PJB-2018-686
Effects of PEG induced water stress on growth and physiological responses of rice genotypes at seedling stage
A. Shereen, M.A. Khanzada, M.A. Wahid Baloch, Asma, M.U. Shirazi, M.A.Khan and M. Arif
Abstract
Studies were conducted to evaluate the effect of water deficit imposed by three different concentrations of polyethylene glycol-6000 (PEG-6000; w/v - 10, 15 & 20% equivalent to osmotic potential -0.19, -0.36 and -0.58 MPa along with non treated control) on plant growth and physiological traits of eight rice genotypes at seedling stage. The results showed that all growth and physiological responses of rice genotypes were affected with varying intensities under water stress conditions. These effects were comparatively low at 0.19and 0.36 MPa, PEG-6000. The concentration of 0.58 MPa, PEG-6000 drastically affected germination (up to 50%) and growth (more than 80%) in some genotypes. The results of physiological attributes revealed that relative water contents (RWC) and chlorophyll were significantly reduced in leaves with increased concentration of PEG-6000. On the contrary to this electrolyte leakage, proline, and potassium contents increased with varying intensities among rice genotypes. Genotypic comparison has shown that genotypes IR-50, IR-72, DR-92 and IR-6 exhibited tolerance potential against water stress. Tolerant genotypes exhibited differential osmo-regulatory responses in term of solute production. Correlation studies among growth and physiological traits have revealed significant positive correlation of shoot growth with relative water contents and chlorophyll. The parameters of proline, electrolyte leakage and sugars were negatively related with growth attributes. Thus, these attributes can be used as screening tool for drought tolerance in rice.
To Cite this article:
Shereen, A., M.A. Khanzada, M.A.W. Baloch, Asma, M.U. Shirazi, M.A. Khan and M. Arif. 2019. Effects of PEG induced water stress on growth and physiological responses of rice genotypes at seedling stage. Pak. J. Bot., 51(6): DOI: http://dx.doi.org/10.30848/PJB2019-6(13)
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