开放式臭氧浓度升高对水稻叶片光合作用日变化的影响

Effects of O_3-FACE(Ozone-free Air Control Enrichment)on Gas Exchange and Chlorophyll Fluorescence of Rice Leaf

运用开放式臭氧浓度升高系统(O3-FACE:Ozone-free air controlled enrichment)平台,以武运粳21(粳稻)和两优培九(杂交稻)两个耐性不同的品种为材料,研究了大气臭氧浓度升高对水稻叶片光合作用日变化的影响,旨在为高臭氧浓度条件下水稻生产和国家粮食安全的制定提供理论依据。结果表明,臭氧胁迫未改变光合作用日变化规律,处理和对照下净光合速率和气孔导度日变化相似,均呈现单峰曲线,高峰值出现在11:00—15:00之间;胞间CO2浓度日变化趋势与气孔导度和净光合速率日变化不一致;臭氧处理55d对净光合速率和气孔导度影响较小,随着处理时间的延长,相关指标降低幅度变大,而胞间CO2浓度没有降低,说明臭氧对水稻的影响是一个累积过程,净光合速率降低的主要因素是由非气孔限制引起的;武运粳21的净光合速率和气孔导度在臭氧处理时的降低幅度小于两优培九,这种品种间的差异表明武运粳21比两优培九对臭氧耐受性强。

In order to elaborating the response of rice to high ozone concentration, the leaf diurnal photosynthesis of two rice varieties （Wuyunjing 21 and Liangyoupeijiu） was investigated via O3-FACE（ozone- free air control enrichment） platform. This research could provide a theoretical basis for the development of rice production and national food security under high ozone concentration. Ozone fumigation began on July 1, 2008, and ended on Oct 10, 2008.56% of the time was used for active fumigation. The results showed that ozone stress did not change the diurnal pattern of photosynthesis;the maximum diurnal net photosynthetic rate（Pn） and stomatal conductance （Gs） occurred at 11：00-15：00. The diurnal pattern of internal cellular CO2 concentration（ Ci ） was inconsistent with that of ht and Gs （Ci did not significantly decreased during ozone fumigation ）. Ozone had little effect on/On and Gs at 55 days treatment, afterwards, with the extension of fumigation time the reductions of Pn and Gs were enlarged, however, no significant impact on leaf intercellular CO2 concentration was found. This indicated that the impact of ozone on rice was a cumulative effect and the depression of net photosynthetic rate was mainly restricted by nonstmatal factors. The Pn and Gs of Liangyoupeijiu decreased more than those of Wuyunjing 21, indicating that Wuyunjing 21 was more tolerant to ozone than Liangyoupeijiu.