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.

Screening of Elite Coarse Rice Lines for Drought Stress Simulated by Polyethylene Glycol (PEG) at Seedling Stage

“…This could be a result of the negative impacts of water stress on the growth of root cells, which would impede nutrient uptake and negatively impact photosynthesis, which is necessary for biomass buildup and, consequently, shoot and root elongation. Therefore, it appears that under water stress, plants' ability to absorb and use water is reduced to the point where their droughttolerance mechanisms cannot support continued normal development (Ashaduzzaman et al, 2020;Islam et al, 2018;Magar et al, 2019).…”

Drought stress induced by polyethylene glycol (PEG) in local maize at the early seedling stage

“…It has been reported by Batool et al [ 38 ] that 15% PEG treatments to sensitive and tolerant plants resulted in a decrease in chlorophyll (a, b, total), carotenoids, and relative water content, but an increase in enzymes such as ascorbate peroxidase, catalase, peroxidase, and superoxide dismutase. Magar et al [ 11 ] also found that PEG treatment up to −15 bars decreased germination percent, root and shoot length, fresh and dry weight, and vigor index of seedling maize. With an increase in PEG to 6%, Asghar et al [ 39 ] observed a decrease in relative water content, chlorophyll a and b , photosynthetic rates, and stomatal conductance.…”

“…Polyethylene glycol (PEG-6000) treatment can be applied to identify local maize varieties as sensitive or tolerant to drought stress before germination [ 10 , 11 ]. This method can be used to identify the best varieties for drought-prone areas and help in conservation efforts.…”

Elucidating Drought Tolerance Potential of Maize (Zea mays L.) Inbred Lines through Polyethylene Glycol Induced Drought Stress

“…" Maize is essential for global food security. The current trends of climatic changes increase water scarcity and reduce maize productivity by 15-30%" [5]. There are several abiotic factors limiting maize production in different parts of the world.…”