Abstract

Papaya, an important fruit crop in Kenya is commercially propagated through seeds which lead to production of non-true-to-types plants. Conventional vegetative propagation methods are not carried out, hence, the need for micropropagation for mass multiplication of selected lines. An assessment for the effect of 6-benzylaminopurine (BAP) at 0.1, 0.5, 1.0 and 2.0 mg/l combined with α-naphthalene acetic acid (NAA) at 0.05, 0.1, 0.5 and 1.0 mg/l and a control on shoot multiplication and elongations, and indole-3-butyric acid (IBA) at 0, 0.1, 0.5, 1.0, 2.0, 2.5 and 3.0 mg/l on root induction were evaluated. Number of shoots and their length were recorded every three weeks for 12 weeks. Number of roots, root length and percentage rooting induction were recorded after eight weeks. The highest number of shoots was recorded in 0.5 mg/l BAP combined with 0.1 mg/l NAA and the longest shoots were recorded in 0.1 mg/l BAP combined with 0.05 mg/l NAA across the three lines. IBA at 2.5 mg/l produced the highest number of roots, root length and highest percentage of rooting induction. An in vitro regeneration of selected papaya lines through shoot tip culture was established.

Key words: Carica papaya, in vitro regeneration, shoots multiplication, rooting.