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Allelopathic Effects of Walnut Leaves Aqueous Extracts on Seed Germination and Seedling Growth of Four Medicinal Plants

Authors Li Qian; He Jun; Lv Wen; Zhang Shuoxin

Journal Southwest China Journal of Agricultural Sciences , DEC 2009,4:63

DOI 10.1007/s12231-009-9103-6

Abstract 【Objective】The objective of this study is to elucidate the allelopathic effects of walnut leaves aqueous extracts on 4 medicinal plants( Isatis tinctoria L., Atractylodes macrocephal Koidz., Polygala tenuifolia Willd. and Salvia miltiorrhiza Bge. ), and provide a theoretical basis for the intercropping between the Chinese herbs and forest.【Method】By using bio-assay method,the allelopathic effects of walnut ( Juglans regia L. ) leaves aqueous extracts were investigated on the seed germination,seedling growth and fresh weight of 4 medicinal plants.【Result】The results showed that the aqueous extracts of walnut leaves existed different allelopathic effects on different test medicinal plants. All aqueous extracts significantly inhibited the germination capacity of I. tinctoria., but for A. macrocephala,there existed inhibitory /stimulatory effects on the germination rate,and P. Willd. had good adaptability during the seed germination process under the aqueous extracts of walnut leaves. The root length were more sensitive than shoot length to the water-soluble allelochemicals of walnut leaf aqueous extracts, the inhibitory effect of root length of S. miltiorrhiza. was more enhanced with the concentrations increasing of walnut leaves aqueous extracts.【Conclusion】The studies suggested that there existed different effects with concentration of walnut leaf extracts and receptor plant species,so allelopathic effects exhibited different selectivity and specificity. We preliminarily suggest that Polygala tenuifolia Willd could be used as a suitable medicinal material for walnut intercropping.

Species covered 丹参 Salvia miltiorrhiza 远志 Polygala tenuifolia 胡桃 Juglans regia