中文摘要：

为了探讨毛竹（Phyllostachys pubescens）非同化器官茎秆的光合特性,测定了毛竹出笋后快速生长期内（2011年4月13日到6月2日）的光合色素含量以及光合酶活性,并通过激光共聚焦显微镜对其叶绿体分布进行了观察。结果表明：毛竹茎秆中的叶绿体主要集中分布在表皮以下的基本组织中,此外维管束鞘周围的细胞内也存在大量的叶绿体,此特征类似于C4植物的花环结构。在毛竹出笋后快速生长期内,随着茎秆不断生长,叶绿素a、叶绿素b和类胡萝卜素含量均极显著（p〈0.01）增加。在出笋10天时,茎秆中核酮糖-1,5-二磷酸羧化酶/加氧酶（Rubisco）活性、磷酸烯醇式丙酮酸羧化酶（PEPC）活性和NADP-苹果酸酶（NADP-ME）活性最高,之后随茎秆生长逐渐降低,生长30天时酶活性与10天时相比分别降低了88.55%（p〈0.01）、77.46%（p〈0.01）和72.50%（p〈0.01）,而PEPC/Rubisco比值则随茎秆生长逐渐增加,30天时比值达到12.83,明显高于C3植物。这表明毛竹茎秆内可能存在C4光合途径,此途径有利于毛竹提高光合效率,进而促进其出笋后的快速生长。

英文摘要：

Aims Our objective was to reveal photosynthetic characters in Phyllostachys pubescens stems.We determined the distribution of chloroplasts and detected changes of pigment content and photosynthetic enzyme activity in the stems during their rapid growth stage.Methods We detected the pigment content and photosynthetic enzyme activity by the colorimetric method and observed the distribution of chloroplasts using a laser scanning confocal microscope.Important findings Chloroplasts were mainly distributed in the ground tissues under the epidermis and in cells around the vascular bundle,similar to Kranz anatomy in C4 plants.The content of chlorophyll a,chlorophyll b and carotenoid was significantly（p 〈0.01） increased with the growth of the stems of P.pubescens.The activities of ribulose-1,5-bisphosphate carboxylase change/add oxygen enzymes（Rubisco）,phosphoenolpyruvate carboxylase（PEPC） and nicotinamide-adenine dinucleotide phosphate-malic enzyme（NADP-ME） in the stems reached the highest level after 10 days,and they declined gradually with the growth of the stems.After 30 days,the activities decreased by 88.55%（p 〈0.01）,77.46%（p 〈0.01） and 72.50%（p 〈0.01）,respectively,compared with after 10 days.The ratio of PEPC/Rubisco increased gradually and reached 12.83 after 30 days,which was markedly higher than that in C3 plants.These results indicated that there was C4 photosynthetic pathway in the stems,and the pathway may play an important role in the efficient photosynthesis and rapid growth of P.pubescens.