Central Research Institute for Dryland Agriculture (CRIDA), India
Sunitha Vaidya completed M.Sc. (Biosciences specialization in Biotechnology) and MPhil (Biosciences) from Sri SathyaSai Institute of Higher Learning, Puttaparthi, India. She had received Smt. Eshwaramma Gold medal for excellence in MPhil in 2010 and currently pursuing Ph.D. (Botany) in Central Research Institute for Dry Land Agriculture (CRIDA), Hyderabad registered under Osmania University.
Five groundnut (Arachis hypogea.L) cultivars- Jl-24, ICGV91114, Narayani, Abhaya and Dharani were evaluated under ambient (390 ppm) and elevated (550 ppm) CO2 in OTCs during 2013 Kharif. Observations were recorded on leaf area, biomass accumulation at flowering (30 DAS) and pegging stages (45 DAS) and photosynthetic rate (Anet), stomatal conductance (gs) and transpiration rate (Tr) on pegging stage (39 DAS). Elevated CO2 enhanced the total biomass of all the genotypes at both sampling points. Improvement in total biomass due to elevated CO2 was higher (34%) with ICGV 91114 and Narayani at 30 DAS, with JL-24 at 45 DAS. At 550 ppm CO2, Dharani recorded highest root length, shoot length and leaf area at 30 DAS and Jl-24 at 45 DAS. The response of leaf biomass and specific leaf weight of ICGV 91114 at elevated CO2 was highest at 30 DAS. The allocation of biomass was not similar with all genotypes, at elevated CO2 more biomass was allocated to stem in JL-24 whereas to roots in ICGV 91114 and not influenced in Dharani. The Anet increased with enhanced CO2 in all the genotypes ranging from 21% (Abhaya) to 42% (Narayani) where as reduced gs and Tr was recorded with Abhaya and Dharani. JL-24 had the highest per se value for leaf level intrinsic WUE at 550ppm with 41% advantage due to enhanced CO2 condition. It is evident that the response of groundnut crop to elevated CO2 is cultivar, growth stage and component specific.