利用脉冲振幅调制叶绿素荧光仪对不同光照和温度条件下长石莼（缘管浒苔）光合作用和培养条件进行了优化。结果表明，长石莼（缘管浒苔）在25 ℃和72 μmol/(m2·s)条件下，其F_v/F_m、F_m、F_v和α值最高，分别高达0.74、4 567、3 406和0.305，低于该点为光不饱和，高于该点为光抑制，偏离越大，下降越显著（P<0.01），其中在5 ℃和35 ℃时最小，分别是25 ℃最高值的32.24%~64.88%和22.99%~53.44%；光强为18 μmol/(m²·s)和216 μmol/(m²·s)时最小，其F_v/F_m、F_m、F_v和α值分别是25 ℃和72 μmol/(m²·s)条件下最高值的44.94%~82.62%和51.82%~76.72%。F₀变化不太明显，5~30 ℃为先上升后下降或再上升变化趋势，35 ℃为先下降后上升变化趋势。拟合参数α显示，长石莼（缘管浒苔）在达到光饱和点前通过增加光能吸收来增强光合作用，在光抑制后则迅速减少。rETR_maxDuncan检验表明，高温/低温和高光强对长石莼（缘管浒苔）光合作用影响显著（P<0.01）。总体上看，长石莼（缘管浒苔）光合作用和生长适宜条件为15~25 ℃和54~72 μmol/(m²·s)，过高或过低均不适宜。且温度排序为25>20>15>30>10>5>35 ℃，光照强度排序为72>54/108>36/162>18/216 μmol/(m²·s)。

In this paper, the optimization for blade photosynthesis and culture conditions at different light intensity and temperature in Ulva linza with pulse amplitude modulation chlorophyll fluorometer (PHYTO-PAM). The results showed that F_v/F_m, F_m, F_v and α value were the highest at 25 ℃ temperature and 72 μmol/(m²·s) light intensity, up to 0.74, 4567, 3406 and 0.305 respectively. When temperature and light intensity were lower than the point, light unsaturation would occur. And the farther the temperature and light intensity was from the point, the greater their F_v/F_m, F_m, F_v and α value decreased (P<0.01). At 5 ℃ and 35 ℃ with 72 μmol/(m²·s) light intensity, the F_v/F_m, F_m, F_v and α values were the lowest, about 32.24%-64.88% and 22.99%-53.44% of that at 25 ℃ with 72 μmol/(m²·s) light intensity, respectively. And at 18 μmol/(m²·s) and 216 μmol/(m²·s) light intensity with 25 ℃, the F_v/F_m, F_m, F_v and α values also were lowest, which were 44.94%-82.62% and 51.82%-76.72% of that at 72 μmol/(m²·s) light intensity with 25 ℃, respectively. F₀ did not change much. At 5-30 ℃, F₀ first increased and then decreased or increased again, while at 35 ℃, it firstly declined and then increased. As for fitting parameter α, it was showed that Ulva linza enhanced photosynthesis by increasing light energy absorption before light saturation point, but after that, they would increase photosynthesis by rapid declining light energy absorption. rETRmax Duncan test showed that the high / low temperature and high light intensity inhibited photosynthesis rate significantly (P<0.01). It indicated that the temperature between 15 ℃ and 25 ℃ and light intensity between 54 μmol/(m²·s) and 72 μmol/(m²·s) were feasible photosynthesis and growth conditions for Ulva linza, and too high or too low were not good. The temperature order for photosynthesis and growth rate was 25> 20> 15> 30> 10> 5> 35 ℃, and the light intensity order was 72>54/108>36/162>18/216 μmol/(m²·s).

国家海洋局绿潮灾害专项；国家自然科学基金（30371101）；教育部博士点基金资助项目；上海市浦江人才计划项目（05PJ14086）；上海市水生生物学重点学科资助项目(S30701)；上海高校选拔培养优秀青年教师科研专项基金（SSC08002）