The mutagenicity was done by prophage induction of Pseudomonas aeruginosa strains through a known technique. The number of plaque forming unit, transduction, clear plaques, and survival percent were detected as indications for mutagenicity.1. Mutagenic activity of 2-NP :a. Spunta cv. recorded maximum N and P total uptake by plant and Cara cv. recorded maximum values of K total uptake by plant.b. Plants produced from stem cuttings transplants gave higher N and K total uptake by potato plants compared to those produced from tissue culture.c. Plants of Spunta cv. produced from stem cuttings transplants recorded maximum N and K total uptake, also the plants of Spunta cv. produced from tissue culture transplants recorded maximum P total uptake.5.2.5 Yield and its Componentsa. Diamant cv. recorded maximum number of tubers less than and above 10 gm /plant, yield of tuber above 10 gm /plant and /fed and total yield/feddan. On the other hand, Spunta cv. recorded maximum average tuber weight less than and above 10 gm.b. The plants produced from stem cuttings transplants gave the highest average tuber weigh above 10 gm and yield of tubers above 10 gm /plant and /fed and total yield /feddan compared to the plants produced from tissue culture transplants. The plants produced from tissue culture transplants produced maximum number of tubers less than and above 10 gm /plant.c. Diamant cv. produced from stem cuttings transplants gave the highest yield of tubers above 10 gm/plant and /fed. Diamant plants produced from tissue culture transplants gave the highest number of tubers less than and above 10 gm /plant, while Spunta cv. produced from stem cuttings transplants gave the highest values of average tuber weight less than and above 10 gm.5.2.6 Tuber Qualitya. Diamant cv. recorded maximum starch (%), carbohydrates (%) and dry matter (%), while Spunta cv. recorded maximum total sugar (%) in tubers.b. Plants produced from stem cuttings transplants gave the higher values of starch (%) and carbohydrates (%) in tubers.c. Diamant cv. produced from stem cuttings transplants recorded maximum starch (%), carbohydrates (%) and DM (%), while Spunta cv. plants produced from stem cuttings transplants recorded maximum total sugar(%).It could be concluded that potato plants produced from stem cuttings recorded maximum tuber seeds yield/plant and/fed for Diamant, Cara and Spunta cultivars, compared to those from tissue culture.5.3 THIRD EXPERIMENT: COMPARING THE TUBER SEEDS PRODUCED FROM TRANSPLANTS WITH LOCAL TUBER SEEDS PRODUCED FROM SUMMER CROPThis experiment was conducted during summer seasons of 2004 and 2005 to compare the yield of three sources of tuber seeds (tuber seeds produced from stem cuttings, tissue culture plantlets and local seed tubers) . The obtained results could be summarized as follows:5.3.1 Sprout Numbera. Diamant and Cara recorded maximum number of sprout/tuber followed Spunta cv.b. Local seed tubers gave the highest sprout number/tuber followed seed tubers produced from stem cuttings.c. Local tuber seeds or tuber seeds produced from stem cuttings of Diamant and Cara cvs. recorded maximum sprout number /tuber.5.3.2 Plant Growth5.3.2.1 Morphological charactersa. Spunta cv. were the tallest plants and gave the number of branches/plant, while Cara cv. recorded maximum number of both leaves and main stem/plant.b. The plants produced from local tuber seeds were the tallest plants, and gave the highest number of leaves, main stems and branches/plant.c. Spunta plants produced from local tuber seeds or tuber seeds produced from stem cuttings recorded the tallest plant and gave the highest and number of branches/ plant, while Cara plant produced from local tuber seeds or tuber seeds produced from stem cuttings recorded maximum number of both leaves and main stems/plant.5.3.2.2 Fresh and dry weighta. Cara cv. recorded maximum fresh weight/plant, dry weight of leaves, aerial stems and total dry weight/plant.b. Plants produced from local tuber seeds recorded maximum total fresh weight/plant, dry weight of leaves, aerial stems and total dry weight/ plant.c. Cara plants produced from local tuber seeds or tuber seeds produced from stem cuttings gave the highest total fresh weight/ plant, dry weight of leaves, aerial stems and total dry weight/ plant5.3.3 Yield and its Componentsa. Spunta cultivar gave the highest average tuber weight, followed by Cara cultivar.b. Plants produced from local tuber seeds recorded maximum tuber number/ plant, average tuber weight, yield / plant and yield/feddan.c. Spunta, Diamant and Cara plants produced from local tuber seeds or tuber seeds produced from stem cuttings recorded maximum tuber number/plant, average tuber weight, yield/ plant and feddan compared with the other treatments.5.3.4 Tubers Qualitya. Diamant cv. gave the highest carbohydrates and dry matter % in tuber, while Spunta cv. gave the highest total sugar (%) in tubers.b. The plants produced from local tuber seeds gave the highest values of starch, carbohydrates and DM%c. Diamant plants produced from local tuber seeds recorded maximum starch (%), carbohydrates (%) and DM (%).It could be concluded that plants produced from local tuber seeds or tuber seeds produced from stem cuttings gave the highest sprout number/tuber, tuber number/plant, average tuber weight, yield/plant and per feddan for Spunta, Diamant and Cara cultivars.