The relationship between changes in photosynthesis and growth for radish plants fumigated with SO2 and O3

Journal Article (Journal Article)

The effects of possible ambient concentrations of SO and O on biomass production and gas exchange of radish (Raphanus sativus L, cv. Cherry Belle) are examined, the relationship between photosynthesis and growth is defined and the mechanisms behind pollutant induced changes in growth are elucidated. Ozone was shown to be considerably more phytotoxic than SO . Fumigation at a concentration as low as 5 μmol O m (0.12μl 1 ) produced ‘visible’ injury. No ‘visible’ injury symptoms were apparent with plants fumigated with SO . The effect of fumigation with O at concentrations greater than 2.5 μmol m (0.06 μl 1 ) was to reduce biomass production and alter carbon partitioning. This was not so for SO , fumigated plants. Ozone‐fumigated plants showed a significant reduction in their photosynthetic efficiency (NAR) and despite an increase in LAR, RGR was still depressed below control values. The relationship between photosynthesis and biomass production for fumigated plants was examined and whole plant carbon acquisition was calculated from gas‐exchange measurements. On comparing calculated carbohydrate production with measured biomass accumulation, it was dear that changes in A were closely related to changes in growth. Light‐ and CO ‐response curves were used to determine maximum light‐saturated photosynthesis (A ), incident quantum yield QY and carboxylation efficiency (d.A/de ), RuBP‐regeneration capacity (J ) respectively. The presence of SO over a concentration of 2.5–8.3 μmol m (0.12–0.20 μl ) enhanced A . QY and J , However, dA/dc , was reduced at all concentrations. This reduction was offset by an increase in J . At the smallest O concentration (2.5 μmol m ) A was stimulated and at the higher concentration severely reduced. Q Y was not negatively influenced by the presence of O , but d.A/dc and J were reduced, particularly as the dose increased. Copyright © 1988, Wiley Blackwell. All rights reserved 2 3 2 3 2 a 2 2 max 1 max 2 max max 1 max 3 max 3 1 max −3 −1 −3 −1 −3 −1 −3

Full Text

Duke Authors

Cited Authors


Published Date

  • January 1, 1988

Published In

Volume / Issue

  • 110 / 2

Start / End Page

  • 173 - 184

Electronic International Standard Serial Number (EISSN)

  • 1469-8137

International Standard Serial Number (ISSN)

  • 0028-646X

Digital Object Identifier (DOI)

  • 10.1111/j.1469-8137.1988.tb00250.x

Citation Source

  • Scopus