Screening of Groundnut (Arachis hypogaea L.) Varieties for Drought Tolerance using Polyethylene Glycol

Identifying groundnut varieties that are tolerant to drought will be of great importance to the improvement of the crop.Drought has been a major environmental factor contributing to the reduction of crop productivity. This study aimed to screen groundnut varieties for drought tolerance using polyethylene glycol (PEG 6000), with treatments comprising28 groundnut varieties, including cultivars and advanced breeding lines. Different concentrations of PEG 60000 such as 5, 10, 15, 20% were used for this study. The treatments were laid out in a Completely Randomized Design with three replications, where 15% PEG concentration was identified as the LD50 value for TMV 1.Data were collected on germination percentage, germination velocity index, and root length in both control and simulated drought using polyethylene glycol. The drought tolerance of each variety was determined by calculating the percent reduction over the control for each trait. A significant (P<0.05) reduction was observed in all the treatments as the concentration of PEG increased. The results indicated that VRI5 recorded the lowest reduction over control in germination percentage, CO7 the lowest reduction in germination velocity index, and CO2 the lowest reduction in root length, identifying them as the drought-tolerant varieties. Conversely, VRI 3 showed the highest percent reduction across all three traits, suggesting high drought susceptibility. The results indicated that PEG (6000) can be used for simulating water stress under in vitro conditions. This study will serve as a baseline for future in vitro screening for drought tolerance in groundnut.