Response of alfalfa populations to salinity stress
Alfalfa is a moderately salt- tolerant crop with high economic return and is, therefore, more suitable for production with lower-quality water than most high-value crops. New research published in Crop Science examines the effects of water composition types (Cl- or SO42-) of the irrigation water and salinity levels (electrical conductivity of irrigation water from 0.85 to 24.5 dS m-1) on biomass production, salt tolerance, and ion concentration of 15 populations.
The populations showed similar performance in response to salinity under both salt types, thus, Cl- ion toxicity does not appear to be a factor in alfalfa salt tolerance. Although there was a correlation between tolerance and shoot Na+, the shoot ion concentration provides only a partial explanation of the salt tolerance. The knowledge generated provides information to continue a breeding program, with ‘SISA 14’ as a promising experimental population based on both its salt tolerance and biomass production under saline conditions.
Future studies to improve alfalfa salt tolerance should consider selecting plants expressing genes related to Na+ exclusion and translocation as well as growth response under saline conditions. The information about the tolerance of newer cultivars is useful to producers and extension specialists, considering that some alfalfa production is shifting to marginal areas, which includes irrigated semiarid and arid areas that are salt affected and have lower-quality waters available for irrigation.
Read the full paper in Crop Science. Free preview Jan 9 - Jan 16