Developing alfalfa with enhanced salinity tolerance in a changing climate

Authors: Sandhu, Devinder; CONACCHIONE, MONICA - Instituto De Clima Y Agua (INTA); Suarez, Donald; Ferreira, Jorge

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/8/2023
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Salinity presents a significant challenge to global agricultural productivity, particularly affecting alfalfa, the most extensively cultivated perennial forage legume. This challenge is especially pronounced in arid and semi-arid regions where salinity levels are on the rise. To mitigate this issue, it is vital to understand the genetic mechanisms that confer salinity tolerance in alfalfa. This knowledge is pivotal for breeding efforts aimed at enhancing the crop's resilience to salty conditions. Our in-depth studies involving extensive screening of numerous alfalfa genotypes under prolonged saline conditions have yielded promising strategies. Selection criteria focusing on overall biomass production and ionic balance have proven highly efficient in identifying potential candidates. Notably, under saline stress, the observed reduction in biomass yield was attributed primarily to a decrease in shoot number, rather than a diminution in shoot height. Genetic analysis has unveiled a diverse array of genes implicated in salt tolerance. These include genes governing ion transport, ion homeostasis, and intrinsic tissue tolerance. Through gene expression profiling, it has been possible to categorize alfalfa genotypes according to their proficiency in managing various facets of salt tolerance. One particularly successful approach involved the screening of a genetically diverse population derived from the crossbreeding of two salt-tolerant progenitors. This process led to the emergence of exceptionally salt-tolerant genotypes, some of which exhibit an extraordinary ability to endure salinity levels comparable to that of seawater. These robust genotypes are invaluable assets for breeding programs aimed at developing new alfalfa varieties tailor-made for salt-impacted regions across the United States. Advancing our understanding of the genetic foundations of salinity tolerance in alfalfa represents a critical step towards safeguarding and improving alfalfa cultivation in a changing climate challenged by high salinity.