摘要: 目的通过大范围采样分析栓皮栎软木主要化学成分及其环境影响因素，以期为我国软木资源的定向选育与科学利用提供科学参考、�/sec> 方法采集了全�?2个地区栓皮栎软木进行软木脂、木质素等主要化学成分测定分析，通过LSD多重比较、主成分分析和聚类分析等方法，对不同样点软木化学成分进行比较、�/sec> 结果发现栓皮栎软木主要化学成分的平均含量（本文中的化学成分含量指的是质量分数）为可萃取物�?3.94 ± 0.54�?，软木脂�?1.63 ± 1.44�?和木质素�?3.03 ± 2.26�?。以软木脂与木质素含量进行聚类分析可�?2个地理种源划分为3个类群，其中河北临城、江西永修、安徽金寨、江苏南京和河南内乡属于软木脂含量相对较高的类群；河南济源、陕西眉县和甘肃天水属于木质素含量较高的类群；陕西商洛、湖南城步、北京平谷和广西田林则属于中间类群。相关分析发现，二氯甲烷萃取物和总萃取物含量与纬度呈显著负相关关系，而软木脂含量随经度和土壤氮含量的增加呈现增加的趋势。年均温对化学成分含量的影响较小，但年均降水量与软木脂、二氯甲烷萃取物和总萃取物含量均呈现显著正相关关系、�/sec> 结论整体上，我国栓皮栎软木化学成分含量存在一定的地理差异，且主要受纬度、年均降水量和土壤氮含量的影响、�/sec>

关键诌�
• 栓皮栍�/a> /
• 软木化学成分/
• 聚类分析/
• 环境因子/
• 相关�?/a>

Abstract: ObjectiveThis study aimed to analyze the main chemical constituents and environmental influencing factors of cork from Quercus variabilisthrough a wide range of samples in China, which would be helpful to provide scientific reference for the oriented selection and scientific utilization of cork resources. MethodCork from Q. variabiliswas collected from 12 regions in China for the determination of cork resin, lignin and other major chemical components, and the chemical components of cork from different locations were compared by LSD multiple comparison, principal component analysis and cluster analysis. ResultThe average contents of main chemical constituents (the chemical composition content in this paper refers to the mass fraction) of the cork were: the total extractable matter was (13.94 ± 0.54)%, the suberin was (41.63 ± 1.44)% and the lignin was (23.03 ± 2.26)%. According to the content of suberin and lignin, the 12 provenances could be clustered into three groups, among which Lincheng (Hebei Province of northern China), Yongxiu (Jiangxi Province of eastern China), Jinzhai (Anhui Province of eastern China), Nanjing (Jiangsu Province of eastern China) and Neixiang (Henan Province of central China) had relatively high suberin content, while Jiyuan (Henan Province of central China), Meixian (Shaanxi Province of northwestern China) and Tianshui (Gansu Province of northwestern China) belong to the groups with high lignin content. The left provenances, Shangluo (Shaanxi Province of northwestern China), Chengbu (Hunan Province of southern China), Pinggu (Beijing of northern China) and Tianlin (Guangxi of southern China) belong to the middle group. The correlation analysis showed that the content of dichloromethane extract and total extractable matter was negatively correlated with latitude, while the suberin content increased with longitude and soil nitrogen content. The annual mean temperature had little effect on chemical composition content, but mean annual precipitation had significant positive correlation with the suberin, the dichloromethane extract and total extractable content. ConclusionOn the whole, there are certain geographical differences in the chemical composition content of cork from Quercus variabilisin China, and they are mainly affected by latitude, mean annual precipitation, and soil nitrogen content.

Key words:
• Quercus variabilis/
• chemical composition of cork/
• cluster analysis/
• environmental factor/
• correlation

�?nbsp; 1软木化学成分的主成分分析

Figure 1.Principal component analysis of chemical constituents of cork

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�?nbsp; 2各样点软木脂和木质素的聚类分枏�/p>

椭圆�?5%置信区间。Ellipses denote a 95% confidence interval.

