Breeding Efficiency for Salt Tolerance in Alfalfa.

Area of Science:

• Agronomy
• Plant Breeding
• Salinity Stress Physiology

Background:

• Alfalfa (Medicago sativa L.) is a vital forage crop highly susceptible to soil salinity.
• Saline soils significantly reduce crop yield and quality, posing challenges for agricultural productivity.

Purpose of the Study:

• To evaluate breeding efficiency for enhanced salt tolerance in alfalfa.
• To compare selected alfalfa lines against parental means for forage mass and other agronomic traits under varying salinity levels.

Main Methods:

• Selection of alfalfa lines from BC79S, CS, and SII populations based on salt tolerance.
• Measurement of forage mass, stem length, leaf-to-stem ratio (LSR), node number, crude protein (CP), and neutral detergent fiber (NDF).
• Comparison of selected lines and parental means under both non-salt-stressed and salt-stressed field conditions.

Main Results:

• Overall forage mass was 40% lower under salt stress (5783 kg ha⁻¹) compared to non-stressed conditions (9562 kg ha⁻¹).
• Selected lines exhibited a 20% increase in seasonal forage production under salt stress compared to their parents.
• Selected lines showed improved forage mass under both non-stressed and salt-stressed conditions, with some exceeding parental means.

Conclusions:

• The implemented selection protocol effectively enhanced alfalfa's salt tolerance, leading to increased forage mass under saline field conditions.
• Specific selected lines demonstrated superior performance, offering potential for developing more resilient alfalfa varieties for saline environments.