Phytotoxicity of Cardoon (Cynara cardunculus) Allelochemicals on Standard Target Species and Weeds

Abstract

Cardoon (Cynara cardunculus L.) is a native plant to the Iberian Peninsula and the European Atlantic coast and invasive in American environments. Different solvents were used to perform cardoon extracts that were tested in phytotoxic bioassays. The ethyl acetate extract had the highest inhibitory activity so this was tested on the germination and growth of standard target species (lettuce, watercress, tomato, and onion) and weeds (barnyardgrass and brachiaria). The ethyl acetate extract was very active on root growth in both standard target species and weeds and it was therefore fractionated by chromatography. The spectroscopic data showed that the major compounds were sesquiterpene lactones. Aguerin B, grosheimin, and cynaropicrin were very active on etiolated wheat coleoptile, standard target species, and weed growth. The presence of these compounds explains the bioactivity of the ethyl acetate extract. The strong phytotoxicity of these compounds on important weeds shows the potential of these compounds as natural herbicide models.

Isolation of Bioactive Compounds from Sunflower Leaves (Helianthus annuusL.) Extracted with Supercritical Carbon Dioxide

“…Wheat coleoptile bioassays as well as phytotoxicity bioassays on tomato seeds were performed according to previously described procedures. 30 Molecular Modeling. Three-dimensional models for the tested chemicals were obtained from PM3 calculations performed by Hyperchem 7.01 software (Hypercube Inc., Gainesville, FL, USA; 2000).…”

Allelopathic effects of Cynara cardunculus L. leaf aqueous extracts on seed germination of some Mediterranean weed species

“…According to Rial et al (2014), cardoon allelochemicals (primarily aguerin B, grosheimin and cynaropicrin) possess a strong phytotoxicity on the germination and growth of standard target species (tomato, lettuce, onion and watercress) and weeds (barnyardgrass and brachiaria). Moreover, the joint action of binary mixtures of aguerin B, grosheimin and cynaropicrin and one nonactive compound (11,13-dihydroxy-8-desoxygrosheimin) was also investigated on wheat coleoptide (Rial et al, 2016).…”

Activities and Novel Applications of Secondary Metabolite Coumarins

“…Allelochemicals enter the soil rhizosphere in a number of wayssuch as plant degradation, volatilization, leaching from plant leaves, and root exudation -and affect the growth, physiological processes and biochemical traits of surrounding plants. Their continuous presence in the field is important for weed suppression when allelopathic crops are used as cover crops, mulch, smother crops, green manure, or grown in rotational sequences and can be exploited by industry led discovery programs (Hussain and Reigosa, 2011;Macias et al, 2014;Nuria et al, 2014;Rials et al, 2014;Hussain et al, 2015;Hussain and Reigosa, 2017). Many shrubs and exotic invasive trees exhibit allelopathy against other plants and weeds and some of them (particularly invasive plants) have developed allelopathy as a successful strategy for establishment in a new environment (Duke, 1986;.…”