Somatic embryogenesis and in vitro flowering in Hybanthus enneaspermus (L.) F. Muell. – A rare multipotent herb

Abstract

Present study reports the various factors affecting somatic embryogenesis and in vitro flowering in Hybanthus enneaspermus (L.) F. Muell. The effect of the salts strength of Murashige and Skoog's (MS) medium, concentration of sucrose and plant growth regulators were analyzed for the induction of direct somatic embryogenesis using nodal segments as explants. High frequency of somatic embryogenesis was reported on full strength MS medium (with 3% sucrose) and additives supplemented with 0.5 mg/L 6-benzylaminopurine (BAP) and 0.25 mg/L indole-3-acetic acid (IAA). Maximum somatic embryos (207.0 ± 4.2) were germinated on 1/2 strength MS medium augmented with 0.5 mg/L BAP. Microscopic studies revealed the typical developmental patterns in somatic embryogenesis from globular to heart-shaped and followed by bipolar torpedo-shaped somatic embryos from nodal explants. The plantlets raised from the somatic embryos resulted in flowering on full strength MS medium augmented with 1.0 mg/L each of BAP and Kinetin (Kin) + 0.5 mg/L IAA at 50 μmol/(m2·s) SFPD for 13 h/d photoperiod. About 92% plantlets were successfully acclimatized in the greenhouse. Field transferred plants exhibit normal flowering and fruit setting. The study could be exploited for large scale propagation of true to type plants as conservation strategies of this rare and endemic medicinal plant.