Somatic hybridization via protoplasts fusion in Lactuca sativa (Lettuce) and its fused product response to culture media

The improvement in quality traits of lettuce (Lactuca sativa) leaves using somatic hybridization techniques via protoplasts fusion is the main focus of this study. Somatic hybridization between two cultivars of lettuce, Evola and Red Leaf Amboni green and red, respectively, were carried out at Plant Science Laboratory, University of Nottingham, UK during 2006-7 to test the culture of fused protoplasts via polyethylene glycol (PEG) and electro fusion on four types of media i.e. liquid B5 based medium (T1), embedding of liquid B5 medium over agarose (equal volume ratio) (T2), embedding of solid B5 medium over agarose (equal volume ratio) (T3), embedding of liquid B5 medium over MS0.8 medium supplement with 0.5mg/l NAA and 0.04mg/l BAP (T4) under five replications. The treatment T4 in each replication gave significant result for fused protoplasts via chemical and electro- fusion in terms of micro and macro colonies (5 to 73 average micro colonies in petri dishes) culture while other treatments have damaged the protoplast. In all replications under T4 a large number of micro colonies and macro colonies were observed and tested for viability via Fluoresce in diacetate (FDA) test. All macro colonies show 100% viable colonies for regeneration. It has also been observed that electro fusion shows 40.51% protoplast fusion frequency over PEG. Based on the results, it can be concluded that selection of lettuce genotypes on the basis of seed viability using somatic hybridization techniques via protoplast fusion (both methods of fusion) cultured under optimum medium for improvement of lettuce quality could be an important tool in in vitro techniques.