Hi @M_R, Our Silva 132 classifiers are trained on the rep_set/rep_set_all/99/silva132_99.fna file contained in the Silva_132_release.zip file, available here.
As a reminder for anyone looking for the QIIME 2 Silva classifiers: the latest versions are always available on the QIIME 2 data resources page. There are new versions posted there as of yesterday which are trained with QIIME 2 2019.1.