This work was conducted at Laboratory of Tissue Culture and Experimental Farm, Faculty of Agriculture, Zagazig University, Egypt, during the period from 2002 to 2005, to produce tuber seeds of potato by using transplants produced from stem cuttings and tissue culture of Spunta, Diamant and Cara cultivars, also to study the effect of tuber seeds produced from transplants and local tuber seeds of three cultivars on the growth and yield.This work was divided into three experiments as follows5.1 FIRST EXPERIMENT: PRODUCTION OF TRANSPLANTS FROM STEM CUTTINGS AND TISSUE CULTURE PLANTLETS OF SOME POTATO CULTIVARSThis experiment was conducted during 2002 and 2003 seasons to produce transplants from stem cuttings and tissue culture plantlets. The obtained results could be summarized as follows:5.1.1 Production of transplants from stem cuttings5.1.1.1 Number of stem cuttings/mother planta. Spunta cv. plants recorded maximum number of stem cuttings/ plant followed by Cara and Diamant plant.5.1.1.2 Stem cuttings charactersa. Spunta and Cara cvs. plants significantly recorded the highest stem cutting length, number of leaves/stem cutting, fresh and dry weight/stem cutting. While Diamant cv. gave the highest number of rooted cuttings.b. Stem cutting length, number of leaves/stem cutting, fresh and dry weight/stem cutting and number of rooted cutting were significantly high with increasing IBA at 2500 ppm.c. Dipping stem cuttings in IBA at 2500 ppm significantly increased stem cutting length, number of leaves/stem cutting, fresh and dry weight/stem cutting and number of rooted cuttings for Spunta, Diamant and Cara cultivars.5.1.1.3 Transplants characters produced from stem cuttingsa. Spunta cv. gave the highest fresh and dry weight of foliage, while Diamant cv. recorded maximum survival percentage in the second season only.b. The transplant length, number of leaves/transplant, fresh and dry weight of foliage and roots /transplant and survival (%) were significantly high with IBA at 2500 ppm.c. Dipping stem cuttings in IBA at 2500 ppm recorded maximum transplant length, leaf number/transplant, fresh and dry weight of foliage and roots and survival percentage for all cultivars used.5.1.2 Production of transplants from tissue culture5.1.2.1 Plantlets charactersa. Spunta plantlets recorded maximum number of leaves/plantlet in the second season after acclimatization, fresh weight of foliage in both seasons before and after acclimatization.5.1.2.2 Plantlets dry weighta. There were no significant differences among Spunta, Diamant and Cara cvs. for dry weight of foliage and roots before and after acclimatization.It could be concluded that Diamant cv. recorded maximum number of rooted cuttings and survival percentage. Diamant and Cara cvs. recorded maximum survival (%) in vitro plants. Also, dipping stem cuttings in IBA at 2500 ppm recorded maximum survival percentage.5.2 SECOND EXPERIMENT: PRODUCING POTATO TUBER SEEDS BY USING TRANSPLANTS PRODUCED FROM STEM CUTTINGS AND TISSUE CULTURE PLANTLETSThis experiment was conducted 2002/2003 and 2003/2004 seasons to produce tuber seeds from transplants produced from stem cuttings and tissue culture. The obtained results could be summarized as follows:5.2.1 Plant Growth5.2.1.1 Morphological charactersa. Spunta cultivar gave the highest number of leaves and number of branches /plant.b. Plants produced from tissue culture recorded the tallest plant, while plants produced from stem cuttings recorded maximum number of branches/plant.c. Plants produced from tissue culture for cv. Spunta were the tallest plants and number of both main stems and branches/ plant, while plants produced from stem cuttings for cv. Spunta recorded maximum values of number of leaves / plant.5.2.1.2 Fresh and dry weighta. Spunta and Cara cvs. recorded maximum total fresh weight, dry weight of leaves, dry weight of aerial stems and total dry weight /plant , while Diamant cv. recorded minimum total dry weight/ plant .b. Plants produced from stem cuttings transplants gave higher total fresh weight, dry weight of leaves, dry weight of aerial stems and total dry weight/plant compared to those produced from tissue culture transplantsc. Plants of Spunta cv. produced from stem cuttings transplants were the best treatment which recorded maximum total fresh weight, dry weight of leaves, dry weight of aerial stems and total dry weight/plant .5.2.2 Photosynthetic Pigmentsa. Cara cv. recorded the highest concentration of chlorophyll a, b, total (a+b) and carotenoids in leaf tissues followed by Diamant cultivar.b. Plants produced from stem cuttings transplants gave higher concentration of chlorophyll a, b, total (a+b) and carotenoids in leaves tissues compared to those produced from tissues culture.c. The plants of Diamant or Cara cvs. produced from stem cuttings transplants gave the highest chlorophyll a, b, total (a+b) and carotenoids content in leaf tissues of potato.5.2.3 N, P and K Contentsa. Spunta cultivars significantly gave the highest values of N and P contents in stems, and P content in leaves.b. Plants produced from stem cuttings gave higher K content in leaves and stems, while plants produced from tissue culture gave higher N content in leaves and P content in leaves and stems.c. Plants of cv. Spunta produced from tissues culture recorded the highest N and P contents in stems, P contents in leaves, while plants of Cara cv. produced from tissues culture and produced from stem cuttings gave the highest K content in stems and leaves.5.2.4 Total Uptake of N, P and K