Parametric stability analyses of multi-environment yield trials in triticale (xTriticosecale Wittmack)

Abstract

One of the main goals of Triticale (xTriticosecale Wittmack) Breeding Program of Turkey is to improve high yielding and stable genotypes across environments. In this study, 16 parametric stability methods were used to evaluate the genotype x environment interaction (GEI) in 9 (4 officially registered varieties and 5 advanced lines) triticale (xTriticosecale Wittmack) genotypes. The genotypes were evaluated for grain yield at 4 different locations for 3 years in rain-fed areas of Turkey. The testing locations have different climatic and edaphic conditions providing the conditions necessary for the assessment of stability. A combined analysis of variance, parametric stability statistics and rank correlations among them were determined. Significant differences were detected between genotypes and their GEIs. Different parametric stability statistics were used to determine stability of the studied genotypes. The level of association among the statistics was assessed using Spearman's rank correlation. Rank-correlation coefficients between yield and some parametric stability statistics were highly significant. Genotypes mean yield was significantly correlated to the parametric stability statistics Pi (r = 0.95**), PCA1 (r = 0.87**) and Di (r = 0.98**). A principal component analysis based on rank correlation matrix was performed for grouping the different parametric stability statistics studied. In conclusion, based on most parametric stability statistics, the genotype G8 was found to be the most stable and high yielding. This genotype is, therefore, recommended for release as a cultivar for rain-fed areas of Turkey.