桉树无性系光合光响应研究

应用德国Walz公司生产的GFS-3000气体交换—荧光测量系统研究桉树8个无性系的光合作用光响应规律,筛选高光效、耐强光桉树优良无性系。结果表明,参试桉树净光合速率随光合有效辐射升高而迅速增加达到最高点,之后随光合有效辐射增加而缓慢降低并稳定下来,光抑制并不明显,蒸腾速率和气孔导度对光响应的变化趋势与光合速率相似,胞间CO2浓度对光合有效辐射的响应趋势则与光合速率相反。8个参试桉树最大光合速率集中在8.88-14.86μmol.m-2.s-1,最大的为无性系1,最小的为无性系2;光饱和点集中在1 133.33-1 329.12μmol.m-2.s-1,最高的为无性系1,最低的为无性系4;光补偿点集中在7.96-37.26μmol.m-2.s-1,最大的为无性系7,最小的为无性系3;表观量子效率最高的为无性系1、6,最低的为无性系5。通过分析比较了8个桉树无性系的光响应规律,初选获得无性系1为优良的桉树无性系。

Study on light response of photosynthesis of Eucalyptus clones

Light response of photosynthesis of 8 eucalyptus clones were studied for the selection of the high efficiency of light superior clone of eucalyptus clones by using GFS-3000 Gas Exchange & Fluorescence System produced by Gemany Walz company Ltd.The results showed that the photosynthetic rate of 8 eucalyptus clones reached the highest point with the increasing of photosynthetically active radiation and then decreased slowly with the increasing of photosynthetically active radiation,the light suppression was not distinct.The change trend of light response of Tr and Gs was similar with Pn,and the change trend of light response of Ci was opposite with Pn.The maximal Pn between 8.88 and 14.86 μmol·m-2·s-1,the highest was clone 1,the lowest was clone 2;the light saturation point between 1 133.33 and 1 329.12 μmol·m-2·s-1,the highest was clone 1,the lowest was clone 4;the light compensation point between 7.96 and 37.26 μmol·m-2·s-1,the highest was clone 7,the lowest was clone 3;the highest apparent quantum yield of photosynthesis was clone 1 and clone 6,the lowest was clone 5.By analysis for 8 eucalyptus clones of light response law,clone 1 was selected as the eximious eucalyptus clone primarily.