Physiological Analysis of Rabi Sorghum Genotypes for Drought Tolerance

Abstract

Drought triggers a wide variety of plant responses, ranging from cellular metabolism to changes in growth rates and crop yields. Drought induced changes in morphological, physiological and biochemical changes in plants. This study was conducted with the object to study the physiological basis of drought tolerance in Rabi sorghum. A field experiment was conducted at Pulses Improvement Project, MPKV, Rahuri during the year 2013-2014 and 2014-2015. Eight genotypes and two released varieties were grown in a split plot design with three replications. Seeds were grown separately under three moisture regimes viz; moisture stress condition irrigation given at the time of sowing, terminal stress condition, irrigation given at the time of sowing and panicle initiation stage and non stress condition irrigation was given at proper stages of growth. Physiological traits, stomatal frequency (Abaxial/Adaxial), canopy temperature depression, SPAD index were recorded at 50% flowering and dough stage. From the investigation, it was clear that all the physiological traits and grain yield were reduced, whereas canopy temperature increased due to moisture stress than terminal and non stress. Genotypes RSV 1572. RSV 1458, RSV 1237 and Phule Anuradha performed better with respect to canopy temperature, canopy temperature depression, SPAD index values. Therefore, canopy temperature, canopy temperature depression, SPAD index values might be used as selection criteria for drought tolerance. These genotypes had optimum stomatal frequencies on both leaf surfaces. The genotypes RSV 1572, RSV 1458, RSV 1237 and Phule Anuradha could be used for developing new drought tolerant variety in the further breeding program.