Saulo Chaves

• Professor
• Professor at Escola Superior de Agricultura "Luiz de Queiroz"

Incorporating environmental features improved the predictive ability of genomic prediction models under multi-environment trials in tropical conditions. Gathering environmental and genomic information can benefit the breeding of sorghum hybrids by overcoming complications imposed by the genotype-by-environment interaction (GEI). In this study, we e...

General combining ability (GCA) is the major selection criterion for new sweetpotato (Ipomoea batatas) parents in a reciprocal recurrent selection (RRS) scheme. Here we aimed to estimate GCA and specific combining ability (SCA) by using 16 potential testers involved in an 8 × 8 partial diallel and propose a procedure to identify testers in sweetpot...

Genetic competition can obscure the true merit of selection candidates, potentially leading to altered genotype rankings and a divergence between expected and actual genetic gains. Despite a wealth of literature on genetic competition in plant and animal breeding, the separation of genetic values into direct genetic effects (DGE, related to a genot...

This study investigates the effectiveness of high-throughput phenotyping (HTP) using RGB images from unmanned aerial vehicles (UAVs) to assess vegetation indices (VIs) in different soybean pure lines. The VIs were accessed at various stages of crop development and correlated with agronomic performance traits. The field research was conducted in the...

Key message:Eucalyptusbreeding can benefit from strategies that capture dominance effects, as shown by the improvement in mean annual increment of wood volume across cycles of RRS. Abstract: There is no empirical validation of reciprocal recurrent selection (RRS) in Eucalyptus breeding. Our study helps to fill this gap by quantifying the realized r...

Orphan perennial native species are gaining importance as sustainability in agriculture becomes crucial to mitigate climate change. Nevertheless, issues related to the undomesticated status and lack of improved germplasm impede the evolution of formal agricultural initiatives. Acrocomia aculeata - a neotropical palm with potential for oil productio...

Understanding the genotype-by-environment interaction (GEI) and considering it in the selection process is a sine qua non condition for the expansion of Brazilian eucalyptus silviculture. This study’s objective is to select high-performance and stable eucalyptus clones based on a novel selection index that considers the Factor Analytic Selection To...

In many cases, traditional analysis of breeding trials based on analysis of variance (ANOVA) do not allow a suitable genetic evaluation. Alternatively, mixed model-based approaches create the possibility of dealing with unbalanced data and modeling spatial trends. The aims of this study were to compare the goodness-of-fit of the model and the genot...

Water is a scarce, strategic resource and the most important input for economic development, especially in agricultural countries such as Brazil. Cocoa production is directly related to water availability, and, as climate changes, selecting drought-tolerant genotypes is vital to keep cacao crops sustainable. Here, we evaluated cacao genotypes under...

Key message We propose an “enviromics” prediction model for recommending cultivars based on thematic maps aimed at decision-makers. Abstract Parsimonious methods that capture genotype-by-environment interaction (GEI) in multi-environment trials (MET) are important in breeding programs. Understanding the causes and factors of GEI allows the utiliza...

Probabilistic models enhance breeding, especially for the Tahiti acid lime, a fruit essential to fresh markets and industry. These models identify superior and persistent individuals using probability theory, providing a measure of uncertainty that can aid the recommendation. The objective of our study was to evaluate the use of a Bayesian probabil...

Neglecting genotype-by-environment interactions in multi-environment trials (MET) increases the risk of flawed cultivar recommendations for growers. Recent advancements in probability theory coupled with cutting-edge software offer a more streamlined decision-making process for selecting suitable candidates across diverse environments. Here, we pre...

This study investigates the application of random regression models for analyzing multi-harvest data in cacao breeding. The aim was to understand the genetic dynamics over ten harvest years and select high-performing genotypes. The trial was conducted in Ouro Preto D’Oeste, Rondônia, Brazilian Amazon. Twenty biparental cacao crosses were evaluated...

Multi-trait multi-environment (MTME) models were fitted to eucalyptus breeding trials data to assess residual variance structure, genetic stability and adaptability. To do so, 215 eucalyptus clones were evaluated in a randomized complete block design with 30 replicates and one plant per plot in four environments. At 36 months of age, tree diameter...

