马尾松不同产脂力无性系光合特性差异分析

以6个马尾松不同产脂力无性系为试验材料,研究和比较其光合生理特征的差异性。结果表明:不同产脂力无性系净光合速率的日变化皆呈现单峰曲线,峰值出现在09:00—11:00。高产脂力无性系1 d中净光合速率最高为9.81μmol·m-2·s-1,日均值5.57μmol·m-2·s-1,分别为低产脂力无性系的1.29和1.22倍。由光响应曲线分析可知,高产脂力无性系表现出较强的利用强光的能力,其光饱和点最高达1 200μmol·m-2·s-1,饱和点时的最大净光合速率为低产脂力无性系的2.28倍,而光补偿点低至45μmol·m-2·s-1,利用弱光的能力增强。由CO2响应曲线分析可知,高产脂力无性系羧化效率为低产脂力无性系的1.8倍,说明其对CO2的转化效率较高。高产脂力无性系的光合能力强于低产脂力无性系,在强光高温条件下能够迅速启动自我防御措施,特别是在强光条件下,可以保持高效的光合能力,具有较强的环境适应能力。

Di fference of Photosynthetic Characteristics in Pinus massoniana Clones with Different Resin Yield

With six Pinus massoniana clones of different resin yield, we measured their difference of photosynthetic parameters. The diurnal changes of the net photosynthetic rate ( Pn ) of the clones displayed a single peak curve and the peak was at 9 to 11 o’ clock.The Pn of high resin yield clones performed that the largest Pn was 9.81μmol· m-2 · s-1 and the average was 5.57μmol· m-2 · s-1 per day and they were 1.29 times and 1.22 times than the low ones.From light response curves, the high resin yield clones had strong capacity by using high light intensity, and the light saturation point (LSP) could be 1 200μmol· m-2 ·s -1 , when the Pnmax was 2.28 times than the low ones.The light compensation point ( LCP ) could be low to 45μmol· m-2 · s-1 , and the high resin yield clones also used low light.The result of CO2 response curves indicated that carboxylation efficiency ( CE) of the high resin yield clones was 1.8 times than the low ones, so, the clones with high resin yield had some advantage in the utilization of CO2 .The clones with high resin yield preformatted better photosynthesis than lower ones and they could protect themselves under the strong light and high temperature.The photosynthesis could carry on with high-efficiency, especially under the stronger light.Therefore, the high resin yield clones could adapt the dif-ferent environments.