Physio-biochemical responses and defining selection criteria for drought tolerance in Sorghum bicolor

Forty cytoplasmic male sterile (CMS) sorghum lines were evaluated for different physiological and biochemicaltraits under drought stress. Considerable genetic variability was found among all physio-biochemical traits i.e.water potential (Ψ w), stomatal conductance (gs), photosynthetic efficiency, acid detergent fiber (ADF), neutraldetergent fiber (NDF), ash and sugar contents. Results indicated that ash contents were found to be most adverselyaffected by drought stress followed by sugar contents and stomatal conductance respectively. However, thevalues of crude protein, acid detergent fiber (ADF) and neutral detergent fiber (NDF) were observed to be increaseunder stress condition. Principal component analysis (PCA) was applied to recognize drought tolerant lines.Selection criteria was based upon findings of correlation analysis among all studied traits. The positive associationof water potential, stomatal conductance and photosynthetic efficiency with desirable traits viz. ash and sugarcontents; and NDF association with undesirable traits viz. ADF and NDF revealed a way forward to design futurebreeding programs of sorghum crop under the prevailing scenario of climate change