Intra- specific variation in response of Jatropha (Jatropha curcas L.) to elevated CO 2 conditions

Abstract

Twenty genotypes of Jatropha collected from diverse eco-geographic regions from the states of Chhattisgarh (3), Andhra Pradesh (12), Rajasthan (4) and Uttarakhand (1) of India were subjected to elevated CO 2 conditions. All the genotypes showed significant difference (p<0.05 and 0.01) in the phenotypic traits in both the environments (elevated and ambient) and genotype x environment interaction. Among the physiological traits recorded, maximum photosynthetic rate was observed in IC565048 (48.8 μmol m -2 s -1) under ambient controlled conditions while under elevated conditions maximum photosynthetic rate was observed in IC544678 (41.3 μmol m -2 s -1), and there was no significant difference in the genotype x environment interaction. Stomatal conductance (Gs) emerged as the key factor as it recorded significant difference among the genotypes, between the environments and also genotype x environment interaction. The Gs and transpiration (E) recorded a significant decline in the genotypes under the elevated CO 2 condition over the ambient control. Under elevated CO 2 conditions, the minimum values recorded for Gs and E were 0.03 mmol m -2 s -1 and 0.59 mmol m -2 s -1 respectively in accession IC565039, while the maximum values for Gs and E were 1.8 mmol m -2 s -1 and 11.5 mmol m -2 s -1 as recorded in accession IC544678. The study resulted in the identification of potential climate ready genotypes viz. IC471314, IC544654, IC541634, IC544313, and IC471333 for future use. © 2012 Prof. H.S. Srivastava Foundation for Science and Society.