Allelopathic effect of extracts from different parts of Erigeron breviscapus (Vant.) Hand-Mazz on four kinds of crops

【Objective】 The crops which were suitable for intercropping or rotating with Erigeron breviscapus(Vant.) Hand-Mazz were screened based on allelopathy to provide theoretical basis for establishing efficient model of E. breviscapus intercropping or rotation system.【Method】 Extraction solutions of roots, stems and leaves of E. breviscapus were obtained through water extraction method. Three concentration gradients(0.05, 0.10 and 0.15 g/mL) were set for each extract. The allelopathic effects of extraction solution from different parts of E. breviscapus on Capsicum annuum, Zea mays, Oryza sativa and Brassica chinensis were studied with distilled water as the control.【Result】 The aqueous extracts from the roots, stems and leaves of E. breviscapus had strong allelopathic effects on seed germination and seedling growth of the four crops, and the effect intensity increased with the increase of the concentration of aqueous extracts. The aqueous extracts from leaves of E. breviscapus had a dual effect of low promotion and high inhibition on C. annuum seed germination index. Under the treatment of 0.15 g/mL root extract, the seedling root length of C. annuum, Z. mays, O. sativa and B. chinensis significantly decreased by 75.78%, 77.79%, 82.24% and 69.75% respectively compared with the control(P<0.05, the same below). Low concentration(0.05 g/mL) water extracts of E. breviscapus significantly increased the seedling length, seedling length of B. chinensis treated with 0.05 g/mL root extract increased significantly by 60.34% compared with the control. The allelopathic sensitivity of four crops to E. breviscapus was as follows:C. annuum>O. sativa> Z. mays>B.chinensis. Allelopathic effect of aqueous extracts of E. breviscapus on different parts were ordered as aboveground>underground.【Conclusion】 B. chinensis and C. annuum are more suitable for the rotation system of E. breviscapus to alleviate the continuous cropping obstacle of E. breviscapus. The result is in accordance with the actual plantation situation.