Differentiation and morphogenetic potential of Allium commutatum Guss. callus tissue

Differentiation and morphogenetic potential of Allium commutatum Guss. callus tissue was investigated in five subcultures. Callus tissue was derived from root tips of in vitro grown seedlings and maintained on MS medium supplemented with 3% sucrose, 0.8% agar, 4.5 pM 2,4-D and 4.6 pM kinetin. Pieces of calli were subcultured on media with different concentrations and combinations of 2,4-D (1.0,2.5 and 5.0 pM) and kinetin (1.0, 5.0 and 25.0 pM), or without them. After six weeks, the relative increase of callus fresh weight, morphological and histological characteristics as well as the induction of adventi­ tious shoots and roots were investigated. Histological analysis of callui from the 1st sub­ culture showed that callus predominantly consisted of parenchymatous cells surrounded with peripheral meristematic regions. Tracheidal elements, individual and arranged in rows, were observed in all calli investigated. The best callus growth was achieved on me­ dia containing 2.5 pM 2,4-D alone or in combination with kinetin (1.0 and 5.0 pM). Addi­ tion of kinetin to the nutrient medium stimulated adventitious shoot induction. The shoot formation was improved in later subcultures. The highest number of shoots developed on media supplemented with 5.0 pM kinetin alone or in combination with 1.0 pM 2,4-D, as well as on media with 25.0 pM kinetin alone or in combination with 1.0 or 2.5 pM 2,4-D. The induction of adventitious roots was observed during all subcultures on all media tested.