Cupuassu (Theobroma grandiflorum)-based agroforestry system (AFS) can be used for restoration of vegetation around springs and riparian forests of water sources (rivers, streams, lakes etc.), subject to constant flooding. The objectives of this work were to study the relations between morphophysiological traits when flooding occurs, determining the...

Key message We propose an enviromics prediction model for cultivar recommendation based on thematic maps for decision-makers. Parsimonious methods that capture genotype-by-environment interaction (GEI) in multi-environment trials (MET) are important in breeding programs. Understanding the causes and factors of GEI allows the utilization of genotype...

Theobroma grandiflorum is a perennial fruit tree native to the Amazon region. As a perennial species with continuous production throughout the years, breeders should seek well‐conducted trials, accurate phenotyping and adequate statistical models for genetic evaluation and selection that can leverage the information provided by the repeated measure...

Maintaining the past decades current genetic gains for tree species is a challenging task for foresters and tree breeders due to biotic and abiotic factors. Planting a mixture of genotypes or clonal composites can be an alternative to increase the phytosanitary security and yield of forest plantations. These clonal composites are more complex than...

Jatropha curcas has become a prominent source of biofuel, especially because of the high oil content in its fruit. The aim of this study was to test different statistic models and compare the best-fitted model with the compound symmetry model and study the grain yield persistence of J. curcas progenies. A total of 730 individuals from 73 half-sib f...

In cowpea breeding, multi‐environment trials are conducted to select lines with high yield. The occurrence of genetic and/or statistical imbalance is common in these experiments, in addition to the possibility of (co)variance between genetic and non‐genetic effects. We explore the restricted maximum likelihood/best linear unbiased prediction featur...

Genotype‐by‐environment interaction (GEI) is a major concern in tropical maize breeding. Here, we used factor analytic mixed models (FAMM) to study GEI in a tropical maize dataset. Our goal was to select high‐performance and stable hybrids using factor analytic selection tools (FAST) derived from FAMM outputs. Because the dataset comprised two diff...

A avaliação da dissimilaridade genética de acessos é uma etapa fundamental em um programa de melhoramento genético, permitindo o direcionamento de ações e embasando tomadas de decisões que definirão o sucesso do programa. Este estudo objetivou determinar as variáveis mais informativas para analisar a diversidade do Banco Ativo de Germoplasma (BAG)...

The optimization of perennial plant breeding necessarily involves the evaluation of multi-harvest and/or multi-site trials. In these situations, modeling covariance structures can elevate accuracy. This study aimed to evaluate different covariance structures for multi-harvest and multi-site trial analyses, using two datasets (D1 and D2). In D1, 25...

O uso de espécies florestais na produção de mudas tem sido intensificado devido à necessidade de recuperação de áreas desmatadas e produção de biomassa. No entanto, a domesticação de espécies florestais nativas é restrita devido à falta de estudos relacionados à ecologia, fisiologia e morfologia de suas sementes. A espécie Tachigali micropetala (Du...

In fruit tree breeding, selection indices are used to identify the genotypes that combine desirable commercial and non-commercial characteristics. As Theobroma grandiflorum is generally cultivated in agroforestry systems (AFS), there is a need to develop cultivars that are adapted to such environments. In this study, the objective was to select the...

Theobroma grandiflorum is a perennial fruit-bearing species with a long breeding cycle (~ 12 years). In multi-harvest data analyses, one frequently observes heteroscedasticity and genetic/statistical imbalance, which requires adequate statistical methods. This study aimed to (i) compare multi-harvest models with homogenous and heterogeneous residua...

Cocoa tree (Theobroma cacao L.) is cultivated mainly in tropical regions and produces beans that are used for chocolate manufacture. Worldwide, cocoa bean production is threatened by biotic stresses, mainly fungus, oomycetes, virus and other pests. The understanding of the determinism of the plant-pathogen interactions as well as the different and...

A suitable statistical model for the analysis of repeated measures is a prerequisite for an accurate genetic selection of cacao (Theobroma cacao L.) genotypes. Thus, the objectives of this study were to (a) evaluate homoscedastic and heteroscedastic repeatability models, (b) estimate the optimal number of harvest years for genetic selection, and (c...

