温度和氮营养盐对龙须菜生长与光合生理的影响

Effects of temperature and nitrogen nutrient on the growth and photophysiology of Gracilariopsis lemaneiformis

以栽培龙须菜(Gracilariopsis lemaneiformis)为试验材料,设置2个温度水平(LT:20℃;HT:24℃)和3个氮营养盐浓度(LN:3.1μmol/L;MN:30.1μmol/L;HN:103.1μmol/L),研究2个环境因子变化对龙须菜生长和光合生理的影响。结果表明,温度、氮营养盐及二者交互作用对龙须菜的相对生长速率(RGR)均具有显著影响(P<0.05),RGR随着温度的升高、氮营养盐浓度的增加而升高。叶绿素荧光参数分析显示,在同一氮营养盐浓度下,HT处理组的有效光合量子产量[Y(Ⅱ)]在0.18~0.24内波动,均高于LT处理组,在同一温度培养条件下,HN处理组的Y(Ⅱ)普遍高于LN处理组;温度对龙须菜的最大相对电子传递速率(rETRmax)存在显著影响(P<0.05);氮营养盐对不同处理下龙须菜的rETRmax、光能利用效率(α)、饱和光强(Ik)均存在显著影响(P<0.05),二者交互作用对α存在显著影响(P<0.05)。此外,温度、氮营养盐及二者交互作用对龙须菜的光合色素含量均具有显著影响(P<0.05);氮营养盐及二者交互作用对其可溶性蛋白质(SP)含量存在显著影响(P<0.05);在LT或HT条件下,氮营养盐浓度的增加显著促进叶绿素a(Chl a)、类胡萝卜素(Car)和SP的合成(P<0.05)。HN和HT促进了龙须菜的生长,结果为解析龙须菜应对核电站温排水区的环境变化提供了理论数据。

The cultivated Gracilariopsis lemaneiformis was used as the experimental material,and two temperature levels(LT:20℃;HT:24℃)and three nitrogen nutrient concentrations(LN:3.1μmol/L;MN:30.1μmol/L;HN:103.1μmol/L)were set to study the ef⁃fects of temperature and nitrogen nutrient concentration changes on the growth and photophysiology of G.lemaneiformis.The results showed that temperature,nitrogen nutrient and their interaction had significant effects on the relative growth rate(RGR)of G.lemane⁃iformis(P<0.05).The RGR increased with the temperature and nitrogen nutrient concentration increment separately.Further fluores⁃cence parameters showed that the effective photosynthetic quantum yield[Y(II)]of HT treatment fluctuated in the range of 0.18~0.24,which was higher than that of LT treatment under the same nitrogen nutrient concentration and HN promoted the improvement of its Y(II)under the same temperature.Temperature had a significant effect on the maximum relative electron transfer rate(rETRmax,P<0.05),nitrogen nutrient had a significant effect on the rETRmax,light utilization efficiency(α)and saturation irradiance(Ik)(P<0.05)and their interaction had a significant effect on theα(P<0.05).Furthermore,temperature,nitrogen nutrient and their interaction had significant effects on the photosynthetic pigments contents of G.lemaneiformis(P<0.05).Nitrogen and the interaction had significant effects on the SP content(P<0.05).Under LT or HT,the contents of chlorophyll a(Chl a),carotenoids(Car),and SP increased evi⁃dently with the increase of nitrogen nutrient concentration(P<0.05).Our findings suggested that HN and HT significantly promoted the growth of G.lemaneiformis,which provided the theoretical data for the cultivation of G.lemaneiformis in response to environmental changes in the thermal discharge area of Tianwan Nuclear Power Station.