TITLE:
Influence of Rising Atmospheric CO2 Concentrations and Temperature on Morpho-Physiological Traits and Yield of Rice Genotypes in Sub Humid Climate of Eastern India
AUTHORS:
Sharad Kumar Dwivedi, Santosh Kumar, Ved Prakash, Surajit Mondal, Janki Sharan Mishra
KEYWORDS:
Climate Change, Physiological Traits, Rice Genotypes, Yield Attributes
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.6 No.14,
September
16,
2015
ABSTRACT: A possible scenario for
the end of the 21st century is that the atmospheric CO2 concentration
will be in the range of 510 - 760 μl·L-I and that the mean global
temperature will be 1.5°C - 4.5°C higher than present day. One
of the pre-eminent manifestations of climate change is the increase in atmospheric
CO2 concentration. Both CO2 and temperature are the key
variables of global climate and may cause significant changes in crop
productivity. An experiment was conducted inside open top chamber (OTCs) in kharif season 2014 to evaluate the effects of CO2 enrichment and temperature
rise with condition OTC1 (ambient condition), OTC2 (25% higher CO2 than
ambient), OTC3 (25% higher CO2 + 2°C > ambient
temperature) and OTC4 (2°C > ambient temperature) on physiological
traits and yield of rice genotypes to identify the suitable genotypes for
changing climatic conditions. The study revealed that rice genotypes performed
better under elevated CO2, with slight changes in development, such
as growth and in yield attributing traits, depending on the genotypes. However,
the beneficial direct impact of elevated (CO2) on crop yield can be
counteract by elevated temperatures. Rice genotype IR83376-B-B-24-2 was highly
responsive while IR84895-B-127-CRA-5-1-1 was least responsive toward elevated
CO2. Physiological traits like relative water content (RWC %),
membrane stability index (MSI %), chlorophyll content, photosynthetic rate and
TSS content were improved under elevated CO2. However, responses of
these traits were negative with elevated temperature. We point out that studies
related to changes in crop physiology and yield as a consequence of global
climatic changes should be a priority due to their association with food
security.