Effects of Free-air CO_2 Enrichment (FACE) on Growth Duration of Rice (Oryza sativa L.) and Its Cause
HUANG Jian-Ye~1,YANG Lian-Xin~1,YANG Hong-Jian~1,LIU Hong-Jiang~1,DONG Gui-Chun~1,ZHU Jian-Guo~2,WANG Yu-Long~(1,*)(~1 Key Laboratory of Crop Cultivation & Physiology of Jiangsu Province, Yangzhou University, Yangzhou 225009, Jiangsu; ~2 Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, Jiangsu, China)
Global atmospheric CO_2 concentrations () are projected to reach levels of 650-780 μmol·mol~(-1) at the end of this century (IPCC,2000). The increase in atmospheric has the potential to enhance the growth and development of rice. However,little is known about the effect of free-air CO_2 enrichment (FACE) on growth duration of rice and its physiological cause. So we conducted a FACE experiment at Anzhen,Wuxi,Jiangsu Province,in 2001-2003,using the Japonica cultivar Wuxiangjing 14. The target of the FACE plots was 200 μmol·mol~(-1) above that in the ambient air. Three levels of N were supplied:low (LN,150 kg·ha~(-1)),normal (NN,250 kg·ha~(-1)) and high N (HN,350 kg·ha~(-1)). Results showed that:Compared with CK,the duration from sowing to heading, from heading to maturity and the whole growth duration of rice shrank 3-5 d (mean value 3.4 d),1-5 d (mean value 2.4 d),4-9 d (mean value 5.8 d)days in FACE treatment. Increment of nitrogen application rate could weaken the effect of FACE on growth duration. FACE treatment resulted in the obvious decrease of N content in rice plant and obvious increase of P content in rice plant and soluble carbohydrates content in stem and sheath at different growth stage. Multiple regression and path analysis indicated that the sequence of factors which had significant effect on whole growth duration from the biggest to the smallest were N content in rice plant at jointing stage, P content in rice plant at heading stage, soluble carbohydrates content in stem and sheath at heading stage and N content in rice plant at N-n leaf stage. This suggests that one of the physiological reasons for the reduction of whole growth duration is the obvious decrease of N content in rice plant at jointing stage and obvious increase of P content in rice plant and soluble carbohydrates content in stem and sheath at heading stage.
【Fund】： 国家自然科学基金项目(30270777 30471013);; 国家自然科学基金重大国际合作研究项目(40120140817);; 中国科学院知识创新重要方向项目(KZCX2408)资助。
【CateGory Index】： S511
【CateGory Index】： S511