Organic nitrogen stimulates caulogenesis from hypocotyl callus of Phyllanthus fraternus

Factors involved in promoting caulogenesis from hypocotyl explants of Phyllanthus fraternus were studied. Hypocotyl explants were cultured on B₅ medium supplemented with 2,4-D or NAA in the presence and absence of BAP (at concentrations 0, 10^–7, 10^–6 and 10^–5M). Adventitious shoots differentiated from callus developed from the cut ends of 12.5% of the hypocotyl segments cultured on medium supplemented with 10^–6M BAP in combination with 10^–6M 2,4-D or 10^–6M NAA. Profuse rooting occurred from the hypocotyl explants on medium supplemented with 10^–6M BAP + 10^–6M NAA. Incorporation of casein hydrolysate in B₅ medium along with 10^–6M BAP + 10^–7M 2,4-D enhanced the frequency of cultures with adventitious shoots upto 68.0%. Glutamine, glutamic acid or proline could partially substitute for the effect of casein hydrolysate. Amongst the hypocotyls from 3–14 d old seedlings, the best caulogenesis was obtained with hypocotyls from 7 d old seedlings both in presence or absence of casein hydrolysate. Best rooting of shoots was achieved on half-strength B₅ medium supplemented with 10^–6M IBA. After hardening, plantlets were successfully transferred to the soil.Abbreviations BAP 6-benzylaminopurine - 2,4-D 2, 4-dichlorophenoxyacetic acid - IBA indole-3-butyric acid - NAA 1-naphthaleneacetic acid - CH casein hydrolysate - Arg L-arginine - Glu L-glutamic acid - Gln L-glutamine - Leu L-leucine - Lys L-lysine - Pro L-proline