A laboratory experiment was conducted to evaluate the effect of five different levels of water potential (xp) viz., 0.00; -4.09; -8.18; -12.28 and -16.36 bars on the uptake and accumulation of K‘, Ca" and Na" contents of six cultivars of Sorghum bicolor L. seedlings. Mannitol was used as an osmotic alongwith half strength Hoagland culture solution. Results depicted tl1at in relation to different levels of water potential all mentioned cations responded significantly (P < 0.05). Cultivars response was also found to be significant. Results further revealed that as water potential level increased, K*, Ca" and Na* contents of both root and shoot were generally decreased. Maximum level of K" (13.69 mg g") and Na* contents (308.10 mg kg") in roots were obtained for water potential level of - 4.09 bars. While in case of shoot, maximum level of Ki (25.37 mg g") was also recorded in - 4.09 bars. Whereas, maximum Ca" both for root and shoot (7.47 and 4. 050 mg g") was found in control level of water potential. Data also showed that in general there was an increase uptake of 39. 08 and 79.75 % in Ca'° and Na° contents of root over shoot, respectively. Whereas, shoot Ki contents was 14.16 % greater over their respective roots. Relatively much higher concentration of cations in root than in shoot suggests that the upward translocation! uptake of these ions were influenced by imposed water potential levels. Results based on cumulative drought tolerance index (%) of cations accumulation, Sorghum bicolar cv. Giza-3 could be rated as drought tolerant and cv. 1CSV = 107 and Pak. S.S.ll as drought sensitive. While remaining three cultivars viz., I747, S.E.T P = 14 - 2 and ICSH = 479 could be rated as drought intermediate in response, respectively.
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