Association of Stability Models in Measuring Stability of Common Bean Varieties

Plant breeders have been challenged with genotype by environment (G x E) interaction to develop high yielder and stable varieties. They have been using different univariate stability models to simplify the challenge. The major ones are coefficient of variation (CVi), absolute rank difference (Si1), variance of rank (Si2), σi2, Wi, bi, Si2d, Pi, ASV and r2. This study was designed in order to increase information on the associations and reliability that might exist among stability models. The study was carried out on 15 common bean varieties replicated three times at Kobo, Sirinka, Jari, Chefa, Shewarobit and Kogo in 2011-2012 and 2012-2013 in Ethiopia. A combined analysis of variance, stability statistics and rank correlations among stability parameters and yield were determined. The varieties differed significantly for seed yield at P = 0.001. The different stability parameters were categorized into three types. Based on the correlation analysis SY, CVi (type I), Pi, (type II), bi and r2 (type III) were strongly correlated. Moreover, Si1, Si2 (type I), Wi2, σi 2(type II), Si2d and ASV (type III) were correlated at P = 0.01. On the other hand, SY with CVi and Pi; CVi with bi and r2; bi with Pi; Pi with r2 were correlated negatively at P = 0.01 while r2 with Si1, Si2, Wi2and σi2 were moderate and negatively correlated. Coefficient of determination (r2) had strong association with eight of the stability parameters. AMMI Stability Value (ASV) and deviation from regression (Si2d) had also strong association with five of the models. Consequently, they can explain stability of varieties better following coefficient of determination. Thus, bean breeders can use those three stability models for better explanation and interpretation of G x E interaction of varieties/genotypes.