【目的】 研究臭氧胁迫下不同敏感型水稻叶片表观响应特征,为耐性水稻品种的选育提供参考。【方法】 利用自然光气体熏蒸平台,以23个水稻品种或株系为供试材料,臭氧设置室内对照（10 nL/L）和高臭氧浓度（100 nL/L）两个处理。采用组内最小平方和动态聚类方法,根据供试材料地上部最终生物量对高浓度臭氧的响应从小到大依次分为A、B和C 3个类别,研究臭氧胁迫下不同敏感类型水稻叶片伤害指数（LBS）特别是顶3叶叶色值（SPAD值,土壤、作物分析仪器开发）的动态响应及其与最终生长量变化的关系。【结果】 臭氧胁迫使A、B和C 3类水稻成熟期地上部生物量平均分别下降19%、39%和52%,后两者降幅达极显著水平。臭氧处理水稻的LBS随生育期推移呈明显的增加趋势,但不同敏感类型水稻间均无显著差异,各测定时期表现一致。与对照相比,臭氧胁迫使不同测定时期的叶片SPAD值显著下降,降幅随熏蒸时间延长和叶位下移明显增加。全生育期平均,臭氧胁迫使所有供试材料倒1叶、倒2叶和倒3叶SPAD值分别下降11%、18%和30%,均达极显著水平。与此不同,臭氧胁迫对叶片SPAD值的影响不同水稻类型间无显著差异,不同测定时期趋势相同。相关分析表明,尽管臭氧胁迫水稻成熟期地上部生物量的响应与部分测定时期LBS存在一定的相关性,但其与所有测定时期叶片SPAD值变化的相关性均不显著,不同叶位趋势一致。【结论】在本研究条件下,臭氧熏蒸叶片的伤害指数和SPAD值的响应均不宜作为水稻生长对臭氧耐性程度的评价指标。

【Objective】In order to provide reference for ozone-tolerant rice breeding, the leaf characteristics of rice with different ozone sensitivity in response to ozone stress were studied.【Method】By using glasshouse-type fumigation chambers, 23 rice cultivars or lines were grown in soil from around a week after transplanting to maturity at two ozone concentrations: low ozone concentration as control (C-O₃, 10 nL/L) and high ozone concentration as elevated O₃ treatment (E-O₃, 100 nL/L). Based on the decrease in the above-ground biomass under high ozone concentration, these rice genotypes were clustered into three types by the MinSSw (dynamic clustering method-minimum sum of squares within groups) method, namely A, B and C in the order of ozone sensitivity from low to high, respectively. The effects of ozone stress on leaf bronzing score (LBS) and Soil and Plant Analyzer Development (SPAD) values of the top three leaves were examined, and the relationships between leaf LBS or SPAD under ozone stress and the ozone-induced changes in the above-ground biomass at maturity stage were studied.【Result】Ozone stress decreased the above-ground biomass of three rice types A, B and C at maturity by 19%, 39% and 52%, respectively, and significant treatment effects were detected in B and C. The LBS of rice under ozone stress increased along with the process of plant growth, but no significant difference was detected among different types of rice, irrespective of growth stages. Compared to the control, ozone stress significantly decreased the leaf SPAD values of all growth stages, and the decline was increased with the prolonging fumigation time and the lowering leaf position. Averaged across all growth stages, ozone stress significantly decreased the leaf SPAD values of the first, second and third leaf from the top by 11%, 18% and 30%, respectively. On the contrast, the influence of ozone stress on the leaf SPAD values showed no significant difference among different types of rice, and different growth stages showed the same trend. Correlation analysis showed that, although there were positive correlations between the ozone-induced changes in the rice above-ground biomass and LBS of a few growth stages, the ozone-induced changes in the above-ground biomass were not closely associated with that of the leaf SPAD values of all growth stages, and same trends were observed for all leaves at different leaf positions.【Conclusion】The above results indicated that under current experimental conditions, leaf bronzing score and leaf SPAD value were not suitable index to evaluate the rice tolerance to ozone stress.