【摘要】 以从原生地(30°43′N,108°50′E,海拔1 585.2m)迁入中国林科院(39°57′N,116°17′E,海拔57.5m)的崖柏幼苗为对象,研究其叶片形态、光合作用和叶绿素荧光参数对迁入地秋冬季节性自然降温的响应。结果表明:在迁入地持续低温降到日均温-7.77℃,最低温度-13.96℃时,大部分崖柏幼苗叶片卷曲,出现明显地冻害症状;在叶片受害症状出现之前,随着温度的不断下降,叶片的净光合速率(Pn)、最大光合速率(Pmax)、表观量子效率(Ф)、蒸腾速率(Tr)、气孔导度(Gs)、叶绿素含量、PSⅡ原初光能转换效率(Fv/Fm)、PSⅡ潜在活性(Fv/Fo)、PSⅡ有效光量子产量(Fv′/Fm′)、光化学淬灭系数(qP)和非光化学淬灭系数(NPQ)等均呈下降变化趋势。胞间CO2浓度(Ci)总体呈现增加趋势,暗呼吸速率(Rd)逐渐增强。当持续低温降至日平均气温-6.40℃,日最低气温-10.46℃时,崖柏幼苗的净光合值接近于0。光合机构受损是崖柏幼苗在迁入地秋冬季节性自然降温过程中光合能力下降的主要原因。更多还原

【Abstract】 This paper focused on the Thuja sutchuenensis,which moved to Chinese Academy of Forestry from its original habitat.Study on the response of leaf shapes,photosynthetic characteristics and chlorophyll fluorescence parameters of T.sutchuenensis seedlings to the process of seasonal cooling in resettlement areas in autumn and winter.The results showed that: when the daily average air temperature decreased to-7.77℃,the daily minimum air temperature decreased to-13.96℃,most of T.sutchuenensis seedling leaves were curled,appeared to freeze injury symptoms.The net photosynthetic rate(P n),the maximum photosynthetic rate(P max),apparent quantum yield(Ф),transpiration rate(T r),stomatal conductance(G s),chlorophyll content,PSⅡprimary energy conversion efficiency(F v/F m),PSⅡpotential activity(F v/F o),photochemical efficiency of PSⅡin the light(F v ′/F m ′),photochemical quenching(qP) and non-photochemical quenching(NPQ) decreased along with the temperature continued to decline before the freeze injury symptoms.While intercellular CO2concentration(C i) showing an overall increasing trend,and dark respiration rate(R d) was gradually increased.When the continuous low temperature dropped to daily average temperature of-6.40℃and-10.46 ℃ daily minimum temperature,the net photosynthesis value of T.sutchuenensis seedlings closed to 0.Therefore,the damage to the photosynthetic apparatus is the main reason for the decline of the photosynthetic capacity of T.sutchuenensis seedlings to the process of seasonal cooling in resettlement areas.更多还原