Potatoes are the principal and widespread crop used to fill the nutritional gap. Potatoes as a food crop is considered an axis of multiple manufacturing operations. Unfortunately, it is a crop susceptible to fungal and bacterial infections that threaten productivity. The constant search for alternative methods is an urgent need for potato propagation to ensure the production of virus-free seedlings. Therefore, tissue culture represents the best technique for this purpose. This current study aiming investigation the best conditions for obtaining potato callus with high vitality and fragility. The present investigates two certificated potato cultivars (Spunta and Cara) for sprouting and callus induction by using suitable phytohormones like 0.1 g/L gibberellin (GA) and 3mg/L of 2,4-dichlorophenoxyacetic acid (2,4-D) with an osmoticum like PEG6000 of 50g/L for improving callus fragility. The results showed that GA remarkedly stimulated sprouting in both cultivars. While 2,4-D hormone-induced potato callus on potato callus medium modified from Murashige and Skoog (MS), responsively. The fresh weight of the produced calli significantly increased by PEG application in the successive subcultures. The translucent calli is converted into fragility by PEG, enabling friable callus subsequent subcultures. Sprouting stimulation by GA may be due to its effect in improving carbohydrate metabolism and releasing potato dormancy. Also, 2,4-D has a role in callus induction on callus induction media.

The study ensures using an osmoticum like PEG for obtaining a vital callus during successive subcultures to improve callus fragility and vitality as expressed by the fresh weight increase.