Role of polyamines during in vitro rhizogenesis of Nothofagus nervosa using successive culture media

An in vitro rooting protocol for producing Nothofagus nervosa microplants using successive steps during tissue culture is reported. Qualitative and quantitative changes in putrescine, spermidine, and spermine tissue contents, during the rooting process and their correlation with other biochemical markers and morphological changes, provided the rationale for their use during the study of a successive in vitro culture protocol for N. nervosa, as well as the use of their inhibitors. The polyamine tissue content was maximum before root emergence (spermine raised to 100 nmol/g FW to later decreased to ca. 50 nmol/g FW in the following days), but it was lower in improved rooting media (197 nmol/g FW compared to 264 nmol/g FW of the control medium). It was concluded that polyamines qualitatively and quantitatively improve in vitro rhizogenesis, and the best successive culture media included 10 mu M spermine during the expression phase.