Effects of elevated atmospheric CO2 concentration on morphology of leaf blades in Chinese yam |
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Authors: | Nguyen Cong Thinh Etsushi Kumagai Hiroyuki Shimono |
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Institution: | 1. The United Graduate School of Agricultural Sciences, Iwate University, Iwate, Japan;2. Agro-Environmental Research Division, NARO Tohoku Agricultural Research Center, Iwate, Japan |
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Abstract: | ABSTRACTThe effects of elevated carbon dioxide concentration on the morphology of leaf blades in two Chinese yam lines under different temperature conditions were determined. Plants were grown under two CO2] levels, ambient (about 400 µmol mol?1) and elevated (ambient + 200 µmol mol?1) in the daytime, and two mean air temperature regimes, approximately ambient temperature (22.2°C) and high temperature (25.6°C). The palisade layer was thicker under elevated CO2] than under ambient CO2] in both temperature regimes, and the whole yam leaf blade was thicker under elevated CO2] than under ambient CO2] in the approximately ambient temperature regime. The numbers of chloroplasts per palisade cell and spongy cell as well as per unit profile area of palisade cell, number of starch grains per chloroplast, profile area of the starch grain, and starch-to-chloroplast area ratio in both palisade and spongy cells were higher under elevated CO2] than under ambient CO2] in both temperature regimes. Furthermore, the stomatal density on the abaxial side of the leaf blade in Chinese yam was greater under elevated CO2] than under ambient CO2] under both temperature regimes, and stomatal-pore length was higher under elevated CO2] than under ambient CO2] in the approximately ambient temperature regime. These results indicate that elevated CO2] positively affects the photosynthetic apparatus. The results of this study provide information for understanding the response characteristics of the leaf blade under elevated CO2] and a possible explanation for the positive photosynthetic responses of Chinese yam to elevated CO2] in our previous study.List of Abbreviations:CO2]: carbon dioxide concentration |
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Keywords: | Chinese yam chloroplast elevated CO2 morphology starch grain |
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