Investigation of genetic variability parameters for Septoria tritici blotch resistance and quantitative traits in bread wheat genotypes

Septoria tritici Blotch (STB) is one of the most devastating diseases of wheat in Ethiopia and worldwide. The present study was conducted to assess the genetic variability of yield and yield parameters among different bread wheat genotypes grown under the stress of Septoria tritici Blotch. A total of 180 bread wheat lines, advanced genotypes and released varieties were included in the investigation. Genetic variance, heritability, correlation and ANOVA were estimated for S.tritici, and yield and yield parameters. The genetic variance was relatively high for grain yield, percentage of disease severity (% severity) and Septoria progress coefficient (SPC). Heritability and genetic advance were relatively higher for grain yield, and moderate heritability and high genetic advance were computed for disease parameters such as coverage of pycnidia, Septoria progress coefficient and % severity. A negative correlation was found between plant height and pycnidia coverage on the four uppermost leaves (PCD), SPC and severity. Days to maturity and heading inversely correlated with disease resistance parameters. This indicated that the genotypes having short plant height and short maturity period could be resistant to Septoria tritici Blotch. The results help researchers to utilize the promising genotypes of this study in future breeding programmers for narrowing the yield gaps between the potential and actual in the areas where the Septoria tritici Blotch infection is a problem.