Developing a micro propagation protocol for local pineapple (Ananas Comosus L. Merr) variety (Smooth Cayenne)

Abstract

Pineapple is one of the most important tropical fruits in the world and it is considered as one of the promising fruit crops in Uganda. However, its production is greatly affected due to conventional propagation materials being in short supply, diseased, of poor quality and are not uniform. This study was carried out to define some of the requirements for shoot multiplication of pineapple using tissue culture technique on Murashige and Skoog media (sterilization time and optimal hormone concentration) using crown tips. Modifications were undertaken on growth regulators (cytokinine). Terminal buds from crowns were treated with 20% (v/v) sodium hypochlorite for 10, 15 and 20 minutes and placed in different media. Explants were transferred to MS basal medium and kept for 2-4 months under 16/8 h photoperiod and 28 ± 2ºC. Results showed that exposure for 20minute of explants in 20% jik was the best sterilization time (60%contamination) for pineapple ex-plants followed by 15minutes (80% contamination) and lastly 10minute (100% contamination). However, in the second experiment for shoot multiplication, cultures from 15minute were used because it gave better regeneration rates than 20 minutes. The major cause of unsuccessful regeneration of crown tip of 20% cultures was injuries (bleaching) of the tips rather than contamination. The overall cause of low regeneration for the whole experiment was suspected to be due to genotype. No significant differences were observed among the different sterilization times. These modifications were found enhancive for mass production of pineapple plants. Results also showed that higher multiplication rates for Ananas comosus L. were obtained with 6- Benzyl Amino Purine (BAP) concentrations of 8 mgl-1 after 12 weeks.