南岳山区五种树木吸收根形态和解剖性状对季节变化的响应  

Response of Absorptive Roots Morphology and Anatomical Traits of Five Tree Species to Seasonal Changes in Nanyue Mountainous Region

作　　者：王娜 胡文萍 彭震东 桂佳乐 胡婷 周畅 WANG Na;HU Wenping;PENG Zhendong;GUI Jiale;HU Ting;ZHOU Chang(School of Life Science,Hengyang Normal University,Hengyang 421008,China;Hunan Key Laboratory for Conservation and Utilization of Biological Resources in the Nanyue Mountainous Region,Hengyang Normal University,Hengyang 421008,China)

机构地区：[1]衡阳师范学院生命科学学院,湖南衡阳421008 [2]衡阳师范学院南岳山区生物资源保护与利用湖南省重点实验室,湖南衡阳421008

出　　处：《湖南生态科学学报》2024年第4期49-56,共8页Journal of Hunan Ecological Science

基　　金：湖南省自然科学基金(2022JJ40012);湖南省教育厅科学研究项目(21B0642,20A067);衡阳师范学院创新平台开放基金项目(2021HSKFJJ036);衡阳师范学院科研启动项目(2020QD18)。

摘　　要：【目的】树木吸收根主要承担着为植株生长、发育提供养分和水分的功能。本研究的主要目的在于探究树木吸收根形态和解剖性状随季节变化的响应规律,这有利于深入认识树木在不同季节的养分获取策略。【方法】本研究以南岳山区5种乔木为研究对象(杜英、玉兰、木莲、青檀、美叶柯),于春、夏、秋、冬四个季节采集根系样品,测定不同季节、不同树种的1~5级根序的形态特征以及解剖构造。【结果】本研究发现,吸收根的形态和解剖性状均受到树种、季节、根序的显著影响。随根序增加,吸收根直径增加,并伴随着比根长降低,皮层厚度的减小和中柱直径的增加,皮层厚度与中柱半径比例也相应减小。与其他季节相比,夏季各个根序中吸收根直径最高,并具有最高的吸收根数量比例,以及最高的皮层厚度和中柱直径;冬季的吸收根特征与夏季相反。例如,木莲的1级根在夏季最粗(300.40±9.54μm),冬季最细(184.32±9.62μm);美叶柯1级根的皮层厚度、中柱直径同样在夏季最高,分别为55.04±2.85μm、73.39±3.80μm,在冬季这两个指标均降低47%。此外,这种季节变化规律在5个树种的不同根序间表现基本一致,这可能与不同季节的气候、资源条件和树木的生长需求有关。【结论】本研究说明树木吸收根可以通过形态和解剖性状的调整适应不同季节的环境变化,对揭示树木吸收根在不同季节的资源获取策略,优化不同季节的森林营养管理和提高森林生产力均具有重要理论意义。【Objective】Tree absorptive roots are mainly responsible for providing nutrients and water for plant growth and development.The main purpose of this study is to explore the response of tree absorptive roots’morphology and anatomical traits with seasons,which is conducive to in-depth understanding of the nutrient acquisition strategies of trees in different seasons.【Method】In this study,the roots of five tree species(Elaeocarpus glabripetalus,Magnolia denudata,Manglietia fordiana,Pteroceltis tatarinowii,Lithocarpus calophyllus)in Nanyue mountainous region were collected in spring,summer,autumn and winter,and the morphological characteristics and anatomical structure of 1st-5th roots of different tree species in different seasons were determined.【Result】The results showed that absorptive roots’morphology and anatomical traits were significantly affected by tree species,root order and season.With the increase of root order,the diameter increased,correspondingly with the decrease of specific root length,the decrease of cortical thickness,the increase of stele diameter and the decrease of the ratio of cortical thickness to stele radius.Compared with other seasons,in summer trees had the highest absorptive roots diameter and the highest proportion of the number of absorptive roots,as well as the highest cortical thickness and stele diameter;the absorptive roots characteristics in winter were opposite to those in summer.For example,the first-order roots of Manglietia fordiana were the thickest in summer(300.40±9.54μm)and the thinnest in winter(184.32±9.62μm).The cortex thickness and stele diameter of the first-order roots of Lithocarpus calophyllus were also the highest in summer,which were 55.04±2.85μm and 73.39±3.80μm,respectively,and these two indexes decreased by 47%in winter.In addition,this seasonal variation pattern was basically consistent among the different order roots in five tree species,which might be related to the climate,resource conditions and tree growth needs in different season

关 键 词：南岳山区 季节变化 吸收根 形态 解剖结构 

分 类 号：Q948[生物学—植物学] S723[农业科学—林木遗传育种]