Figure 2.Cluster analysis on the content of suberin and lignin across sites

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�?nbsp; 3软木化学成分含量与主要环境因子的相关系数

*p< 0.05为显著性相关；**p< 0.01为极显著性相关�?p< 0.05 means significant correlation; **p< 0.01 means extremely significant correlation.

Figure 3.Correlation coefficients between the chemical components of cork and environmental factors

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�?nbsp; 1取样点地理位置与环境信息

Table 1.Location and environmental information of the sampling sites

样点 Sample site	纬度 Latitude	经度 Longitude	海拔 Altitude/m	年均�?br/>Mean annual temperature/ℂ�/td>	年均降水野�br/>Mean annual precipitation/mm	土壤磷含野�br/>Soil phosphorus content/ (g∙kg�?)	土壤氮含野�br/>Soil nitrogen content/ (g∙kg�?)	土壤酸碱�?br/>Soil pH	径向生长速率/ (mm·a�?) Radial growth rate/(mm·year�?)	DBH/cm	树龄/a Tree age/year	郁闭�?br/>Canopy density
北京平谷 Pinggu, Beijing (BJ)	40°16�?8″N	117°08�?4″E	372.7 ± 152.0	9.52	575.72	0.50 ± 0.01	3.0 ± 1.1	5.28 ± 0.98	2.65 ± 1.51	18.50 ± 3.09	31.3 ± 8.2	0.73 ± 0.03
河北临城 Lincheng, Hebei (LC)	37°28�?7″N	114°06�?8″E	707.7 ± 59.8	11.95	617.41	0.50 ± 0.00	1.2 ± 0.1	6.59 ± 0.42	2.29 ± 0.38	20.16 ± 2.76	34.0 ± 1.0	0.82 ± 0.03
河南济源 Jiyuan, Henan (JY)	35°06�?6″N	112°21�?5″E	465.7 ± 14.0	13.49	570.38	0.20 ± 0.01	0.9 ± 0.7	4.97 ± 0.49	2.24 ± 0.66	19.96 ± 3.46	33.3 ± 6.9	0.67 ± 0.03
河南内乡 Neixiang, Henan (NX)	33°30�?6″N	111°54�?6″E	981.3 ± 264.3	12.88	918.54	0.40 ± 0.01	1.9 ± 0.2	4.62 ± 0.04	2.79 ± 0.84	19.16 ± 8.75	41.7 ± 5.8	0.81 ± 0.02
江西永修 Yongxiu, Jiangxi (YX)	29°04�?8″N	115°36�?6″E	415.7 ± 37.2	16.18	1707.23	0.50 ± 0.01	2.8 ± 0.5	4.05 ± 0.25	1.76 ± 0.21	19.59 ± 3.11	50.0 ± 0.0	0.74 ± 0.01
湖南城步 Chengbu, Hunan (CB)	26°17�?4″N	110°07�?8″E	1348.3 ± 18.7	12.17	1763.38	0.30 ± 0.00	3.1 ± 0.1	4.09 ± 0.16	2.04 ± 0.40	21.29 ± 4.97	39.0 ± 2.5	0.72 ± 0.02
广西田林 Tianlin, Guangxi (TL)	24°22�?8″N	105°50�?4″E	539.0 ± 63.2	21.13	863.20	0.30 ± 0.02	1.0 ± 0.3	4.77 ± 0.38	1.56 ± 0.06	15.50 ± 2.38	30.0 ± 3.1	0.83 ± 0.02
甘肃天水 Tianshui, Gansu (TS)	34°11�?4″N	106°19�?2″E	1264.3 ± 10.7	10.21	519.55	1.20 ± 0.10	1.6 ± 1.3	6.16 ± 1.67	1.93 ± 0.19	18.61 ± 2.22	32.7 ± 4.2	0.82 ± 0.03
陕西眉县 Meixian, Shaanxi (MX)	34°05�?3″N	107°41�?4″E	1138.0 ± 182.8	12.33	656.57	0.40 ± 0.02	1.4 ± 0.7	6.47 ± 2.09	2.49 ± 1.88	26.37 ± 1.72	39.7 ± 7.4	0.85 ± 0.00
陕西商洛 Shangluo, Shaanxi (SL)	33°49�?1″N	109°57�?5″E	911.0 ± 54.5	12.87	600.13	0.50 ± 0.02	1.1 ± 0.1	4.10 ± 0.21	1.84 ± 0.31	20.91 ± 2.31	48.3 ± 2.3	0.80 ± 0.03
安徽金寨 Jinzhai, Anhui (JZ)	31°18�?6″N	115°43�?1″E	1179.7 ± 0.6	10.14	1765.70	1.00 ± 0.02	3.2 ± 0.8	4.36 ± 0.16	1.28 ± 0.24	19.73 ± 1.68	52.7 ± 2.6	0.76 ± 0.03
江苏南京 Nanjing, Jiangsu (NJ)	32°07�?8″N	119°12�?9″E	175.7 ± 23.1	15.30	1158.85	0.30 ± 0.01	2.1 ± 0.9	4.12 ± 0.08	1.51 ± 0.21	23.25 ± 0.95	61.7 ± 1.7	0.84 ± 0.03

