基于开放式臭氧浓度升高O_3-FACE(Free-Air Concentration Elevation of O_3)实验平台,利用前期水稻O_3-FACE试验的基础数据,通过建立水稻产量与不同评价指标(累积气孔O_3吸收通量PODY和O_3浓度指标AOTX)的响应关系,比较了水稻产量损失...基于开放式臭氧浓度升高O_3-FACE(Free-Air Concentration Elevation of O_3)实验平台,利用前期水稻O_3-FACE试验的基础数据,通过建立水稻产量与不同评价指标(累积气孔O_3吸收通量PODY和O_3浓度指标AOTX)的响应关系,比较了水稻产量损失与各评价指标的相关性差异,通过对暴露剂量、吸收通量相关参数取值与产量损失的观察和分析结果的比较,找出更为合理的农作物臭氧风险评估阈值。结果表明:随着通量阈值Y[0~11 nmol O_3·m^(-2)PLA·s^(-1)(PLA:projected leaf area,投影叶面积)]和暴露浓度阈值X(0~50 n L·L^(-1))的增加,回归分析R^2值逐渐增加,当Y为11 nmol O_3m^(-2)PLA·s^(-1)和X为50 n L·L^(-1)时,气孔臭氧吸收通量POD11和累积暴露剂量AOT50与水稻相对产量的相关性最大,当通量阈值Y为8~13 nmol O_3·m^(-2)PLA·s^(-1)和暴露阈值X为46~58 n L·L^(-1)时,可获得较高的R^2值取值范围,分别为0.70~0.75和0.70~0.745。参考文献发现,目前地表臭氧污染可能引起的水稻产量损失范围为5%~8%,对照圈中POD9~10和AOT40~45产量损失的预测值亦在这区间,但前者R^2值(0.73~0.74)明显高于后者R^2值(0.64~0.69),表明基于气孔臭氧通量的评价指标能更好地反映水稻产量的变化。通过进一步分析发现,当通量阈值Y为9 nmol O_3·m^(-2)PLA·s^(-1)时,能更准确地评估水稻产量损失,且其R^2值(0.73)高于通量指标POD6(0.57)。以上研究结果表明,通量指标POD9更适合评估亚热带地区O_3污染对水稻作物的影响。展开更多
From 1986 to 1990 typical physiological races of Piricularia oryzae were chosen from 7 local groups,and the resistance spectrum for 768 rice varieties (strains) was determined. The resistance percentage of 34 varietie...From 1986 to 1990 typical physiological races of Piricularia oryzae were chosen from 7 local groups,and the resistance spectrum for 768 rice varieties (strains) was determined. The resistance percentage of 34 varieties constituting 4.4% of the total was up to 80-100%, while that of 109 moderate resistance varieties constituting 14. 2% of the total was up to 60 -79%. The other 625 varieties were susceptible. Moreover, 74 highly resistant varieties were tested and divided by 10 races from the 7 groups. There were 4 types with resistance percentage up to 90% ,and 3 types with resistance percentage up to 80%. According to the distribution of the dominant physiological races in different areas .resistant varieties can be selected to facilitate variety rotation. The results above showed that the spectrum of resistance was relatively stable and had a practical value to production and breeding.展开更多
文摘From 1986 to 1990 typical physiological races of Piricularia oryzae were chosen from 7 local groups,and the resistance spectrum for 768 rice varieties (strains) was determined. The resistance percentage of 34 varieties constituting 4.4% of the total was up to 80-100%, while that of 109 moderate resistance varieties constituting 14. 2% of the total was up to 60 -79%. The other 625 varieties were susceptible. Moreover, 74 highly resistant varieties were tested and divided by 10 races from the 7 groups. There were 4 types with resistance percentage up to 90% ,and 3 types with resistance percentage up to 80%. According to the distribution of the dominant physiological races in different areas .resistant varieties can be selected to facilitate variety rotation. The results above showed that the spectrum of resistance was relatively stable and had a practical value to production and breeding.
