Volatiles from biofumigant plants have a direct effect on carpogenic germination of sclerotia and mycelial growth of Sclerotinia sclerotiorum

Abstract

Original citation:Warmington, Rachel and Clarkson, John P. (2015) Volatiles from biofumigant plants have a direct effect on carpogenic germination of sclerotia and mycelial growth of Sclerotinia sclerotiorum. Plant and Soil. doi: 10.1007/s11104-015-2742-8 Permanent WRAP url: http://wrap.warwick.ac.uk/74305 Copyright and reuse:The Warwick Research Archive Portal (WRAP) makes this work by researchers of the University of Warwick available open access under the following conditions. Copyright © and all moral rights to the version of the paper presented here belong to the individual author(s) and/or other copyright owners. To the extent reasonable and practicable the material made available in WRAP has been checked for eligibility before being made available.Copies of full items can be used for personal research or study, educational, or not-for profit purposes without prior permission or charge. Provided that the authors, title and full bibliographic details are credited, a hyperlink and/or URL is given for the original metadata page and the content is not changed in any way. Publisher's statement:"The final publication is available at Springer via http://dx.doi.org/10.1007/s11104-015-2742-8." A note on versions:The version presented here may differ from the published version or, version of record, if you wish to cite this item you are advised to consult the publisher's version. Please see the 'permanent WRAP url' above for details on accessing the published version and note that access may require a subscription. AimsSclerotia of Sclerotinia sclerotiorum survive in soil and germinate to produce apothecia which release airborne ascospores. Current control methods rely predominantly on the use of fungicides to kill ascospores. The aim of this research was to identify potential biofumigation treatments which suppress sclerotial germination, providing a potential alternative and long-term approach to disease management. MethodsMicrocosm and in vitro experiments were conducted using dried and milled plant material from six different biofumigant crop plants to determine effects on carpogenic germination of sclerotia and mycelial growth of S. sclerotiorum. ResultsAll biofumigant plants significantly reduced germination of S. sclerotiorum sclerotia in the microcosm experiments, but were less effective against larger sclerotia. In vitro experiments showed a direct effect of biofumigant volatiles on both the mycelial growth of S. sclerotiorum, and carpogenic germination of sclerotia, where the most effective treatment was B. juncea 'Vittasso'.Conclusions It was clear from this study that biofumigant crop plants have potential as part of an integrated disease management system for control of S. sclerotiorum. The microcosm experiments described here provide a straightforward and reliable screening method for evaluating different biofumigants for activity.

Biofumigation to protect oilseed crops: focus on management of soilborne fungi of sunflower

“…The breakdown of resistance and the current context of agroecological transition have decreased the use of broadspectrum fumigants (Warmington and Clarkson, 2016) and increased interest in alternative methods of crop protection (Martin, 2003). Reliance on combined and natural mechanisms to protect crops has been encouraged by Integrated Pest Management (IPM), as described in the EU Framework Directive 2009/128/EC.…”

“…To control V. dahliae, S. sclerotiorum and M. phaseolina, mustard varieties, especially Brassica juncea (brown/Indian mustard), were used mainly as a source of GSLs and ITCs in biofumigation studies. Mustard species often showed significant suppression of V. dahliae (Olivier et al, 1999;Neubauer et al, 2015;Seassau et al, 2016), S. sclerotiorum (Ojaghian et al, 2012;Rahimi et al, 2014;Warmington and Clarkson, 2016) and M. phaseolina (Mazzola et al, 2017). Some cultivars of turnip rape (Brassica rapa), forage radish Table 1.…”

Inoculum potential of Sclerotinia sclerotiorum sclerotia depends on isolate and host plant

“…Sclerotia in the size class >6.7 mm were only obtained from OSR and in this case, due to their size, only 16 sclerotia were placed in each box (three replicate boxes). The germination of S. sclerotiorum sclerotia produced on the crop plants was compared with those produced on sterilized wheat grain in vitro , as used routinely for production of sclerotia in several previous studies (Mylchreest & Wheeler, ; Liu & Paul, ; Warmington & Clarkson, ). As before, three replicate boxes (30 sclerotia per box) were set up for each size class with the exception of those >6.7 mm where a single box was set up due to low numbers of sclerotia of this size being produced on wheat grain.…”

“…Other researchers also demonstrated that, in vitro , different isolates of both S. sclerotiorum and S. trifoliorum produced different numbers and weights of sclerotia under the same conditions (Akram et al ., ; Li et al ., ; Vleugels et al ., ). Furthermore, it has been shown that larger S. sclerotiorum sclerotia tend to produce more apothecia than smaller ones and are also more likely to germinate (Ben‐Yephet et al ., ; Dillard et al ., ; Hao et al ., ; Warmington & Clarkson, ). However, these studies used sclerotia produced on a single crop type (lettuce; Ben‐Yephet et al ., ), or on detached potato tubers (Hao et al ., ) or produced artificially in vitro (Dillard et al ., ; Warmington & Clarkson, ).…”

“…Furthermore, it has been shown that larger S. sclerotiorum sclerotia tend to produce more apothecia than smaller ones and are also more likely to germinate (Ben-Yephet et al, 1993;Dillard et al, 1995;Hao et al, 2003;Warmington & Clarkson, 2016). However, these studies used sclerotia produced on a single crop type (lettuce; Ben-Yephet et al, 1993), or on detached potato tubers (Hao et al, 2003) or produced artificially in vitro (Dillard et al, 1995;Warmington & Clarkson, 2016). Hence, both crop type and S. sclerotiorum isolate potentially have a significant impact on the build-up of inoculum in the field by affecting the number and size of sclerotia produced.…”