Physiological Markers for Screening Sorghum (Sorghum bicolor) Germplasm under Water Stress Condition

Seed of eighty accessions collected from the National Agricultural Research Council, Islamabad, Pakistan were subjected to drought stress for ten days in greenhouse. Leaf stomatal conductance, osmotic potential, water potential, turgor pressure, shoot length and root length were measured to select physiological markers for drought tolerance and evaluate the potential of different sorghum accessions for drought tolerance. The accessions differed significantly in all physiological parameters. In most accessions, reductions were observed under water stress for all traits. In contrast, significant increases in measurements of root length were also observed under water stress conditions in some accessions. Among proportional contribution of osmotic potential, water potential, turgor pressure, root length, shoot length and stomatal conductance towards drought tolerance: the osmotic potential was the highest contributing among all parameters for drought tolerance. So, it might be used as selection trait for drought tolerance. Among 80 sorghum accessions, only five accessions (80265, 80114, SS-95-4, SS-97-7 & 80377) were most water stress tolerant. © 2010 Friends Science Publishers