Variation in salinity tolerance, early shoot mass and shoot ion concentrations within Lotus tenuis: towards a perennial pasture legume for saline land

Authors

Natasha L. Teakle, The University of Western Australia
A Snell, University of Western Australia
Daniel Real, Department of Agriculture and Food, WAFollow
Edward G. Barrett-Lennard, Department of Agriculture and Food, Western AustraliaFollow
Timothy D. Colmer, The University of Western AustraliaFollow

Document Type

Article

Publication Date

5-12-2010

Journal Title

Crop and Pasture Science

ISSN

Print: 1836-0947 Electronic: 1836-5795

Keywords

germination, Medicago sativa, narrow-leaf birdsfoot trefoil, perennial pasture legume, salinity, saltland pastures, salt tolerance, shoot Cl–, shoot Na+

Disciplines

Agronomy and Crop Sciences

Abstract

Perennial legumes are needed for productive pastures in saline areas. We evaluated 40 lines of Lotus tenuis for tolerance to salinity at both germination and vegetative growth stages. Salt tolerance during the early vegetative stage was assessed in a sand-tank experiment with NaCl concentrations of 0–450 mm NaCl for 5 weeks. Most L. tenuis lines were more salt tolerant and had at least 50% lower shoot Na+ plus Cl– (% dry mass (DM)) compared with some other common pasture legumes, Medicago sativa, M. polymorpha and Trifolium subterraneum. Within L. tenuis significant variation in salt tolerance was found, with C50 values (concentrations of NaCl that decreased shoot dry matter to 50% of control) ranging from ~100 to 320 mm. Shoot concentrations of Cl–, Na+ and K+ did not always correlate with salt tolerance; some tolerant lines had low shoot Na+ and Cl– (and thus better nutritive value), while others tolerated high shoot Na+ and Cl–. We also found variation within L. tenuis for salt tolerance of seeds, with lines ranging from 0 to 70% germination after recovery from a prior exposure to 800 mm NaCl for 15 days. There was no relationship between salinity tolerance of scarified seeds and subsequent growth of seedlings; therefore, testing of seeds alone would not be an appropriate screening method for salt tolerance in L. tenuis. This study of 40 L. tenuis lines has shown significant genetic variation for salt tolerance within this species, and we have identified key lines with potential to be productive in saltland pasture systems.

Recommended Citation

Teakle N. L., Snell A., Real D., Barrett-Lennard E. G., Colmer T. D. (2010) Variation in salinity tolerance, early shoot mass and shoot ion concentrations within Lotus tenuis: towards a perennial pasture legume for saline land. Crop and Pasture Science 61, 379-388. https://doi.org/10.1071/CP09318