*barbara.laddomada@ispa.cnr.it

Enhancing wheat resistance against the granary weevil, Sitophilus granarius (L.), is urgent to counteract the severe quantitative and qualitative wheat grain losses caused by this pest during post-harvest. The actual control strategy of the granary weevil relies on the use of fumigants and broad-spectrum contact insecticides, but due to their impacts on health, food safety and environment, there is an urgent need for a more sustainable and low-impact control approach.

The development of resistant wheat varieties is one of the most promising alternatives to insecticides in the integrated management of stored grain pests. Here we present a project recently funded by the Italian Ministry of University and Research (MUR) aimed at investigating on the sources and mechanisms of host-plant resistance to S. granarius in wheat. Previous studies showed that granary weevil adults perceive and behaviorally respond to a range of wheat grain volatile organic compounds (VOCs) [1,2].

In fact, differently from yellow wheats, some Ethiopian purple wheats besides being unattractive to S. granarius adults have antifeedant and toxic effects associated to anthocyanins accumulation [3]. Our project has the ambition to gain a deeper insight into the defense mechanisms of purple wheat against S. granarius. To this aim we will evaluate the biological, chemical, and genetic factors involved in the host finding and host acceptance by adult weevils.

A set of durum and bread wheat Near-Isogenic Lines will be used, each derived from heterogeneous inbred families contrasting for the color of the pericarp due to the diverse anthocyanin composition and content. Next generation technologies will be used to search for molecular markers associated to the key variants and target genes that significantly change their expression level within each NIL pair.

(1) Germinara GS. et al. 2015. J. Pest. Sci. 88, 675–684

(2) Germinara GS. et al. 2019. J Pest Sci 92, 653-664.

(3) D’Isita I., et al. 2023. Sci Rep. 13, 14246.