遮荫对红毛五加生长、光合及指标成分积累的影响

Effect of Shading on Growth,Photosynthetic and Accumulation of Index Components of Acanthopanax giraldii Harms

以栽培红毛五加为试材,在全光照(CK)、中度遮荫(A1)、重度遮荫(A2)3种光照环境下测定了红毛五加的生长、光合及指标成分积累等指标,以探讨红毛五加栽培适宜的光环境。结果表明:同对照组相比,遮荫导致红毛五加叶片变薄,变大,比叶面积增加,特别是中度遮荫下的叶片明显大于其它2组;重度遮荫减弱了红毛五加的分枝能力,抑制了新枝条的生长,而中度遮荫对红毛五加分枝能力及新枝条生长的抑制作用不明显,且在一定程度上能促进红毛五加枝条向上生长。遮荫导致红毛五加叶中光合色素含量明显上升,光合速率下降,特别是重度遮荫下的光合速率下降最为明显;遮荫导致Fv/Fm明显上升;ΦPSII、ETR、qN明显下降(P<0.05);qP有所上升,特别是中度遮荫下的qP上升最为明显(P<0.05)。重度遮荫明显抑制了红毛五加茎皮中绿原酸、刺五加苷E 2种指标成分的积累,但中度遮荫下绿原酸含量同全光照下无明显差异(P>0.05)。综合分析认为,重度遮荫明显不利于红毛五加生长、光合及指标成分积累,但中度遮荫下的红毛五加表现出较强的弱光适应性。因此,在实践中可在夏季光照较强时搭建一层透光率在50%的遮阳网,在新枝集中萌发或光照减弱季节及时拆除遮阳网,以确保红毛五加正常生长。

The cultivated Acanthopanax giraldii Harms was used as material,growth,photosynthetic and accumulation of index components under different light environments respectively full illumination（CK）,moderate shading（A1）and heavy shading（A2）were analyzed,in order to select the suitable light environment for cultivation.The results showed that compared with control group,shading could ruduce the leaf thickness,increase leaf area and specific leaf area,especially the leaf area of A1 was obviously bigger than that of CK and A2（P〈0.05）;heavy shading could decrease the branching ability of Acanthopanax giraldii Harms,inhibit the growth of new branch.However,the inhibitory effect of moderate shading was not obvious,but also,to some extent moderate shading could be beneficial to the upward growth of Acanthopanax giraldii Harms.Fv/Fm was significantly increased,ΦPSII,ETR and qN significantly decreased under shading（P〈0.05）.qP increased greatly,especially the qP under the moderate shading significantly increased（P〉0.05）.The accumulation of chlorogenic acid and medofenoxate glycoside E in the stem bark of the Acanthopanax giraldii Harms was significantly inhibited by the shading,especially the heavy shading,but there was no significant difference on the content of chlorogenic acid between the A1 and CK（P〈0.05）.After comprehensive analysis,heavy shading went against the growth,photosynthetic and accumulation of index components of Acanthopanax giraldii Harms;however,Acanthopanax giraldii Harms under the moderate shading exhibited a strong adaptability of weak light tolerance strain.Therefore,in practice,it was necessary to build a layer of shade nets whose photopermeability rate was 50%,when the light was stronger in summer,dismantle shading network,demolite shading network when the light was weak or in the germination season of new branches,so as to ensure the normal growth of Acanthopanax giraldii Harms.