using growth parameters for in-vitro screening of potato varieties tolerant to salt stress

salt stress negatively impacts crops yield throughout the world. nine varieties of potato (solanum tuberosum l.) were screened for salt stress tolerance by measuring in-vitro growth of the aerial plant parts, as well as roots. salt stress was evaluated by adding 25, 50, 75, 100, 125, 150 and 200 mm of nacl to murashige- skoog (ms) medium and compared to ms medium without nacl. plant length and stem thickness, leaf area, roots number, length, and thickness, and plant fresh and dry weights were measured. osmotic pressure (ψmedium, mpa) and electrical conductivity (ecmedium, ms cm-1) of media ranged from −0.2 to −0.91 mpa and 5.8 to 24 ms cm-1, respectively. salt stress adversely affected the plant growth, and varieties differed in their responses. progressive reduction in the studied parameters occurred as nacl levels increased. grouping all the varieties by cluster analysis, based on the growth parameters response to salt stress, resulted in three distinct groups: (1) salt tolerant group of two varieties, namely, taurus and sultana; (2) moderately salt tolerant group of four varieties, namely, loane, diamant, amarin, and sylvana; and (3) salt sensitive group of three varieties, namely, toscana, soraya, and kenita. the response variation of these potato varieties under nacl indicated the possibility of using them for developing salt tolerant varieties for production in syria.