Salt tolerance screening of selected Australian woody species - a review

This review critically evaluates the strategies for selection of salt toler ant woody Australian species for land reclamation. There is evidence that i n selecting material to screen, provenances from saline areas will show hig her levels of salt tolerance than those from non-saline areas. However, the re are sufficient numbers of exceptions to justify inclusion in trials of s ome material from non-saline areas. Because of the complexity and long term nature of field trials, large numbers of species and provenances have been screened as juvenile plants (up to 1 year old) in the glasshouse. For very few of these, has the match between performance in glasshouse and field be en checked. In Eucalyptus, the genus for which most species have been scree ned, the assessment of salinity tolerance is the same in the field and glas shouse for 20 species, three appear more tolerant in the field than the gla sshouse and five are less tolerant in the field than would be expected from glasshouse results. For 13 eucalypt species there are conflicting results between different glasshouse and/or field trials. A similar picture emerges for Melaleuca, Acacia and Casuarina though in these genera fewer species h ave been tested in both glasshouse and field. Glasshouse trials have a role where specific information is needed from juvenile plants such as the abil ity of a species to exclude salt from the leaves, or performance under cont rolled conditions of waterlogging or saline waterlogging. However, as the o bjective of most experiments is to identify superior salt tolerant lines fo r the field, despite the complexity and cost, well designed and monitored f ield trials are the ultimate test. Researchers are also encouraged to consi der inclusion of appropriate standard lines of Eucalyptus camaldulensis and E. occidentalis to enable better comparisons between trials. (C) 2000 Else vier Science B.V. All rights reserved.