ABSTRACT. Selection practices are maximized when plant breeders have the availability of consolidated parameters, which will guide direct and indirect selection methods. This study aimed to apply a biometric alternative to minimize residual variance and maximize selection parameters by parent-progeny regression, interim controls, and mixed linear models intrinsic to breeding. The obtained data were subjected to the assumptions of the statistical model, which identified the normality and homogeneity of the residual variances and model additivity. Subsequently, two analysis scenarios were created. The first preserved all information obtained in the experiment, both from segregating families and pure-line cultivars, and was called original scenario. The other scenario preserved progeny data, but the residual variability of controls was restricted using as criterion observations contained between the interval of the first sample standard deviation. Thereby, an acceptable residue limit could be obtained. Both scenarios were submitted to three consolidated frequentist methods (genitor-progeny regression; sum of squares of augmented block design with interim controls; and mixed linear models, wherein random genetic effects are taken as weighted genetic parameters by the genealogical matrix). Restricting residual variation in parents or controls can maximize genetic parameters and genetic gains in soybean breeding. Significant heritability estimate gains were obtained in the augmented blocks with interim control approach. Mixed linear models with random genetic effects can be considered a great tool to obtain genetic parameters in experiments with a high magnitude of common and regular treatments.

A cultura da mamona (Ricinus communis L.) é uma das mais importantes para a região semiárida do Brasil, sendo o cultivo efetuado, principalmente, com variedades crioulas, sem melhoramento genético e com baixa qualidade fisiológica. Face ao exposto, o objetivo deste trabalho foi avaliar a qualidade fisiológica de sementes de mamona crioula var. carrapatinho em função da posição do rácemo (cacho). O ensaio foi realizado na Universidade Estadual do Sudoeste da Bahia. Foi efetuada análise estatística - Delineamento Inteiramente Casualizado em esquema fatorial 2x3, correspondente a 2 situações morfológicas das sementes de mamona (presença e ausência de carúncula) provenientes dos rácemos localizados em 3 ramos distintos da planta (ramo primário, secundário e terciário). Os dados foram colhidos em condições laboratoriais e em estufa. Ao final do ensaio os dados foram submetidos a testes de homogeneidade de variância e teste de normalidade, e as médias obtidas foram comparadas pelo teste de Tukey ao nível de 5%. Concluiu-se que a qualidade das sementes crioula da variedade carrapatinho foi afetada pela posição do rácemo na planta, e que a remoção da carúncula afetou positivamente a maioria das características avaliadas nos testes de qualidade fisiológica de sementes, principalmente a condutividade elétrica.

The castor culture (Ricinus communis L.) is one of the most important crops for the semi-arid region of Brazil. Cultivation mainly relies on landraces, without breeding and low physiological quality. The objective of this study was to evaluate the physiological quality of Creole castor seeds var. Carrapatinho depending on the position of the raceme. The experiment was conducted at the State University of Southwest Bahia. The statistical analysis included a completely randomized design in a 2x3 factorial, corresponding to 2 morphological situations of castor seeds (presence and absence of wattle) from the racemes located in 3 different branches of the plant (primary branch, secondary and tertiary). Data were collected in laboratory conditions and in a greenhouse. At the end of the experiment the data were submitted to variance homogeneity and normality tests, and the averages were compared by Tukey test at 5%. It was concluded that the quality of Creole seeds variety Carrapatinho was affected by the racemes position in the plant, and that removal of caruncles positively affected most of the characteristics evaluated in the physiological quality tests on seeds, especially the electric conductivity.