摘要
【目的】研究施氮肥对树种间根尖功能性状如解剖结构与形态特征和组织氮浓度的关联,及其对土壤氮素有效性的响应,为深入了解树木根系结构与功能的关联机制提供理论参考。【方法】以温带6个常见树种(包括针叶和阔叶)成熟人工林为试验材料,将连续两年施氮肥处理与不施肥处理进行比较,分析根尖的解剖结构和表型特征(形态特征和组织氮浓度)差异,并采用Pearson相关系数(r)和冗余分析(RDA)评价施肥处理对根尖解剖结构与形态特征和组织氮浓度在种间关系的影响。【结果】在不施肥处理中,根尖组织氮浓度与中柱直径和导管特征(平均导管直径、导管总数和总导管面积)在种间呈极显著负相关(r=-0.822^-0.523)(P<0.01,下同),与皮层厚度和皮层细胞层数呈极显著正相关(r=0.596~0.876);根尖中柱直径和导管特征与根尖直径和组织密度在种间呈极显著正相关(r=0.434~0.798),与比根长呈极显著负相关(r=-0.852^-0.655);相比之下,根尖皮层特征与形态特征的相关性依赖于具体的指标。施氮肥增加了6个树种林分土壤氮的有效性,同时增加树种的根尖直径和组织氮浓度、降低比根长,而组织密度的变化依赖于树种。施氮肥后根尖的中柱和导管特征普遍显著增加(P<0.05),而皮层厚度和皮层细胞特征变化不显著(P>0.05)。施氮肥后,除了根尖组织氮浓度与皮层厚度和皮层细胞层数间的正相关程度在种间增强外(不施肥处理:r分别为0.596和0.876;施氮肥处理:r分别为0.746和0.935),根尖其他解剖特征与表型特征在种间的关联均普遍减弱。对根尖解剖指标进行RDA分析,发现中柱直径和平均导管直径对于形态特征和组织氮浓度改变的贡献最大,分别可解释其变化的59.4%(施氮肥处理)~68.9%(不施肥处理)和54.8%(施氮肥处理)~67.0%(不施肥处理)。【结论】在树种间,根尖解剖结构与形态特征和组织氮浓度紧密相
【Objective】To study the association of nitrogen fertilizer application on root tip functional traits such as anatomical structure,morphological characteristics and tissue nitrogen concentration,and the effects on soil nitrogen availability,which could provide theoretical basis for deeply understanding the mechanism of the connection between root structure and function in trees.【Method】Taking two-year nitrogen fertilization as fertilization treatment and non-fertilized treatment as control. Comparing differences in anatomical structure and phenotypic characteristics of root tips,such as morphological traits and nitrogen concentration between unfertilized and fertilized treatments in six common temperate tree species including conifer and broad-leaved species from mature artificial forests. The effects of nitrogen fertilization on relationships between root tip anatomy versus morphology and between root tip anatomy versus nitrogen concentration among species were evaluated by Pearson correlation coefficient(r)and redundancy analysis(RDA).【Result】In the unfertilized treatment,nitrogen concentrations of root tips were extremely negatively correlated to both stele diameter and conduit traits among species(r=-0.822 to-0.523)(P<0.01,the same below),and extremely positively correlated to cortical thickness and cortical cell traits(r=0.596-0.876). Stele diameter and conduit traits both extremely positively correlated to root tip diameter and tissue density among species(r=0.434-0.798)and extremely negatively related to specific root length(r=-0.852 to-0.655). By comparison,correlation between cortical cell traits and morphological traits depended on specific indexes. Nitrogen fertilization increased soil nitrogen availability in six tree species. Nitrogen fertilization generally increased root tip diameter and nitrogen concentration,decreased specific root length in all species,while changes of tissue density differed among species. The stele radius and conduit traits of root tips also significantly increased
作者
李应
邓雨奇
林声威
王治博
唐水昌
康雨辰
庄子楠
许海武
王文娜
LI Ying;DENG Yu-qi;LIN Sheng-wei;WANG Zhi-bo;TANG Shui-chang;KANG Yu-chen;ZHUANG Zi-nan;XU Hai-wu;WANGWen-na(College of Forestry,Hainan University/Key Laboratory of Germplasm Resources Biology of Tropical Special Ornamental Plants of Hainan,Haikou 570228,China)
出处
《南方农业学报》
CAS
CSCD
北大核心
2020年第12期2985-2992,共8页
Journal of Southern Agriculture
基金
海南省基础与应用基础研究计划(自然科学领域)高层次人才项目(2019RC159)
大学生创新创业训练计划项目(201910589407)。
关键词
根尖
解剖结构
形态特征
氮浓度
施氮肥
种间关联
root tip
anatomical structure
morphological trait
nitrogen concentration
nitrogen fertilization
interspecific correlation
