Abstract:

In this study, the gas exchange parameters, chlorophyll fluorescence parameters and grain yield of foxtail millet and green millet grown in the CO₂ open top chambers (380 or 560 ppm) were investigated. During elongation and heading stages, the elevated atmospheric CO₂ increased P_n more in green millet than in foxtail millet, especially during 10:00-14:00. Meanwhile, the e[CO₂] increased the Φ_PSII, qP and ETR for green millet but not for foxtail millet. In the heading stage, the e[CO₂] down-reguated P_n in green millet but not in the foxtail millet. In the harvest stage, the e[CO₂] increase panicle weight, grain weight per panicle and shoot biomass more in green millet than in foxtail millet. In conclusion, the e[CO₂] contributed to improve photosynthesis for green millet more than for foxtail millet, which may affect the foxtail millet production in future.

Key words: Elevated CO₂, Setaria viridis, Setaria italica, Photosynthesis

摘要：

比较了开顶式生长室中不同CO₂浓度（380 ppm与560 ppm）下狗尾草（Setaria viridis）与谷子（Setaria italica）光合作用的长期适应性。高浓度CO₂下，拔节与抽穗期狗尾草P_n显著高于谷子，且中午前后升高显著。高浓度CO₂下狗尾草抽穗期主要叶绿素荧光参数（Φ_PSII，qP和ETR）、收获期单株茎叶生物量、籽粒产量提高幅度均高于谷子。总之，高浓度CO₂对狗尾草光合能力的提高作用显著大于谷子，未来可能对谷子生产造成较大影响。

关键词: CO₂浓度升高, 狗尾草, 谷子, 光合作用