Salt tolerance of halophytes, research questions reviewed in the perspective of saline agriculture

Physiological responses of halophytic C₄ grass Aeluropus littoralis to salinity and arbuscular mycorrhizal fungi colonization

“…Optimal growth in these species can be evidenced with salinity concentrations as high as 200 mM (Caldwell 2012). As related to monocotyledonous halophytes, they often have optimum growth in the absence of salt or, if growth is stimulated, this is by a low (50 mM or less) concentration of NaCl (Flowers and Colmer 2008, Shabala and Mackay 2011, Rozema and Schat 2013. Contrastingly, our data here indicated clearly that growth of A. littoralis was stimulated in the presence of 200 mM salt.…”

“…Saltaffected soils occupy more than 7% of the earth land surface (Asharf and Harris 2004). Halophytes are highly salt-tolerant species and occupy naturally saline habitats and can complete their lifecycle in salinities equivalent to 200 mM NaCl or higher (Flowers and Colmer 2008, Shabala and Mackay 2011, Rozema and Schat 2013. However, the important criterion is the growth stimulation of halophytes in the presence of NaCl (100 mM and higher) in the soil solution (Flowers and Colmer 2008).…”

Optimization of culturing conditions and selection of species for the use of halophytes as biofilter for nutrient-rich saline water

“…Recently, Diaz et al (2013) demonstrated a good performance of various halophyte species in a saline drainage water reuse system. Additionally to the promising application of halophytes as biofilter and valuable co-product it is highly beneficial to foster the use of saline water for agricultural production because freshwater is a declining resource in many regions of the world (FAO, 2008(FAO, , 2012Rozema and Schat, 2013).…”

Biomass production and Symbiotic Nitrogen Fixation in the Legume Sulla carnosa in its Natural Biotope (sebkha ElKelbia)

“…This Legume offers grazing opportunities during an important period of the year regarding its high capacity of regeneration. Rozema and Schat [15] suggested that these species of halophytes help, not only to exploit saline's zones, but also give opportunities to use sea water in irrigation. When water is not a limiting factor (plants transferred in greenhouse), sulla carnosa can produce 45 g of fresh biomass after 45 days, even maintained on sebkha saline soil (EC = 13.5 mS/ Cm), and 133 g of fresh biomass after 90 days.…”

“…A soil is considered saline if the electric conductivity of a saturated paste (equivalent to the available salts in the soil pore water) of that soil is over 4 dS/m (equivalent to ± 40 mM NaCl, which is roughly equivalent to 7% of seawater salinity). Notwithstanding the sensitivity of many plants to salinity, some plants can survive and grow vigorously under saline conditions [15]. The use of such plants would be extremely helpful not only to reclaim salinized areas, but also because it would allow us to use brackish or salt water for irrigation in agriculture.…”