Grain traits contributing to resistance to Sitophilus oryzae: A comparative analysis of 17 wheat genotypes

Stored wheat suffers significant losses due to various storage pests, with Sitophilus oryzae being one of the most destructive. With limited plant protection products available, it is important to explore host plant resistance as a valuable tool in pest control. Wheat genotypes exhibit varying levels of resistance or susceptibility to S. oryzae , and identifying resistance-associated traits may contribute to improved resilience against storage pests. In this study, we evaluated the resistance and susceptibility of 17 wheat genotypes cultivated in Serbia, ranging from traditional landraces to contemporary cultivars, to S. oryzae , with the aim of identifying grain traits associated with reduced susceptibility and developing an optimal ideotype. Our approach combined grain phenotypic, biochemical, and physical traits with insect bionomic traits. The results showed that historical cultivars and landraces generally exhibited higher resistance to S. oryzae than most modern genotypes. After four months of infestation, the most resistant genotypes, including Garulja, Novosadska rana 2, Bankut 1205, and Crnozrna, showed low progeny production (19–33 individuals) and minimal grain consumption (0–3%), whereas the most susceptible modern cultivars, Dunav, Novosadska 100, and Libellula, had 188–247 individuals and 70–89% grain consumption. Reduced susceptibility was associated with darker grain pigmentation, higher protein and gluten contents, and selected biochemical traits, particularly flavonoids, which were negatively correlated with insect development. Together, these traits form a biochemical and physical profile linked to reduced susceptibility. This study provides a comprehensive assessment and new insights into trait associations linked to reduced susceptibility and offers a foundation for breeding wheat ideotypes with improved post-harvest protection.