摘要
【目的】探讨酚酸类自毒物质香草酸的自毒作用,研究其对花生种子萌发和幼苗生长的影响,揭示根际土壤微生物在花生生育期内对自毒物质的响应规律。【方法】以花生品种阜花12号150GY为试材,培养皿培养试验设6个处理:0、0.01、0.03、0.05、0.07、0.09 mmol?L^(-1)香草酸溶液;营养钵种植试验设5个处理:0、0.01、0.03、0.05、0.07 mmol?L^(-1)香草酸溶液;盆栽试验设5个处理:香草酸用量分别为0、0.01、0.03、0.05、0.07 mg?kg-1干土。分别研究外源添加香草酸对花生种子萌发、幼苗生长及根际微生物区系的影响。【结果】(1)经不同浓度香草酸溶液处理后,花生种子的发芽率、发芽势和发芽指数均低于CK,与对照存在显著性差异。当香草酸溶液浓度为0.09 mmol?L^(-1)时,发芽率、发芽势和发芽指数与对CK相比分别降低39%、66.3%和55.9%,自毒效应响应指数达到最大值。(2)经不同浓度香草酸溶液处理后,花生幼苗的主根长、单株干重、叶绿素含量、净光合速率和气孔导度均低于CK,与对照存在显著性差异,当香草酸溶液浓度为0.07 mmol?L^(-1)时,各指标与对CK相比分别降低37.3%、40.0%、19.0%、53.9%和49.1%,自毒效应响应指数达到最大值。胞间CO2浓度变化趋势与以上指标相反,随香草酸浓度的增大而呈现上升趋势,当香草酸溶液浓度为0.07 mmol?L^(-1)时,胞间CO_2浓度比对照提高46.1%。(3)香草酸浓度≥0.03 mmol?L^(-1)时,花生根系总吸收面积、活跃吸收面积和根系活力(活跃吸收面积/总吸收面积)低于CK,叶片的MDA含量高于对照,均与对照存在显著性差异,当香草酸溶液浓度为0.07 mmol?L^(-1)时,各指标与对照相比分别降低22.4%,54.2%和40.6%,MDA含量提高43.3%。(4)根际放线菌数量在花生生育前期随着香草酸浓度的增大而显著降低,进入结荚期后各处理间差异不显著。根际细菌数量在花生生育前期时各处理间差异不显著,而进入结荚期后随着香草酸浓度的增大而显著降低。高浓度的香草酸(0.07 mg?kg^(-1)干土)对根际真菌生长具有抑制作用,而低浓度的香草酸(0.01 mg?kg^(-1)干土)对根际真菌生长具有促进作用。【结论】香草酸对花生种子萌发和幼苗生长存在一定的抑制作用,香草酸亦会抑制花生幼苗的光合作用,降低根系活力,促进幼苗叶片产生丙二醛。此外,不同浓度的香草酸溶液均会使花生根际细菌和放线菌的数量降低,抑制根际土壤中细菌和放线菌的生长繁殖,而对土壤真菌的影响呈现低促高抑的现象,即低浓度的香草酸溶液促进花生根际土壤中真菌的生长;而高浓度则对真菌生长具有一定的抑制作用。
【Objective】 Experiments were carried out to investigate the autotoxicity of vanillic acid and its effect on seed germination and seedling growth of peanut, so as to reveal the response rules of rhizosphere microbes to the autotoxic substances in peanut growth period.【Method】Peanut(Arachis hypogaea L. cv Fuhua 12 150 GY) was used in this study, and petri dish method, nursery pot and pot culture experiment were adopted to explore the effect of vanillic acid on the peanut seed germination, seedling growth and rhizosphere microflora. Six vanillic acid application treatments in petri dish experiment were set with application of different vanillic acid amounts: 0, 0.01, 0.03, 0.05, 0.07, 0.09 mmol·L^-1, five treatments in nursery pot experiment were 0, 0.01, 0.03, 0.05, 0.07 mmol·L^-1, and five treatments in pot culture experiment were 0, 0.01, 0.03, 0.05, 0.07 mg?kg-1 dry soil.【Result】(1) The seed germination ratio, germination energy and germination index were lower than CK after treatment with different concentrations of vanillic acid. When the concentration of vanillic acid was 0.09 mmol·L^-1, the seed germination ratio, germination energy and germination index respectively decreased by 39%, 66.3% and 55.9% compared with CK, and the response index(RI) reached the maximum.(2) The root length, plant dry weight, chlorophyll content, net photosynthetic rate and stomatal conductance were lower than CK after treatment with different concentrations of vanillic acid. When the concentration of vanillic acid was 0.07 mmol·L^-1, all above indexes decreased by 37.3%, 40.0%, 19.0%, 53.9% and 49.1%, respectively, compared with CK, and the response index(RI) reached the maximum. Conversely, the intercellular CO_2 concentration was the opposite of the above indexes, it went up with the increase of the concentration of vanillic acid. When the concentration of vanillic acid was 0.07 mmol·L^-1, the intercellular CO2 concentration increased by 46.1% compared with CK.(3) when the concentration of vanillic acid ≥0.03 mmol·L^-1, the total absorption area, active absorption area and root activity were lower than CK, while the MDA content were higher than CK. When the concentration of vanillic acid was 0.07 mmol·L^-1, all above indexes respectively decreased by 22.4%, 54.2% and 40.6% compared with CK, the MDA content increased by 43.3%.(4) The number of rhizosphere actinomycetes were markedly reduced with the increase of vanillic acid concentration at the early stage of peanut, and the differences between the treatments were not significant at the late stage of peanut. The number of bacteria in different treatments were not significant difference at the early stage of peanut, and it substantially reduced with the increase of vanillic acid concentration at the late stage. A high concentration of vanillic acid(0.07 mg?kg-1 dry soil) had inhibitory effect on rhizosphere fungal growth, and low concentration of vanillic acid(0.01 mg?kg-1 dry soil) had a promoting effect of fungal growth. 【Conclusion】 Vanillic acid had a significant autotoxinc-effect, which inhibited the photosynthesis of peanut seedling, reduced the root activity and promoted seedling leaf malondialdehyde. In addition, the number of rhizosphere bacteria and actinomycetes decreased after treated with vanillic acid, indicating that vanillic acid inhibited the growth of rhizosphere bacteria and actinomycetes; while it promoted the growth of rhizosphere fungi at low concentration but inhibited the growth at high concentration.
作者
黄玉茜
杨劲峰
梁春浩
陈堔平一
刘欣宇
耿坷睿
姚玉晨
张宇
韩晓日
HUANG YuQian;YANG JinFeng;LIANG ChunHao;CHEN ShenPingYi;LIU XinYu;GENG KeRui;YAO YuChen;ZHANG Yu;HAN XiaoRi(College of Land and Environment, Shenyang Agricultural University, Shenyang 110866;Plant Protection Research Institute, Liaoning Academy of Agricultural Sciences, Shenyang 110161)
出处
《中国农业科学》
CAS
CSCD
北大核心
2018年第9期1735-1745,共11页
Scientia Agricultura Sinica
基金
国家自然科学青年基金项目(31401948)
国家现代农业产业技术体系建设专项(CARS-14
CARS-13)
关键词
香草酸
花生
自毒物质
光合特性
根系活力
微生物区系
vanillic acid
peanut
autotoxic substances
photosynthetic characterization
root activity
microflora