Identifying suitable temperate forage legume species for saline areas

Abstract

Summary. The salt tolerance of 29 lines of annual and perennial forage legume species was evaluated in 4 separate experiments over 0–100 mol NaCl/m3 in the greenhouse with the aim of identifying genetic material that is more salt tolerant than the more traditionally grown forage legume species. Several species or lines showed potential as salt-tolerant germplasm including Trifolium tomentosum, 2 lines of T. squamosum and T. alexandrinum cvv. Mescani and Wardan which were all more salt tolerant than T. subterraneum. Two lines of Lotus tenuis and 1 line of L. corniculatus were also relatively salt tolerant. Some of this material had never been assessed before under saline conditions. In contrast, several other species (T. arvense, T. vesiculosum, T. angustifolium and T. pratense) were found to be extremely salt sensitive and/or produced very small amounts of dry matter over all NaCl concentrations. We believe that further selection and field evaluation (including selection for increased productivity and salt tolerance over a range of growth stages) is required for the material that showed potential in order to fully assess its performance under saline soil conditions.

Genetic variability in salt tolerance of selected boreal woody seedlings

“…High salinity increased necrosis and decreased dry biomass of seedlings. These results are in agreement with other studies (Khan and Ungar, 1995;Renault et al, 1998Renault et al, , 2000Rogers et al, 1996Rogers et al, , 1997. Indeed, an excess of sodium salts in plant tissues can lead to enzyme inactivation, inhibition of nucleic acid and protein synthesis, membrane lesions that result in leakage of solutes from the cells and cause injury to tissues (Banuls et al, 1996;Renault et al, 1998Renault et al, , 2000.…”

“…This suggests that there is a high degree of individual resistance within the species and that genetic differences should be considered in the selection of salt tolerant trees. Our results and others (Rogers et al, 1996(Rogers et al, , 1997 suggest that, in order to fully evaluate potential species for saline conditions, it may be worthwhile exploiting the intra-specific variation for dry matter production and survival that exists within species and selecting for increased productivity and survival. Therefore, the use of aggregation indices such as those presented in this study or more refined selection indices appears essential for the selection of seed lots and families, but also for clonal selection within-seed lots or families (Khasa et al, 1995a).…”

Growth and ion relations in response to combined salinity and waterlogging in the perennial forage legumes Lotus corniculatus and Lotus tenuis

“…tenufolius L. P. Fourn) is a perennial pasture legume that has naturalized in the flooding Pampa region of Argentina (Kade et al 2003). Previous studies have reported L. tenuis to be salt tolerant (Ayers 1948;Schachtman and Kelman 1991;Rogers et al 1997a) and waterlogging tolerant (Vignolio et al 1999;Mendoza et al 2005;Striker et al 2005) and have suggested this species has potential for use in saline discharge areas (Dear et al 2003). However, the impact of combined salt and waterlogging stress on L. tenuis has not been studied and the mechanisms underlying salt tolerance in L. tenuis have not been elucidated.…”

Salt tolerance and avoidance mechanisms at germination of annual pasture legumes: importance for adaptation to saline environments

“…While several studies have examined salinity tolerance in the vegetative stage of annual pasture legumes (West and Taylor 1981;Rogers and Noble 1991;Rogers et al 1997Rogers et al , 2008a, few studies have investigated salinity tolerance at germination. West and Taylor (1981) showed reductions in germination of T. subterraneum at concentrations above 70 mM NaCl, while Rogers and Noble (1991) found a 50% reduction in germination of T. michelianum and T. subterraneum in 110 mM NaCl.…”