College of Horticulture，Hunan Agricultural University，Key Labortory for Vegetable Biology of Hunan Province，Engineering Research Center for Horticultural Crop Germplasm Creation and New Variety Breeding，Ministry of Education，Key Laboratory for Evaluation and Utilization of Gene Resources of Horticultural Crops（vegetables，tea，etc.），Ministry of Agriculture and Rural Affairs of China，Huangpu Innovation Research Institute of Hunan Agricultural University，Changsha 410128，Hunan，China
Abstract：In order to investigate the effects of exogenous EBR and ALA on over-summer growth of chilli seedlings under high-temperature stress，this experiment took 2 chilli varieties‘Bolahongniu’and ‘Changyanqingxiang’，as test material，and sprayed different concentrations EBR（0.001，0.01，0.1，and 1.0 mg · L-1）and ALA（15，30，45，and 60 mg · L-1）. The results showed that exogenous EBR and
ALA all could enhance seedling ability of resisting high-temperature adversity to different extent. After spraying different concentrations of EBR and ALA，the growth indexes of chilli seedlings including plant height，stemthickness，dry and fresh mass，and sound seedling index，etc. all showed an upward trend. The activities of antioxidant enzymes as SOD，POD，and CAT were strengthened. The content of MDA was reduced.The contents of proline，soluble sugar，and soluble protein were increased. The activities of key nitrogen metabolism enzymes like NR，NiR，GS，etc. were significantly enhanced. The treatment of 0.01 mg · L-1 EBR and 45 mg · L-1 ALA had the best effect on relieving high-temperature stress.
