光强对马兰形态、生理及黄酮类化合物含量的影响

摘要

以马兰为实验材料，通过梯度遮光处理，研究不同光照强度（100％，62．29％和35．17％透光率）下不同处理时间对马兰形态、生理指标和黄酮类化合物的影响。结果显示，1）随着处理时间的延长，马兰节间长均呈增长趋势，但遮光抑制马兰的节间长度，尤其在透光率为62．29％时抑制更显著；在透光率为35．17％时能增强马兰的分枝能力，透光率为62．29％时作用不明显；遮光处理抑制了马兰的直立生长，在透光率为62．29％时对马兰株高产生显著抑制；在透光率为35．17％时更有利于马兰叶的长度、宽度和叶锯齿个数的增加，透光率为62．29％时作用不显著。2）透光率为35．17％时显著抑制叶片叶绿素a、b和叶绿素的总含量；随着处理时间的延长，O2-·含量呈先降后升再降的趋势，SOD活性和 MDA含量呈先降后升的趋势，POD活性呈先升后降的趋势；随着光照强度的减弱， POD活性和 MDA含量呈下降趋势，SOD活性呈先下降后升高趋势；在透光率为35．17％时CAT活性显著低于对照，抑制作用显著。3）随着光照强度的降低，黄酮含量在叶中呈下降趋势，根中呈上升趋势，透光率为62．29％时茎中含量最高，自然光照次之，透光率为35．17％时最低。%The effects of light intensity (100%,62.29%,35.17%of full light radiation)and different exposure times on biological characteristics,physiological indexes and flavone content of Kalimerisindica were studied. 1 )With increased treatment time,the internode-length of all treatment types showed an increasing trend,but shading inhibited K. indica’s internode-length elongation,especially at 62.29%of full light radiation.Shading stimulated K. indica’s branching ability at 35.17% of full light radiation,but this was not significant at 62.29% of full light radiation.Shading,especially light shading,inhibited erect growth of K. indica.Deeper shading (35.17% of full light radiation)was conducive to increased leaf length,width and sawtooth,but was not significant at 62.29% of full light radiation.2)Chlorophyll a,b and total chlorophyll content decreased at 35.17% of full light radiation.The content of O2 -· increased after an initial decrease and then decreased again with an increase of exposure time to light radiation.The activity of SOD and the MDA content increased after an initial decrease with time while the activity of POD showed the opposite trend.With a reduction of light in-tensity,the activity of POD and MDA content increased and the activity of SOD also increased after an initial decrease.At 35.17% of full light radiation,K. indica’s CAT activity was significantly lower than that of the control.3)With a decline of light intensity,the flavonoids content decreased in the leaves,increased in the roots and was highest in the stems at 62.29% of full light radiation.