Testing Salt Tolerance Variability Among Tall Wheatgrass Lines
1978
Shannon, Michael C.
The vague symptoms of moderate salt stress on plants and the lack of understanding about the mechanisms that confer salt tolerance have hampered efforts to develop reliable screening procedures for this trait. In the present study a screening procedure was evaluated to determine its usefulness in detecting variation among introductions of tall wheatgrass [Agropyron elongatum (Host) Beauv.]. In greenhouse sand flats, 32 lines tall wheatgrass were established and subjected to stepwise increases in salinity up to 765 meq/liter or until severe leaf damage resulted. The lines were classified into five groups based on relative leaf damage and recovery rates from salt treatment. Repeating the screening procedure on seven each of the most tolerant and most sensitive lines reaffirmed the results of the first screening. Mineral analyses indicated that tolerance was associated with restricted accumulation of Na, Ca, and Cl in the shoots. Proline and soluble sugars contributed to osmotic adjustment at high salinities, but sensitive and tolerant lines did not differ in proline content. This screening technique appears to discriminate between lines with different ion transport properties and different salt tolerances. The sensitive and tolerant lines identified may be beneficial in future breeding and physiological studies.
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