Research Article
Sunitha Vaidya, Vanaja M, S
Abstract
Impact of Elevated CO2 on Growth and Physiological Parameters of Groundnut (Arachis hypogaea L.) Genotypes Five groundnut (Arachis hypogaea L.) genotypes- JL-24, ICGV 91114, Narayani, Abhaya, Dharani were evaluated at elevated (550 ppm) CO2 in OTCs during 2013 kharif to assess the variability in growth, biomass and physiological parameters. Elevated CO2 enhanced biomass and physiological parameters of all the selected groundnut genotypes, however the magnitude of response varied. Total biomass of genotypes was improved by 19% at 550 ppm and maximum response (34%) was recorded in ICGV 91114 and Narayani. The genotype ICGV 91114 recorded significant improvement of leaf and root biomass, total biomass and specific leaf weight with elevated CO2. Genotype Dharani recorded maximum root length, shoot length and leaf area at flowering stage and JL-24 at pegging stage. At elevated CO2, higher biomass was allocated to stem in JL-24, to roots in ICGV 91114, and no influence in Dharani as compared to other genotypes revealing its differential influence on biomass allocation. Increased Anet at enhanced CO2 was recorded in all the genotypes and it ranged from 18% (Abhaya) to 36% (Narayani), and the less efficient genotype at ambient condition recorded highest response and vice versa. The response of gs to elevated CO2 varied, whereas reduced Tr was recorded in all genotypes. At 550 ppm, groundnut genotypes showed 44% improvement in leaf level intrinsic WUE and maximum advantage (62%) was registered by Dharani. It is evident that the magnitude of groundnut crop response to elevated CO2 is cultivar, growth stage and component specific.