Yield and photosynthetic characteristics of flag leaves in Chinese rice (Oryza sativa L.) varieties subjected to free-air release of ozone
Yield and photosynthetic characteristics of flag leaves in Chinese rice (Oryza sativa L.) varieties subjected to free-air release of ozone
复制标题
DOI：
10.1016/j.agee.2009.03.012
复制
发表时间：
2009-08
期刊：
影响因子：
--
通讯作者：
J. Pang;K. Kobayashi;Jianguo Zhu
中科院分区：
文献类型：
--
作者：
J. Pang;K. Kobayashi;Jianguo Zhu
研究了高浓度O3（[O3]）对水稻产量和剑叶光合特性的影响。以籼型杂交种SY 63和常规粳稻品种WYJ 3为材料，研究了两个籼型杂交种的遗传多样性。在江苏省江都市，采用空气富氧技术，分别在常温（A-O3）和高氧（E-O3，常温×1.5）条件下，对两个品种进行田间试验。E-O 3显著降低了地上生物量（p=0.047）和籽粒产量（p=0.0046），但对不同品种的收获指数（p=0.18）无显著影响。杂交籼稻SY 63对E-O3的敏感性高于常规粳稻WYJ 3。SY 63和WYJ 3的地上生物量分别减少了17.6%和6.6%，而籽粒产量分别减少了20.7%和6.3%。一个勉强不显着（p=0.079）之间的互作O3和品种对籽粒产量的杂交品种：SY 63的敏感性较高。SY 63旗叶光合特性对E-O_3的响应较早、较强。SY 63的光饱和光合速率（Asat）在237日龄（DOY）时首次出现下降，季节平均下降23.1%。而常规品种WYJ 3在266 DOY前对Asat的影响可忽略不计，Asat的季节平均下降率仅为9.4%。叶绿素a荧光参数也有相同的变化趋势。在SY 63中，PSII（p=0.007）和qp（光化学猝灭）（p=0.002）的实际量子产率在248 DOY时显著降低，并且在旗叶的其余寿命中持续下降趋势。在WYJ 3中未观察到此类变化。SY 63旗叶经臭氧处理后，在整个功能期内发生坏死，叶绿素含量下降12.6-43.6%。至于WYJ 3，叶绿素保持不受影响，直到25.7%的下降出现在278 DOY下E-O3。将观测到的产量损失与两种现有的水稻产量损失关系进行了比较。SY 63的产量损失远大于两种估计值，而WYJ 3的产量损失与一种估计值相当，但略大于另一种估计值。这就需要进一步研究更多的品种。露天O3释放可作为大规模筛选水稻品种提高[O3]的最佳平台。
The effects of elevated O3concentration ([O3]) on grain yield and photosynthetic characteristics of flag leaves in rice (Oryza sativa L.) were studied using a hybrid indica cultivar SY63 and a conventional Japonica cultivar WYJ3. Both cultivars were grown in the field under ambient (A-O3) and elevated [O3] (E-O3, ambient×1.5) using free-air O3enrichment in Jiangdu city, Jiangsu province, China. The E-O3significantly reduced above-ground biomass (p=0.047) and grain yield (p=0.0046), but had no significant effect on harvest index (p=0.18) across cultivars. The hybrid Indica cultivar SY63 was more sensitive to E-O3than the conventional Japonica cultivar WYJ3. The above-ground biomass was reduced by 17.6% for SY63 and 6.6% for WYJ3, whereas the grain yield was reduced by 20.7% for SY63 and 6.3% for WYJ3. A barely non-significant (p=0.079) interaction between O3and cultivar on grain yield suggested a higher sensitivity of the hybrid variety: SY63. In SY63, flag leaves exhibited an earlier and stronger response in photosynthetic characteristics to E-O3. Depression in light-saturated photosynthetic rate (Asat) was first observed at 237 day of year (DOY) in SY63, and the seasonal mean Asatwas reduced by 23.1%. In contrast, for WYJ3, the conventional cultivar, the impact of E-O3on Asatwas negligible until 266 DOY, and seasonal mean decrease of Asatwas only 9.4%. The same trend was found in chlorophyll a fluorescence parameters. In SY63, actual quantum yield of PSII (p=0.007) and qp(photochemical quenching) (p=0.002) were significantly decreased at 248 DOY and the downward trends persisted throughout the rest of the life span of flag leaves. No such changes were observed in WYJ3. In the ozonated flag leaves of SY63, necrotic damages occurred and chlorophyll contents declined significantly by 12.6–43.6% through the entire functional duration of the leaf. As for WYJ3, chlorophyll remained unaffected until a 25.7% decrease appeared at 278 DOY under E-O3. The observed yield losses were compared with those estimated from two existing exposure–yield loss relationships for rice. The yield loss in SY63 was much greater than either estimate, whereas that in WYJ3 was comparable to one estimate but was moderately larger than the other. This warrants further studies with a much larger number of varieties. Open-air O3release would serve as the best platform for such a large-scale screening of rice varieties to increasing [O3].