不同浓度Ni、Cu处理对骆驼蓬光合作用和叶绿素荧光特性的影响水

以骆驼蓬幼苗为材料,采用盆栽试验研究不同浓度(0、50、100、200、400 mg·kg-1)Ni、Cu处理对骆驼蓬叶片光合作用、叶绿素荧光特性及生长状况的影响.结果表明:随着Ni浓度的增加,骆驼蓬幼苗叶片的光合色素含量、净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、PS Ⅱ最大光化学效率(Fv/Fm)、PS Ⅱ电子传递量子产率(φpsⅡ)、光化学猝灭系数(qp)及各项生长指标均呈显著下降趋势,而细胞间隙CO2浓度(Ci)和非光化学猝灭系数(qn)呈显著增加趋势,其中Pn的下降主要是由非气孔限制所致;骆驼蓬幼苗叶片的光合色素含量、Pn、Gs、Tr、Ci、Fv/Fm、φpsⅡ、qp及各项生长指标均在50 mg·kg-1Cu处理时达到峰值,叶绿素a和b、Pn、Gs、Tr、Ci、Fv/Fm及各项生长指标值在100 mg·kg-1Cu处理时仍微高于对照,而后随Cu浓度的增加,光合色素含量、Pn、Gs、Tr、Ci、Fv/Fm、φpsⅡ、qp及各项生长指标均呈下降趋势,qN呈增加趋势,其中Pn的下降主要是由气孔限制所致.

Influence of different concentration Ni and Cu on the photosynthesis and chlorophyll fluorescence characteristics of Peganum harmala

A pot experiment was conducted to study the influence of different concentration (0, 50, 100, 200, and 400 mg kg(-1)) Ni and Cu on the growth, photosynthesis, and chlorophyll fluorescence characteristics of Peganum harmala seedlings. With increasing concentration Ni in the medium, the seedlings growth parameters, photosynthetic pigment content, net photosynthetic rate (P(n)), stomatal conductance (G(s)), transpiration rate (T(r)), maximal photochemical efficiency of PS II (F(v)/F(m)), quantum efficiency of electric transport of PS II (phi (PS II)), and coefficient of photochemical quenching (q(P)) of P. harmala decreased significantly, while the intercellular CO2 concentration (C(i)) and the coefficient of non-photochemical quenching (q(N)) were in adverse. The decrease of P(n) under Ni stress was mainly caused by non-stomatal limitation. At 50 mg kg(-1) Cu, the growth parameters, photosynthetic pigment content, P(n), G(s), T(r), C(i), F(v)/F(m), phi(PS II), and q(P) reached their peak values; at 100 mg kg(-1) Cu, the growth parameters, chlorophyll a and b contents, P(n), G(s), T(r), C(i), and F(v)/F(m) were still slightly higher than the control; while with the further increasing Cu concentration in the medium, all the test indices except q(N) tended to decrease. The decrease of P(n) under Cu stress was mainly caused by stomatal limitation.