Abstract

Cactus in northern Ethiopia is an endangered plant due to the attack by cochineal scale insect (Dactylopius coccus). The aim of this study was to micro propagate disease-free and cochineal resistance cactus pear by in vitro regeneration culturing technique. The study started with young cladodes carefully removed from mother plants. The surface-sterilized 1 cm2 cladode with one areole was cultured on shoot initiation MS media supplemented with 0, 0.5, 1.0, and 1.5 mg/l BAP alone. The already established explants were cultured on shoot multiplication media fortified with BAP at 0, 1.0, 2.0, and 3.0 mg/l. The proliferated cultures were inoculated for rooting on half-strength MS media supplemented with NAA alone at 0, 0.5, 1.0 and 1.5 mg/l. The MS medium appended with 0.5 mg/l BAP produced significantly the highest shoot number per explant (3 ± 1) and highest micro shoot length (3.27 ± 0.40). The highest multiplication factor (9.93 ± 2.25) was observed on a medium containing 1 mg/l BAP while the highest shoot lengths or elongation (3.03 ± 0.26) were observed on the medium containing 2 mg/l BAP. The best highest root number (6.06 ± 0.92) was recorded on the half MS Basal medium containing 0.5 mg/l NAA and highest root length (3.03 ± 0.27) was verified on the half MS Basal medium containing 1.0 mg/l NAA. The well-rooted plantlets were transferred for acclimatization purposes using coco peat substrate and 100% of the plants survived and established as vigorous plants under modern greenhouse conditions. The creation of a successful micro propagation method that allows for the production of more than 10,000 rooted plantlets from a single longitudinally divided shoot explant in just short period of time.

Key words: Opuntia ficus-indica, in vitro, tissue culture, areoles, cladodesba.