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(-5)M). Adventitious shoots differentiated from callus developed from the cut ends of 12.5% of the hypocotyl segments cultured on medium supplemented with 10(-6)M BAP in combination with 10(-6)M 2,4-D or 10(-6)M NAA. Profuse rooting occurred from the hypocotyl explants on medium supplemented with 10(-6)M BAP + 10(-6)M NAA. Incorporation of casein hydrolysate in B5 medium along with 10(-6)M BAP + 10(-7)M 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(-6)M IBA. After hardening, plantlets were successfully transferred to the soil.