Exogenously Applied Gibberellic Acid, Indole Acetic Acid and Kinetin as Potential Regulators of Source-Sink Relationship, Physiological and Yield Attributes in Rice (Oryza sativa) Genotypes under Water Deficit Conditions

Abstract

To cite this paper: Khan, S.U., A.R. Gurmani, Jalal-Ud-Din, A. Qayyum, K.S. Abbasi, M. Liaquat and Z. Ahmad, 2016. Exogenously applied gibberellic acid, indole acetic acid and kinetin as potential regulators of source-sink relationship, physiological and yield attributes in rice (Oryza sativa) genotypes under water deficit conditions. AbstractRice is one of the important cereal crops drastically affected by water scarcity in rice ecosystems. In a pot study, the impact of externally applied gibberellic acid (GA3), indole acetic acid (IAA) and kinetin was investigated on assimilates mobilization and yield parameters of rice under water stress. Twenty five days seedlings of two rice genotypes KS-133 and Basmati-2000 were transplanted in soil filled pots and sprayed with GA3, IAA and kinetin each of 10 -5 M concentration at panicle initiation stage. Water stress was imposed to plants 80 days after transplanting for 10 days. Water stress (p≤ 0.05) reduced leaf chlorophyll content and yield of rice but increased the concentration of proline, leaf soluble protein and enhanced mobility of assimilates from leaves to grains. Application of GA3 and kinetin significantly (p≤ 0.05) increased chlorophyll content, growth and yield attributes in both genotypes under water stress conditions. However, IAA application did not improve the grain yield in rice genotypes under water stress. The positive impact of GA3 and kinetin spray was imitated in the form of enhanced solute accumulation; enhanced growth and greater grain assimilate deposition. This may be concluded that GA3 and kinetin can be applied exogenously prior to flower initiation in rice to reduce panicle sterility by increasing assimilates mobility under water deficit for optimal economic yield.

Thigmotropic responses of Oryza sativa L. to external rubbing stimulation

“…The soluble protein in R30 significantly increased after rubbing stimulation. Plants adapt to stress by increasing their soluble protein levels [46].…”

Evaluation of water deficiency impacts on antioxidant enzymes activity and lipid peroxidation in some tomato (Solanum lycopersicum L.) Lines

“…(Lum et al, 2010). Destructing unsaturated fatty acids peroxides produces Malonyl dialdehyde as an indicator to determine stress damage, and the intensity of oxidative damage to the lipids plant cell memberans (Khan et al, 2016). In working with Dendrobium mononiliforme under drought stress, Xiaolu et al (2016) reported that peroxidase activity and (Malonyl dialdehyde) content were significantly increased in the leaves under some treatments.…”

“…In working with Dendrobium mononiliforme under drought stress, Xiaolu et al (2016) reported that peroxidase activity and (Malonyl dialdehyde) content were significantly increased in the leaves under some treatments. Osmolites such as proline also are effective to stimulate the tolerance to water deficiency caused by drought stress (Khan et al, 2016). Relative water content may provide an equilibrium between the plant water content and leaf transpiration rate more efficiency than the other components reflecting the water relations (Assah et al, 2015).…”

“…Relative water content may provide an equilibrium between the plant water content and leaf transpiration rate more efficiency than the other components reflecting the water relations (Assah et al, 2015). Therefore, it has been as considered a good indicator to show the plant and leaf water status (Khan et al, 2016). As environmental stresses bring about changes in plant membranes which are often associated with the increases in permeability and loss of integrity (Mohawesh, 2016); the capability of cell membranes to control the rates of ion movement in and out of cells have been used in order to test the damages imposed on plant.…”

“…By investigating the impact of drought stress on sunflower, Masoumi et al (2010) found a huge decrease in the content of chlorophyll a, chlorophyll b, and total chlorophyll in all the studied varieties. Khan et al (2016) reported that the amount of reduction in chlorophyll content has a correlation with the relative water content of leaves. Zhai et al (2015) reported that under drought conditions, proline content and electrolyte leakage were increased, while, chlorophyll content and relative water content had reducing pattern.…”