峨嵋拟单性木兰光合特性的初步研究

A Primary Study on Photosynthetic Characters of Parakmeria Omeiensis

本研究取材于峨嵋拟单性木兰成年树,测定树上几种叶片类型的光合作用特性,主要结果: 1.本种为中生性植物,其光合作用特性类似于黄心夜合和四川木莲;2.春至初夏,气温和光照强度分别在20℃和50klux以下时,两年生叶的净光合率日变化为单峰并与气温与光照程度呈正相关趋势。但气温超过25℃以上时,净光合率明显下降;3.3年生叶仍具光合能力,花后一年生叶净光合率最高;4.阴面叶和阳面叶在光合作用无差别;5.净光合作用变化与生长季节有关。

This paper studies photosynthetic characters of several kinds of the leaf-blade type collected from a adult sample tree of Parakmria omeiensis. The main results are as follows: 1. The species is a neutral plant,which is similar to Michelia martinii and Manglirtia szechuanica in photo-synthetic characters. 2. The diurnal changes in the net photosynthetic rate of its two years old leaves show a single peak curve and have a tendency towards a positive correlation with temperature and light intensity below 20℃and 50,000 Lux during spring and early summer. 3. The three years old leaves still have some a-bility in photosynthesis and after florescence the rate of one year old leaves is the highest. 4. The shade-leaf is not different from the sun-leaf in photosynthesis. 5. The changes in net photosynthesis are related to growing seasons.