574 PB 047 STABILITY OF A VARIANT LEAF TYPE OF `THORNLESS EVERGREEN' BLACKBERRY FOLLOWING A REGENERATION CYCLE IN VITRO
Rubus laciniatus Willd. `Thornless Evergreen' (TE) is a chimeral blackberry with a thornless epidermis that overlies a genetically thorny interior. Most canes of TE produce leaves with 5 finely cut (lacinate) leaflets. Occasionally, canes appear which produce leaves with entire leaflets. Genetically pure thornless plants were regenerated from epidermal cells of chimeral TE with lacinate leaves. These regenerants exhibited somaclonal variation for growth habit, degree of thornlessness, and fruitfulness. All had lacinate leaves. When moved to the field, some of these regenerants produced canes with entire leaflets. To examine the stability of the entire leaflet characteristic, plants were regenerated from lacinate leaves and entire leaves of both dwarf and normal pure thornless TE regenerants. Regenerants were rooted, moved to soil, and grown in the greenhouse for observation. Stability of this characteristic will be discussed.