Repeatability of Physical and Chemical Characteristics in Pequi Fruits

Abstract

The aim of this study was to estimate the effects of populations and mother trees over some characteristics on pequi (Caryocar brasiliense Camb.) fruits as well as their repeatability coefficient. Data came from two populations with 15 mother trees each, covering three years. The following physical and chemical characteristics were evaluated: total fruit weight; external mesocarp weight; number of putamens per fruit; total weight of putamens; total and average pulp weight; and proportion of the weight of lipids and proteins in relation to pulp weight. Analysis of variance was performed using a nested design model. The effects of mother trees within populations were highly significant for all variables under study, while the effects of populations were not for any characteristic, showing that for populations and mother trees, efforts must be focused on the number of mother trees per population rather than on populations. The estimated repeatability coefficients showed high genetic control for total fruit weight; external mesocarp weight; average weight of putamens; average pulp weight; and proportion of the weight of lipids in relation to pulp weight. Therefore, the expression of these characteristics on descendants, by cloning selected mother trees, is likely to be effective. REPETIBILIDADE DE CARACTERÍSTICAS FÍSICAS E QUÍMICAS EM FRUTOS DE PEQUIRESUMO -O objetivo deste trabalho foi estimar os efeitos de populações, matrizes e do coeficiente de repetibilidade em frutos de pequizeiro (Caryocar brasiliense Camb.). Foram coletados dados de duas populações, por três anos consecutivos, das seguintes características: massa massa total do fruto; massa do mesocarpo externo; número de putâmens por fruto; massa total e média de putâmens; massa total e média da polpa; e a proporção da massa de lipídeos e proteínas em relação à massa total da polpa. A análise de variância foi feita usando-se um modelo de classificação hierárquica. Os efeitos de matrizes dentro de populações foram altamente significativos para todas as características estudadas, ao passo que os efeitos destas populações não o foram para nenhuma característica, evidenciando que no dimensionamento de testes de populações e progênies, deve-se optar pelo maior número de matrizes por população em detrimento do número de populações. As estimativas de repetibilidade encontradas permitem inferir um alto controle genético para as características massa total do fruto; massa do mesocarpo externo; massa média de putâmens; massa média da polpa; e teor de lipídeos e, portanto, uma maior probabilidade de expressão destas características nos descendentes clonais de matrizes selecionadas. Termos para indexação: Caryocar brasiliense, coeficiente de repetibilidade, matrizes.1 (Paper 209-15).

GENETIC DIVERGENCE IN POPULATIONS OF Caryocar brasiliense Camb. FROM THE PHYSICAL CHARACTERISTICS OF THE FRUITS

“…However, this does not imply that the genetic variability for such a characteristic is also low, since such contribution to divergence is relative to the other characteristics. Proof of this is the significance of the mother trees effect within populations for such characteristics (Table 1), as well as the 51% estimate found for the repeatability of this characteristic in these same mother trees and years (Soares et al, 2017).…”

“…The preponderance of genetic variation within populations in relation to variation between them is observed in several tree species for different phenotypic characteristics (Fernandes, 2008;Silva et al, 2012;Costa et al, 2016;Soares et al, 2017). These observations are also confirmed by studies carried out with the pequi tree in regions of northern Minas Gerais, where it was found that divergences among populations or between groups of populations for this species are relatively low (Melo Júnior et al, 2004;Fernandes, 2008).…”

“…Indeed, when the variations observed in these characteristics between mother trees are analyzed individually through univariate analyzes, they can be of great magnitude. On the other hand, from these analyzes it is observed that the effects of populations are not significant for the majority of populations (Oliveira et al, 2009;Silva et al, 2012;Soares et al, 2017). In this sense, the use of multivariate techniques is necessary to confirm these observations.…”

“…Among the savanna formations of the world, the Cerrado stands out as one of the centers of great biodiversity, with diverse flora and is rich in endemic species (Lehmann et al, 2014). The fruit species native to this biome have great acceptance in the consumer market, since their fruits have remarkable and peculiar flavors with high levels of vitamins, proteins and minerals (Silva et al, 2015;Soares et al, 2017). Among the species, the pequizeiro (Caryocar brasiliense Camb.…”

“…The effect of populations and mother trees on variations in characteristics such as fruit size and pulp thickness is popularly known by people living with the species. In this way, researchers who are attentive to the observations of these communities perceive their preferences to certain mother trees whose fruits bear some qualities mainly related to the thickness and the flavor of the pulp (Soares et al, 2017).…”