Salinity and waterlogging tolerance amongst accessions of messina (Melilotus siculus)

Abstract

Melilotus siculus (common name messina) has shown potential as a productive annual forage legume in saline and waterlogged areas in temperate Australia. The salt and waterlogging tolerances of 30 M. siculus accessions were evaluated at germination and as established plants. Many accessions germinated at 240 mm NaCl, but germination was <15% at 320 mm NaCl. In vegetative plants, accessions differed in the degree of growth reduction at 300 mm NaCl, with some producing >90%, but others <20%, of non-saline controls. A negative relationship (r = 0.47, P < 0.001) was found between dry weight under non-saline conditions and relative salt tolerance (i.e. salt-treated as % of controls). Concentrations of Cl– and Na+ in shoots of all accessions increased significantly with increasing NaCl in the medium, although these differed among accessions. No relationships were found between shoot Cl–, Na+, or K+ concentrations and relative salt tolerance at 300 mm NaCl, whereas net K+ : Na+ selectivity to shoots was positively correlated with relative salt tolerance (r = 0.30, P = 0.1). All accessions showed good tolerance to stagnant, O2-deficient conditions in the root medium, and shoot growth was not reduced by >20% in any accession. Root porosity (% gas volume/root volume) in both the main and lateral roots increased in all accessions when in stagnant medium, but accessions differed in root porosity. Lateral root porosity was not, however, correlated with either shoot dry weight or root dry weight in stagnant conditions. No single accession of M. siculus had the highest tolerance to saline conditions both at germination and the vegetative stage, but some accessions (e.g. SA 40002 and SA 40004) performed consistently well under saline and waterlogged conditions. Further research and selection is warranted on these accessions with the aim to release a cultivar.

Barley responses to combined waterlogging and salinity stress: separating effects of oxygen deprivation and elemental toxicity

“…So far, most studies dealing with the combined effects of salinity and waterlogging stress have been conducted with deoxygenated solution (stagnant agar solution or N 2 aerated solution) or waterlogged sand (Barrett-Lennard, 2003; Teakle et al, 2006, 2010; Rogers et al, 2011). Being very useful to clarify the underlying mechanisms of this interaction, these results may be at some discrepancy with the real situation in the natural stressed environment, due to the lack of the factor of elemental toxicity, typically present in waterlogged soils.…”

“…The vast collection of barley germplasms and the recent completion of the barley genome sequencing (The International Barley Genome Sequencing Consortium, 2012) makes it possible to thoroughly explore the potential mechanisms of tolerance of different barley cultivars to individual or combined stress conditions and utilize the more tolerant lines to breed suitable varieties for the corresponding environment. Up to now, saltland agriculture has relied heavily on the use of pasture halophylic species such as Atriplex, Maireana, Puccinellia, Thinopyrum, Lotus , and Melilotus (Teakle et al, 2006; Bennett et al, 2009; Rogers et al, 2011). Barley is a crop that can be used not only for animal feed, but also for alcoholic and non-alcoholic beverages and human food.…”

Root aeration via aerenchymatous phellem: three‐dimensional micro‐imaging and radial O2 profiles in Melilotus siculus

“…, 2000; Colmer, 2003). Therefore, the aerenchymatous phellem probably contributes substantially to the waterlogging tolerance of M. siculus (Rogers et al. , 2008, 2011; Teakle et al.…”

Physiological response and ion accumulation in two grasses, one legume, and one saltbush under soil water and salinity stress

“…Melilotus siculus, T. pergranulata, C. dactylon, and T. ponticum were chosen as test plants because of their reported ability to function in saline conditions in either extreme dryness or waterlogging (Semple et al, 2006;Flowers and Colmer, 2008;Jenkins et al, 2010;Rogers et al, 2011).…”