不同遮阴条件下麦冬光合和叶绿素荧光特性研究

Photosynthesis and Chlorophyll Fluorescence Characteristics of Ophiopogon japonicus (L.F.) Ker-Gawl Under Different Shade Conditions

不同植物具有不同的生理特征,其对光照的应激性也不相同。因此,在进化过程中植物形成了特有光照需求量来适应自身生长。利用LI-6400XT型便携式光合作用测定仪测定5种光强处理(透光率分别为95%、72%、48%、24%和8%)下麦冬叶片的光合指标及叶绿素荧光参数指标。随相对光强的增加,表观量子效率(AQE)随着光照强度的增大表现出先升高后减小的趋势,麦冬叶片的色素含量和初始荧光强度(F0)增加,叶绿素ab值呈现先增加后减小的趋势;荧光参数PSⅡ最大光能转化效率升高,作用光下实际的PSⅡ光化学效率(ΦPSⅡ)、PSⅡ有效光化学量子效率(Fv'/Fm')、电子传递速率(ETR)和光化学淬灭系数(q P)在相对光强72%-48%处理下呈现升高趋势。在相对光强72%-48%的条件下,麦冬的PSⅡ反应抗逆性更加强大,该条件有利于麦冬的生长发育,大规模种植中应对麦冬采取适当遮阴措施。

Different plants have varied physiological characteristics,thus their irritability to light is also different. Therefore,plants form unique light requirements to adapt themselves to their own growth during evolution. Photosynthetic index and leaf green fluorescence parameters of Ophiopogon japonicus（L.F.）Ker-Gawl leaves were measured by LI-6400 XT portable photosynthesis analyzer under 5 light intensity treatments（light transmittance of 95%,72%,48%,24%,and 8%）. With the increase of relative light intensity,the apparent quantum yield（AQE）presented the trend of first increase and then decrease with the increase of light intensity. O. japonicus（L.F.）Ker-Gawl leaf pigment content and initial fluorescence intensity（F0）increased. Chlorophyll ab value was also in the trend of first increase and then decrease. Fluorescence parameter PS Ⅱ maximum light energy conversion efficiency increased. The actual PS Ⅱ photochemical efficiency（ΦPSⅡ）under the action of light,PS Ⅱ effective photochemical quantum efficiency（Fv＇/Fm＇）,electron transfer rate（ETR）,and photochemical quenching coefficient（q P）% had a rising trend under the relative light intensity of 72%-48%. Under the relative light intensity of 72%-48%,the response of O. japonicus（L.F.）Ker-Gawl to PS Ⅱ was stronger,which was conducive to the growth and development of O. japonicus（L.F.）Ker-Gawl. Therefore,appropriate shade measures should be employed in large-scale cultivation of O. japonicus（L.F.）Ker-Gawl.