Handbook of Plant and Crop Physiology

Figure 4 Photosynthesis and immediate export rates of source leaves of 42 species measured at ambient CO 2
(35 Pa, A and C) and at short-term exposure to elevated (90 Pa, B and D) CO 2 levels. Export rates were expressed
in absolute values (A and B) and as relative C efflux rate calculated as a percentage of the photosynthesis rate
(C and D). Each panel was divided into four areas (quadrants) so that the data among panels could be compared
easily. The species included C 3 types (numbers alone) as well as C 4 and C 3 -C 4 intermediate types, which are in-
dicated by * and (next to the numbers), respectively. The 42 species were 1, Alstroemeriasp. cv. Jacqueline;
2,Amaranthus retroflexus; 3, Apium graveolens; 4, Avena sativaL. cv. Elgin; 5, Capsicum annuumcv. Cu-
bico; 6, Chrysanthemum morifolium; 7, Coleus blumei; 8, Cucumis sativuscv. Revenue; 9, Flaveria bidentis;
10,Flaveria chloraefolia; 11, Flaveria floridana; 12, Flaveria linearis; 13, Flaveria pringlei; 14, Flave-
ria robusta; 15, Flaveria trinervia; 16, Gomphrena globosa; 17, Helianthus annuus; 18, Hordeum vulgare;
19,Nepeta faassenii; 20, Nicotiana tabacum; 21, Panicum antidotale; 22, Panicum bisulcutum; 23, Panicum
bulbosum; 24*, Panicum capillare; 25, Panicum decipiens; 26, Panicum dichotomiflorum; 27, Panicum
laxum; 28, Panicum leavifolium; 29, Panicum makarikariense; 30, Panicum maximum; 31*, Panicum mili-
aceum; 32, Panicum milioides; 33, Panicum trichanthum; 34, Panicum virgatum; 35, Phaseolus vulgaris;
36,Pisum sativumcv. Improved Laxton’s Progress; 37, Rosa hybridacv. Samantha; 38, Salvia splendenscv.
Bonfire; 39, Sandersonia aurantiaca; 40, Sorghum bicolorcv. Sudan; 41, Triticum aestivumcv. Karat; 42,
Zea mays. Measurements were made under light saturating conditions and at the growing temperature (25°C ex-
cept for the Panicumspecies, which was 30°C). Each point is an average of at least four leaves on four different
plants. The SEs of the means are not shown for graphical clarity. Starting from top to bottom and from left to
right, species’ numbers that overlap within each panel were: A (30, 31), (16, 26), (15, 24), (9, 14), (34,
32), (28*, 30), (13, 18), (35, 10, 5), and (22, 37); B (36, 15*), (32, 6, 34), and (27, 1); C (24, 26, 16),
(32, 8), (18, 13), (29, 28, 30), and (10, 5); and D (19, 16), (34, 25), (32*, 29), and (31, 15, 36).
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