CO2浓度增高对盆栽牡丹品种‘凤丹白’生长及光合特性的影响

在开顶式塑料薄膜气室设施条件下,通过LI-6400便携式光合测定系统测定,研究4年生盆栽牡丹品种‘凤丹白’生长和叶片净光合速率对高CO2浓度的响应。结果表明：在各自生长环境下,处理组OTC1[（1000±100）μmol/mol CO2]和OTC2[（700±100）μmol/mol CO2]的净光合速率在整个处理期间均高于对照组CK[（400±50）μmol/mol CO2]。处理30d时日平均净光合速率,OTC1和OTC2分别比CK高125.78%、73.29%;处理60 d时,OTC1和OTC2分别比CK高135.34%、117.71%;处理90 d时,OTC1和OTC2分别比CK高261.10%、71.01%;处理120 d时,OTC1和OTC2分别比CK高239.49%、73.02%。生长量方面,处理60 d时,OTC1和OTC2的株高、单叶面积、基茎、株鲜质量、株干质量分别比CK增加8.61%、16.68%、2.56%、9.48%、9.63%和4.12%、6.35%、0.64%、5.56%、7.08%;处理120 d时,OTC1和OTC2的分别比CK增加8.41%、9.64%、2.50%、14.76%、9.20%和5.88%、12.90%、1.87%、10.52%、7.78%。CO2浓度增加,导致牡丹品种‘凤丹白’叶片气孔导度、蒸腾速率降低,水分利用率显著提高。

Effects of CO2 Enrichment on Plant Growth and Photosynthesis Properties of Paeonia ostii Cultivar ' Feng Dan Bai'

The response of growth and the net leaf photosynthetic rate（Pn） of four-year-old pot grown plants of Paeonia ostii cultivar ＇Feng Dan Bai＇ to high CO2 concentration in the top-open plastic chamber was studied by means of applying LI-6400 photosynthesis system（LI-COR）.The results showed that the net leaf photosynthetic rate（Pn） of plants growing under（1 000 ± 100）μmol/mol CO2 concentration（OTC1） and（700±100）μmol/mol CO2 concentration（OTC2） was both higher than that of the plants in the control group grown under ambient（400±50）μmol/mol CO2 concentration throughout the whole experiment period.Compared to the control,the average diurnal Pn of the plants in group OTC1 increased by 125.78%,135.34%,261.10% and 239.49% respectively after having been treated for 30 d,60 d,90 d and 120 d.The average diurnal Pn of the plants in group OTC2 increased by 73.29%,117.71%,71.01% and 73.02% compared to the control respectively after having been treated for 30 d,60 d,90 d and 120 d.After having been treated for 60 d,the plant height,single leaf area,basal diameter,fresh weight and dry weight of the plants in group OTC1 was 8.61%,16.68%,2.56%,9.48% and 9.63% higher than those of the control.After having been treated for 60d,the plant height,single leaf area,basal diameter,fresh weight and dry weight of the plants in group OTC2 was 4.12%,6.35%,0.64%,5.56% and 7.08% higher than those of the control.After having been treated for 120d,the plant height,single leaf area,basal diameter,fresh weight and dry weight of the plants in group OTC1 was 8.41%,9.64%,2.50%,14.76% and 9.20% higher than those of the control.After having been treated for 120d,the plant height,single leaf area,basal diameter,fresh weight and dry weight of the plants in group OTC2 was 5.88%,12.90%,1.87%,10.52% and 7.78% higher than those of the control.With the increase of CO2 concentration,the stomatal conductance and transpiration rate of the Paeonia ostii cultivar ＇Feng Dan Bai＇ seedlings decreased whereas the water use efficiency rose significantly.