Role of Morphological and Phenological Traits in Passive Resistance to Fusarium Head Blight in Wheat

Fusarium head blight (FHB) is a serious concern for wheat production worldwide. The current study was conducted to identify morpho-phenological traits that contribute to passive resistance against FHB. For this purpose, a set of 332 spring wheat genotypes from different origins was used. Eight morpho-phenological traits and FHB severity were evaluated using spray inoculation under field conditions in 2022 and 2023. A non-parametric test was performed to evaluate genotypic variation for all studied traits, revealing significant differences among genotypes across the three years. Correlation analysis demonstrated a strong negative association between phenological traits and FHB severity and a low to medium negative correlation between spike length, spikelets per spike, and FHB resistance. Furthermore, there was a significant negative but weak association between anther extrusion and FHB severity. Random forest regression analysis demonstrated that a complex of eight morpho-phenological traits predicted FHB severity with an accuracy of 65% in 2023 and 57% across two years. According to permutation importance analysis, days to flowering, heading, and anther extrusion had the highest contribution to FHB severity, and all three traits had a significant effect on FHB prediction.