Chemical Characterization of Plant Extracts and Evaluation of their Nematicidal and Phytotoxic Potential.

Raúl Velasco-Azorsa,María Del Rocío Gutiérrez-Ortiz,Claudia Villanueva-Cañongo,Marco Vinicio Ramirez-Mares,Beatriz Hernández-Carlos,Raúl Salas-Coronado,Héctor Cruz-Santiago,Ignacio Cid Del Prado-Vera,Norma Francenia Santos-Sánchez,Karla Isabel Lira-De León

doi:10.3390/molecules26082216

Abstract

Nacobbus aberrans ranks among the “top ten” plant-parasitic nematodes of phytosanitary importance. It causes significant losses in commercial interest crops in America and is a potential risk in the European Union. The nematicidal and phytotoxic activities of seven plant extracts against N. aberrans and Solanum lycopersicum were evaluated in vitro, respectively. The chemical nature of three nematicidal extracts (EC50,48h ≤ 113 µg mL−1) was studied through NMR analysis. Plant extracts showed nematicidal activity on second-stage juveniles (J2): (≥87%) at 1000 µg mL−1 after 72 h, and their EC50 values were 71.4–468.1 and 31.5–299.8 µg mL−1 after 24 and 48 h, respectively. Extracts with the best nematicidal potential (EC50,48h < 113 µg mL−1) were those from Adenophyllum aurantium, Alloispermum integrifolium, and Tournefortia densiflora, which inhibited L. esculentum seed growth by 100% at 20 µg mL−1. Stigmasterol (1), β-sitosterol (2), and α-terthienyl (3) were identified from A. aurantium, while 1, 2, lutein (4), centaurin (5), patuletin-7-β-O-glucoside (6), pendulin (7), and penduletin (8) were identified from A. integrifolium. From T. densiflora extract, allantoin (9), 9-O-angeloyl-retronecine (10), and its N-oxide (11) were identified. The present research is the first to report the effect of T. densiflora, A. integrifolium, and A. aurantium against N. aberrans and chemically characterized nematicidal extracts that may provide alternative sources of botanical nematicides.

Highlights

The plant parasite nematode, Nacobbus aberrans (Thorne, 1935; Thorne & Allen, 1994), known as false root-knot, is distributed in Argentina, Bolivia, Chile, Ecuador, Mexico, Peru, and the USA
From the nine extracts evaluated in this study (Table 1), G. mexicanum and A. integrifolium achieved the maximum paralysis effect at 1000 μg mL−1 after 24 h
Nematicidal (72 h *) and nematostatic effects (72 h) at 1000 μg mL−1 occurred at similar immobility percentages for A. aurantium, A. integrifolium, A. subviscida, G. mexicanum, and H. terebinthinaceus, while the rest of the extracts showed their nematicidal effects at lower immobility percentages due to recovery of mobility (6.3–11%) (Table 1)

Summary

Introduction

The plant parasite nematode, Nacobbus aberrans (Thorne, 1935; Thorne & Allen, 1994), known as false root-knot, is distributed in Argentina, Bolivia, Chile, Ecuador, Mexico, Peru, and the USA. Management strategies of plant-parasitic nematodes are cultural practices (crop rotation), mixed-cropping, organic amendments, resistant crop cultivars, biological control [3,4,5,6], Molecules 2021, 26, s2t2r1a6tegies of plant-parasitic nematodes are cultural practices (crop rotation), mixed-cropping, organic amendments, resistant crop cultivars, biological control [3,4,5,6], chemical nematicides, and bioactive products of plant origin. Among these strategies, natural product usage represencthseamvicitaallnoepmtiaotnicifdoersc, oanntdroblliionagctpivheytporpoadtuhoctgseonficpnlaenmt aotroidgeins. In the search vulgare to contrfolrMboetlaoindiocgnyenme;ainticvidiveos,esxopmereimofetnhtesmshooswt reedcetnhtisperoffpeoctsa[7ls,8a]r.eInusthinegcSatseevioafrebaudiana and

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Results

Conclusion