Elimination of browning exudate and in vitro development of shoots in Pistacia vera L. cv. mateur and Pistacia atlantica Desf. Culture

Abstract

We report diminution and/or elimination of browning exudate followed by in vitro establishment of in Pistacia vera cv. mateur and Pistacia atlantica explants. Soaking P. vera cv. mateur explants prior to culture in L-cysteine HCl for 15 min (100 µM) inhibits blackening of the modified Murashige and Skoog medium - MS + 400 mg/l NH₄NO₃ - and of the explants; while shoot formation was increased. The browning in P. vera cv. mateur and P. atlantica explants dissolved when modified MS and Quoirin and Lepoivre - QL.4 - media were supplemented with activated charcoal (from 1 to 3 g l^-1) and with 4 and 8 days of darkness. These treatments were enough to eliminate browning from the explants and to improve the shoots elongation, but symptoms of chlorosis were detected. On the other hand, AgNO₃ (from 15 to 40 µ1V1) showed a very strong antibrowning effect on the medium and explants of P. atlantica. Thus shoot organogenesis was best achieved and the developing sturdy shoots had large and green leaves.