hayne, Limonium axillare Forssk. Thwaites were collected from different areas of the state of Qatar. All plant species are native to Qatar and not endangered or threaten species. They were collected after proper permissions and all methods were carried out in accordance with relevant guidelines and regulations. Seeds were cleaned from debris, inert material and damaged and infected seeds using a magnifying lens and sieves with different mesh sizes, as recommended by Rao et al. During the storage period 1—2 months , the seeds of each species were characterized for their weight, colour and dimensions and then photographed in the Scientific Photography Laboratory at Environmental Science Center of Qatar University. The above-mentioned conditions were preliminary investigated and found to be the best for the selected species. Only seeds of Acacia tortilis have a hard seed coat, so the mechanical scarification clipping off part of seed shell was done for the seed to break the thick seed coat. For Salsola setifera naked seeds without perianths, while for Caroxylon imbricatum seeds with perianths were used in germination experiment For C. Three layers of cotton cheesecloth were placed onto the bottom of the 10 cm diameter Petri plate. The experiment is one factor with seven treatment levels including the control treatment distilled water and six different concentrations of NaCl: 50, , , , and mM NaCl. Three ml of each of the assigned treatment were transferred to the respected Petri plate. Ten seeds of each halophyte species were placed on the moistened cotton cloth in each Petri plate. The Petri plates were arranged in a completely randomized design, with five replications. Around 2—3 ml of appropriate treatment solution was applied on alternate days to each Petri plate after rinsing out the previous solution with distilled water. Seeds were considered to have germination whenever the radicle emerged. The number of germinated seeds was daily counted for around 3 weeks. The experiment was terminated whenever there was no further germination in treatments for three consecutive days. The following are the main parameters used to describe the germination of the tested plants:. The maximum value using this index is All seeds from the previous germination tests which did not germinate after 3 weeks at different salinity levels, were placed in new Petri plates with filter paper moistened with deionized water, and incubated under the same conditions for additional period to study recovery of germination. The germination recovery percentage was calculated using the following formula 28 :. Five halophytes species were selected based on their high abundance and occurrence at Qatar university Campus to be tested for seedling growth experiments: C. This experiment was divided into two groups: Group-1 for seedlings of C. The seedlings were collected after proper permissions and all methods were carried out in accordance with relevant guidelines and regulations. The trays were periodically irrigated with tap water and kept under greenhouse conditions. Sodium chloride treatments were applied to 6-week-old seedlings of: Suaeda aegyptiaca and Caroxylon imbricatum and 8-week-old seedlings of: Acacia tortilis, Tetraena qatarensis and Aeluropus lagopoides. The experiment lasted for 7 weeks for each experiment. The used concentrations of salt treatments were 0, 50, , , and mM of NaCl. At the initial stage and prior to experimental treatments, the salt concentration was given to seedlings in an irrigation regime through gradually increasing the salt concentration as described in Table 1. The appropriate salt concentration was reached prior or at 6 days of NaCl pretreatment. Plants were watered twice a day, one in the afternoon using the assigned NaCl treatment and the second in the early morning of the next day with tap water only to prevent salt built up in the substrate the above-mentioned irrigation regime was chosen based on a preliminary study. The measured parameters were 1 plant height at time of treatment and 6 weeks after treatments. The plants were harvested and gently washed with tap water to remove soils and then cut to separate above ground from below ground parts. The washed plant parts were wrapped in tissue paper for around 30 s to remove excess of water and then the fresh weight of the above and belowground parts were measured. After drying, the dry weights of each part was measured and recorded. Means were compared on the transformed scale and were converted back to the original scale for presentation of results. For providing base knowledge about the seeds of