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�?nbsp; 2各地栓皮栎软木主要化学成分比辂�/p>

Table 2.Comparison of main chemical components in the cork ofQuercus variabilisfrom various sites

样点 Sample site	主要化学成分含量（质量分数） Content (mass fraction) of main chemical components/%						软木厚度 Cork thickness /cm
	二氯甲烷萃取� Dichloromethane extract	乙醇萃取� Ethanolic extract	水萃取物 Water extract	可萃取物总量 Total extractable matter	软木� Suberin	木质� Lignin
BJ	5.86 ± 0.57abcd	3.25 ± 0.54ab	4.63 ± 0.61a	13.74 ± 0.54ab	41.56 ± 4.46a	23.02 ± 5.04ab	0.853 ± 0.255abcd
LC	5.89 ± 0.46abcd	3.57 ± 0.60ab	4.57 ± 0.32a	14.03 ± 0.68ab	43.37 ± 2.63a	19.36 ± 1.75b	0.990 ± 0.107abc
JY	5.16 ± 0.17d	3.38 ± 0.48ab	5.13 ± 0.45a	13.67 ± 0.62ab	39.62 ± 2.16a	24.55 ± 2.86ab	0.685 ± 0.055bcd
NX	6.48 ± 0.28a	3.76 ± 0.67a	4.93 ± 0.96a	15.17 ± 1.41a	42.80 ± 4.19a	22.42 ± 2.94ab	1.000 ± 0.404ab
YX	5.98 ± 0.84abc	3.15 ± 0.46ab	5.09 ± 0.75a	14.22 ± 1.52ab	42.93 ± 4.01a	19.78 ± 1.77b	0.353 ± 0.050d
CB	6.17 ± 0.71ab	3.20 ± 0.74ab	4.73 ± 1.00a	14.10 ± 1.43ab	41.58 ± 0.68a	24.57 ± 3.13ab	0.678 ± 0.207bcd
TL	6.10 ± 0.34ab	3.24 ± 0.57ab	5.10 ± 0.22a	14.45 ± 0.18ab	41.15 ± 4.48a	21.50 ± 5.27ab	0.434 ± 0.153d
TS	5.56 ± 0.44bcd	2.67 ± 0.22b	4.86 ± 0.60a	13.10 ± 0.73b	40.17 ± 0.55a	26.37 ± 1.96a	0.916 ± 0.327abc
MX	5.25 ± 0.14cd	3.32 ± 0.89ab	5.12 ± 0.66a	13.69 ± 0.24ab	39.89 ± 1.80a	26.34 ± 1.78a	1.025 ± 0.269ab
SL	5.66 ± 0.09bcd	2.99 ± 0.52ab	4.64 ± 0.67a	13.28 ± 1.27b	40.05 ± 3.93a	24.16 ± 4.94ab	1.169 ± 0.324a
JZ	6.03 ± 0.10ab	2.93 ± 0.37ab	5.05 ± 0.73a	14.00 ± 0.74ab	43.34 ± 2.93a	22.03 ± 1.21ab	0.900 ± 0.211abc
NJ	5.91 ± 0.40abcd	3.39 ± 0.59ab	4.55 ± 0.21a	13.85 ± 0.94ab	43.03 ± 3.64a	22.31 ± 5.28ab	0.532 ± 0.177cd
平均 Mean	5.84 ± 0.38	3.24 ± 0.29	4.87 ± 0.23	13.94 ± 0.54	41.63 ± 1.44	23.03 ± 2.26	0.818 ± 0.320
注：同一列不同字母表示经LSD法检测在0.05水平上差异显著。Note: different letters in the same column indicate significant differences at the level of 0.05 detected by LSD.

