Genetic variability for drought tolerance in maize using germination and seedling traits under different PEG treatments

Abstract

Drought stress significantly affects maize productivity, necessitating the development of drought-tolerant varieties. This research was carried out to identify drought-tolerant maize genotypes using polyethylene glycol (PEG) treatments which were achieved through estimation of genetic parameters for drought related traits. A completely randomized design was employed by exposing the maize genotypes to 0%, 5%, and 10% PEG treatments. This was carried out by using 5% of PEG dissolved in water to moisten the seeds sown in petri dishes, similar procedure was carried out for 10% PEG treatment and distilled water was only used to moisten the seeds sown in petri dishes as control. The petri dishes were replicated three times and the sowed seeds were kept in the incubator for 48 hours. Data were collected on the following germination traits such as; germination energy, germination capacity, root length (lateral and tap root), shoot height, number of roots, fresh shoot, and dry shoot weights. Stress tolerance indices (STIs) ranked genotypes based on drought tolerance. The results showed that there were significant genetic variation among the maize genotypes, Tap root length in the control had 2.99 cm while it is lowest in 10 % PEG with 1.36 cm therefore, selection based on rank mean with values in parenthesis identified genotypes 2 (2.5), 5 (3.38), 6 (3.88), 8 (4.13), and 9 (1.75) lower than the grand mean rank mean of 4.69 as drought-tolerant and those with higher values identified genotypes 1 (7.75), 3 (5.38), 4 (5.75), and 7 (7.75) as susceptible. The findings based on the identified drought tolerant maize genotypes can aid in the development of drought resilient maize genotypes which would enhance food security and sustainability. © 2025 The Author(s)