Theobroma grandiflorum is a perennial fruit-bearing species with a long breeding cycle (~ 12 years). In multi-harvest data analyses, one frequently observes heteroscedasticity and genetic/statistical imbalance, which requires adequate statistical methods. This study aimed to compare the adequacy of multi-harvest models with homogenous and heterogen...

Uma das principais dificuldades na implantação dos sistemas agroflorestais está na escolha das espécies componentes. Esta pesquisa objetivou verificar a viabilidade de utilização de duas espécies amazônicas em sistema agroflorestal, quantificando a possível interferência da espécie dominante (mogno-brasileiro) sobre a espécie do dossel inferior (cu...

Forest plantations are strong allies in preserving natural resources, providing social and economic benefits. The plantations carried out in the coming years will be vital to meet the growing demand for forest products. To ensure the continuity of genetic progress and the good results achieved with the improvement of forest species, statistical met...

Este estudo visou avaliar a potencialidade de genótipos de cupuaçuzeiro embasando-se na caracterização física do fruto e físico-química da polpa. Foram empregados clones de cupuaçuzeiro oriundos de um ensaio de campo instalado no município de Tomé Açu, Pará, Brasil. Os dados obtidos com a caracterização foram submetidos à análise de variância univa...

The cultivation of Theobroma grandiflorum in the Brazilian Amazon is mainly conducted by family farmers who use a range of different management strategies. Thus, breeding programs of the species must address the challenge of developing cultivars that are adapted and stable in a variety of cultivation environments. In this context, this study aimed...

The cultivation of Theobroma grandiflorum in the Brazilian Amazon is mainly conducted by family farmers who use a range of different management straegies. Thus, breeding programs of the species must address the challenge of developing cultivars that are adapted to and stable in a variety of cultivation environments. In this context, this study aime...

The cultivation of Theobroma grandiflorum in the Brazilian Amazon is mainly conducted by family farmers who use a range of different management strategies. Thus, breeding programs of the species must address the challenge of developing cultivars that are adapted to and stable in a variety of cultivation environments. In this context, this study aim...

The objective of this work was to select cupuaçu (Theobroma grandiflorum) tree progenies and individuals based on their agronomic traits, and, indirectly, to identify those adapted to an agroforestry system (AFS) environment in the Brazilian Amazon. For this purpose, 25 full-sib progenies were planted and tested in consortium with black pepper (Pip...

In this study, we evaluated triple-cross Theobroma grandiflorum progenies from two successive hybridizations aiming to select families and individuals within them that aggregate high fruit production with resistance to the witches’ broom disease, as well as to evaluate the possibility of incorporating the production methodology of triple-cross hybr...

In Brazil, the productive and sustainable use of Amazonian soils under agroforestry systems (AFS) has been considered a research challenge. This study aimed to evaluate the physicochemical attributes of a soil under AFS, comparing it with the soil under an adjacent secondary forest (SF). The study was carried out in an AFS area cultivated with pass...

This study aimed to evaluate and select progenies and matrices of cupuassu-tree siblings, and to select Brazilian mahogany matrices with superior characteristics to be used in agroforestry systems (AFS). Twenty-five full cupuassu tree sibling progenies and one Brazilian mahogany half-sibling progeny were evaluated. The study was conducted for 14 ye...

This study aimed to use the canopy replacement technique to reduce the field evaluation time and to select promising cupuassu tree clones. The study was carried out under field conditions using fifteen-year-old trees. The crowns were replaced using 16 treatments (clones). The experiment was conducted using randomized blocks design with 18 replicate...

The objective of this work was to study the behavior of cupuassu trees intercropped with African mahogany in order to define the viability of using these species in AFS and to evaluate the performance of African mahogany itself, aiming its application in reforestation projects. Both species were tested in the municipality of Tomé Açu - PA, between...

The cultivars BRS Careca, BRS Fartura, BRS Duquesa, BRS Curinga, and BRS Golias of Theobroma grandiflorum are characterized by high levels of fruit production and diverse sources of resistance to witches’ broom disease. These cultivars are recommended for replacing the tree canopy of low yielding genotypes or forming new orchards.

In agroforestry systems, little is known about the influence of the dominant species on that located in the lower layer of the canopy. The aim of this study was to evaluate if S. mombin plants, when in consortium with T. grandiflorum, caused some type of depression in the performance of T. grandiflorum and also to identify the most favorable S. mom...