摘要
采用盆栽控水试验方法,设置正常水分(T1,田间持水量的70%—80%)、轻度胁迫(T2,田间持水量的50%—60%)和严重胁迫(T3,田间持水量的30%—40%)3个水分梯度,对6个油松(Pinus tabulaeformis Carr.)种源(陕西洛南LN,陕西桥山QO,山西灵空山LK,辽宁千山QN,河北雾灵山WL和山西芦芽山LY)的光合参数和叶绿素荧光参数进行比较,探讨种源间光合和水分利用特征的差异及其与气孔导度和荧光参数的关系。结果表明,3个水分梯度下6个种源的净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)、水分利用效率(WUE)、原初光能转换效率(Fv/Fm)和PSⅡ潜在活性(Fv/Fo)差异均极显著(P<0.01),在T1和T3下,各种源的实际光量子效率ФPSⅡ和电子传递速率ETR差异显著(P<0.05)。在T2下,LK和WL的Pn达到最大,具有轻度胁迫下提高光合生产力的倾向。在T3下,QN种源的Pn和WUE较高(除LK的WUE最高外),而WL的Pn和WUE较低(除LK的Pn最低外);6个种源中QN的Pn、ФPSⅡ和ETR最大,LY和QO的光合生产力仅次于QN,而LN、LK和WL的Pn、Gs、ФPSⅡ和ETR比较低,其光合生产力及光量子产量受干旱胁迫影响较大。LK的WUE在各个水分梯度下均显著高于其它种源(P<0.05)。在T3下,各种源通过降低Tr提高WUE。在T1下,气孔限制是影响油松Pn的主要因素;在T2和T3下,Pn和WUE均与气孔导度、PSⅡ反应中心的光量子产量和电子传递速率密切相关。
Chinese Pine （Pinus tabulaeformis Carr. ） is the most widely distributed conifer in North China. Due to its wide adaptability to natural conditions and higher tolerance to environmental stresses such as drought and nutrient deficiency, Chinese Pine has played the most important role in forestation and water and soil conservation in North China. Against a wide range of natural water conditions across the entire distribution area, some of the provenances of Chinese Pine may have evolved a higher degree of adaptability to water stress than others. In this study the possible differences in photosynthetic and chlorophyll fluorescence characteristics among six provenances of this species were investigated. Seedlings of six provenances of Chinese Pine, including provenances Luonan （LN） and Qiao Mountain （QO） from Shannxi, provenances Lingkong Mountain （LK） and Luya Mountain （LY） from Shanxi, provenance Qian Mountain （QN） from Liaoning and provenance Wuling Mountain （WL） from Hebei, were transplanted in pots in a greenhouse and treated with progressive water stress. The parameters of photosynthesis and chlorophyll fluorescence for them were measured under three soil water treatments （ T1, normal water condition ; T2, mild stress ; and T3 , severe stress ; with 70%--80% , 50%---60% and 30%--40% of the field capacity, respectively）. The difference in photosynthesis and water utilization characteristics, and the relationships of photosynthetic and water use parameters with stomatal conductance and chlorophyll fluorescence parameters among these provenances were analyzed. The results showed that there were significant differences （P〈0.01 ） in net photosynthetic rate （Pn）, transpiration rate （Tr） , stomatal conductance （ Gs）, water use efficiency （ WUE）, potential efficiency of primary conversion of light energy of PSⅡ （ Fo/Fm ） and potential activity of PS II （ Fv/Fo ） among these provenances under T1, T2 and T3. Significant differences （ P〈0.05 ） in actual quantum yield of PS Ⅱ electron transport （ ФPSⅡ ） and apparent photosynthetic electron transport rate （ETR） were detected under T1 and T3. Provenances LK and WL had the highest Pn under T2, and showed stronger adaptability to mild water stress. Under T3, provenance QN had higher Pn and WUE than the rest except for the WUE of provenance LK, and provenance WL had lower Pn and WUE than the others except for the Pn of provenance LK; provenance QN had the highest Pn, ФPSⅡ and ETR among all the provenances; and provenances QO and LY had the second highest Pn; while provenances LK, WL and LN had lower Pn, Gs, ФPSⅡ and ETR, and it indicated that the severe water stress had larger effect on the photosynthetic ability and quantum yield of PSⅡ in provenances LK, WL and LN. Provenance LN showed decreasing Fv/Fm with increasing Fo under T3 compared with T1 , and it suggested that its PSⅡ reaction centre might be destroyed or temporarily inactivated. The Pn,Gs, ФPSⅡ and ETR in provenance LK were significant lower than in the rest under T3（ P〈0.05 ）, and provenance LK had significant higher WUE than the rest under every treatment （P〈0.05）. The WUE in all the provenances increased due to the decrease of Tr under T3. The result of correlation analysis showed that the stomatal conductance was the main influencing factor on Pn of Chinese Pine under T1; and that Pn and WUE were closely related with the stomatal conductance, quantum yield of PSⅡ and electron transport rate under T2 and T3.
出处
《生态学报》
CAS
CSCD
北大核心
2011年第23期7031-7038,共8页
Acta Ecologica Sinica
基金
国家自然科学基金(31070459)
山西省科技厅攻关项目(2006031099-01)
山西省自然科学基金(2007021032)
关键词
油松
光合参数
叶绿素荧光参数
水分胁迫
Pinus tabulaeformis Carr
photosynthetic parameters
chlorophyll fluorescence parameters
water stress
