Selection of Triticale Sources of High Kernel Hardness

Abstract

Abstract: Goal of the work - to differentiate comprehensively valuable triticale accessions by kernel hardness in the breeding material of the Yuriev Plant Production Institute; to evaluate the year-to-year variability and uniformity of triticale accessions by the hardness trait; to select genotypes with increased kernel hardness as starting materials for food triticale breeding. The study was conducted in the Eastern Forest-Steppe of Ukraine. The kernel hardness of 46 comprehensively valuable spring triticale lines was determined in 2021 and 2023; in addition, the kernel hardness of 330 spring triticale lines and 220 winter triticale lines was determined in 2023. The kernel hardness was measured on a YPD-300D direct-acting hardness tester. The significance of differences and contributions of factors were assessed by  one-way and multi-way ANOVA. The weather in the study years differed significantly, allowing for objective assessments of the condition effects on hardness. On average for two study years, the hardness of 46 spring triticale accessions varied from 110 N to 183 N, meaning that there were soft, medium-soft, and semi-hard accessions in the sample. Most spring triticale accessions had soft or medium-soft kernels; however, very soft- and hard-kernelled accessions were detected in some years. The genotype and environmental conditions were the factors that made the greatest contributions to the total variability of the trait - 29.9 and 18.6%, respectively. The genotype-environment interaction exerted a much weaker but statistically significant effect of 8.1%. The accessions differed significantly in intra-accession hardness uniformity. The coefficient of intra-accession variation was 3–50%. Accessions with a high (CV ≤ 10 %), medium (CV = 10–20 %), and low (CV≥ 20 %) uniformity of kernel hardness were selected. The most stable and uniform across the years accessions are most valuable as sources of certain levels of kernel hardness. The most stable accessions were identified in three groups of kernel hardness: soft - YaTKh 102-23 (CV = 4%), YaTKh 18-23 (CV = 6%), and YaTKh 40-23 (CV = 7%); medium-soft – YaTKh 132-23 (CV = 3%), YaTKh 11-23 (CV = 7%), and YaTKh 15-23 (V = 10%); semi-hard – YaTKh 108-23 (CV = 10%) and YaTKh 99- 23 (CV = 13%). Accessions with increased and more stable hardness of kernels were selected; they can be used in breeding as sources of this trait. In addition, accessions with stable hardness can be used as references within different hardness groups. To find new genotypes with high potentials of kernel hardness, kernel hardness was additionally evaluated in a much bigger sample of genotypes in 2023: 330 spring and 220 winter triticale accessions. The distribution of the accessions by hardness groups was similar for spring and winter forms. Soft- and medium-soft-kernelled genotypes accounted for a larger share (78–80%). The share of hard-kernelled accessions was 3%, both among the spring and winter forms. In 2023, which was a favorable year for high hardness, the highest kernel hardness was recorded for the following spring accessions: YaTKh 456-23 (247 N), YaTKh 139-23 (208 N), YaTKh 437-23 (207 N), YaTKh 565-23 (206 N), and YaTKh 382-23 (201 N). As to winter triticale, the  highest kernel hardness was recorded for TKhZ 883-23 (247 N), TKhZ 487-23 (212 N), TKhZ 406-23 (207 N), TKhZ 736-23 (205 N), and TKhZ 178-23 (202 N). These values correspond to durum wheat standards or exceed them. All accessions of the hard group showed high or medium intra-accession uniformity (coefficient of variation CV = 5–20%). The selected accessions, considering rather high and uniform hardness of kernels, are of considerable breeding value but require further evaluations of the stability of this characteristic under different environmental conditions.