310-1 Comparison of Salt Tolerant Alfalfa (Medicago sativa) Genotypes: Seed Germination, Emergence, and Dry Matter Yield and Mineral Composition of Mature Plants.
See more from this Division: SSSA Division: Soil & Water Management & ConservationSee more from this Session: Soil & Water Management & Conservation: I
For mature plants, the relative yield (RY) for shoots and for root+ crown dry matter yield decreased significantly when the ECw was > 5 dS/m. The most tolerant varieties had a RY for shoot dry weight of 39.5 to 84.1% at 10 dS/m ECw; whereas for sensitive varieties, RY for shoots was only 0.5 to 2.3% at this salinity level. Shoot biomass was more sensitive to salinity than was root biomass, consequently the shoot / root + crown biomass ratio decreased with salinity. For most varieties, Na+ and Cl- concentrations in shoots (and roots + crowns) steadily increased (and K+ decreased) as salinity increased. However, the most tolerant varieties exhibited relatively little increase in Na+ and Cl- (and decrease in K+) in shoot tissue, indicating that toxic ion exclusion and K+ discrimination (over Na+) are key tolerance mechanisms in these alfalfa varieties.
See more from this Session: Soil & Water Management & Conservation: I