Abstract

EFFECTS OF ELEVATED CO2 AND VARIATION IN ATMOSPHERIC TEMPERATURE ON TWO CONTRASTING RICE CULTIVARS

N. Dwivedi, V. Jain, H. K. Maini, K. B. Sujatha, K. Singh, S. Shukla, M. J. Baig, P. Swain, T. B.Bagchi, & S. G. Sharma

Study was conducted to understand the changes in morpho-physiological parameters of two tropical high yielding rice cultivars CR-1014 and Naveen of CRRI, Orissa. These were grown under elevated (600µmol mol-1 ) using FACE technology and ambient (370µmol mol-1 ) CO2 concentration in IARI, New Delhi fields. Elevated CO2 resulted in significant changes in morpho-physiological parameters such as plant height, tiller number, leaf number, leaf area, photosynthesis, stomatal conductance, chlorophyll and carotenoid content. In addition to elevated CO2 its combinations with variations in atmospheric temperature during the phenological stages of growth showed contrasting results in the two selected rice cultivars. The observed differences could be due to difference in the flowering time resulting in differences in maturation of these two cultivars. We conclude that elevated CO2 in combination with lower atmospheric temperature can cease flowering in CR-1014 cultivar while with higher atmospheric temperature and elevated CO2 increased grain yield in Naveen cultivar.