Diversity, correlating traits and phenotypic distance among modern durum wheat genotypes

Krasimira Taneva, Rangel Dragov, Maria Videva, Violeta Bozhanova

Abstract: The studies of phenotypic/genetic diversity, correlating traits between various agronomic and quality traits in specific environmental conditions and phenotypic distance among genotypes, that are included in hybridization programs, are essential for building an appropriate breeding strategy for durum wheat improvement. In this regard 90 modern durum wheat genotypes of diverse origins were grown under field conditions for three years, and 14 traits related to yield and grain quality were monitored. The greatest variation and correspondingly the highest coefficient of variation was found for the traits: SDS-sedimentation value (CV- 41.6%), grain yield (CV-14.3%) and kernels weight per spike (KWS) – (CV-11.9 %). According to the analysis of variance (ANOVA) genotype, years of cultivation and interaction between them had a reliable effect on the variation of the all studied traits. The expression of three grain quality traits: SDS-sedimentation value, vitreousness and yellow index and six yield related traits: thousand kernel weight, test weight, number of spikelets per spike, number of kernels per spike and spike length depends in our conditions to the greatest extent on the genotype. The еnvironment/year of cultivation has a determining influence on the phenotypic variation of the traits: grain yield, plant height, grain protein content and grain wet gluten. Both positive and negative correlations were established between agronomic and quality-related indicators in our study. A positive correlation was found between yield and grain protein content (r=0.28) contrary to the commonly accepted negative correlation between these traits. Positive correlations were also found between grain protein content and plant height (r=0.48); wet gluten content in grain and plant height (r=0.50). Positive correlations were found for grain vitreousness with the following traits: plant height (r=0.52), test weight (r=0.39), yield (r=0.43), number of kernels per spike (r=0.30), kernels weight per spike (r=0.39). These positive correlations can help to increase the yield and quality of the genotypes, and therefore, it is recommended to breed for these traits under our conditions. The strong, positive, and significant correlations established in our study between number of kernels per spike and kernels weight per spike (r=0.79), and between number of spikelets per spike with number of kernels per spike (r=0.64), suggest that these traits can be considered as important factors in the selection of genotypes with higher grain yield. The largest variation and, respectively, the highest coefficient of variation was reported for SDS-sedimentation value (CV-41.6%).

Keywords: analysis of variance; cluster analysis; correlation analysis; quality; variation analysis; yield

Citation: Taneva, K., Dragov, R., Videva, M. & Bozhanova, V. (2026). Diversity, correlating traits and phenotypic distance among modern durum wheat genotypes. Bulg. J. Agric. Sci., 32(1), 100–113

Date published: 2026-02-25