Abstract:

【Objective】In order to provide a theoretical basis for solving cropping obstacles of garlic, the inhibition of garlic root exudates on the genus Allium was studied. 【Method】In order to avoid interferences from external factors, this paper studied the autotoxicity of garlic root exudates on welsh onion, onion and Chinese leek scallion, by using tissue culture under sterilized condition. 【Result】Garlic and receptor crops, such as welsh onion, onion and Chinese leek, are belong to the genus Allium. Root exudates of garlic could inhibit the germination and growth of receptor crops, the inhibitory degree increased progressively and significantly with increasing root exudates concentrations of garlic, and the maximal inhibition rates of germination rate, mean time to germination, embryo and radicle length, embryo and embryo fresh weight were 51.72%, 48.20%, 51.57%, 51.57%, 82.14% and 82.29%, respectively. Garlic root exudates decreased root activity of receptor crops, and significant differences were observed except the lowest concentrations (T1) on welsh onion and onion, compared to control. Compounds involved in the garlic root exudates were isolated and identified by gas chromatography/mass spectrometer (GC-MS), including 2,2′-methylenebis[6-(1,1-dimethylethyl)- 4-methyl-Phenol, mono (2-ethylhexyl) phthalate, eicosanoic acid, ferulic acid, 9-hexadecenoic acid, tetradecanoic acid, diallyl disulphide, etc., ferulic acid and myristic acid which had been identified as growth inhibitory substances.【Conclusion】The germination and growth of receptor crops were inhibited by garlic root exudates, which were released to field year by year and could lead to garlic continuous cropping obstacles.