Chlorophyl fluorescence transient from initial to maximum fluorescence （“P”step） throughout two intermedi-ate steps （“J”and“I”） （JIP-test） is considered a reliable early quantitative indicator of stress in...Chlorophyl fluorescence transient from initial to maximum fluorescence （“P”step） throughout two intermedi-ate steps （“J”and“I”） （JIP-test） is considered a reliable early quantitative indicator of stress in plants. The JIP-test is particularly useful for crop plants when applied in variable field environments. The aim of the present study was to conduct a quantitative trait loci （QTL） analysis for nine JIP-test parameters in maize during flowering in four field environ-ments differing in weather conditions. QTL analysis and identification of putative candidate genes might help to explain the genetic relationship between photosynthesis and different field scenarios in maize plants. The JIP-test param-eters were analyzed in the intermated B73 ？ Mo17 （IBM） maize population of 205 recombinant inbred lines. A set of 2,178 molecular markers across the whole maize genome was used for QTL analysis revealing 10 significant QTLs for seven JIP-test parameters, of which five were co-localized when combined＆amp;nbsp;over the four environments indicating polygenic inheritance and pleiotropy. Our results demonstrate that QTL analysis of chlorophyl fluorescence parameters was capable of detecting one pleiotropic locus on chromosome 7, coinciding with the gene gst23 that may be associated with efficient photosynthe-sis under different field scenarios.展开更多
探讨O3处理对‘赤霞珠’葡萄叶片光系统功能Ⅱ（PSⅡ）的伤害机制及O3胁迫发生阈值。以一年生‘赤霞珠’为试材,设置不同O3浓度（25、40、55、80和105 n L·L-1）,测定叶片叶绿素含量、气体交换和叶绿素荧光参数,分析不同O3浓度处...探讨O3处理对‘赤霞珠’葡萄叶片光系统功能Ⅱ（PSⅡ）的伤害机制及O3胁迫发生阈值。以一年生‘赤霞珠’为试材,设置不同O3浓度（25、40、55、80和105 n L·L-1）,测定叶片叶绿素含量、气体交换和叶绿素荧光参数,分析不同O3浓度处理对葡萄叶片PSII活性的影响。结果表明,随着O3浓度升高,叶片净光合速率（Pn）、气孔导度（Gs）、PSII的实际光化学效率（ΦPSII）、光下最大光化学效率（Fv’/Fm’）、捕获光能用于QA以后的电子传递的概率（ΨEo）、单位面积有活性反应中心的数量（RC/CSm）均呈下降趋势;PSII激发压（1-qP）、K点的相对可变荧光（Wk）、慢相荧光淬灭（qI）呈现上升趋势;在低O3浓度条件下（25~55n L·L-1）,Pn的下降主要是由于气孔限制引起的,O3浓度达到并超过80 n L·L-1时,叶绿素含量显著降低,非气孔限制占主导因素,PSII功能开始受到抑制;浓度达到105 n L·L-1时叶片出现较明显的表观伤害症状,电子供体侧伤害程度大于受体侧。实验结果说明,葡萄叶片可以在短时间内（8 h）忍受一定浓度（不超过55 n L·L-1）的O3胁迫,O3浓度达到或超过80 n L·L-1时,PSII功能受到较严重的抑制。展开更多
基金supported by research grants 073-0731674-1673,073-0731674-0841 and 073‐0730463-0203 from Ministry of Science,Education and Sports,Republic of Croatia
文摘Chlorophyl fluorescence transient from initial to maximum fluorescence （“P”step） throughout two intermedi-ate steps （“J”and“I”） （JIP-test） is considered a reliable early quantitative indicator of stress in plants. The JIP-test is particularly useful for crop plants when applied in variable field environments. The aim of the present study was to conduct a quantitative trait loci （QTL） analysis for nine JIP-test parameters in maize during flowering in four field environ-ments differing in weather conditions. QTL analysis and identification of putative candidate genes might help to explain the genetic relationship between photosynthesis and different field scenarios in maize plants. The JIP-test param-eters were analyzed in the intermated B73 ？ Mo17 （IBM） maize population of 205 recombinant inbred lines. A set of 2,178 molecular markers across the whole maize genome was used for QTL analysis revealing 10 significant QTLs for seven JIP-test parameters, of which five were co-localized when combined＆amp;nbsp;over the four environments indicating polygenic inheritance and pleiotropy. Our results demonstrate that QTL analysis of chlorophyl fluorescence parameters was capable of detecting one pleiotropic locus on chromosome 7, coinciding with the gene gst23 that may be associated with efficient photosynthe-sis under different field scenarios.
文摘探讨O3处理对‘赤霞珠’葡萄叶片光系统功能Ⅱ（PSⅡ）的伤害机制及O3胁迫发生阈值。以一年生‘赤霞珠’为试材,设置不同O3浓度（25、40、55、80和105 n L·L-1）,测定叶片叶绿素含量、气体交换和叶绿素荧光参数,分析不同O3浓度处理对葡萄叶片PSII活性的影响。结果表明,随着O3浓度升高,叶片净光合速率（Pn）、气孔导度（Gs）、PSII的实际光化学效率（ΦPSII）、光下最大光化学效率（Fv’/Fm’）、捕获光能用于QA以后的电子传递的概率（ΨEo）、单位面积有活性反应中心的数量（RC/CSm）均呈下降趋势;PSII激发压（1-qP）、K点的相对可变荧光（Wk）、慢相荧光淬灭（qI）呈现上升趋势;在低O3浓度条件下（25~55n L·L-1）,Pn的下降主要是由于气孔限制引起的,O3浓度达到并超过80 n L·L-1时,叶绿素含量显著降低,非气孔限制占主导因素,PSII功能开始受到抑制;浓度达到105 n L·L-1时叶片出现较明显的表观伤害症状,电子供体侧伤害程度大于受体侧。实验结果说明,葡萄叶片可以在短时间内（8 h）忍受一定浓度（不超过55 n L·L-1）的O3胁迫,O3浓度达到或超过80 n L·L-1时,PSII功能受到较严重的抑制。
