梨杂种苗童区和成年区叶片光合荧光特征及超微结构研究

Photosynthetic fluorescence characteristics and ultrastructure of juvenile zone and adult zone in pear hybrid seedlings

为进一步揭示梨实生树童区和成年区的生理差异,以7 a生华酥×西子绿梨杂种单株为试材,比较分析了童区和成年区叶片光合荧光特性及超微结构差异。结果表明,童年区和成年区叶片光合荧光各参数随光强增加的变化趋势基本一致,但是在同一光强下,成年区叶片净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间CO2浓度(Ci)以及光饱和点(Im)、表观量子效率(AQY)、光化学猝灭系数(qP)、非光化学猝灭系数(NPQ)、PSⅡ电子传递量子产率(ФPSⅡ)、电子传递速率(ETR)等指标参数均显著高于童区叶片。其原因可能在于成年区叶片具有较高的叶绿素含量、叶绿体紧贴细胞壁、个体大、片层清晰、排列有序,而童区叶绿体个体相对较小、片层结构垛叠紧密且数量较多。

7-year-old pear hybrid seedlings of Huasu × Xizilv were used to investigate the photosynthetic fluorescence characteristics and ultrastructure characteristics of juvenile zone and adult zone.Results indicated that under different light intensities,the photosynthetic fluorescence characteristic variation trends of leaves are similar in juvenile zone and adult zone.But the leaves in adult zone have much higher net photosynthetic rate（Pn）,stomatal conductance（Gs）,transpiration Rate of winter wheat（Tr）,intercellular CO2 concentration（Ci）,light saturation point（Im）,apparent quantum yield（AQY）,photochemical quenching（qP）,quantum yield of PSII photochemistry（ФPSⅡ）,non-pho-tochemical quenching（NPQ） and electron transport rate（ETR）compared to juvenile zone,which maybe correlated with the different chlorophyll content and ultrastructure characteristics.