Allelopathic potential of plant extracts from the stem of Cuscuta campestris Yunck

Abstract

Allelopathic processes involve interactions between living organisms via secondary metabolites (allelochemicals). Cuscuta species are known for their large production of chemical compounds characterized by various biological activities. This study aimed to test the allelopathic effects of plant extracts isolated from the stem of Cuscuta campestris on the germination and early seedling growth of two weed species (Amaranthus retroflexus and Portulaca oleracea). Additionally, the goals were to also conduct an analysis of the plant extracts and determine their antioxidant properties. The chemical analysis has shown that the obtained plant extract is a rich source of phenolic compounds. HPLC analysis separated by content of the following compounds: quercetin (5.62 mg g -1), catechin (3.71 mg g -1), diadzin (2.85 mg g -1), luteolin (1.82 mg g -1), and rutin (1.16 mg g -1). In addition, higher concentrations (0.75% and 1%) of the plant extract of this parasitic flower had an inhibitory effect on the germination and early growth of A. retroflexus and P. oleracea seeds. A. retroflexus proved to be a more sensitive test plant compared to P. oleraceae, which is confirmed by the inhibition percentages of seed germination of 88% (A. retroflexus) and 8% (P. oleraceae), i.e. the inhibition of seedling growth was 77% (A. retroflexus) or 70% (P. oleraceae). The obtained results have shown the allelopathic properties of the stem extracts of the C. campestris.