不同光照强度对紫鸭跖草色素及叶绿素荧光强度的影响

Effects of Different Light Intensity on Pigment and Chlorophyll Fluorescence of Setcreasea purpurea

为紫鸭跖草的栽培繁育和园林绿化应用上适宜光照强度的选择提供理论依据,通过MINIPAM-Ⅱ超便携式调制叶绿素荧光仪研究100%光照、65%光照、30%光照及5%光照4种光照强度处理对紫鸭跖草叶绿素含量和叶绿素荧光参数的影响。结果表明:4种光照处理下紫鸭跖草叶片的叶绿素a含量、叶绿素b含量及叶绿素总含量均随着处理时间延长呈下降趋势,60d时,叶绿素含量下降幅度:30%光照和65%光照较5%光照和100%光照大,但各处理间差异不显著;紫鸭跖草的最大荧光值(Fm’)、光系统Ⅱ最大量子产量(Fv/Fm)和光系统Ⅱ电子传递(Fm/Fo)均随着遮光程度的增大而增加,遮光处理提高其光化学效率;紫鸭跖草受到不同程度的光抑制,抑制程度依次为100%>5%>30%>65%。100%光照下受到严重光抑制,30%光照和65%光照较适宜紫鸭跖草生长,65%光照下紫鸭跖草的观赏性最好。

To provide a theoretical basis for selecting suitable light intensity for the cultivation and breeding of Setcreasea purpurea and landscaping applications,the MINI-PAM-Ⅱultra-portable modulated chlorophyll fluorometer was employed to study the effects of various light intensity,including 100%light,65%light,30%light and 5%light,on the chlorophyll content and chlorophyll fluorescence parameters of S.purpurea.Results:The chlorophyll a content,chlorophyll b content and total chlorophyll content of the leaves of S.purpurea under the four light treatments all showed a downward trend with treatment time.At 60 days,the chlorophyll content decreased greater by 30%light and 65%light than by 5%light and 100%light,but no significant difference observed among treatments;The maximum fluorescence(Fm’),maximum quantum yield of optical systemⅡ(Fv/Fm)and electron transfer of optical systemⅡ(Fm/Fo)of S.purpurea all increased with shading degree,and shading treatment improved photochemical efficiency;S.purpurea was subject to different degrees of light inhibition,and the degree of inhibition ranked as 100%>5%>30%>65%.It was severely light-inhibited under 100%light,30%light and 65%light were more suitable for the growth of S.purpurea,and it was of the best ornamental value under 65%light.