遮阴对石灰花楸幼苗生长和光合特性的影响  

Effects of shade treatment on growth and photosynthesis characteristics of Sorbus folgneri seedlings

作　　者：张振英[1] 段朋娜 陈昕[1] 

机构地区：[1]南京林业大学森林资源与环境学院,江苏南京210037

出　　处：《甘肃农业大学学报》2014年第6期138-143,共6页Journal of Gansu Agricultural University

摘　　要：以一年生石灰花楸为材料,研究了0%、67%、76%、92%4种遮阴处理下石灰花楸幼苗形态、生物量积累及分配、光合生理和叶解剖结构的变化.结果表明:遮阴使幼苗高生长、主根长减少,地径、叶面积增加;67%的遮阴能促进生物量积累,而76%、92%的遮阴则抑制生物量的积累;遮阴下根、茎生物量比降低,叶生物量比增加,比叶面积和冠根比的增加有利于增加光能的捕获.随着遮阴程度的增加,叶片厚度逐渐降低,表皮细胞变薄,栅栏组织由2层减为1层,栅海比逐渐减小,栅栏组织有向海绵组织转化的趋势;各处理叶绿素含量均显著上升,而叶绿素a/b值在2.3左右无差异性,净光合速率和蒸腾速率日变化均呈单峰曲线,没有"午休"现象,且日均值都随遮阴程度的增加依次降低.遮阴处理后,石灰花楸幼苗对弱光环境表现出了一定驯化适应性,适度遮阴有利于石灰花楸生长发育.Morphological,biomass accumulation and allocation,physiological responses and leaf anatom-ical structure of 1-year-old Sorbus folgneri seedlings were examined with 4 shade levels （0%,6 7%,7 6%and 92%）.The results showed that the shade treatments produced plants with less height and main root length,greater stem diameter and leaf area.Shading screens of 67% increased but 76% and 92% decreased biomass accumulation.Shading treatments caused root and stem mass ratio,and higher leaf mass ratio, higher specific leaf area and shoot to root ratio were beneficial to the increase of light energy capture.With the increase of shading rate,thickness of bladereduced,skin cells thickness,the 2 layer of palisade paren-chyma reduced to 1 layer,palisade/spongy ratio decreased and showed a tendency of palisade tissue turning into spongytissue.Concentration of chlorophyll increased,Chla/b decreased without obvious difference and the value about 2.3.The curve of diurnal variation of net photosynthetic rate and transpiration rate had one peat in a day,without midday depreesion phenomenon,and daily mean all got lower with the increase of shading rate.The results indicated that S.folgneri had the ability to adj ust to shading,a moderate amount of shade was favorable to the growth and development.

关 键 词：石灰花楸幼苗 遮阴 光合特性 生物量分配 叶解剖结构 

分 类 号：S792.25[农业科学—林木遗传育种]