Abstract
Weed control by crops through growth suppressive root exudates is a promising alternative to herbicides. Buckwheat (Fagopyrum esculentum) is known for its weed suppression and redroot pigweed (Amaranthus retroflexus) control is probably partly due to allelopathic root exudates. This work studies whether other weeds are also suppressed by buckwheat and if the presence of weeds is necessary to induce growth repression. Buckwheat and different weeds were co-cultivated in soil, separating roots by a mesh allowing to study effects due to diffusion. Buckwheat suppressed growth of pigweed, goosefoot and barnyard grass by 53, 42, and 77% respectively without physical root interactions, probably through allelopathic compounds. Root exudates were obtained from sand cultures of buckwheat (BK), pigweed (P), and a buckwheat/pigweed mixed culture (BK-P). BK-P root exudates inhibited pigweed root growth by 49%. Characterization of root exudates by UHPLC-HRMS and principal component analysis revealed that BK and BK-P had a different metabolic profile suggesting that buckwheat changes its root exudation in the presence of pigweed indicating heterospecific recognition. Among the 15 different markers, which were more abundant in BK-P, tryptophan was identified and four others were tentatively identified. Our findings might contribute to the selection of crops with weed suppressive effects.
Highlights
Plants perceive their above- and belowground environment by gathering information on the availability of the resources light, nutrients and water or chemical cues such as volatile compounds, leachates and root exudates (Weston and Mathesius, 2013; Fernandez et al, 2016)
Root exudates are important in mediating interactions with microbes and neighboring plants
We have previously shown that redroot pigweed (Amaranthus retroflexus) aboveground biomass was significantly reduced by buckwheat independently of resource competition and we concluded that allelopathic root interactions were promoting this growth inhibition (Gfeller et al, 2018)
Summary
Plants perceive their above- and belowground environment by gathering information on the availability of the resources light, nutrients and water or chemical cues such as volatile compounds, leachates and root exudates (Weston and Mathesius, 2013; Fernandez et al, 2016). After recognition of neighboring weeds, rice (Oryza sativa) and sorghum (Sorghum bicolor) change root exudation through the increased production of allelopathic root exudates such as momilactone and sorgoleone respectively (Zhao et al, 2005; Dayan, 2006; Kato-Noguchi and Peters, 2013). In a context of low herbicide use, plant breeders have an interest in the selection of allelopathic crops that are able to recognize and effectively suppress weeds. It is important to characterize to which extend neighboring plants interact
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
