PJB-2018-89
Individual and combined effect of terminal drought and heat stress on allometric growth, grain yield and quality of bread wheat
Abdul Sattar, Ahmad Sher, Muhammad Ijaz, Malik Saad Ullah, Niaz Ahmad and Ummed Ud-Din Umar
Abstract
Among the abiotic stresses, terminal drought and heat stress are two critical threats to crop production worldwide. The objective of this study was to quantify the separate and combined effects of drought and heat stress (during heading and grain-filling stages) on allometric growth, yield, yield components, grain characteristics and grain quality of bread wheat. Experimental treatments were comprised of control (well-watered/normal condition), drought stress (50% field capacity), heat stress (inside the plastic tunnel) and drought + heat (50% field capacity and inside the plastic tunnels). Heat and drought + heat were found to have a much greater influence on the leaf area index, leaf area duration, crop growth rate and net assimilation of wheat plants than drought stress alone and control treatment. More reduction in yield and yield components of wheat was noted where combined stress (drought and heat) was applied. Moreover, heat and heat+drought stress reduced both the grain growth duration and the grain growth rate that decreased the 100 grain weight of wheat. A significant reduction in chlorophyll contents while higher concentration of proline and soluble protein of flag leaf over control was observed after drought heat stress treatment. In addition, quality traits of wheat grain were significantly affected under drought, heat and drought +heat stress conditions. Heat and drought+heat decreased the starch contents of grain while protein and gluten contents were predominantly increased under heat or drought + heat stress than drought alone and control treatment. It was concluded that effect of simultaneously applied drought and heat stress is more severe as compared to individual effect drought and heat stress.
To Cite this article:
Sattar, A., A. Sher, M. Ijaz, M.S. Ullah, N. Ahmad and U.D. Umar. 2020. Individual and combined effect of terminal drought and heat stress on allometric growth, grain yield and quality of bread wheat. Pak. J. Bot., 52(2): DOI: http://dx.doi.org/10.30848/PJB2020-2(5)
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