Morphogenetic analysis of common bean genotypes in response to Diabrotica speciosa (Germar, 1824) (Coleoptera: Chrysomelidae)

The defense mechanisms that plants have developed in response to herbivory can be chemical, physical, or morphological, which, acting alone or combined, can reduce the damage caused by insects. In this study, the morphogenetic traits capable of attributing resistance to common bean cultivars to Diabrotica speciosa were analyzed, which will serve as a basis for use in the organic system and serving as parents to compose variability in breeding programs. The susceptibility and resistance of cultivars to D. speciosa were determined through tests of feed preference no-choice and free-choice and preference for consumption, the enzymatic activity of CAT, POD, and SOD, expression of PvbZIP1 , PvWHIRLY3 and PvNPR1 genes, analysis of morphological and chemical components of the plant. The studied morphogenetic components showed insect-plant interaction, where the cultivars, in response to damage caused by D. speciosa increased enzyme activity and expression of defense genes. Trichomes in the abaxial surfaces of the leaves, and phosphorus content demonstrated a negative correlation with the feed preference and consumption by D. speciosa . The resistance of the cultivars to D. speciosa was also correlated with nitrogen, sugar, and chlorophyll content since they can modify the plant’s chemical composition and increase resistance to herbivory. Morphogenetic analysis indicates that BRS Esplendor and IPR Curió has traits providing greater susceptibility, while IPR Uirapuru and IPR Tangará present features bringing greater resistance to D. speciosa . Therefore, they are promising genotypes for cultivation in an organic system and as parents to compose variability for breeding programs, research development, and selection to resist D. speciosa or other herbivorous insects.