Abstract: In order to improve the quality and yield of F.suspensa,the F.suspensa leaves were sprayed with 1,0.1, and 0.01 mmol/L MeJA.Taking the spraying water treatment as a control, the effects of spraying different concentrations of MeJA on the photosynthetic characteristics,SPAD value,PAL activity and the content of secondary metabolites such as total flavonoids, forsythin, and forsythoside A of F.suspensa leaves were studied.The results showed that, different concentrations of MeJA and different treatment time had different effects on the Pn,Tr,Gs and Ci of F.suspensa leaves.For a certain period, MeJA showed inhibition of high concentration and promotion of low concentration on Gs and Tr.The SPAD value showed a trend of first declining and then rising with the extension of the time after spraying.At 2,6,24,48 and 72 hours 0.01 mmol/L MeJA treatment increased the accumulation of total flavonoids by 18.70%,34.13%,30.16%,40.57%,11.02% compared with the control, respectively.The 0.01 mmol/L MeJA treatment increased forsythin to a certain extent,but it showed an inhibitory effect on the accumulation of forsythoside A.At 2 h and 6 h after spraying MeJA,the PAL activity of each treatment increased compared with the control.At 48 h after spraying, the PAL activity of 1,0.1,0.01 mmol/L MeJA spraying treatments decreased by 15.88%, 12.38% and 12.56% compared with the control, respectively. In summary,the accumulation of secondary metabolites of F.suspensa leaves at 48 h after spraying 0.01 mmol/L MeJA can be significantly increased.

Key words: Forsythia suspensa, MeJA, Leaf, Photosynthesis, Secondary metabolism

摘要： 为提高连翘的品质与产量，以连翘为试材，设置1、0.1、0.01 mmol/L 3个茉莉酸甲酯(MeJA)喷施浓度处理，以喷施清水处理为对照，研究叶面喷施不同浓度MeJA对连翘叶片光合特性、SPAD值、苯丙氨酸解氨酶（PAL）活性以及总黄酮、连翘苷、连翘酯苷A等次生代谢产物含量的影响。结果表明，不同浓度MeJA及喷施后不同时间对连翘叶片光合速率（Pn）、胞间CO2浓度（Ci）、气孔导度（Gs）和蒸腾速率（Tr）的影响不同，在一定时间内，MeJA浓度对Gs和Tr表现出低促高抑的作用；SPAD值随喷施后时间延长整体呈现先下降后上升的趋势；0.01 mmol/L MeJA喷施后2、6、24、48、72 h，连翘叶总黄酮含量分别较对照增加18.70%、34.13%、30.16%、40.57%、11.02%；0.01 mmol/L MeJA喷施后连翘苷含量在整体上较对照有一定的提升，但对连翘酯苷A的积累表现为抑制作用。喷施MeJA后2、6 h，3个喷施处理PAL活性均较对照增加，而在喷施后48 h，1、0.1、0.01 mmol/L MeJA喷施处理较对照分别降低15.88%、12.38%、12.56%。综上，0.01 mmol/L MeJA喷施后48 h可明显促进连翘叶次生代谢产物的积累。

关键词: 连翘, 茉莉酸甲酯, 叶片, 光合作用, 次生代谢