[Response of rice grain quality traits to free-air CO2 enrichment]

The study showed that under field condition, when the CO2 concentration was elevated 200 micromol x mol(-1) above control, the average brown rice rate of japonica variety Wuxiangjing 14 was 1.4% higher, while lead milled rice rate was 12.3% lower than control. The brown rice rate increased at lower nitrogen supply level (LN), while lead milled rice rate increased at higher nitrogen supply level (HN). The percentage of chalky grain was 11.9% higher, and chalkiness degree was 2.8% higher than control, but no obvious difference was found in chalkiness area between the FACE and the control. The chalkiness area, percentage of chalky grain and chalkiness degree decreased at HN plus higher phosphorus supply level (HP). The gelatinization temperature was elevated 0.52 degrees C, gel consistency increased, while amylose content was not statistically significant. The amylose content decreased at HN plus HP, while gel consistency and gelatinization temperature decreased at LN plus HP and at LN, respectively. The protein content was decreased 0.6% under FACE treatment and at LN plus lower phosphorus supply level.