halophytes collected from Qatar, the seeds were photographed and characterized Fig. Almost all the species did not show any germination at higher NaCl concentration and mM. As the salt concentration increased, a decreasing trend of final germination occurred in all species. Cumulative percentage of seed germination of halophytes as dependent on NaCl concentration. Figure 3 shows that non-germinated seeds from and mM treatments recovered when salt stress conditions were alleviated. Percentage of seeds that able to recover germination when subjected to distilled water after three weeks of NaCl treatments. The absence of letters in a graph means no significance among treatments. The recovery germination percentage was ca. The dry weight of A. Acacia tortilis, although it can grow similar to control treatment up to mM NaCl, showed a significant low biomass at and mM. The response of the aboveground and belowground biomass to salinity gradient had similar trends in all studied species Figs. Dry weight of seedling under the influence of different NaCl concentrations. Percent of growth change in height of seedling under the influence of different NaCl concentrations. The post-treatment plant height was recorded for each plant after 6 weeks of salinity treatments. For Aeluropus lagopoides the percent change in height at 50, and mM of NaCl was higher than control, and mM treatments Fig. In the present study, the results showed that seeds of different species responded differently to salinity gradient and the increased concentration of salt treatment generally decreased the germination percentage and germination rate of all studied species. Previous studies have reported similar findings for other halophyte species 32 , 33 , 34 , Many studies on seed germination of halophytes reported that the halophyte seeds germinated well in non-saline water or at salinity less than mM of sodium chloride 21 , 24 , Furthermore, the degree of salt tolerance during the germination stage of the seeds varies among halophyte species. Some halophyte seeds have the ability to germinate in a concentration up to mM e. Haloxylon ammodendron 36 and others up to mM e. Salicornia herbacea 37 On the other hand, certain halophyte seeds were reported to fail to germinate on a concentration more than mM NaCl, among those Salicornia brachystachya Moreover, many halophytes can tolerate salt on their mature plant form, but their seeds still failed to germinate on concentration of above mM NaCl Similar to what obtained by 32 , 40 , 41 , seeds of Halopeplis perfoliata were not dormant and ready to germinate at the control treatment Fig. In the present study, H. Similar to our results, in Saudi Arabia, the ability of seeds of H. Exposure to high salinity not only reduced the total germination percentage, but also reduced the germination rate Table 3. The responses of recovery of seeds vary among halophyte Some species like seeds of the salt marsh halophyte H. This enforced dormancy due to salinity is a key adaptive feature of halophyte seeds that maintain a persistent soil seed bank so that seedling recruitment is expected after sufficient rain 31 , 37 , The plant has potential economic uses in soap and glass manufacturing industries 47 and can serve in ecological restoration as sand dune stabilization in coastal deserts. Germination of seeds of T. Germination percentage of Z. Results about another relative species, the succulent desert annual, Z. In the present study , exposure to high salinity is not only reduced the germination percentage, of T. Similar results were recorded for Z. Other studies reported that Z. Soleimani et al. Salsola setifera is classified as a dwarf succulent shrub inhabits inland salt flats and coastal sandy and rocky shores in Qatar As a succulent plant, high internal salt levels are compensated by high water storage and excess salt is converted to crystals in the chlorenchyma tissue with increase in plant succulence as both water and salt absorption increases It could be used as either forage or fodder, fuel wood, as well as a source of large quantities of carbonate of soda that can be used for the soap and glass industry For the germination of Aeluropus lagopodes , our findings indicate higher germination than what was obtained by Joshi et al. In Pakistan, Gulzar and Khan reported that the seeds of A. In the present study, it lasted around This may be due to other factors that interact in seed germination, like temperature and species genetic diversity In Qatar, Aeluropus lagopoides inhabits inland wetlands, inland salt flats, coastal high marshes, and coastal sandy shore