Revista de fisiología y patología vegetal

Impact of Elevated CO2 on Growth and Physiological Parameters of Groundnut (Arachis hypogaea L.) Genotypes

Sunitha Vaidya, Vanaja M, Sathish P, Anitha Y and Jyothi Lakshmi N

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.