Evaluation of In-vitro Response of Dennettia tripetala (Pepper Fruit) Bak. f. Seedlings as Shoot Explants to a Combination of Plant Growth Regulators

Abstract

Dennettia tripetala (Pepper fruit) an important tree crop deeply ingrained in the socio-cultural life of the people of Nigeria, faces the threat of extinction due to inconsistent fruiting, poor seed germination and slow seedling growth. Hence, the objective of this paper was to evaluate the in-vitro response of Dennettia tripetala (pepper fruit) seedlings as shoot explants to growth regulators using standard procedures by culturing 10 weeks old seedlings of the plant as shoot explant in three (3) levels of Naphthalene acetic acid (NAA) and six (6) levels of 6-Benzyl amino purine (BAP) or Kinetin supplemented in Murashige and Skoog (MS) medium. Data collected included the weight of callus, period of callogenensis, texture and colour of callus. From the results obtained, D. tripetala shoot explants cultured in Murashige and Skoog (MS) medium supplemented with various levels of NAA in combination with BAP/Kinetin at different levels effected callus formation at varying degrees. Generally, the nature of the callus observed was either friable or compact with the former occurring more. The colour of the callus was either white or brown. The highest callus intensity was observed in the media containing NAA at 0.5mg/l in combination with Kinetin at 1mg/l and also in the media containing 2.5 mg/l NAA in combination with 1 mg/l BAP. MS media supplemented with 1.5 mg/l NAA+0.1 mg/l BAP and 2.5 mg/l NAA + 1 mg/l BAP were optimum for early callogenesis in NAA+BAP combinations while 2.0 mg/l NAA + 1.0 mg/l Kinetin was optimum for early callogenesis in NAA + Kinetin combinations. The result shows that shoot explants of the plant are amenable to tissue culture when subjected to appropriate hormonal combination. Further work is needed in the area of embryogenensis, plantlet production and subsequent regeneration of the tree crop.