四种优良四川桤木家系光合生理特性研究

采用LI-6400便携式光合仪对4种优良四川桤木家系的日变化光合生理特性进行测定.结果表明:(1)4种四川桤木家系Pn日变化都为双峰曲线,午休现象明显,影响Pn的主要是气孔导度与蒸腾速率,造成午休现象既有气孔限制因素,也有非气孔限制因素.(2)4个家系全天的水分利用效率高低依次为:J-05＞H-01＞J-10＞H-12.(3)采用逐步回归分析方法对4种家系的Pn影响因子分析,RH-R、Trmmol、Ci、Cond、PARi是影响净光合速率的重要因子.H-01对光照强度变化不是很敏感,J-10受胞间CO2,浓度影响较小.

Study on the Photosynthesis Characterstics of Four Improved Alnus Cremastogyne Burk Families

Measurements of photosynthetic characteristics for four improved Alnus cremastogyne Burk families by LI-6400 portable photosynthesis system indicated that:(1)All the diurnal variation curves of net photosynthetic rate(Pn)of four improved Alnus cremastogyne showed two typical peaks with obvious midday depression.Factors that affected Pn were mainly stomatal conductance and transpiration rate,while factors that caused midday depression included both stomatal and non-stomatal limitations.(2)Water use efficiency all day long for four families were ranked as follows:J-05>H-01>J-10>H-12.(3)Stepwise regression for four families showed that RH-R,Trmmol,Ci,Cond,and PARi were major impact factors over net photosynthetic rate.Family H-01 was not very sensitive to changes of light intensity.And family J-10 had been impacted smaller by its intercellular CO2 concentration.