Optimization of in-vitro regeneration of pineapple (ananas comosus (l) merr)

Master ThesisThe objectives of this study were to determine the optimum concentrations of 6- Benzylaminopurine (BAP) and Naphthalene Acetic Acid (NAA) and Murashige and Skoog (MS) media state on in vitro multiplication of local pineapple cv. “Smooth Cayenne”. Experiments were carried out at Mikocheni Agricultural Research Institute from September 2016 to July 2017. In the first experiment, crown and ratoon derived explants were cultured in MS medium supplemented with BAP at 0, 2, 3, 4, 5, 5.5mg/L in combination with NAA at 0, 0.01, 0.05, 0.1 and 2mg/L while in the second experiment, ratoon and crown derived explants were cultured in MS semi-solid, solid and liquid media. MS semi-solid and solid media were prepared by adding 1.25 and 2.5g/L of phytagel as gelling agent. The pineapple explant were divided into four portions, planted in MS media with different BAP and NAA combinations and then incubated in a growth room at temperature of 26` ± 2 °C and photoperiod of 16h dark and 8h light per day. Data on number of plantlets per quarter explant and weight of plantlets at 16th week from the date of culture initiation were collected. Data were analyzed using Gen Stat Computer Software version 12th based on split plot in a completely randomized design, and treatment separation was performed based on Duncan Multiple Range Test at p ≤ 0.05. Crown derived explants cultured in BAP at 5mg/L and NAA at 2mg/L produced the highest number of 16 plantlets per quarter explant each weighing 1.979g. Moreover, crown derived explants cultured in semi-solid MS media produced the largest number of plantlets of 16.33 plantlets per quarter explant each weighing 1.966g. It is recommended that tissue culture propagators should improve in vitro propagation of pineapple by culturing crown-derived explants in MS semi-solid media supplemented with BAP at 5mg/L and NAA at 2mg/L. Further studies are required to determine the effect of crown and ratoon-derived seedlings on field performance of pineapple.Commission for Science and Technology (COSTECH