干旱胁迫对杂交鹅掌楸无性系光合特性的影响

Effects of Drought Stress on Photosynthetic Characters of Hybrid Tulip Tree Clones

以5个杂交鹅掌楸无性系(NE04、NE22、NE23、NE25、NE78)1a生扦插苗为试材,研究了干旱胁迫对各无性系叶片净光合速率(Pn)、蒸腾速率(Tr)、胞间CO2浓度(Ci)和气孔导度(Gs)等光合特性的影响。结果表明:各无性系随胁迫程度加剧,Pn、Tr和Gs逐渐下降,而Ci则呈先降后升的趋势,但各指标变化幅度因无性系不同而异。Pn下降是气孔因素与非气孔因素双重作用的结果,轻度干旱胁迫下主要是由气孔限制引起的,而严重干旱胁迫下非气孔限制是Pn下降的主要原因。采用隶属函数法对上述指标进行综合分析,可得出其抗旱能力从大到小依次为:NE25>NE78>NE22>NE04>NE23。

With one-year old steckling of the six clones of hybrid tulip tree（NE04,NE22,NE23,NE25,NE78）as the experimental materials,the effects of drought slress on the photosynthetic characteristics of the clones such as net photosynthetic rate（Pn）,transpiration rate（Tr）,intercellular CO2 concentration（Ci）,and stomatal conductance（Gs）were studied.The result showed that Pn,Tr and Gs decreased gradually as increasing of drought stress level.The Ci declined first,and raised continually later,but the variation level of indexes in five clones were different.Pn was induced by both stomatal factor and non-stomatal factor.Under low drought stress,the decline of Pn was mainly limited by stomatal factor,while that under high drought stress was due to non-stomatal factor.Drought resistance ability of clones were evaluated by using the subordinate function,the drought resistance of the experimental materials from high to low were NE25,NE78,NE22,NE04,NE23.