Variations in Leaf Gas Exchange Traits of Saccharum Including Feral Sugarcane, Saccharum spontaneum L.

Abstract

The effects of photosynthetic photon ñux density (PPFD) and temperature on leaf gas exchange rates often lines of Saccharum spontaneum L. collected from the tropics to temperate regions in North-West Pacific zones, S. sinense Roxb. cv. Yomitanzan, native sugarcane in South-West Islands, and Saccharum hybrid cv. NCo310 were investigated. The relationship of gas exchange traits and rates was examined. Significant line- and species-differences (P<0.05) were found in the carbon dioxide exchange rate (CER) at high PPFD (1700 µM photon m−2s−1), leaf stomatal conductance at low PPFD (180 µM photon m−2s−1), contents of total nitrogen, soluble protein, and chlorophyll, PEP carboxylase and malic enzyme activity, and specific leaf area (SLA). CER at high PPFD (P<0.05) of Tainan, S. spontaneum was significantly higher than that of Saccharum hybrid cv. NCo 310, while CERs of JW2, JW32, and JW41 of S. spontaneum were significantly higher than that of S. sinense Roxb. cv. Yomitanzan. CER of Tainan exhibited the highest value in a range of 20 to 35°C. Consequently, this suggests that S. spontaneum such as Tainan, is a useful germplasm source in sugarcane breeding. CER of Saccharum correlated significantly with leaf stomatal conductance (r = 0.496, P<0.01), the malic enzyme activity of Mn type (r = 0.838, P<0.01) and Mg type (r = 0.547, P<0.01), and the chlorophyll content (r = 0.466, P<0.01). © 1994, CROP SCIENCE SOCIETY OF JAPAN. All rights reserved.