Polyethylene Glycol Induced Osmotic Stress Affects Germination and Seedling Establishment of Wheat Genotypes

Abstract

Wheat is globally an important cereal crop. Environmental stress, especially drought stress can play an important role in the reduction of plant growth, specifically during germination in arid and semi-arid regions. Polyethylene glycol (PEG) treated hydroponic conditions create negative osmotic potential which is compared with moisture deficit stress. The main objective of this study was to investigate the effects of PEG 6000 induced moderate osmotic stress on germination indices of 22 wheat varieties. In order to study the effects of osmotic stress on germination indices in wheat cultivars, an experiment was conducted, using a completely randomized design with three replications under two different levels of PEG-6000: 0% and 10%. PEG stress significantly reduced percent germination, shoot length and root length. PEG stress significantly increased root-shoot ratio and oven dry weight. Principal component analysis revealed response of traits of tolerant wheat varieties under osmotic stress. Correlation study revealed the significant relationships among germination indices. The variety BARI Gom-30 recorded comparatively higher root length (6 cm), shoot length (7.8 cm), root-shoot ratio (1.37) followed by the variety Sonalika whereas the variety Kalaysona recorded the lowest root length (2.7 cm) and shoot length (2.8 cm) under PEG stress. Evolved information of this research including selected traits such as germination percentage, root-shoot ratio and dry weight of seedlings could be exploited in wheat breeding program for drought and osmotic stress tolerance.