不同浓度氟对茶树幼苗光合作用的影响

Effect of Fluoride-stress on Photosynthesis of Tea Leaves

以10月龄扦插‘瑞香’茶[Camellia sinensis(L.)O.Kuntze cv.Ruixiang]苗为试验材料,通过沙培试验,设置5个F处理浓度(0、100、200、600、1 800mg·L-1),每周3次,处理后6周,利用LI-6400便携式光合作用测定仪进行测定。结果表明,茶树叶片的CO2同化速率、气孔导度、蒸腾速率、胞间CO2浓度、叶绿素含量等均在低浓度氟(100mg·L-1)处理时会出现较小幅度的上升而后下降;在供氟达到600mg·L-1时[叶片氟含量(2880±220)mg·kg-1],茶树开始表现出氟中毒症状,此时CO2同化速率、气孔导度、蒸腾速率显著下降,而胞间CO2浓度、水分利用率、单位面积干重等均未发生显著变化。

Effect of Fluoride （F）-stress on photosynthetic gas exchange parameters was studied using 10-month-old clonalplantsofthetea,Camelliasinensis （L.）O.Kuntzecv.Ruixiang.Theplantsweregrowninpotsand fertilized with a nutrient solution containing 0 ,100 ,200 ,600 or 1 800 mg · L -1 F on a three times a week ,24-week application .The photosynthesis characteristics of the tea leaves were determined using a portable photosynthesis system （Li-6400） .The result showed that the tea leaves had increased CO2 assimilation ,stomatal conductance , transpiraition rate , intercellular CO2 concentration , and chlorophyll content when the F level was below 100 mg · L -1 .With the F concentration increased up to 600 mg · L -1 ,the CO2 assimilation ,stomatal conductance and transpiration rate decreased , but no differences in the intercellular CO2 concentration , water use efficiency or biomass .Symptoms of F-stress were apparent when the F concention was beyond 600 mg · L -1 （F content in the tea leaves was （2880 ± 220） mg · kg -1 .