关键词: 水稻, 大气CO₂浓度增加, 稻米外观品质, 稻米加工品质, 稻米蒸煮品质, 稻米蛋白质含量

Abstract: In a growth experiment, five relatively constant gradients of total nitrogen (TN) and phosphorous (TP) concentrations were installed to study the endurance of Elodea nuttallii to high concentrations of nitrogen and phosphorus. The pH value, DO, planktonic chlorophyll a, and periphytic chlorophyll a in the culture solutions as well as the height, wet and dry weights, and chlorophyll a concentration of E. nuttallii were compared among the treatments. Elodea uttallii could endure the stress of TN=10 mg·L^-1and TP=0.4 mg·L^-1, and no abundant phytoplankton occurred under this stress. However, under the stress of TN=50 mg·L^-1and TP=2 mg·L^-1and of TN=100 mg·L^-1and TP=4 mg·L^-1, E. nuttallii growth was obviously limited, and plankton increased but periphyton decreased markedly, which suggested that the high concentration TN and TP in water body could have direct damage to E. nuttallii, and the shading caused by phytoplankton multiplication could partly limited the growth of E. nuttallii. As for Taihu Lake, in which, the average concentrations of TN and TP were lower than 10 mg·L^-1and 04 mg·L^-1, respectively, the decline of submerged aquatic macrophytes could not be caused by the direct harm and stress of nitrogen and phosphorus.

Key words: Rice, Free-air CO₂ enrichment, Appearance quality of rice grain, Milling quality of rice grain, Cooking quality of rice grain, Protein content of rice grain