Repeatability of some phenotypic stability parameters - a resampling approach

Abstract

The aim of this study was to estimate the repeatability of some phenotypic stability parameters: reliability index (I), regression coefficient (b 0 e b 1), ecovalence, and the mean of the absolute scores (MAS), and to check the implications of estimating stability parameters using a reduced number of environments. A dataset comprising 25 common bean lines assessed in 36 environments was used. These environments comprise different locations, sowing seasons, and years. Different experimental groups, from three to 18 environments, were simulated. For each group, analysis of variance was performed and the stability parameters were estimated. The greater repeatability estimates were observed for the mean (b 0), followed by the I and b 1. Ecovalence and MAS had the lowest values for the repeatability estimates, which is not desirable for breeding programs aiming at selection for high stability. The phenotypic stability parameter should not be estimated from fewer than 12 environments.

Genetic parameters, correlation and repeatability of agronomic characters of yellow passion fruit genotypes in three harvest cycles

“…The evaluation of genotypes in breeding programs is time-consuming and costly, so reduction of the evaluation period without compromising accuracy of the information is extremely relevant (Neves et al 2010;Cavalcante et al 2017Cavalcante et al , 2018Mendes and Ramalho 2018). Passion fruit production is low in the first year, tends to increase in the second year and decreases again in the third year (Pimentel et al 2008).…”

Simultaneous selection of peach rootstocks by mixed models

“…The term adaptability refers to the ability of a genotype to respond supportively to environmental stimulus, while stability is the predictability of genotypic behavior (Mendes & Ramalho, 2018). Several methods have been proposed to evaluate phenotypic adaptability and stability such as AMMI (Gauch, 1992) and GGE biplot (Yan & Rajcan, 2002), however, for the breeder, the major interest is in adaptability and genotypic stability.…”

Environmental Stratification of the Corn Second Season on the West and Mid-Western of Paraná

“…For the selection of consistent genotypes, the experimental areas should represent the different conditions of the region under study. It is essential to identify whether there are environments of similar or complementary patterns (Pereira et al, 2010), thus reducing the number of environments without generating losses in the selection process (Mendonça et al, 2007;Mendes and Ramalho, 2018). Thus, the identification of the similarity or complementarity of environments is mad through enviromental stratificatio.…”

“…In each factor, environments are linearly correlated and weakly correlated with those grouped in the other factors (Garbuglio et al, 2007), generating not only two groups of environments (favorable and unfavorable), which is a questionable fact for other methodologies (Cruz and Carneiro, 2006). Factor analysis has been used by several authors for studies of environmental adaptability and stratification (Garbuglio et al, 2007;Mendonça et al, 2007;Pereira et al, 2013;Carvalho et al, 2014;Mendes and Ramalho, 2018).…”