Responses of parasitoids to volatiles induced by Chilo partellus Oviposition on Teosinte, a wild ancestor of maize
Date
2015Author
Mutyambai, Daniel M.
Van den Berg, Johnnie
Khan, Zeyaur R.
Bruce, Toby J.A.
Midega, Charles A.O.
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Show full item recordAbstract
Maize, a genetically diverse crop, is the domesticated
descendent of its wild ancestor, teosinte. Recently, we
have shown that certain maize landraces possess a valuable
indirect defense trait not present in commercial hybrids. Plants
of these landraces release herbivore-induced plant volatiles
(HIPVs) that attract both egg [Trichogramma bournieri
Pintureau & Babault (Hymenoptera: Trichogrammatidae)]
and larval [Cotesia sesamiae Cameron (Hymenoptera:
Braconidae)] parasitoids in response to stemborer egg deposition.
In this study, we tested whether this trait also exists in the
germplasm of wild Zea species. Headspace samples were collected
from plants exposed to egg deposition by Chilo
partellus Swinhoe (Lepidoptera: Crambidae) moths and unexposed
control plants. Four-arm olfactometer bioassays with
parasitic wasps, T. bournieri and C. sesamiae, indicated that
both egg and larval parasitoids preferred HIPVs from plants
with eggs in four of the five teosinte species sampled.
Headspace samples from oviposited plants released higher
amounts of EAG-active compounds such as (E)-4,8-dimethyl-
1,3,7-nonatriene. In oviposition choice bioassays, plants
without eggs were significantly preferred for subsequent oviposition
by moths compared to plants with prior oviposition.
These results suggest that this induced indirect defence trait is
not limited to landraces but occurs in wild Zea species and
appears to be an ancestral trait. Hence, these species possess a
valuable trait that could be introgressed into domesticated
maize lines to provide indirect defense mechanisms against
stemborers
URI
http://hdl.handle.net/10394/18824http://dx.doi.org/10.1007/s10886-015-0570-1
http://link.springer.com/article/10.1007/s10886-015-0570-1