不同种源杉木细根解剖性状的差异分析

Analysis of differences in fine root anatomical traits of Chinese fir from different provenances

为探究杉木细根解剖性状在不同地理种源间的表型差异,揭示杉木细根功能性状对不同种源地环境的响应特征,选取我国杉木分布区内16个种源地40年生的杉木人工林为研究对象,进行不同种源杉木细根直径、维管束直径、皮层厚度、维根比及皮层占比等细根解剖性状的调查分析,比较不同种源杉木细根解剖性状的差异,分析不同种源杉木细根解剖结构特征与种源地环境因子之间的相关关系。结果表明:不同种源杉木细根的解剖性状存在显著差异(P<0.05)。杉木细根直径和维管束直径大小为北带>中带东区>中带中区>中带西区>南带,其中,福建上杭和河南信阳种源杉木细根表现出较大的细根直径和维管束直径,江西上饶种源杉木的细根直径和维管束直径较小。不同种源杉木细根皮层厚度大小为北带>中带西区>中带东区>中带中区>南带,其中,河南信阳种源杉木的细根皮层组织较薄,而江西上饶和湖北罗田种源杉木的细根则表现出较厚的皮层组织。冗余分析结果表明,杉木细根皮层厚度、皮层占比与土壤P含量呈正相关,与土壤N含量呈显著负相关(P<0.05),维根比与种源地纬度呈显著正相关(P<0.05),与土壤P含量呈显著负相关(P<0.05)。杉木细根解剖性状对不同种源地生境条件的响应特征有所不同,表明杉木细根为适应不同种源地的生境条件产生了功能性状和生态适应策略的变异。

Forty-year-old Chinese fir(Cunninghamia lanceolata)plantations from 16 different provenances in China were selected as the study object to identify the differences in the phenotypes of the anatomical traits of their fine roots,and the characteristics of the responses of the functional traits of fine roots to different geographical environments were analyzed.The fine root diameter(FRD),stele diameter(SD),cortical thickness(CT),ratio of stele to root diameter(SDR),and ratio of cortex to cross-section(CCS)of the fine roots were measured.The differences in the anatomical traits of the fine roots of Chinese fir were compared at the distribution area level,and the correlation between these anatomical traits and environmental factors were examined.The findings revealed significant differences in the anatomical traits of the fine roots among the different provenances(P<0.05).The FRD and SD of the fine roots of Chinese fir in different locations were ranked in the following descending order:northern belt>east of middle belt>center of middle belt>west of middle belt>southern belt.The FRD and SD of the fine roots of the trees in Shanghang(Fujian)and Xinyang(Henan)were larger than those in the other provenances,whereas those of the fine roots of the trees in Shangrao(Jiangxi)were the smallest.The CT of the fine roots of Chinese fir in the different areas decreased in the following order:northern belt>west of middle belt>east of middle belt>center of middle belt>southern belt.The CT of the fine roots of trees in Xinyang(Henan)was thinner than that in other provenances,whereas the fine roots of the trees in Shangrao(Jiangxi)and Luotian(Hubei)showed thicker cortical tissue.The results of redundancy analysis showed that the CT and CCS of the fine roots positively correlated with the soil phosphorus content and significantly negatively correlated with the soil nitrogen content(P<0.05).The SDR of the fine roots showed a significant positive correlation with latitude(P<0.05)and a significant negative correlation with soil phosphorus content(P<0.05).The response characteristics of the anatomical traits of the fine roots of Chinese fir in different habitat conditions differed,indicating that the fine roots of Chinese fir produce variations in functional traits and implement various ecological strategies to adapt to the environmental conditions in different provenances.