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�?nbsp; 3栓皮栎软木主要化学成分含量（质量分数）比辂�/p>

Table 3.Comparison in the content (mass fraction) of main chemical components of virgin cork inQuercus variabilis

树种 Tree species	文献来源 Literature sourc	取样� Sampling site	水萃取物 Water extract/%	二氯甲烷萃取� Dichloromethane extract/%	乙醇萃取� Ethanolic extract/%	可萃取物总量 Total extractable matter/%	软木脁�br/> Suberin/%	木质� Lignin/%
栓皮� Quercus variabilis	刘艳贝�sup>[7]Liu Y Z[7]	陕西宁陕 Ningshan, Shaanxi	7.0	4.0	2.3	13.3	34.0	28.0
	张丽丛等[16] Zhang L C et al.[16]	陕西宁陕 Ningshan, Shaanxi	5.1	4.2	5.2	14.5	33.9	28.0
	赵泾峰等[17] Zhao J F et al.[17]	陕西商洛 Shangluo, Shaanxi	7.88 ± 0.60	4.47 ± 0.75	4.51 ± 0.91	17.10 ± 0.15	41.18 ± 1.81	20.37 ± 0.98
	姚慧军等[15] Yao H J et al.[15]	陕西秦岭 Qinling, Shaanxi	5.15	2.35	3.65	11.15	37.95	23.15
	陈慧筈�sup>[8] Chen H et al.[8]	陕西太白 Taibai, Shaanxi	8.77	1.40	2.16	12.33	38.47	22.72
	陈慧筈�sup>[8] Chen H et al.[8]	陕西略阳 Lueyang, Shaanxi	6.99	1.29	2.31	10.59	39.91	23.36
	陈慧筈�sup>[8] Chen H et al.[8]	陕西洋县 Yangxian, Shaanxi	8.10	1.67	2.49	12.27	38.27	24.09
	Miranda筈�sup>[5] Miranda et al.[5]	中国，具体不� Details not available, China	4.9	2.7	2.0	9.6	39.2	22.2
	Ferreira筈�sup>[13] Ferreira et al.[13]	中国，具体不� Details not available, China	5.3	2.8	1.1	9.2	37.4	27.6
	本研� This study	�?span class="xref">�?SeeTab.1	5.84 ± 0.38	3.24 ± 0.29	4.87 ± 0.23	13.94 ± 0.54	41.63 ± 1.44	23.03 ± 2.26
栓皮槟�br/>Q. suber	Pereira[11]	葡萄� Portugal	5.8 ± 0.8	5.9 ± 0.9	4.5 ± 1.6	16.2 ± 3.9	42.8 ± 6.2	22.0 ± 3.3

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