引种地被石竹光合特征与生理生态因子的关系

以上海地区引种的一年生地被石竹实生苗为材料,研究其苗高生长变化、生物量积累和分配、光合特性及其变化规律,并分析主要生理生态因子对其净光合速率的影响。结果表明:(1)3～6月份为地被石竹苗高生长速生期,生长量为年生长量的65.93%,实生苗各部分器官的生物量总体呈现上升的趋势;3～6月份苗木以地上部分生物量积累为主,其占总生物量的比例从46.89%升至65.60%,6月份以后地下部分生物量所占比例从34.40%升至53.11%。(2)地被石竹叶片净光合速率(Pn)日变化在春季和秋季呈单峰曲线型,而在夏季表现为双峰曲线,且具有典型的光合"午睡"现象。(3)影响光合变化的主要决定生理生态因子:春季为蒸腾速率和气温,夏季为气孔导度和大气CO2摩尔分数,秋季为胞间CO2摩尔分数和光合有效辐射;限制地被石竹Pn日变化生理生态因子:春季为胞间CO2摩尔分数和光合有效辐射,夏季为蒸腾速率和空气相对湿度,秋季为气孔导度和气温。(4)地被石竹具有较高水平的光补偿点(56.94μmol·m-2·s-1)和光饱和点(780.07μmol·m-2·s-1),应属于喜光植物。

Relationship between Photosynthesis and Physio ecological Factors of Dianthus plumarius Introduced

One-year old Dianthus plumarius introduced in Shanghai was used as materials to study growth dynamic of seedling height,accumulation and allocation of biomass,and photosynthetic characteristics.Also,this paper analyzed the relationship between net photosynthetic rate(Pn) and physio-ecological factors.The results were as follows:(1)Prosperous phase of growth of seedling height was from March to June,and increment for this period accounted for 65.93%.In general,biomass of each organ of seedling increased gradually,D.plumarius seedlings allocated more biomass to the aboveground parts during March to June,and the biomass ratio of aboveground parts to the whole plant increased from 46.89% to 65.60%.After June,the biomass ratio of aboveground parts to the whole plant increased from 34.40% to 53.11%.(2)The diurnal variation of Pn had a single curve in spring and autumn and the double-peak curve in summer which had obvious midday photosynthetic depression.(3) The main physio-ecological factors affecting the characteristics of Pn of D.plumarius were transpiration rate and temperature in spring,stomatal conductance and atmospheric CO2 concentration in summer;and intercellular CO2 concentration and photosynthetic active radiation in autumn;The main limiting factors were intercellular CO2 concentration and photosynthetic active radiation in spring,transpiration rate and relative humidity in summer;and stomatal conductance and temperature in autumn.(4)The light compensation point of D.plumarius was about 56.94 μmol·m-2·s-1 and the light saturation point was around 780.07 μmol·m-2·s-1,so D.plumarius is a heliophyte.