Abstract: | Ca deficiency disorders are common in micropropagated plantlets but little is known regarding the uptake of Ca in vitro. Ca uptake by in vitra-grown potato (Solanum tuberosum L. cvs. Bintje and Norland) plantlets was investigated when Ca levels were maintained but the total macroelement salts or just NH4, the major competing cation, were reduced in Murashige and Skoog (MS) medium. This increased the ratio of Ca:cations or Ca:NH4 as well as the osmotic potential of the medium. The increased Ca-cations improved Ca uptake of shoot tips, leaves, and stems while increased Ca:NH4 had no effect. MS medium macroelement dilution may improve Ca uptake by micropropagated plantlets and prevent Ca deficiency disorders. |