AUTHOR=Ali Jamin , Covaci Anca D. , Roberts Joe M. , Sobhy Islam S. , Kirk William D. J. , Bruce Toby J. A. 

TITLE=Effects of cis-Jasmone Treatment of Brassicas on Interactions With Myzus persicae Aphids and Their Parasitoid Diaeretiella rapae

JOURNAL=Frontiers in Plant Science

VOLUME=12

YEAR=2021

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2021.711896

DOI=10.3389/fpls.2021.711896

ISSN=1664-462X

ABSTRACT=<p>There is a need to develop new ways of protecting plants against aphid attack. Here, we investigated the effect of a plant defence activator, <italic>cis</italic>-jasmone (CJ), in a range of cultivars of <italic>Brassica napus, Brassica rapa</italic> and <italic>Brassica oleracea</italic>. Plants were sprayed with <italic>cis</italic>-jasmone or blank formulation and then tested with peach potato aphids (<italic>Myzus persicae</italic> Sulzer) (Hemiptera: Aphididae) and their parasitoid <italic>Diaeretiella rapae</italic> (M'Intosh) (Hymenoptera: Braconidae). CJ treated plants had significantly lower aphid settlement than control plants in a settlement bioassay. Conversely, in a foraging bioassay, <italic>D. rapae</italic> parasitoids spent a significantly longer time foraging on CJ treated plants. Our results reveal that CJ treatment makes plants less attractive to and less suitable for <italic>M. persicae</italic> but more attractive to <italic>D. rapae</italic> in a range of brassica cultivars. It is likely that these effects are due to changes in volatile emission indicating activation of defence and presence of conspecific competitors to aphids but presence of prey to parasitoids. Increases in volatile emission were found in CJ induced plants but varied with genotype. Among the synthetic volatile compounds that were induced in the headspace of CJ treated brassica cultivars, methyl isothiocyanate, methyl salicylate and <italic>cis</italic>-jasmone were most repellent to aphids. These results build on earlier studies in <italic>Arabidopsis</italic> and show that tritrophic interactions are influenced by CJ in a wide range of brassica germplasm. The implication is that CJ is a promising treatment that could be used in brassica crops as part of an integrated pest management system.</p>