低温对樟树抗寒性生理指标的影响

Effects of low temperature on the cold resistance physiology index of camphor tree

以油樟[Cinnamomum camphora(terpineol-type)]和芳樟[C.camphora(linalool-type)]的1年生实生苗为研究对象,设置不同低温(0、6、12℃)及处理时间(0、2、4、6 d),探讨叶绿素含量、叶绿素荧光参数以及SOD活性等生理生化指标变化,并利用模糊隶属函数对其抗寒性进行评价,为耐寒樟树筛选提供参考。结果表明:不同低温条件下,2种樟树叶片内脯氨酸和MDA含量、SOD活性、相对电导率均随胁迫时间的延长呈持续增加的趋势,而叶绿素含量及最大光化学效率(F v/F m)则呈逐渐下降的趋势。此外,12℃条件下,2种樟树的初始荧光(F 0)呈先降后升的趋势;而6℃和0℃条件下,均持续上升。0 ℃条件下至第6天时,油樟的SOD活性较CK增加显著 ( P <0. 05 ) ,而芳樟的叶绿素和MDA含量则较CK下降显著 ( P <0. 05 ) 。相同低温条件下,随胁迫时间的延长,油樟叶绿素含量和 F v/ F m的降幅,以及MDA含量、相对电导率和 F 0的增幅均小于芳樟,而脯氨酸含量及SOD活性的增幅则大于芳樟。模糊隶属函数评价结果表明,油樟低温胁迫的适应性大于芳樟。

Using Cinnamomum camphora(terpineol-type)and C.camphora(linalool-type)as experimental materials,the dynamic variation of physiological and biochemical indexes such as chlorophyll content,SOD activity,and chlorophyll fluorescence parameters were investigated under conditions of 0,6,12℃over 0,2,4,and 6 d;moreover,the cold resistance of the two camphor tree species was also analyzed.The results showed that:the content of proline and MDA,SOD activity,and relative conductivity of the two camphor species continuously increased,but the chlorophyll content and F v/F m decreased with the prolonged low-temperature treating time.The F 0 of two camphor species decreased first but increased later at 12℃,but the F 0 showed a continuous increase at 6℃and 0℃.In addition,the SOD activity of C.camphora(terpineol-type)increased significantly compared to that of CK(P<0.05),while the contents of chlorophyll and MDA of C.camphora(linalool-type)decreased significantly compared to those of CK(P<0.05).During the different low-temperature stress conditions,the amplitude reduction of chlorophyll content and F v/F m,amplitude increase of MDA content,and relative electrical conductivity and F 0 of C.camphora(terpineol-type)were lower than those of C.camphora(linalool-type).However,the amplitude increase of the proline content and SOD activity was greater than that of C.camphora(linalool-type).Finally,the cold resistance of two camphor tree species was evaluated as C.camphora(terpineol-type)>C.camphora(linalool-type)using the fuzzy mathematics method.