摘要
【目的】从自毒角度出发,探讨我国西南地区特有物种樟科植物米槁天然更新不良的原因,为解决米槁天然更新困难问题提供技术支持和种群保育提供一定的科学依据。【方法】采用米槁主要凋落物组分(叶片、果皮、种子、细枝)处理其盆栽幼苗,测定在不同凋落物组分与浸提液处理下幼苗的生长情况、土壤微生物组成、土壤营养元素(N、P、K)含量、土壤酶活性4方面的差异,从自毒角度揭示米槁种群天然更新障碍的原因。【结果】在试验浓度范围内,米槁叶片凋落物对米槁幼苗的苗高、生物量、叶面积均有负面影响;相反,在0.03、0.04 g·mL^(-1)浓度处理组中,果皮、种子、细枝凋落物对幼苗苗高、生物量、叶面积均有显著增加作用。各处理下土壤脲酶活性随着处理浓度的升高而逐步升高,叶片处理下酸性磷酸酶呈现出逐步下降的趋势。其余处理下过氧化氢酶、磷酸酶、蔗糖均没有明显变化规律。速效K、P的变化随着处理浓度升高逐步上升,速效N在叶片处理中亦呈现逐步上升的趋势。不同凋落物组分处理对土壤真菌的影响在组间具有明显差异,组内具有一定相似性,但细菌的组成在组间和组内相似性均较低。【结论】米槁叶片凋落物是米槁自毒物质的主要来源,其自毒作用机制可能是微生物、土壤酶与凋落物中自毒物质相互作用的结果。
【Objective】From the perspective of autotoxicity,this study explored the causes of poor natural regeneration of Cinnamomum migao,an endemic species in southwest China.The work has provided a scientific basis for solving the problem of natural regeneration and population conservation of C.migao.【Methods】The main litter components(leaves,pericarp,seeds,branch)of C.migao were used to treat its potted seedlings.The changes of growth index,soil microbial composition,N,P,K contents and soil enzyme activity of C.migao seedlings under different treatments were determined.The natural characteristics of C.Migao population were revealed from the perspective of autotoxicity.【Result】The results showed that the leaf litter had a negative effect on height,biomass and leaf area of C.migao seedlings within the experimental concentration range.On the contrary,pericarp,seeds and branch litter significantly increased seedling height,biomass and leaf area of C.migao in the 0.03 and 0.04 g·mL^(-1) concentration treatment groups.Soil urease activity increased gradually with the increase of treatment concentration,while the activity of catalase,phosphatase and invertase showed no obvious changes.The contents of available K,P increased gradually with the increase of treatment concentration,while there were no obvious change rules of total N,P and K contents.There were significant differences in the composition of soil fungi among different groups and there were certain similarities within the groups,while there was no correlation between and within the groups for bacteria.【Conclusion】From the above results,it can be concluded that the leaf litter is the main source of autotoxic substances in C.migao,and the autotoxicity mechanism may be mainly due to the interaction of microorganisms,soil enzymes and the autotoxic substances in the litter.
作者
唐子燕
陈敬忠
刘济明
廖小锋
TANG Ziyan;CHEN Jingzhong;LIU Jiming;LIAO Xiaofeng(College of Forestry,Guizhou University,Guiyang 550025,Guizhou,China;Forest Ecology Research Center of Guizhou University,Guiyang 550025,Guizhou,China;Institute of Mountain Resources,Guizhou Academy of Sciences,Guiyang 550002,Guizhou,China)
出处
《中南林业科技大学学报》
CAS
CSCD
北大核心
2022年第2期65-74,共10页
Journal of Central South University of Forestry & Technology
基金
贵州省科技计划项目“米槁种源筛选及菌根化育苗技术研究”(黔科合支撑〔2019〕2774号)。
关键词
米槁凋落物
土壤微生物
自毒
土壤酶
生长状况
Cinnamomum migao litter
soil microorganisms
autotoxicity
soil enzymes
growth status
