Phenotypic variation in Fusarium crown rot resistance and early-stage salt tolerance among triticale genotypes identifies candidate germplasm for breeding

Abstract

Fusarium crown rot (FCR) and soil salinity are major constraints to cereal establishment and productivity worldwide. Triticale (×Triticosecale Wittmack), a wheat–rye hybrid, is recognized for its broad adaptation; however, variation in FCR resistance and salinity tolerance among breeding materials remains insufficiently characterized. In this study, 85 triticale genotypes were evaluated for FCR resistance and germination-stage salinity responses, while 49 entries were evaluated for seedling-stage salt tolerance and 48 triticale genotypes were evaluated for agronomic traits. Salinity responses were assessed under 0, 200, 300, and 400 mM NaCl. Significant phenotypic variation was observed for FCR severity, germination performance, seedling salt injury, and agronomic traits. Germination and seedling performance declined with increasing salinity, although the magnitude of reduction differed substantially among genotypes. Several genotypes maintained comparatively high germination under severe salinity and low seedling injury during early vegetative growth, while FCR screening identified lines with reduced disease severity. Correlation and principal component analyses indicated that germination-stage and seedling-stage salinity responses were significantly associated but represented partially distinct aspects of the phenotypic response to salinity. In contrast, FCR resistance showed only weak associations with salinity-tolerance and agronomic traits. Agronomic evaluation under non-stress conditions identified several genotypes that showed favorable phenotypic responses in the FCR and salinity evaluations together with above-average yield-related characteristics. These findings provide a comprehensive phenotypic assessment of FCR resistance, salinity tolerance, and agronomic performance in triticale and identify candidate germplasm for further evaluation in breeding programs targeting multiple production constraints.