Adaptability and stability evaluation of maize hybrids using Bayesian segmented regression models

Abstract

The occurrence of genotype by environment interaction (G x E), which is defined as the differential response of genotypes to environmental variation, is frequently reported in maize cultures, making it challenging to recommend cultivars. Methods allowing to study the potential nonlinear pattern of genotype responses to environmental variation allied to prior beliefs on unknown parameters are interesting to evaluate the phenotypic adaptability and stability of genotypes. In this context, the present study aimed to assess the adaptability and stability of maize hybrids, by using the Bayesian segmented regression model, and evaluate the efficacy of using informative and minimally informative prior distributions for the selection of cultivars. Randomized complete-block design experiments were carried out to study the yield (kg/ha) of 25 maize hybrids, in 22 different environments, in Northeastern Brazil. The Bayesian segmented regression model fitted using informative prior distributions presented lower credibility intervals and Deviance Criterium of Information values, compared to those obtained by fitting using minimally informative distributions. Therefore, the model using informative prior distributions was considered for the adaptability and stability evaluation of maize genotypes. Once most northeastern farmers in Brazil have limited capital, the genotype P4285HX should be considered for planting, due to its high yield performance and adaptability to unfavorable environments.

Extreme Weather Events Affect Agronomic Practices and Their Environmental Impact in Maize Cultivation

“…We emphasize that all hybrids used in the study belong to a similar maturity group (sown and harvested at the same time); therefore, the result of the higher yield potential was a response to a genetic trait. This is in line with previous studies from different parts of the world [74][75][76][77][78], where authors agreed that future research should involve modifying the maize selection criteria to combine tolerances to both drought and wet condition stresses.…”

Adaptability and Stability of Coffea Canephora to Dynamic Environments Using Bayesian Approach

“…Note that in this example of any genotype used to illustrate (Figure 1), not only were the credibility intervals much smaller compared to the confidence intervals, but the estimates of some parameters were changed/corrected. This reduction in the limits of the credibility interval very well described when it was proposed 51,52 has also been evidenced by other studies using this approach with similar models for Stability and Adaptability 28,41,43,44,53 , but not for coffee cultivation. For example, this genotype would have its negative estimate for the parameter referring to the unfavorable environment, whereas in the Bayesian approach, its estimate was close to zero (probably positive) and the error estimate much lower (parameter related to stability).…”

“…The modified bisegmented regression model 34 showed can be performed by the Bayesian approach 6,28 , where the likelihood function and the joint posterior distribution can be founded. In summary, assuming 𝑒 𝑖𝑗 |𝐼𝜎 𝑖𝑒 2 ~𝑁(0, 𝐼𝜎 𝑖𝑒 2 ), each observation 𝑦 𝑖𝑗 has a distribution 𝑦 𝑖𝑗 ~𝑁(𝛽 𝑖0 + 𝛽 𝑖1 𝐼 𝑗 + 𝛽 𝑖2 𝑇(𝐼 𝑗 ); 𝐼𝜎 𝑖𝑒 2 ), and the likelihood function for each genotype is given by:…”

“…We left from a minimally informative prior distributions as tested in the works described in the literature 41 , which were represented by distributions with large variances:…”

“…This modeling of Genotype x Environment interaction (GE) can be defined as the differential response of genotypes to environmental variation. Basically, it is necessary to discriminate cultivars as to the most stable ones, that is, those with less significant GE, or those more adapted to specific environments as more responsive to a good environment 6 .…”