RAPD markers associated with salt tolerance in Acacia auriculiformis and Acacia mangium

In order to investigate the influence of genetic background on salt tolerance in Acacia species, seedlings of three provenances form each of Acacia auriculiformis and Acacia mangium were subjected to salt stress for I month. Plant growth, leaf osmotic adjustment and RAPD analysis were studied. In comparison to control plants, the plant growth in all provenances was decreased by salt stress and provenances A3 and M1 were more tolerant than others in A. auriculiformis and A. mangium, respectively. Salt stress decreased leaf osmotic potential in all provenances. The difference in osmotic adjustment between the provenances was not correlated with the concentrations of minerals examined such as Na+, K+, and Ca2+ in both species, but it was correlated with the leaf proline concentration in A. auriculiformis. These results suggest that the provenance variation for salt tolerance can be partially accounted for by plant physiological measures. The genetic polymorphism between the provenances was detected by RAPD analysis. Thirty-nine out of 71 bands and 18 out of 63 bands detected were polymorphic for the provenances of A. auriculiformis and A. mangium, respectively. The similarity indices between the studied provenances were less than 65% in A. auriculiformis and 86% in A. mangium suggesting that the provenance variations for salt tolerance were mainly due to the difference in genetic background. The RAPD specific markers for each provenance were determined. These markers can be considered as RAPID markers associated with salt tolerance in the two Acacia species. (C) 2004 Elsevier Ireland Ltd. All rights reserved.