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[Objective ] The present paper aimed to explore the effects of low phosphorus stress on physiological indexes of Eucalyptus coleziana leaves, to provide reference basis for the study of low phosphorus resistance mechanism of E. coleziana and the popularization and planting of seedlings. [ Method]The seedlings of E. coleziana clones 1203 and 1212 were hydroponically cultured with Hoagland nutrient solution with low phosphorus concentration ( 0. 1 mmol/L) and normal phosphorus concentration ( 1. 0 mmol/ L) . After 20 days, the protective enzyme activity, malondialdehyde ( MDA) content, photosynthetic pigment content and chlorophyll fluorescence parameters of seedlings of E. coleziana clones 1203 and 1212 were measured, and single-factor analysis of variance and Pearson correlation coefficient were used to analyze the physiological indexes of leaves of E. coleziana seedlings treated with different phosphorus. [Result] Under low phosphorus treatment, the content of MDA in the leaves of clones 1203 and 1212 were 0. 0032 and 0. 0037 μmol/g FW, the SOD activity were 18. 42 and 16. 25 U/ g FW, the PPO activity were 894. 13 and 1138. 00 U/ g FW, the POD activities were 579. 67 and 471. 33 U/ g FW, the APX activities were 1598. 89 and 688. 33 U/ g FW respectively, which were significantly higher than that of normal phosphorus treatment( P < 0. 05). The total chlorophyll contents were 1. 65 and 1. 51 mg/ g, and the carotenoid contents were 0. 17 and 0. 12 mg/ g, respectively, which were lower than normal phosphorus treatment. The initial fluorescence( F 0 ) of the PS II reaction center both were both 0. 082, the non-photochemical quenching coefficients ( NPQ) were 1. 44 and 1. 35, respectively, which were higher than those of normal phosphorus treatment. The maximum fluorescence ( Fm ) were 0. 37, and 0. 40, the variable fluorescence( Fv) were 0. 29 and 0. 31, the maximum photochemical quantum efficiency( Fv/F m) were 0. 78 and 0. 79,and the actual photochemical efficiency (ΦPPSII) were 0. 31and0. 32 respectively, which were lower than that of normal phosphorus treatment. The results of correlation analysis showed that low phosphorus stress had different effects on the physiological indexes of E. coleziana seedlings, especially had the most significant influence on chlorophyll fluorescence parameters. [ Conclusion ] Low phosphorus stress can cause a large amount of MDA accumulation in the leaves of E. coleziana seedlings, resulting in irreversible damage to the leaf tissue, and then cause the abnormal function of leaf photosynthetic mechanism. However, E. coleziana seedlings can reduce the damage caused by low phosphorus stress through the comprehensive regulation of protective enzymes such as SOD, PPO, POD and APX, and NPQ, especially PPO and NPQ, which may play an important role in reducing the leaf damage of E. coleziana seedlings. [ABSTRACT FROM AUTHOR]

[ Objective] The present paper aimed to analyze the chemical composition and content of volatile oil in the seeds and leaves of different provenances of Cryptocarya concinna, and to provide theoretical basis for the comprehensive development and utilization of C. concinna. [Method] The volatile oil was extracted from the seeds and leaves of 8 provenances [Jinxiu(JX), Yongfu(YF), Longsbeng (LS), Shangsi (SSl and SS2), Guiping (GP), Longan (LA) and Wuming (WM)] by Soxblet extraction method. The oil content of the seeds was determined. The fatty acid composition of the volatile oil in the seeds was determined by gas chromatography( GC). The chemical composition of the volatile oil in the leaves was determined by gas chromatography-mass spectrometry (GC-MS), and comparative analysis of chemical constituents of volatile oil from different provenances of C. concinna was conducted. [Result] The average oil content of the seeds from 8 provenances was 1. 70% -4. 67%, and the volatile oil extraction rate of the seeds from YF provenance was the highest. Nine types of fatty acids were detected in the volatile oil of its seeds, all of which were mainly unsaturated fatty acids, with a content of 76. 45 % - 81. 15 %. A total of 89 chemical components were identified from the volatile oil of the leaves of 8 provenances, including 20 alcohols, 2 phenols, 1 aldehyde, 11 ketones,8 alkanes, 24 olefins, 19 esters and 4 other types. There were differences in the composition and content of volatile oil compounds in leaves of different provenances. Among them, the relative content of stigmastan-3, 5-diene was the highest in the volatile oil of SSl, GP and LA provenances, reaching 39. 31 %, 32. 61 % and 45. 01 %, respectively. The relative content of (-) -spathulenol was the highest in the volatile oil of YF, LS and WM provenances, which was 23. 98%, 18. 70% and 16. 59%, respectively. The relative content of-y-sitosterol in the volatile oil of SS2 provenance leaves was the highest, which was 23. 45%. The relative content of 16-hentriacontanone was the highest in the volatile oil of JX provenance leaves, which was 30. 91 %. Each provenance had its own unique chemical composition. [Conclusion] The extraction rate of volatile oil from the seeds of C. concinna from YF provenance was the highest; The content of unsaturated fatty acids in the volatile oil of 8 provenances was higher than that of saturated fatty acids. The volatile oils of the leaves of different provenances of C. concinna contained a variety of common chemical components and unique components, but the contents were different. Therefore, in the development of perfume industry, daily chemical industry, pharmaceutical industry and health care products, the appropriate provenances of C. concinna can be selected according to different oil characteristics and chemical composition contents. [ABSTRACT FROM AUTHOR]