以定植后2 年菠萝蜜树为试验材料，分别用不同浓度ALA喷施叶面后用LI-6400 便携式光合系统分析仪测定相关光合参数，以研究外源5-氨基乙酰丙酸对菠萝蜜光合作用的影响。结果表明，低浓度ALA可显著促进菠萝蜜树的光合作用，各处理浓度中，以10 mg/L 处理效果最佳，该处理Pn、Tr、WUE、Gs、Ci 比CK 分别提高了56.0%、30.6%、19.4%、23.8%、54.2%，Ls 降低了37.6%，均达到极显著差异水平。浓度高达20 mg/L 时，其Pn、Tr、Gs、Ci 比CK分别降低了2.2%、28.4%、31.1%、11.6%，WUE、Ls 升高 了36.3%、8.1%。由此可见，适宜浓度ALA可以有效促进菠萝蜜的光合效能，浓度过高反而产生抑制作用。

After being sprayed with different concentration ALA for 4 days, photosynthesis parameters of 2 a jackfruit tree were analyzed with a LI-6400 portable photosynthesis system analyzer to study the effect of ALA on photosynthetic physiology in jiackfruit. The results showed that low concentrations of ALA could significantly promote jackfruit tree photosynthesis, in which, the Pn, Tr, WUE , Gs, Ci of 10 mg/L ALA respectively increased 56.0%, 30.6%, 19.4%, 23.8%, 54.2% than CK,Ls reduced 37.6%. But thePn, Tr, Gs, Ci of 20 mg/L were respectively reduced 2.2%, 28.4%, 31.1%, 11.6% than CK, and theWUE, Ls increased by 36.3%, 8.1%. Thus it can be seen appropriate concentration of ALA can be effectively enhance the jackfruit photosynthesis, but the high concentration not.