EFFECT OF CYTOKININS ON THE in vitro PROPAGATION OF MEXICAN AGAVES

Abstract

The lack of efficient propagation systems is one factor limiting the rational use of several species of Agave, which in many cases have had a dangerous reduction of their populations due to the overexploitation of wild materials. In this work in vitro propagation protocols were developed for Agave cupreata, A. difformis, A. karwinskii, A. obscura and A. potatorum. Meristematic tissues from in vitro germinated seedlings were used as explants. Multiple shoot formation from basal explants was achieved on MS medium supplemented with 30 g L^-1 sucrose, 8 g L^-1 agar and various treatments with cytokinins [6-benzylaminopurine (BA), 6-γ,γ-dimethylallylaminopurine (2iP), kinetin (Kin), thidiazuron (TDZ) and meta-topolin or N6- (meta-hydroxybenzyl)adenine (MT)]. The highest shoot production efficiencies for A. cupreata and A. karwinskii were obtained with 1.5 and 1 mg L^-1 BA, which rendered 10.5 and 6.1 shoots per explant, respectively. In A. difformis and A. obscura the best responses were obtained with 0.2 mg L^-1 TDZ, which yielded 8.5 and 11 shoots per explant, respectively. In A. potatorum the best response occurred with 3 mg L^-1 Kin where 6.9 shoots per explant were produced. Rooting of the in vitro generated shoots was achieved on MS basal media with frequencies ranging from 80 to 100 %, and survival of plants transferred to soil was 72 %, on the average.