Protocol Development for Micropropagation of an Elite BlackPepper (Piper nigrum L.) Cultivar: Sl -3/

Abstract

VABSTRACTBlack pepper (Piper nigrum L.) is a perennial woody climbing shrub that belongs to the familyPiperaceae It is one of the oldest and most important spices, and is still used universally in foodflavoring. It is christened as the ̔ king of spices’. The spiciness and quality of black pepper iscontributed by two chemical components: piperine (C17H19NO3) contributes to pungency whilepepper oleoresin and essential oil is responsible for the aroma and flavor. Accession Sl-3/80,which was introduced from abroad and adapted well in Ethiopia, is an improved hybrid cultivarwith a relatively high yield and good quality. Lack of an adequate supply of high quality plantingmaterial is the major bottle neck problem in conventional propagation method. Plant tissueculture is a biotechnological approach to alleviate this problem. Therefore, this study wasinitiated with the objective of developing an efficient and reproducible in vitro mass propagationprotocol for 3/80 cultivar of P. nigrum L. through micropropagation using shoot tip explants.Three experiments were carried out in this study. All the experiments were laid in CRD withfactorial treatment combinations of four replications, five explants per jar under each replicate.The experiments were laid after sterilization of shoot tip explants with 15% berekina for 20minutes. For shoot induction experiment, maximum percentage 62.50 + 0.00% was observed onhalf MS medium supplemented with 2mg/l BAP. In shoot multiplication experiment, ½ MS +2mg/l BAP + 1.5mg/l KN resulted in 4.60 + 0.00 shoot number with best vigor andmorphological appearance. In the in vitro rooting experiment best shoot elongation and rootingcondition was recorded on 1/2MS + 1 mg/l IBA which resulted mean values of 8.20 + 0.00 rootnumber, 6.33 ± 0.10 cm root length and 4.45 + 0.75 cm shoot height followed by 1/2 MS + 1mg/l NAA with 6.41 + 0.05 root number, 6.10 + 0.00cm root length and 3.52 + 0.75 cm shootlength. The results obtained in this study permit the development of mass propagation protocolusing shoot tip explant sources that could enable large scale commercial production of thishighly demanded 3/80 cultivar of P. nigrum L. true-to type and provide a possible systemtowards genetic improvement of the crop.