Agriculture, Ecosystems and Environment 87 (2001) 273–285
Effects of elevated CO
2
and O
3
on tuber quality in potato
(Solanum tuberosum L.)
Alison Donnelly
a
, Tracy Lawson
b
, Jim Craigon
a,∗
,
Colin R. Black
a
, Jeremy J. Colls
a
, Geoff Landon
a
a
University of Nottingham, Sutton Bonington Campus, Loughborough LE12 5RD, UK
b
Department of Biological Sciences, John Tabor Laboratories, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, UK
Received 3 July 2000; received in revised form 30 October 2000; accepted 17 November 2000
Abstract
This study examined the effects of season-long exposure to elevated carbon dioxide (CO
2
) and/or ozone (O
3
) on tuber
quality in potato (Solanum tuberosum L. cv. ‘Bintje’). Stands of potato were grown to maturity in open-top chambers (OTCs)
in 1998 and 1999 under a factorial combination of three CO
2
(ambient, 550 and 680 mol mol
-1
) and two O
3
levels (ambient
and elevated; 8 h per day seasonal means of 50 and 65 nmol mol
-1
in 1998 and 1999, respectively). The intermediate CO
2
concentration was omitted from analysis of tuber quality. In 1999, the starch content of tubers and the viscosity of the
resulting paste were increased by elevated CO
2
(P< 0.05). Tuber nitrogen content was reduced by elevated CO
2
in both
years (P< 0.05), but nitrate content was decreased only in 1999 (P< 0.05). Elevated CO
2
reduced citric acid content
in 1998 (P< 0.05) and increased Vitamin C content in 1999 (P< 0.05). Elevated CO
2
also tended to decrease the total
glycoalkaloid content of tubers (P< 0.08) by decreasing their -chaconine content. Elevated O
3
had less marked effects
on tuber quality even though AOT40 values (accumulated O
3
exposure above a threshold of 40 nmol mol
-1
) of 12,461 and
27,113 nmol mol
-1
h were applied in 1998 and 1999, respectively. In 1998 the paste produced from tubers produced under
elevated O
3
was more viscous (P< 0.05) and in 1999 the starch granules were less resistant to swelling (P< 0.05) than in
tubers produced under ambient O
3
. Total glycoalkaloid content was increased in 1999 because of an increase in -solanine
content (P< 0.05). No CO
2
× O
3
interactions were detected for any of the quality parameters examined. The results are
discussed in the context of the likely effects of predicted changes in climatic conditions on tuber quality. © 2001 Elsevier
Science B.V. All rights reserved.
Keywords: Carbon dioxide; Ozone; Potato; Solanum tuberosum L.; Tuber quality; Open-top chambers (OTCs); United Kingdom
1. Introduction
Future climatic conditions are likely to differ appre-
ciably from those currently experienced (IPCC, 1996).
∗
Corresponding author. Tel.: +44-115-951-6252;
fax: +44-115-951-6334.
E-mail address: jim.craigon@nottingham.ac.uk (J. Craigon).
Atmospheric carbon dioxide (CO
2
) concentration
has increased from 290 mol mol
-1
in pre-industrial
times to ca. 370 mol mol
-1
, and is expected to reach
ca. 550 mol mol
-1
by the middle of the present cen-
tury (Houghton et al., 1992; Schimel et al., 1996).
Tropospheric ozone (O
3
) concentration is also ris-
ing at an annual rate of ca. 0.5% (Hertstein et al.,
1995); O
3
is not only a “greenhouse gas”, but is also
0167-8809/01/$ – see front matter © 2001 Elsevier Science B.V. All rights reserved.
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