绿斑病藻寄生对夏橙叶片光合作用特性的影响

Effects of Apatococcus lobatus parasitization on leaf photosynthesis characteristics of orange (Citrus cv. Olinda).

以盆栽的2年生奥灵达夏橙为试材,研究了绿斑病藻寄生对夏橙叶片光合作用特性的影响.结果表明,轻度病叶对叶绿素总量(Chla+b)、类胡萝卜素含量(Car)、净光合速率(Pn)、胞间CO2浓度(Ci)、原初光能转换效率(Fv/Fm)、光合电子传递量子效率(ΦPSⅡ)和光化学猝灭系数(qP)无显著影响;中度病叶和重度病叶的Chla+b、Car、Pn、Fv/Fm、ΦPSⅡ和qP较对照分别下降了23.85%、26.49%、43.3%、4.5%、35.1%、22.5%和37.61%、44.04%、64.5%、8.6%、63.6%、40.1%,与对照差异显著,而Ci较对照显著上升.绿斑病藻的大量寄生减弱了夏橙叶片的光合作用,而净光合速率的下降主要是由非气孔因素限制引起.

With 2-year pot-grown grafted Citrus cv. Olinda as teat material, this paper studied the effects of Apatococcus lobatus parasitization on its leaf photosynthesis characteristics. No significant differences were observed between slightly affected and control leaves in their total chlorophyll （Chl a ＋ b） and carotenoid （Car） contents, net photosynthetic rate （P,）, intercellular CO2 concentration （ Ci ）, primary maximum photochemical efficiency of PS Ⅱ （Fv/Fm）, quantum efficiency of noncyclic electron transport of PS Ⅱ （ФPS Ⅱ ）, and photochemical quenching （qP）, but for medium and severely affected leaves, their Chla ＋ b, Car, Pn, Fv/Fm, ФPS Ⅱ and qP decreased by 23.85%, 26.49%, 43.3%, 4.5%, 35.1% and 22.5%, and 37.61%, 44.04%, 64.5%, 8.6%, 63.6% and 40. 1%, respectively, while Ci increased, with significant differences to the control. It could be concluded that the massive parasitization of A. lobatus caused a stress to orange plant, and non-atomatal limitation was the dominating factor of Pn reduction.