Rice cultivar responses to elevated CO2 at two free-air CO2 enrichment (FACE) sites in Japan

• Published in: Functional plant biology : FPB Vol. 40; no. 2; pp. 148 - 159
• Main Authors: Hasegawa, Toshihiro, Sakai, Hidemitsu, Tokida, Takeshi, Nakamura, Hirofumi, Zhu, Chunwu, Usui, Yasuhiro, Yoshimoto, Mayumi, Fukuoka, Minehiko, Wakatsuki, Hitomi, Katayanagi, Nobuko, Matsunami, Toshinori, Kaneta, Yoshihiro, Sato, Takashi, Takakai, Fumiaki, Sameshima, Ryoji, Okada, Masumi, Mae, Tadahiko, Makino, Amane
• Format: Journal Article
• Language: English
• Published: 01.01.2013
• Subjects: air temperature; brown rice; carbon dioxide; cultivars; grain yield; Japan; yield components; Japan
• ISSN: 1445-4408; 1445-4416; 1445-4416
• DOI: 10.1071/FP12357

There is some evidence that rice cultivars respond differently to elevated CO2 concentrations ([CO2]), but [CO2] × cultivar interaction has never been tested under open-field conditions across different sites. Here, we report on trials conducted at free-air CO2 enrichment (FACE) facilities at two sites in Japan, Shizukuishi (2007 and 2008) and Tsukuba (2010). The average growing-season air temperature was more than 5°C warmer at Tsukuba than at Shizukuishi. For four cultivars tested at both sites, the [CO2] × cultivar interaction was significant for brown rice yield, but there was no significant interaction with site-year. Higher-yielding cultivars with a large sink size showed a greater [CO2] response. The Tsukuba FACE experiment, which included eight cultivars, revealed a wider range of yield enhancement (3–36%) than the multi-site experiment. All of the tested yield components contributed to this enhancement, but there was a highly significant [CO2] × cultivar interaction for percentage of ripened spikelets. These results suggest that a large sink is a prerequisite for higher productivity under elevated [CO2], but that improving carbon allocation by increasing grain setting may also be a practical way of increasing the yield response to elevated [CO2].