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ARS Home » Pacific West Area » Logan, Utah » Forage and Range Research » Research » Publications at this Location » Publication #409246

Research Project: Improved Plant Genetic Resources and Methodologies for Rangelands, Pastures, and Turf Landscapes in the Semiarid Western U.S.

Location: Forage and Range Research

Title: Breeding Efficiency for Salt Tolerance in Alfalfa

item Peel, Michael

Submitted to: Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 11/6/2023
Publication Date: 11/10/2023
Citation: Peel, M., Anower, M., Wu, Y. 2023. Breeding Efficiency for Salt Tolerance in Alfalfa. Plant Science. 13(11): 2188.

Interpretive Summary: Alfalfa an important forage crop for livestock does not grow well on soil high in salt. The study was designed to examine the effectiveness of increasing the ability of alfalfa to withstand high salt levels by examining forage yield, growth characteristics, crude protein and fiber digestion of alfalfa lines from three sources and compared them to their unimproved parents. Tests were completed under salt stressed and non-salt stressed field conditions. Without salt stress the improved alfalfa lines from two populations produced 4% less forage than their parents while lines from the third produced 9% more forage than their parents. When tested under salt stress all lines showed much more overall forage production than their parents. Alfalfa stem growth characteristics, crude protein and fiber digestion tended to be like their parents and not negatively affected. It was demonstrated that the improvement method utilized resulted in a universal increase in forage production under salt stressed field conditions of selected alfalfa lines and showed there was alfalfa that produced more forage in both non-stressed and salt-stressed tests than their parents.

Technical Abstract: Alfalfa (Medicago sativa L.) one of the most extensively grown forage crops is sensitive to saline soils. We measured breeding efficiency for increased salt tolerance by comparing lines selected from populations BC79S, CS and SII with their unselected parental means for forage mass and associated changes in stem length, leaf-to-stem ratio (LSR), node number per stem, crude protein (CP), and neutral detergent fiber (NDF). Overall forage mass in a non-salt-stressed test (9,562 kg ha-1) was greater (p=0.001) than under salt-stress (5,783 kg ha-1), or a 40 % production advantage. In a non-salt-stressed test BC79S and CS lines averaged 4% lower production than their parents while SII lines averaged 9 % greater production. Conversely, in the salt-stressed test all lines showed 20% overall greater seasonal production than their parents. Some selected lines produced more forage mass in both non-stressed and salt-stressed tests than their parents. Stem length, LSR, node number, CP, and NDF of selected lines varied with respect to non-stressed vs stressed but, they tended not to differ greatly from their respective parental means under either non- or salt-stress. The selection protocol provided a universal increase in forage mass under salt-stressed field conditions of se-lected lines. Furthermore, we identified lines with forage mass greater than their parental means under non- and salt-stressed field conditions.