Pepper domestication enhances parasitoid recruitment to herbivore-damaged plants
- PDF / 776,633 Bytes
- 9 Pages / 595.276 x 790.866 pts Page_size
- 95 Downloads / 200 Views
ORIGINAL PAPER
Pepper domestication enhances parasitoid recruitment to herbivore‑damaged plants Michael Garvey1,3 · Curtis Creighton2 · Ian Kaplan3 Received: 6 August 2020 / Accepted: 10 October 2020 © Springer Nature B.V. 2020
Abstract Plant breeding has improved traits such as fruit flavor and yield but may have compromised direct and indirect defenses to herbivores compared to their wild ancestors. This has been termed the plant domestication-reduced defense hypothesis. We present evidence that domestication of Capsicum annuum (the chili pepper) from its wild progenitor, Capsicum annuum var. glabriusculum, has not affected resistance to the insect herbivore, Manduca sexta (the tobacco hornworm). Caterpillars performed equally well on the domesticated and wild pepper. Subsequent behavioral choice assays with one of the main natural enemies of M. sexta, the parasitoid wasp Cotesia congregata, showed that parasitoids preferentially chose herbivore-damaged domesticated pepper plants over their wild relative. To investigate this tri-trophic interaction further, we then assessed the efficiency of C. congregata to parasitize M. sexta on numerous wild pepper accessions and domesticated pepper cultivars in a large foraging enclosure. We found that herbivores feeding on domesticated plants were parasitized at more than twice the rate of those on wild genotypes. These results imply that pepper domestication has not changed resistance to herbivorous insects (i.e., leaf palatability as a direct defense), but rather has improved volatile attraction to recruit natural enemies. Keywords Solanaceous · Tradeoff · Pepper · Manduca sexta · Cotesia congregata
Introduction The plant domestication-reduced defense hypothesis proposes that domesticated crops are more susceptible to insect herbivores than their wild relatives (Gaillard et al. 2017). This change in susceptibility is thought to have occurred in two ways: first, through an inadvertent loss of direct plant defenses, likely due to selection by crop breeders for yield or palatability for human consumption; and second, inadvertent changes in tri-trophic interactions such as plant volatile organic compounds (VOCs hereafter), resulting in impaired Handling Editor: Jarmo Holopainen and Heikki Hokkanen. * Michael Garvey [email protected] 1
Department of Biological Sciences, Louisiana State University, 232 Life Sciences Building, Baton Rouge, LA 70803, USA
2
Department of Biological Sciences, Purdue University Northwest, Hammond, IN 46323, USA
3
Department of Entomology, Purdue University, West Lafayette, IN 47907, USA
plant signaling of natural enemies. These unintended consequences due to anthropogenic selection that lowers plant resistance to herbivores are now well documented in the literature (reviewed in Chen et al. 2015a; Whitehead et al. 2017); however, despite the presumed generality of this hypothesis, results are highly crop dependent. In one of the most thorough examinations of this topic to date, 29 wilddomesticated crop pairings were experimentally c
Data Loading...