habitats The plant is characterized by thick cuticles and a cover of waxy layers with hairs on leaves and stems, their seeds remain dormant at a high salinity, and recover when returned to distilled water The plant possess forage economical values and known to be as traditional fodder of arid regions Recovery was the highest for seeds that have been pre-treated Fig. Abari et al. Germination percentage for Caroxylon imbricatum seeds previously known as Salsola imbricata was the highest at distilled water Fig. They found that seeds of C. In Kuwait, Zaman et al. In Pakistan, Salsola imbricata germinated on a concentration of up to mM In the present study, the germination was completely inhibited lesser concentration. However, there was no recovery recorded by Mehrunnisa et al. It can be realized that there were variability on responses of the C. The plants are traditionally known to provide relief in diseases like cold, flu and cough and skin diseases Interestingly, the highest germination percentage for Limonium axillare was at salinity treatment instead of distilled water Fig. Data presented by Mahmoud et al. It took around 2. This rapid germination was also recorded for another species of Limonium , L. The plant is a well-adapted halophyte and known to have well developed salt glands 17 , High concentrations of organic compounds i. For seedling growth, the effect of salinity on overall growth varies according to literatures 1 , Halophytes respond differently toward increasing salinity from stimulation to inhibition of growth 1. In general, many dicotyledonous halophytes showed optimal growth at concentrations ranged from 50 to mM NaCl 58 while monocotyledonous halophytes showed optimal growth at concentration less than 50 mM NaCl In the present study, seedlings of Tetraena qatarense, Suaeda aegyptica and Caroxylon imbricatum showed no reduction in biomass, including both aboveground and belowground dry weight, against the salinity gradients up to mM NaCl. Analyzing of the percent change in plant height during the period of experiment for T. Available records about seedling growth of other species belong to genus Suaeda, S. These results indicate that the Suaeda species are potential candidates for growing halophyte crops for different applications i. Our study pointed out that the seedlings of A. Moreover, the growth remained similar to that of control treatment at mM NaCl treatment. The change in height for A. This may explain the success of abundance of this species in Sabkhas saline soil habitats of Qatar. Coincide with our results, Joshi et al. Although Acacia tortilis is not classified as halophyte due to the non-highly saline natural habitats, it was described as highly salt-tolerant plant. In the present study, A. Leaf shedding is one of the mechanisms of halophytes to get rid of accumulative effect of salt 29 , The effect of salinity on seedling of A. They suggested that the two species are suitable for growth on saline affected soils. In conclusions, halophytes recently play important roles for restoration of coastal ecosystems and for future saline agriculture. The results of this research provide baseline information for future research in exploring economic benefits of halophytes in the State of Qatar. Halophytes had different responses to salt stress at seed germination stage. Except for Salsola setifera all the seven species failed to germinate on concentration of more than mM NaCl. When the seeds were exposed to higher concentration of salts, they became more ready to germinate in freshwater treatment. This may indicate that salt stress exposure might be a stimulator of germination if followed by freshwater exposure. Thus, the halophytes examined in this study would be of considerable economic value for improvement of the affected saline soils and increasing yield productivity in coastal areas. However, in order to evaluate the feasibility of halophytes to be stand as a commercial agricultural crop, forage crop or for other ecological or commercial purposes, further studies should be conducted under field conditions and for the entire growing season with different saline water irrigation regimes. The long-term well-monitored field studies are necessary prior to any made decision about long-scale halophyte agriculture. Flowers, T. Salinity tolerance in halophytes. New Phytol. Article Google Scholar. Gallagher, J. Halophytic crops for cultivation at seawater salinity. Plant Soil 89 , — Shaer, E. Halophytes and salt-tolerant plants as potential forage for ruminants in the Near East region. Small Rumin. Glenn, E. Productivity and irrigation