Cytomorphological studies on somatic embryogenesis of Gentiana tibetica (King) and G. cruciata (L.)

Abstract

The process of plant regeneration via somatic embryogenesis of two gentianas, Gentiana tibetica and G. cruciata was described. For this purpose seedling explants were cultured on agar medium and later maintained in cell suspension. For callus initiation seedling explants like: cotyledons, hypocotyl and root were plated on a callus induction medium (CIM) composed of MS (1962), supplemented with 0.5 mg/l 2,4-D and 1.0 mg/l Kin. For the formation of cell suspension culture, embryogenic callus was transferred into liquid maintained medium (MM) composed of MS (1962), supplemented with 1.0 mg/l Dic + 0.1 mg/l NAA + 2.0 mg/l BAP + 80.0 mg/l SA. The conversion of somatic embryo into plantlets required a new medium (ECM) based on MS (1962) mineral salts, supplemented with 0.5 mg/l GA₃ + 1.0 mg/l Kin + 0.5 mg/l NAA. For cytomorphological studies of particular stages of embryogenesis, specimens were stained with dyes and reagents: 1. PAS reaction with leukofucsin, 2. Safranin + fast green, 3. Erlich's hematoxylin.