Callus Mediated In vitro Regeneration of Naga Chilli (Capsicum chinense Jacq.): The Fiery Pepper from North East India

Abstract

Naga chilli or Bhut jolokia is extensively cultivated all over northeast India including Assam. This chilli is of high commercially value due to its pungent trait called capsaicin. The chilli is well known to have extreme potential for numerous pharmaceutical applications apart from being used for culinary purposes. Despite being such an important spice crop, demand of Naga chilli is deteriorating owing to natural cross pollination and mutation which in turn reduce its capsaicin content. Therefore, an attempt was made to conserve the germplasm through standardization of an efficient micropropagation protocol using different plant hormones, silver nitrate (AgNO 3 ) and tryptophan as the key components. In vitro propagation was carried out with leaf explants. MS medium was supplemented with different combinations of BAP, 2,4-D, GA 3 , NAA and IBA alongside AgNO 3 and tryptophan. Maximum callus induction took place in the presence of 2,4-D (3.5mg/L), AgNO 3 (3mg/L) and trptophan (3mg/L). Addition of AgNO 3 to the culture medium greatly enhanced shoot proliferation in the selected in vitro plantlets. In vitro flower induction and fruit formation were successfully carried out in the presence of GA 3 (3.5mg/L) and AgNO 3 (3.5mg/L). Maximum root initiation was observed in the MS medium supplemented with IBA (3mg/L), GA 3 (2.5mg/L) and AgNO 3 (3mg/L). Hardening of in vitro raised plantlets was successful in sterile soil enriched with vermicompost and vermiculite. Percentage of plant survival was 84.75%. Addition of biofertilizers greatly improved the chances of acclimatization of in vitro raised healthy plantlets. K e y w o r d sNaga chilli, In vitro propagation, Silver nitrate, tryptophan