requirements of halophytes grown with seawater in the Sonoran desert. Arid Environ. Salicornia bigelovii Torr. Salt tolerance and crop potential of halophytes. CRC Crit. Plant Sci. Amin E. Wild Plants of Qatar. Vol 2; Abdel Bari, E. Halophytes in the State Of Qatar. Doha: Qatar University; Accessed May 31, Abdel-Bary, E. The Flora of Qatar. Jammazi, R. Environment degradation, economic growth and energy consumption nexus: A wavelet-windowed cross correlation approach Physica. Zhou, M. Salinity improves zinc resistance in Kosteletzkya Pentacarpos in relation to a modification in mucilage and polysaccharides composition. Rezapour, S. Assessment of the quality of salt-affected soils after irrigation and cultivation in semi-arid condition. Batanouny, K. Ecology and Flora of Qatar. Doha: the Alden Press Ltd. Sayed, O. Adaptational responses of Zygophyllum qatarense Hadidi to stress conditions in a desert environment. Abdulfatih, H. Anatomy of desert halophytic leaves from Qatar. Arab Gulf J. Google Scholar. Abulfatih, H. Halophytes and soil salinity in Qatar. Qatar Univ. CAS Google Scholar. Yasseen, B. Fahmy, G. Ecophysiology of the holoparasitic angiosperm Cistanche phelypaea Orobancaceae in a coastal salt marsh. Norton, J. Ungar, I. Seed development and germination; Bueno, M. Germination and growth of Atriplex prostrata and Plantago coronopus: Two strategies to survive in saline habitats. Tobe, K. Effects of NaCl on seed germination of five nonhalophytic species from a Chinese desert environment. Seed Sci. Khan, M. Halophyte seed germination: Success and Pitfalls. Gul, B. Germination strategies of halophyte seeds under salinity. Germination responses of the subtropical annual halophyte zygophyllum simplex. Zia, S. Effect of light, salinity, and temperature on seed germination of Limonium stocksii. Germination responses of Salicornia rubra to temperature and salinity. Halophyte seed germination. In: Vol 40; Ecophysiology of wild plants and conservation perspectives in the State of Qatar. In Agricultural Chemistry. The effect of salinity and temperature on the germination of polymorphic seeds and growth of Atriplex triangularis. Mahmoud, A. Germination of two halophytes: Halopeplis perfoliata and Limonium aillare from Saudi Arabia. Gulzar, S. Seed germination of a halophytic grass Aeluropus lagopoides. Joshi, A. Salt tolerance at germination and early growth of two forage grasses growing in marshy habitats. Seed germination and radicle growth of a halophyte. Chapman, V. Salt marshes and salt deserts of the world. Huiskes, A. Germination ecology of Salicornia dolichostachya and Salicornia brachystachya. Acta Bot. Comparative influence of salinity and temperature on the germination of subtropical halophytes. Halophyte Uses Differ. I Ecol. El-Keblawy, A. Aerial seed bank affects germination in two small-seeded halophytes in Arab Gulf desert. Rasool, S. Seeds of Halopeplis perfoliata display plastic responses to various abiotic factors during germination. Studies on germination of Cressa cretica L. Weed Sci. High salt tolerance in germinating dimorphic seeds of Arthrocnemum indicum. Liu, X. Comparative effect of NaCl and seawater on seed germination of Suaeda salsa and Atriplex centralasiatica. Cao, D. Dormancy cycling and persistence of seeds in soil of a cold desert halophyte shrub. Pilcher, N. Al-Oudat, M. The halophytic flora of Syria. Ismail, A. Germination ecophysiology in populations of Zygophyllum qatarense Hadidi from contrasting habitats: Effect of temperature, salinity and growth regulators with special reference to fusicoccin. Shahba, M. On the ecophysiology and seed germination of Zygophyllum album native to the Western Mediterranean Coastal Habitats in Egypt. Basic Appl. Soleimani, H. Effect of salinity and drought by using NaCl. Halophytes of Pakistan: characteristics, distribution and potential economic usages. In Sabkha Ecosystems — Springer, Saleh, M. A desert plant from Egypt, Anabasis setifera : An efficient natural factory of carvacrol and thymol. Food Chem. Germination of salt tolerant shrub Suaeda fruticosa from Pakistan: Salinity and temperature responses. Salinity, temperature and light affect germination of Salsola imbricata. Zaman, S. Seed germination and viability of Salsola imbricata Forssk. Mehrunnisa, K. Dormancy, germination and viability of Salsola imbricata seeds in relation to light, temperature and salinity. Efficiency of biochemical protection against toxic effects of accumulated salt differentiates Thellungiella halophila from Arabidopsis thaliana. Plant Physiol. Article PubMed Google Scholar. The mechanism of salt