Eucalyptus - callus on the leaves

[Regina Caetano Quisen <quisen@WRITEME.COM>]

Hi everyone,
In an effort to maintain in vitro plantlets of Eucalyptus camaldulensis,
I have observed substantial callus formation on the leaves of the
explants after few days in culture. The modification of several culture
conditions still hasn't fully solved the problem (?ethylene
?carbohydrate accumulation).
I would like to know how could I solve this problem.
Thanks in advance,
Regina Quisen