论文部分内容阅读
采用开顶式气室装置研究不同臭氧浓度对3种基因型杨树(‘546’、‘90’和‘84K’)光合作用特征的影响.结果表明,随着O_3浓度的升高,净光合速率(P_n)、蒸腾速率(T_r)、水分利用效率(WUE)、电子传递速率(ETR)、PSⅡ反应中心激发能捕获效率(F’_v/F’_m)、光化学猝灭系数(q P)、PSⅡ实际光化学量子效率(Phi PS2)、叶绿素a(Chla)、叶绿素b(Chlb)、叶绿素总量(Chla+b)和类胡萝卜素(Car)均显著降低,胞间CO_2浓度(c_i)显著升高,气孔导度(G_s)变化不显著.不同基因型杨树各项光合生理指标之间均存在显著性差异,基因型‘546’各项光合指标(除G_s外)与O_3剂量(AOT40,小时O_3浓度大于40nmol·mol~(-1)的累计值)间具有显著的线性相关关系(P<0.01),并且光合色素含量随着O_3浓度的升高而显著降低.但高浓度O_3对基因型‘90’和‘84K’光合色素影响不显著.从多数光合特征指标特别是叶绿素总量的O_3剂量线性响应关系来看,基因型‘546’表现出最大的斜率,基因型‘90’次之,基因型‘84K’斜率最小,因而可得知随着O_3浓度升高,三者的臭氧敏感性为‘546’>‘90’>‘84K’.该研究结果为O_3污染环境下杨树基因型筛选与培育,以及保护杨树免受O_3伤害提供科学依据.
The effects of different ozone concentrations on the photosynthetic characteristics of three genotypes poplar (’546’, ’90’ and ’84K’) were studied using an open top chamber. The results showed that with the increase of O_3 concentration, net photosynthesis (P_), transpiration rate (T_r), water use efficiency (WUE), electron transfer rate (ETR), capture efficiency of PSⅡ reaction center (F’_v / F’_m), photochemical quenching coefficient PSⅡ, Chla, Chlb, Chla + b and Car were significantly decreased, and the intercellular CO 2 concentration (c_i) was significant (P <0.05), and there was no significant change in stomatal conductance (G_s) .All photosynthetic physiological indexes of poplar with different genotypes were significantly different. The photosynthetic indexes (except G_s) and O_3 dose (AOT40 (P <0.01), and the content of photosynthetic pigment decreased significantly with the increase of O 3 concentration.However, the concentration of O 3 was higher than that of 40 nmol · mol -1 (P <0.01) Genotype ’90’ and ’84K’ photosynthetic pigments had no significant effect.From the most of the photosynthetic characteristics, especially the total amount of O_3 chlorophyll In terms of sexual response, genotype ’546’ showed the largest slope, with the genotype ’90’ followed by the genotype ’84K’ with the smallest slope. Thus, it was found that with the increase of O 3 concentration, the ozone sensitivity of the three ’546’> ’90’> ’84K’ .The results of this study provide a scientific basis for screening and breeding poplar genotypes under O_3 pollution and protecting poplars from O_3 damage.