摘要
【目的】我国植胶区砖红壤钾、镁缺乏现象日益突出,研究钾、镁缺乏对橡胶幼苗根系形态和养分吸收的影响,可为橡胶平衡施肥和优质高产栽培提供理论依据。【方法】选用‘热研7-33-97’橡胶(Hevea brasiliensis)幼苗为研究材料,在人工气候箱内用营养液培养。采用二因素二水平的析因试验设计,设置4个处理:对照(CK)、缺钾(-K)、缺镁(-Mg)和缺钾镁(-K-Mg),培养3个月后,取样测定橡胶幼苗干物质量、根系构型参数、根系活力和养分含量等指标。【结果】1)与CK相比,-K和-K-Mg处理显著降低了单株干物质量和根冠比,干物质量降幅分别为8.4%和27.5%,根冠比降幅分别为20.4%和26.9%,而-Mg处理对干物质量和根冠比均无显著影响;K、Mg交互作用对茎干、根和单株干物质量及根冠比均有显著影响(P<0.05)。2)与CK相比,各缺素处理均显著降低了橡胶幼苗吸收根(直径<2 mm)的根长、根表面积、根体积、总根尖数及根系活力等根系构型参数,而不同程度增加了平均根粗。方差分析结果表明,K、Mg交互作用对吸收根的根长、根表面积、根体积及总根尖数有极显著影响(P<0.01)。3)各处理下氮和镁、磷和钾以及钙分别在叶片、根系以及茎皮中的平均分配比例高于其他器官。各缺素处理下,地上部的养分占比呈增加趋势。4)与CK相比,-K处理显著增加了橡胶幼苗单株氮、磷和镁的积累,-K-Mg处理则显著降低了单株氮积累,各缺素处理均显著增加了单株钙的积累;K、Mg交互作用对氮、磷、钙和镁的积累有显著或极显著影响。【结论】钾、镁营养显著影响橡胶幼苗对养分的吸收,缺钾、缺镁显著抑制橡胶幼苗特别是根系的生长发育,同时缺钾缺镁加重抑制效果。因此,橡胶生产上不仅要保证培养基质或土壤的矿质营养充足,还要重视钾、镁元素间平衡关系。
【Objectives】The problems of potassium(K)and magnesium(Mg)scarcity are increasingly highlighted in Latosol of rubber plantations in Southern China.A study of K and Mg deficiency affecting on roots morphology and nutrients absorption of rubber seedlings was conducted to provide theoretical basis for balanced fertilization and high-quality and high-yield rubber cultivation.【Methods】A hydroponic culture experiment was conducted and the seedlings of Hevea brasiliensis‘7-33-97’were grown as the tested materials in artificial climate chamber.Four treatments were setup,including:control(CK),no K supply(-K),no Mg supply(-Mg),no K and Mg supply simultaneously(-K-Mg).The dry matter,root morphological parameters,root activity,and nutrients content of plant samples were measured after three months of rubber seedlings grown in the treated solution.【Results】1)Compared with CK,the single plant dry matter amounts were significantly decreased by 8.4% and 27.5%,and the root/shoot ratios decreased by 20.4% and 26.9% under-K and-K-Mg treatments,while the dry matter amounts and the root/shoot ratios were not significantly affected by-Mg treatment;-K-Mg treatment accelerated the adverse effects of-K and-Mg on the dry matter accumulation of stems,roots and total plants and root/shoot ratios(P<0.05).2)Compared with CK,the root length,root surface area,root volume,total root tip number and absorption activity of root(<2 mm)were significantly reduced under all the three nutrient deficiency treatments(P<0.05),but the average root diameter per plant was increased.Variance analysis showed significant interaction-effect between K and Mg on root length,root surface area,root volume,total root tip number of absorption root(P<0.01).3)The distribution proportion of N and Mg in leaf,P and K in root,Ca in stem bark were higher than those in other organs.Mean whiles compared to CK,the proportion of shoot to whole nutrients showed an increased trend under nutrient deficiency.4)Compared with CK,-K resulted in a significant increase of N and Mg accumulation per plant,-K-Mg treatment resulted in a significant reduce of N accumulation per plant,while all the three treatments resulted in significantly increased Ca accumulation.K and Mg had significant(P<0.05)or extremely significant(P<0.01)interaction on N,P,Ca and Mg accumulation.【Conclusions】Both K and Mg deficiencies will significantly affect plant nutrient absorption,and then stunt the growth and development of shoots and roots of rubber seedlings,and the interaction of simultaneous K and Mg deficiencies will accelerate the adverse impaction.So more attention should be paid on the balanced supply of K and Mg nutrition during the rubber tree production.
作者
薛欣欣
魏云霞
王文斌
罗雪华
赵春梅
王大鹏
张永发
吴小平
XUE Xin-xin;WEI Yun-xia;WANG Wen-bin;LUO Xue-hua;ZHAO Chun-mei;WANG Da-peng;ZHANG Yong-fa;WU Xiao-ping(Rubber Research Institute,Chinese Academy of Tropical Agricultural Sciences/Soil and Fertilizer Research Center/Key Laboratory of Biology and Genetic Resources of Rubber Tree,Ministry of Agriculture and Rural Affairs/Ministry of Agriculture and Rural Affairs-State Key Laboratory Incubation Base for Cultivation&Physiology of Tropical Crops,Haikou,Hainan 571101,China;Tropical Crops Genetic Resources Institute,Chinese Academy of Tropical Agricultural Sciences,Haikou,Hainan 571101,China)
出处
《植物营养与肥料学报》
CAS
CSCD
北大核心
2020年第10期1870-1878,共9页
Journal of Plant Nutrition and Fertilizers
基金
中国热带农业科学院基本科研业务费专项资金(1630022020012,1630022017006)
海南省重点研发计划项目(ZDY2018240)
国家重点研发计划(2018YFD0201100)。
关键词
橡胶
缺钾
缺镁
根系形态
养分积累
rubber seedling
K deficiency
Mg deficiency
root morphology
nutrients accumulation