tolerance in halophytes. Moghaieb, R. Effect of salinity on osmotic adjustment, glycinebetaine accumulation and the betaine aldehyde dehydrogenase gene expression in two halophytic plants, Salicornia europaea and Suaeda maritima. Jun-Feng, Y. Effect of nitrate on root development and nitrogen uptake of Suaeda physophora under NaCl salinity. Pedosphere 20 4 , — Ion relations of plants under drought and salinity. Mehari, A. Effects of NaCl on seedling growth, biomass production and water status of Acacia nilotica and A. Download references. We would like to thanks Mrs. Muneera Al Mesaifri Herbarium supervisor at Qatar University for her help in taxonomy of plants, cleaning, and preservation of seeds. We acknowledged the help and support provided by Mr. Our great appreciation to Department of Agricultural Research, Ministry of Municipality and Environment for using their lab and facilities. The findings achieved herein are solely the responsibility of the author s. Box , Doha, Qatar. Fedae A. You can also search for this author in PubMed Google Scholar. Correspondence to Mohammed H. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. Reprints and permissions. Alhaddad, F. Salt tolerance of selected halophytes at the two initial growth stages for future management options. Sci Rep 11 , Download citation. Received : 16 October Accepted : 26 April Published : 13 May Anyone you share the following link with will be able to read this content:. Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative. Environmental Science and Pollution Research Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily. Skip to main content Thank you for visiting nature. Download PDF. Subjects Environmental sciences Natural variation in plants Plant domestication Plant ecology Plant physiology. Abstract Scarcity of water and the small area of the agricultural land are considered as the crucial environmental issues challenged the Arabian Gulf countries. Effect of salt-alkali stress on seed germination of the halophyte Halostachys caspica Article Open access 08 June Effects of brackish water irrigation with different exogenous salt concentrations on the growth and rhizosphere salinity of Lycium barbarum Article Open access 16 September Halophytes play important role in phytoremediation of salt-affected soils in the bed of Urmia Lake, Iran Article Open access 18 July Table 1 The NaCl pretreatment regime of irrigation used in the halophyte seedling experiment. Full size table. Results Seed germination experiment For providing base knowledge about the seeds of halophytes collected from Qatar, the seeds were photographed and characterized Fig. Figure 1. Full size image. Table 2 Characterization of seeds for the studied species. Figure 2. Table 3 Germination indices of eight halophyte species at different NaCl concentrations. Figure 3. Figure 4. Figure 5. Discussion In the present study, the results showed that seeds of different species responded differently to salinity gradient and the increased concentration of salt treatment generally decreased the germination percentage and germination rate of all studied species. References Flowers, T. Article Google Scholar Gallagher, J. Article Google Scholar Shaer, E. Article Google Scholar Glenn, E. Article Google Scholar Amin E. Article Google Scholar Rezapour, S. Article Google Scholar Batanouny, K. Google Scholar Abulfatih, H. Article Google Scholar Fahmy, G. Article Google Scholar Norton, J. Google Scholar Ungar, I. Article Google Scholar Tobe, K. Google Scholar Khan, M. Google Scholar Zia, S. Article Google Scholar Khan, M. Article Google Scholar Mahmoud, A. Article Google Scholar Joshi, A. Article Google Scholar Ungar, I. Google Scholar Tobe, K. Article Google Scholar Chapman, V. Article Google Scholar Huiskes, A. Google Scholar El-Keblawy, A. Article Google Scholar Liu, X. Google Scholar Ismail, A. Google Scholar Soleimani, H. Article Google Scholar Zaman, S. Google Scholar Mehrunnisa, K. Article Google Scholar Moghaieb, R. Article Google Scholar Flowers, T. Article Google Scholar Mehari, A. Acknowledgements We would like to thanks Mrs. Funding Open access funding provided by the Qatar National Library. Box , Doha, Qatar Fedae A. Box , Doha, Qatar Talaat A. Ahmed Authors Fedae A. Alhaddad View author publications. View author publications. Ethics declarations Competing interests The authors declare no competing interests. Additional information Publisher's note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. About this article. Cite this article Alhaddad, F. Copy to clipboard. 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