五种石斛属植物叶片光合特性比较OA

Taking five Dendrobium species,namely Dendrobium of ficinale,Dendrobium huoshanense,Dendrobium nobile,Dendrobium thyrsiflorum and Dendrobium chrysotoxum,as the experimental materials,the leaf morphology and structure,photosynthetic pigment composition and photosynthetic physiological characteristics were systematically studied by means of leaf phenotypic measurement,stomatal density observation,photosynthetic pigment content analysis and determination of light response curve and CO2 response curve with photosynthesis analyzer,in order to clarify the differences in photosynthetic capacity among different Dendrobium species and provide reference for the regulation of light environment in their large-scale cultivation.The results showed that the photosynthetic characteristics of the five Dendrobium species were significantly different.Dendrobium huoshanense had the smallest leaf area,longitudinal diameter and transverse diameter,but the highest content of photosynthetic pigments.Under saturated light intensity,its net photosynthetic rate,light saturation point,carboxylation efficiency and photorespiration rate were the highest,while the light compensation point and CO2 compensation point were the lowest.Dendrobium officinale had the largest leaf phenotypic indicators and the highest stomatal density among the five species,and its photosynthetic pigment content and multiple photosynthetic parameters were second only to Dendrobium huoshanense.Dendrobium nobile had the lowest chlorophyll content,stomatal density and light saturation point.Dendrobium of ficinale had no outstanding performance in any indicators and was at an intermediate level.Dendrobium chrysanthum had the largest leaf phenotypic,and its chlorophyll content and photosynthetic parameters were at an intermediate level.