天山云杉(Picea schrenkiana)是亚洲中部山地的特有物种, 在中国仅见于新疆, 主要分布在天山南北坡和昆仑山西部北坡, 对天山山地的水源涵养、水土保持和林业生产具有不可或缺的重要性。云杉天然林自然更新不良或障碍和生产力下降等问题的出现已成为长期困惑林业工作者的一大难题。该文从植物间的化感与自毒作用研究着手, 分析云杉针叶水提液的乙醚、乙酸乙酯、正丁醇萃取物对自身种子萌发和幼苗生长影响实验。以种子发芽率、发芽势和发芽指数作为种子萌发参数, 以胚根、胚芽长度和实生苗干湿重的变化作为幼苗生长参数。研究结果表明: 种子萌发实验中乙醚萃取物具有最强的抑制效应(IC₅₀ = 5.84 mg·ml^-1), 而正丁醇萃取物的抑制效应最弱(IC₅₀> 10.00 mg·ml^-1); 幼苗生长实验中, 1.25 mg·ml^-1乙醚萃取物对幼苗生长具有显著抑制作用(p<0.05), 1.25 mg·ml^-1正丁醇萃取物能够促进其幼苗生长, 大于2.5 mg·ml^-1的正丁醇萃取物对幼苗生长具有显著抑制效应(p<0.05)。采用GC-MS-MS和NMR技术分析3种有机萃取物的化学组成, 鉴定并定量分析出了包括酚酸、长链脂肪酸、单宁酸和吲哚类物质在内的17种化合物。乙醚萃取物中存在的2-keto-4a-methyl-8-methoxy-2, 3, 4, 4a, 5, 6, 11, 12-ocahydrochrysene (在该文中, 将其命名为云杉酮)为一新的化感物质。该研究证明了天山云杉针叶中存在的化感与自毒物质是导致其种群天然更新障碍的一个最主要原因, 同时揭示了自毒作用发生的化学物质基础。

Aims Schrenk spruce (Picea schrenkiana) forest is an important zonal vegetation in Tianshan Mountain, northwestern China. In addition to being an important timber resource, P. schrenkiana has important soil and water conservation functions and makes up 98.6% of the total stand volume in the region. Schrenk spruce forest exhibits slow growth, regeneration obstacles, declining productivity and confusing size and age structure. Our aims were to 1) compare autotoxicities of three organic fractions from leaves and 2) identify autotoxins from leaves. Findings could improve understanding the mechanisms of P. schrenkiana autotoxicity.
Methods Fresh leaves were extracted with water and partitioned against diethyl ether, ethyl acetate and n-butanol sequentially. We tested the three organic fractions for inhibitory activity, using germination rate, vigor and index as germination parameters and radicle and plumule elongation and weight (wet and dry) change of seedlings as seedling growth parameters. We investigated the chemical nature of the three fractions using GC-MS-MS and NMR. The chemicals in the samples were estimated on the basis of ion-molecular messenger of MS-MS spectral of samples and MS-MS user library spectra of pure reference compounds. These findings were confirmed by comparing the retention time and mass spectral in the GC-MS-MS of samples with those of reference standards under the same conditions.
Important findings The diethyl ether fraction exhibited the strongest phytotoxicity, reducing seed germination at low concentration (IC₅₀ = 5.84 mg·ml^-1), and n-butanol had the weakest effect (IC₅₀ > 10.00 mg·ml^-1). The diethyl ether fraction had a significant inhibitory effect on seedling growth at a concentration of 1.25 mg·ml^-1, whereas, the n-butanol fraction at 1.25 mg·ml^-1 stimulated it and at 2.5 mg·ml^-1 inhibited it. Seventeen secondary metabolites were identified and quantified in the three fractions, including 2-keto-4a-methyl-8-methoxy-2,3,4,4a,5,6,11,12-ocahydro chrysene in the diethyl ether fraction (this metabolite had been found but not previously reported as an allelochemical). When we used identified components to prepare synthetic mixtures, it showed the same inhibitory effect on seed germination and seedling growth as did the three fractions.