Effect of elevated CO2 concentration on growth, chlorophyll content and yield of mungbean (Vigna radiata L. Wilczek) genotypes
2005
Haque, Md.S.(Bangabandhu Agricultural Univ., Salna (Bangladesh)) | Karim, Md.A. | Haque, Md.M. | Hamid, A. | Nawata, E.
Elevated CO2 concentration promotes growth in most of the C3 plants. This study was initiated to analyze the genotypic variations in growth and yield response to elevated CO2 concentration, using ten yield promising mungbean (Vigna radiata L.) genotypes. Plants were grown under 1) open top chamber (OTC with 570+-20 ppm CO2, 2) OTC with ambient CO2, which was about 370 ppm inside the OTC, and 3) open field (about 370 ppm CO2 level). Elevated CO2 concentration advanced first flowering and pod maturity by 1-3 days. Plant height and leaf area increased in all the genotypes. Number of stomata also increased by elevated concentration of CO2. Total chlorophyll (Chl) content was initially higher under the two OTC conditions. The Chl content at elevated CO2 concentration showed a fast decrease from the flowering stage. Elevated CO2 concentration also significantly increased the number of pods per plant and seed size, although the effect on the number of seeds per pod was not appreciable. Genotypic variations in these characters were evident under all the growing conditions. One genotype, Chainat 36, showed an exceptionally large increase in the 100g-grain weight by OTC and elevated CO2 treatments. Genotypic variations in grain yield and aboveground biomass production were also conspicuous. Chainat 36 displayed a high yield when treated with elevated CO2 concentration as well as under the OTC + ambient CO2 conditions, whereas the yield was low under field conditions. The genotypic variations in the response of various plant characters to elevated concentration of CO2 could be useful for the implementation of crop improvement programs.
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