花生根系分泌物的鉴定和化感作用研究

Identification and allelopathy of chemical compositions of peanut root exudates

【目的】分离鉴定不同花生品种根系分泌物,探讨花生Arachis hypogaea根系分泌物对花生的化感作用.【方法】采用气相色谱质谱联用(GC-MS)技术和生物测定方法,分析鉴定2个花生品种桂花22和A.correntina的水培根系分泌物的主要成分及化感作用.【结果和结论】分离鉴定出的花生根分泌物包括有机酸类、醇类、酯类、酮类、醛类、苯类、烃类等,主要有机化合物有邻苯二甲酸、苯甲醛、草酸、对乙基苯甲酸、丙酰胺、丙氨酸、戊酸等.花生根分泌物中的苯甲醛、对乙基苯甲酸对花生具有化感作用.与对照比,苯甲醛、对乙基苯甲酸和阿魏酸的低浓度处理(1×10-5mol·L^(-1))对2个花生品种的株高、根长、地上部干质量和地下部干质量有促进作用或弱抑制作用,而苯甲醛、对乙基苯甲酸和阿魏酸高浓度处理(1×10^(-3)和1×10^(-4)mol·L^(-1))都存在不同程度的抑制作用,且与对照差异显著(P<0.05).与对照相比,1×10^(-5)、1×10^(-4)、和1×10^(-3)mol·L^(-1)浓度处理的苯甲醛、对乙基苯甲酸和阿魏酸不同程度地增加了2个花生品种的叶片SOD酶活性、POD酶活性和MDA含量,且高浓度处理(1×10^(-3)mol·L^(-1))的叶片SOD酶活性、POD酶活性和MDA含量与对照相比差异达显著水平(P<0.05).

【Objective】To analyze peanut root exudates and study the allelopathic effects of peanut root exudates. 【Method】Compounds extracted from peanut root exudates were identified by GC-MS technique.The allelopathic effects of peanut root exudates on the peanut seeding growth were analyzed using biological test at the concentrations of 0,1 × 10^(-5),1 × 10^(-4) and 1 × 10^(-3)mol·L^(-1).【Result and conclusion】The peanut root exudates included organic acid,alcohol,ester,ketone,aldehyde,benzene,hydrocarbon and so on. Benzaldehyde and 4-ethylbenzoic acid,which showed an allelopathic effect on peanut,were found to be the major components of peanut root exudates. 1 × 10^(-5)mol·L^(-1) Benzaldehyde,4-ethylbenzoic acid and ferulic acid promoted or weakly inhibited peanut seeding stem length,root length,drymass of root and shoot. Compared with the control,1 × 10^(-3) and 1 × 10^(-4)mol·L^(-1) benzaldehyde,4-ethylbenzoic acid and ferulic acid significantly inhibited peanut seedling growth( P < 0. 05). The SOD activity,POD activity and MDA content of two peanut varieties leaf showed a rising trend to varying degrees at different concentration levels of benzaldehyde,4-ethylbenzoic acid and ferulic acid,and there was significant difference between the high concentration treatment( 1 × 10^(-3)mol · L^(-1)) and the control( P <0. 05). In conclusion,there are allelophathic substances in peanut root exudates,which is one of the main factors of continuous cropping barrier of peanut.