title: Yield, chemical composition and nutritional quality responses of carrot, radish and turnip to elevated atmospheric carbon dioxide.
abstract: BACKGROUND
  Future concentration of carbon dioxide in the atmosphere is very important due to its apparent economic and environmental impact in terms of climate change. However, a compressive assessment of its effect on the nutritional and chemical characteristics of food crops has yet to be established. In the present study the impact of elevated atmospheric CO2 on the yield, chemical composition and nutritional quality of three root vegetables, carrot (Daucus carota L. cv. T-1-111), radish (Raphanus sativus L. cv. Mino) and turnip (Brassica rapa L. cv. Grabe) has been investigated.
  
  
  RESULTS
  The yield of carrot, radish and turnip increased by 69, 139 and 72%, respectively, when grown under elevated CO2 conditions. Among the proximate composition, protein, vitamin C and fat contents decreased significantly for all the vegetables while sugar and fibre contents were increased. Response of the vegetables to elevated CO2 , in terms of elemental composition, was different with a significant decrease in many important minerals. Elevated CO2 decreased the amount of majority of the fatty acids and amino acids in these vegetables.
  
  
  CONCLUSIONS
  It was observed that elevated CO2 increased the yield of root vegetables but many important nutritional parameters including protein, vitamin C, minerals, essential fatty acids and amino acids were decreased.
authors.affiliation: Department of Chemistry, University College of Science Shankar, Abdul Wali Khan University Mardan, Mardan, Pakistan; Institute of Chemical Sciences, University of Peshawar, Peshawar, Pakistan.
authors.forename: Andaleeb
authors.initials: A
authors.lastname: Azam
authors.forename: Ikhtiar
authors.initials: I
authors.lastname: Khan
authors.forename: Abid
authors.initials: A
authors.lastname: Mahmood
authors.forename: Abdul
authors.initials: A
authors.lastname: Hameed
mesh_terms: D001205:Ascorbic Acid / Q000032:analysis; D001272:Atmosphere / Q000737:chemistry*; D029688:Brassica napus / Q000737:chemistry* / Q000254:growth & development; D002245:Carbon Dioxide / Q000032:analysis*; D018552:Daucus carota / Q000737:chemistry* / Q000254:growth & development; D004041:Dietary Fats / Q000032:analysis; D004043:Dietary Fiber / Q000032:analysis; D019422:Dietary Sucrose / Q000032:analysis; D008903:Minerals / Q000032:analysis; D009753:Nutritive Value; D010940:Plant Proteins / Q000032:analysis; D018517:Plant Roots / Q000737:chemistry; D031224:Raphanus / Q000737:chemistry* / Q000254:growth & development
chemical_list: D004041:Dietary Fats; D004043:Dietary Fiber; D019422:Dietary Sucrose; D008903:Minerals; D010940:Plant Proteins; D002245:Carbon Dioxide; D001205:Ascorbic Acid
keywords: carrot; elemental composition; elevated CO2; nutritional quality; radish; turnip; yield