Stable sodium sulfate tolerance inBrassica napus cv. Westar callus cultures

Abstract

Sodium-sulfate-tolerant callus ofBrassica napus cv. Westar, selected on medium containing 105 mM Na2SO4, was maintained on medium without the salt to test for stability of tolerance. Tolerance to Na2SO4 was retained even after 18 subcultures on no salt. This tissue also showed tolerance to K2SO4, NaCl, and KCl. However, with the exception of callus grown on KCl fresh weight yields were less than that of tolerant callus maintained continuously on Na2SO4. Tolerant callus maintained on no salt had a mixture of the compact morphology of unselected callus and the friable morphology of tolerant callus. Both callus types expressed salt tolerance.