The objective of this work was to test IBA levels in the in vitro rooting of microcuttings of papaya tree (Carica papaya L. "Tainung 01'). Apical stems of plants at 120 days of age were established and evaluated onto MS supplemented medium with organic complements constituted of sucrose at 87.64 mM, myo-inositol at 555.06 µM, thiamin-HCl at 0.30 µM, pyridoxine-HCl at 2.43 µM, nicotinic acid at 4.06 µM and treated with 0, 0.74, 1.48, 2.96 and 5.92 µM of IBA, in a completely randomized design, with four replications. After 30 days, the percentage of rooted microcuttings, the development of microcuttings, the length of the largest leaf and callus mass were evaluated. It was observed that the largest percentage of rooting happens in the presence of IBA at 5.92 µM during of cultivation. In spite of the fact that larger growth of microcuttings and the largest leaf happened in levels above 0.74 µM of IBA, a larger formation of calluses happens concomitantly in the microcuttings and many of the roots are coming from those calluses, which do not possess connections with the vascular system of the shoots.
Carica papaya; auxin; micropropagation; tissue culture
