Effect of PEG Induced Drought Stress on Germination and Seedling Traits of Maize (Zea mays L.) Lines

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.