Temporary immersion bioreactor as an efficient method for in vitro propagation of Agave marmorata

Agave marmorata is an important wild species in Mexico for mezcal and pulque production. Propagation by suckers and seeds is not sufficient to restore wild populations. The aim of this study was to develop a protocol for large-scale micropropagation of A. marmorata using a temporary immersion bioreactor (TIB). The effect of liquid medium using a TIB and semi-solid medium as the control treatment was compared. Different immersion frequencies and culture medium volumes per explant were evaluated in the TIB. In all treatments, the percentage of hyperhydricity, number of shoots per explant, shoot length, and total chlorophyll and carotenoid content were evaluated. In addition, the survival rate during acclimatization was evaluated. The results obtained show that the TIB with an immersion of 2 min every 8 h and with a culture medium volume of 50 mL had the best developmental parameters, with 19.60 shoots per explant, a shoot length of 1.74 cm and a percentage of hyperhydricity of 3.33 %. The highest chlorophyll content was observed in temporary immersion every 8 h, with 100, 75 and 50 mL of culture medium per explant. Regarding carotenoid content, the highest content was found at the 8 and 12 h immersion frequencies, with the culture medium volumes of 100, 75 and 50 mL per explant. For acclimatization, no differences were found in the survival rate between the culture systems evaluated. In conclusion, this study demonstrates that the use of a TIB is an alternative for large-scale micropropagation of A. marmorata.