1Ningbo Institute of Technology, Zhejiang University, Ningbo, 315100, China.
2College of Forestry, Xinjiang Agricultural University, Urumqi, 830052, China.
3College of Forest Resources and Environment, Nanjing Forest University, Nanjing, 210037, China.
4Department of Forestry and Natural Resources, Clemson University, 261 Lehotsky Hall, Clemson, SC, 29634-0317, U.S.A.
College of Life Sciences, Zhejiang University, Hangzhou, 310058, P. R. China.
*Correspondence author, E. Mail: wangqiangsky@263.net, dajiang@zju.edu.cn.
We studied the potential autotoxicity of aqueous extracts from P. schrenkiana leaves. Water extract was partitioned against diethyl ether, ethyl acetate, and n-butanol sequentially. Inhibitory effects of 3-organic fractions [original water extract and the residual water (after the organic solvent extraction)] were tested on seed germination and seedling growth of P. schrenkiana. All 5-fractions (original water extract, diethyl ether fraction, ethyl acetate fraction and n-butanol fraction) showed different phytotoxic effects on seed germination and seedling growth. Diethyl ether fraction was most phytotoxic and inhibited the seed germination and seedling growth at low concentration of 0.1 mg/mL. The chemical nature of the three organic fractions was also determined using GC-MS-MS and NMR. 17 secondary metabolites [p-hydroxybenzoic acid, 2-keto-4a-methyl-8-methoxy-2, 3, 4, 4a, 5, 6, 11, 12-octahydrochrysene (named as schrenkianaone), cinnamic acid, abscisic acid (ABA), quercetin, umbelliferone, ß-phenyllactic acid, vanillic acid, gallic acid, myristic acid, gentisic acid, ß-resorcylic acid, indole-3-carboxaldehyde, p-coumaric acid, ethyl hematommate, esculetin and caffeic acid] were identified and quantified. Schrenkianaone, which had been found but not reported as an allelochemical previously, was detected in the diethyl ether fraction.
Autotoxicity, germination index, Picea schrenkiana Fisch. et Mey, seedling growth
