In vitro mini-tuber production in commercial caladium (Caladium humboldtii Schott ‘Phraya Savet’)

Abstract

SummaryCulture conditions for tuber induction were successfully established for Caladium humboldtii Schott ‘Phraya Savet’. Shoots with two-to-three leaves were individually cultured for 6 weeks on modified Murashige and Skoog (MS) medium solidified with 5.8 g l−1 agar in the presence or absence of 5 g l−1 activated charcoal (AC), and supplemented with 10 – 35 µM N6-benzyladenine (BA) and 60 or 80 g l−1 sucrose (Suc). The combination of BA and Suc, in the presence or absence of AC, also played a role in significantly increasing mini-tuber fresh weight (FW) and diameter. The greatest mean FWs (1.041 and 0.494 g per tuber), and mean mini-tuber diameters (12.74 and 8.65 mm), were obtained on MS medium without AC, but containing 10 µM BA with 60 g l−1 Suc, or 10 µM BA with 80 g l−1 Suc, respectively. Furthermore, the numbers of regenerated shoots, roots, and leaves were investigated. MS medium supplemented with 10 µM BA and 60 g l−1 Suc was chosen to produce mini-tubers under various medium conditions: solid, semi-solid, stationary liquid, and agitated liquid. Liquid medium was the most effective and produced mini-tubers with the largest diameters (17.32 – 19.01 mm per tuber) and FWs (2.45 – 2.61 g per tuber). There was no significant difference in tuber FWs and diameters between stationary and agitated liquid medium conditions. All mini-tubers were grown successfully, with 100% survival rates.