Morphological Anomalies in Somatic Embryo Structure in Catharanthus roseus: Improving Embryo Germination by Amending Plant Growth Regulators, Activated Charcoal and Sucrose Level

The present study describes the incidence of somatic embryo (SE) irregularities in Catharanthus roseus (L.) G. Don. In this ornamental and anti-cancerous medicinal plant, SEs were developed at a very high rate from hypocotyl callus on MS medium, amended with 1.0 mg l-1 naphthalene acetic acid (NAA) and 1.5 mg l-1benzylaminopurine (BA). But at high (1.5 mg l-1) plant growth regulators (PGRs) levels severe embryo developmental abnormalities were caused. The major aberrant SE types have been described in the present communication. In several cases, the in vitro raised SEs had underdeveloped root ends or with aborted root axis. These irregularities in embryo structure appreciably reduced embryo germination rate and plantlet recovery. Here, we evaluated the effect of various PGRs, activated charcoal (AC), and various levels of sucrose in order to improve SE quality and germination. Medium added with 4.0 % sucrose improved rooting ability and growth. The addition of AC improved plantlet conversion significantly by promoting rooting.