Mesophyll Protoplast Fusion Induced by External Electric Fields PLANT REGENERATION FROM MESOPHYLL PROTOPLASTS OF SOLANUM QUITOENSE LAM. Plant Regeneration from Mesophyll Protoplasts of Astragalus tenuis Cell Wall Regenration During Early Development of Mesophyll Protoplasts of Astragalus melilotoides var. tenuis Studies on Plant Regeneration from Mesophyll Protoplasts of Solanum tuberosum L.