Abstract

In order to evaluate physiological traits related to biochemical basis of drought tolerance under moisture stress, a field experiment with ten sorghum genotypes was carried out in split plot design with three replications. Seeds were grown separately under three moisture regimes viz; moisture stress condition with irrigation applied at the time of sowing, terminal stress condition with irrigation applied at the time of sowing and panicle initiation stage and non stress condition with irrigation applied at various critical growth stages. The accumulation of proline and glycine betaine was higher under moisture stress than terminal stress and non-stress condition. Accumulation of proline and glycine betaine content was recorded at the time of 50% flowering and at dough stage to estimate the efficiency of drought tolerance. Among the genotypes under study, RSV 1237 accumulated more leaf proline, whereas, RSV 1572 accumulated more glycine betaine at 50% flowering stage and dough stage under moisture stress. Genotypes differed significantly with respect to leaf, stem, panicle and total dry matter per plant. RSV 1237 and RSV 1572 had better partitioning of dry matter into reproductive parts under moisture and terminal stress conditions. It was concluded that these genotypes could be useful in sorghum breeding for drought tolerance.

Keywords: Osmolytes, Drought tolerance, Leaf proline, Glycine betaine, Dry matter partitioning.