遮荫下东非狼尾草叶片形态和光合特征变化  

Leaf Morphological and Photosynthetic Characteristics of Pennisetum clandestinum Affected by Shade Environment

作　　者：许喆 代微然[1] 和柏先 孙文君 任健[1] 

机构地区：[1]云南农业大学草业科学系,云南昆明650201 [2]云南省玉龙县畜牧兽医局,云南丽江674100

出　　处：《热带作物学报》2017年第10期1836-1839,共4页Chinese Journal of Tropical Crops

基　　金：云南农业大学教育教学改革研究和课程建设项目(No.2017YAUJY019)

摘　　要：东非狼尾草(Pennisetum clandestinum)是城市绿化和水土保持的优良资源,遮荫却限制了它的进一步利用。本试验以遮荫和全光照下生长的东非狼尾草为研究对象,探讨了光照不足对叶片形态和光合特性的影响。结果表明:与全光照下的植株相比,遮荫下生长的东非狼尾草叶片长度和含水量明显提高,叶片叶绿素a和b含量则提高了50%以上(p<0.05)。而叶片宽度下降、最大光合速率、光饱和点、光补偿点显著降低(p<0.05),其中最大光合速率下降了50.9%,光补偿点则由17.6μmol/(m^2·s)降低至6.56μmol/(m^2·s)。可以看出,东非狼尾草叶片在低光照条件下可塑性强,可通过提高光合色素含量、降低光饱和点、光补偿点等方式增强对散射光的利用,可在适度遮荫下利用。Pennisetum clandestinum is an excellent grass which is widely used on urban greening and soil erosion control, however, but shade limits its further utilization. The effects of shading on the morphological and photosynthetic characteristics of P. clandestinum were studied in our experiment. The results showed the leaf length, leaf water content were significantly increased by shading compared with with plants growing under full sunshine. In term of chlorophyll a and chlorophyll b content, they increased by above 50%（P〈0.05）. In contrast, leaf width, maximal photosynthetic rate（Amax）, light saturation point（LSP） and light compensation point（ LCP） significantly decreased（P〈0.05）. Of them, Amax decreased by 50.9% and LCP decreased from 17.6 to 6.56 μmol/（m^2·s）. From above, it could be concluded that the leaves of P. clandestinum growing under shade environment were adaptable due to its capacity to use scattered-light through increasing the chlorophyll content, decreasing LSP and LCP. As a result, P.clandestinum could be utilized under a certain degree of shade environment.

关 键 词：东非狼尾草 遮荫 光合速率 叶绿素 

分 类 号：S543.9[农业科学—作物学]