Rhynchophorus ferrugineus is a destructive trunk-boring pest of palm plants and exhibits marked polymorphism in adult speckle patterns. This study investigated the genetic basis and molecular mechanisms underlying speckle variation in R. ferrugineus with the aim of identifying key regulatory genes. Integrated genetic analyses and genome-wide association approaches were used to characterize the inheritance and genomic architecture of speckle traits. Pronotum speckle variation was identified as a sex-independent quantitative trait controlled by major loci with additive and dominance effects. Multiple loci and significant quantitative trait nucleotides associated with speckle variation were identified through linkage mapping and association analyses. By integrating genetic mapping results with bioinformatics annotation, three candidate genes, RferTRXR1, RferGH1, and RferLAC2, were identified. Quantitative real-time PCR analysis showed that RferTRXR1 and RferGH1 were more highly expressed in individuals with higher speckle numbers. These findings highlight RferTRXR1 and RferGH1 as potential regulators of speckle pattern variation in R. ferrugineus and provide new insights into the molecular mechanisms underlying phenotypic polymorphism in an important palm pest.
Liu et al. (Tue,) studied this question.