In vitro propagation of three Agave species used for liquor distillation and three for landscape

Abstract

Some species of Agave are highly endangered due to overexploitation and highly inefficient propagation systems. Consequently, an objective of this study was the establishment of reliable in vitro protocols for Agave propagation. In order to obtain a consistent micropropagation system for A. tequilana, 2,4-D-temporary pulses (exposure of explants for 1, 3 or 6 days) with concentrations of 2.3, 4.5, 6.8 and 9.0 mM were applied to apical shoot explants. For in vitro propagation of A. salmiana subspecies crassispina, A. duranguensis, A. oscura, A. pigmaea and A. victoria-reginae, a range of IBA levels (0.049, 0.49 and 2.46 μM) in combination with BA concentrations (0.44, 2.22, 4.44, 13.31 and 26.63 μM) were tested. After 60 days of culture, 12 axillary shoots per explant were obtained when Agave tequilana tissues were treated with 6.8 mM 2,4-D for 3 days. The most axillary shoots per explant were induced on several Agave species using IBA/BA treatments as follows: 3 for A. salmiana subspecies crassispina with 0.49/4.44 μM, almost 6 (5.9) for A. duranguensis with 0.049/4.44 μM, ca. 13 (12.8) for A. oscura with 2.46/4.44 μM, approximately 6 (5.6) for A. pigmaea with 0.49/13.31 μM and ca. 6 (5.5) for Agave victoria-reginae with 2.46/2.22 μM. Although axillary shoot production by different Agave species varied depending on the IBA to BA ratio, low concentrations of these growth regulators improved shoot production compared to those reported in other studies.