Abstract:

Maize is the staple food crop in hilly areas of Nepal. Drought stress is one of the most important crop growth limiting factors leading to lower crop productivity in these areas. Maize seedlings are susceptible to drought stress. Nine lines (Arun-2, NML-1, Rampur Composite, RL-100, RL-105, Rl-106, RL-197, RML-18 and RML-8) of maize obtained from National Maize Research Program, Rampur, Chitwan, Nepal to study their tolerance to drought stress. An experiment was designed to study their drought tolerance by subjecting to four levels of osmotic potential (0, -5, -10 and -15 bar) induced by polyethylene glycol (PEG) 6000 in two factor completely randomized design with three replication at Biotechnology Division, National Agricultural Research Institute, Khumaltar, Lalitpur, Nepal. Effects of different levels of PEG 6000 were found significant on all traits studied viz. Germination rate (%), Speed of germination, Root length, Shoot length, Root Shoot ratio, Seedling length, Seedling fresh weight, Seedling dry weight and Vigor index. Line Arun-2 was recorded as best performer followed by Rampur Composite and RL-105 for all the traits analyzed. Lines RL-100, RL-106, RL-197, RML-18 and RML-8 showed poor performance under the same levels of PEG induced drought stress. Furthermore, the results also showed that maize manifests better genetic expression such as drought tolerance under severe moisture stress conditions in soil. Therefore, Lines Arun-2, Rampur Composite and RL- 105 are suggested for varietal improvement program for drought stress conditions.

Keywords: