Regeneration of plants from seed derived callus of Hybanthus enneaspermus L-Muell., a rare ethnobotanical herb

A procedure was developed for plant regeneration of Hybanthus enneaspermus, a rare ethnobotanical herb from the Deccan peninsula in India, through see d-derived callus. Seeds demonstrated a high induction frequency (69.4+2.8%) and a high yield (364.4+/-2.5 mg) of light-yellow friable callus on Murash ige and Skoog's (MS) medium containing 2.6 mu M NAA and 2.2 mu M BA within 4 weeks of incubation. After I year of subculture, yellow friable and light -green compact calli types were established from initial light-yellow friab le callus. Shoot differentiation was achieved from light-green compact call us, but not from yellow friable callus. Shoot differentiation resulted when light-green compact callus was transferred to MS medium supplemented with 8.8 mu M BA and 2.6 mu M NAA; the highest percentage of calli forming shoot s (66.6+/-4.8%) and the highest number of shoots (8.9+/-0.3) were achieved in this medium. Differentiated shoot buds elongated to 4-5 cm within 4 week s. The addition of casein hydrolysate (500 mg/l) and more potassium phospha te (1.86 mM) to the culture medium enhanced shoot differentiation. Rooting was achieved on the shoots using half-strength MS medium containing 4.8 mu M IBA. About 70% of the plants were established in pots containing pure gar den soil after 2 weeks of hardening. The regenerated plants were morphologi cally uniform and exhibited normal seed set.