UV-B辐射增强及CO_2浓度升高对水稻产量及品质的影响

Effects of Enhancing UV-B Radiation and Elevating Carbon Dioxide on Yield and Quality of Rice( Oryza sativa L. )

于2008年以日本粳稻品种Sasanishiki为研究材料，利用开放式气候室，以正常CO2浓度350±50mg／L和自然光照处理为对照，设置UV-B14．7kJ／（m^2·d）、CO2 700±50mg／L及CO2＋UV—B复合3个处理，研究了CO2浓度升高及UV-B辐射增强对该品种水稻糙米产量及品质的影响。结果表明：（1）水稻单株产量C02浓度升高处理增加21．78％，而千粒重、单株穗数、穗粒数及结实率无显著变化。结实率与单株产量UV-B辐射增强及复合处理分别降低6．44％、6．13％、14．89％、14．79％。千粒重复合处理降低5．28％。（2）CO2浓度升高及复合处理导致糙米的完整粒比率下降（29．54％-42．18％），断裂粒（29．73％-03．25％）和未成熟粒（30．71％～176．36％）的比率增加。UV-B胁迫下，未成熟粒比率增加幅度均小于CO2单独处理及复合处理。（3）UV-B辐射增强、CO2浓度升高及复合处理均显著增加脂肪酸含量（32．6％-76．29％）和蛋白质含量（5．3％-28．0％），而对水分和支链淀粉含量没有影响。综上所述，UV-B辐射增强显著抑制了水稻产量；CO2浓度升高显著增加水稻产量，但在本试验设计范围内，CO2浓度升高并未缓解UV-B辐射增强的抑制效应；UV-B辐射增强、C02浓度升高及二者复合处理均显著改变了该品种稻米的营养品质。

The effects of elevated CO2 concentration 700 ± 50mg/L, enhanced UV-B radiation 14.7kJ/（ m^2 · d） and the combined treatments [ 700 ± 50mg/L, 14.7k J/（ m^2 · d） ] on yield and quality of Japanese japonica varie- ties Sasanishiki were observed in our study with an open climate chamber. The results showed that： （ 1 ） Elevated CO2 concentration significantly increased the yield per plant （21.78%） ,but had no significant influence on thou- sand grain weight, panicles per plant, grains per plant and seed setting rate. The yield and seed setting rate were de- creased by 6.44% ,6. 13%, 14.89%, 14.79% under enhanced UV-B radiation and the combined treatments. Meanwhile, the combined treatments significantly reduced thousand seed weight; （2） Elevated CO2 concentration and the combined treatments led to the decreases in the ratio of perfect kernel （29.54% -42.18% ）, and increases in ratio of broken kernel （29.73% - 103.25% ） and immature kernel （30.71% - 176.36% ）. The broken kernel ratio and immature kernel ratio under enhanced UV-B stress were less than CO2 alone treatment and the combined treatments. （3） Enhanced UV-B radiation, elevated COa concentration and the combined treatments significantly increased fatty acid content （32.6% -76.29% ） and protein content （5.3% -28.0% ） ,while had no effect on water and amylopectin content. In conclusion, enhanced UV-B radiation significantly inhibit the yield, and elevated CO2 concentration significantly increased the yield, but in this experiment, elevated COE concentration did not alle- viate the inhibition effect of enhanced UV-B radiation ; On the other hand, enhanced UV-B radiation, elevated CO2 concentration and the combined treatments all significantly changed the nutritional quality of this rice varieties.