PRODUCTION OF INTERSPECIFIC SOMATIC HYBRID PLANTS BETWEEN ASPARAGUS-OFFICINALIS AND A-MACOWANII THROUGH ELECTROFUSION

Interspecific somatic hybridization was performed between embryogenic callus protoplasts of Asparagus officinalis cv. Mary Washington and ca llus protoplasts of A. macowanii by electrofusion. By utilizing iodoac etamide (IOA) inactivation treatment for A. officinalis protoplasts an d the difference of cell division capacity between the two species, on e callus line, which had an ability to produce somatic embryos, was se lected as a putative hybrid. Normal germination of the somatic embryos was induced only when they were exposed to a period of cold treatment (14 days at 4 degrees C), However, the regenerated plants showed inte rmediate but abnormal morphological characters in vitro as well as aft er transfer to soil. The hybrid nature of the plants derived from this callus was confirmed by isozyme, nuclear rDNA and random amplified po lymorphic DNA (RAPD) analyses and counting the chromosome number.