In Vitro Propagation of Three Species of Columnar Cacti from the Sonoran Desert

In vitro propagation systems were developed for Carnegiea gigantea (Engelm.) Britt & Rose, Pachycereus pringlei (Berger) Britt & Rose and Stenocereus thurberi (Engelm.) Buxb, three North American species of columnar cacti. In vitro germinated seedlings were used as a source of explants. Multiple shoot formation from areoles was achieved for three types of explants (apical, lateral, and transverse) cultured on Murashige and Skoog (MS) basal media supplemented with 3% sucrose, 10 g·L -1 agar and various treatments with growth regulators. The highest shoot production efficiency for C. gigantea was obtained on transverse explants cultured on a medium with 2 mg·µML -1 (8.87 µM) BA, where 5.3 shoots per explant were obtained. In P. pringlei and S. thurberi the best response was obtained using transverse explants on medium with 1 mg·L -1 (4.44 µM) BA (3.8 and 4.3 shoots per explant, respectively). Rooting of the in vitro generated shoots was achieved most efficiently on MS basal media with 3% sucrose, 10 g·L -1 agar and 1 mg·L -1 (4.9 µM) indole-3-butyric acid. Rooting frequencies were 92%, 88%, and 96% for C. gigantea, P. pringlei and S. thurberi, respectively, and the frequency of survival of the plants once transferred to soil was 86% on average. Chemical name used: benzyladenine (BA).