Effect of BA and NAA on in Vitro Culture of Young Leaves of Caladium bicolor Vent

Abstract

Effects of N6-Benzyladenine (BA) and α-Naphthalene acetic acid (NAA) on in vitro
culture of Caladium bicolor Vent. young leaves were investigated. Young leaf explants
(0.5 x 0.5 cm.) were cultured on MS (Murashige and Skoog, 1962) medium supplemented
with combinations of BA at the levels of 0, 1, 2, 3, 4, 5 mg.L-1 with 0 or 0.5 mg.L-1 NAA, and
cultured for 8 weeks. The results showed that the highest callus induction (50%) and
developing shoots were also found in MS medium incorporated with 1 mg.L-1 BA and
0.5 mg.L-1 NAA. Subsequently, callus and shoots were then transferred to MS medium
supplemented with BA at the concentrations of 0, 1, 2, 3, 4 and 5 mg.L-1 and 0 and
0.5 mg.L-1 NAA, and cultured for 8 weeks in order to induce shoot multiplication.
The results showed that the medium containing 3 mg.L-1 BA combined with 0.5 mg/l NAA
was the best shoot multiplication medium and gave the highest percentage of shoot
multiplication from the callus (50%). After sub culturing young shoots on different media,
shoot multiplication was found in all media types. However, MS medium containing
1 mg.L-1 BA produced the best shoot multiplication (4 shoots per explants), whereas MS
medium containing 4 mg.L-1 BA and 0.5 mg.L-1 NAA provided the longest shoot length
(5.3 cm./shoot). All healthy regenerated shoots and roots were then transplanted to the
greenhouse and observed for 5 month. We found that the highest survival rate of plantlets
observed was 90% and occurred when the plantlets were planted on plastic pots
containing dried clay powder, dried grass and rice-husk ash at the ratio of 2 : 1 : 1.