Secondary regeneration in somatic embryos of Aesculus carnea Hayne

Abstract

Somatic embryos of red horse chestnut were subjected to an induction of secondary regeneration. The embryos were divided in 4 classes on the basis of their size (I 1, II 5, III 10 and IV 30 mm), and sub-cultivated on MS media containing 0, 1, 5 or 10 μM kinetin (Kin) or benzyladenine (BA). The pathway of secondary regeneration (somatic embryogenesis or caulogenesis) depended solely on the primary somatic embryo (PSE) stage of development. The PSE of the I and II class produced solely secondary somatic embryos (SSE), the III class PSE formed SSE on media containing Kin, and both SSE and adventitious buds on media containing BA, whereas the IV class PSE developed almost solely adventitious buds. BA promoted bud induction at much higher rate than Kin and slightly higher embryogenic response. The histological study confirmed these findings.