Drought tolerant screening of 20 indonesian sorghum genotypes through leaf water potential measurements under water stress

Understanding drought tolerance status in sorghum (Sorghum bicolor) is very important for the development of sorghum varieties suitable for sub-optimal, drought prone areas in Indonesia. We estimated drought tolerance status of 20 Indonesian sorghum genotypes by observing their leaf water potential under glasshouse condition. Research design was randomized complete block design with 20 sorghum genotypes, 2 water treatments (control and water stress), and 2 replicates. The control plants were irrigated under field capacity, while the water stress treated plants were sown under field capacity followed by drought treatment without watering for one month. Sorghum seeds were cultivated in soil medium containing top soil, organic fertilizer and sand (50:20:30) in four 1x1.2x1 m(3) containers. Seeds were sown in soil media pre-treated with tap water under field capacity. Leaf water potential was observed one month after planting by using WP 4 Dew Point. Plant growth performances, including plant height and leaf width were observed. Leaf water potential observation of the 20 sorghum genotypes showed that 2 sorghums genotypes, KLR and KS, had leaf water potential of -2.43 Mpa and - 2.455 Mpa respectively, which were categorized as tolerance to water stress. Four sorghum genotypes, Buleleng Empok, UPCA, Kawali and WHP, had leaf water potential of -3.7275 MPa, -3.7650, - 3.7700 and - 3.7950 Mpa respectively, were classified to be very sensitive to drought stress. The rest of the sorghum genotypes were classified as medium tolerance with leaf water potential between - 2.5200 Mpa and 3.6550 Mpa. Although it is a preliminary results and needs to be combined with field experimental data, the results obtained was an important step in determining sorghum genotypes which was best suited to be cultivated in drought prone areas and also to identify sorghum genotypes suitable to be used as drought tolerant trait donor.