Controle genético de caracteres determinantes de aspectos visuais e da produção em amendoim

Abstract

Peanut is an oilseed cultivated and appreciated both in Brazil and in the world, playing an important role in the agricultural economy. In this perspective, it is of great interest to search for genetic materials that meet market requirements. Thus, knowledge of the inheritance of characters related to the production and visual aspect of the grains of the crop is essential for the efficient conduct of breeding programs aimed at obtaining new cultivars. In this sense, the objective of this study was to elucidate the genetic control of the visual aspects of peanuts: color and shape of the seed; and of agronomic traits important to production: number of ripe pods, total number of gynophores, number of gynophores in the lower third, height of the main stem, pod length, pod width, seed length and seed width. For this, four divergent accessions of peanuts were used for morpho-agronomic characters, from the germplasm collection of the CCA / UFC, identified by EAC 26, EAC 33, EAC 43 and EAC 69. Hybridizations between the parents were performed in a pot in the scheme full diallel. From the F1’s seeds, the F2’s seeds of all combinations involving the parents were obtained. In the field, in a randomized block design with 3 replications, the following treatments were evaluated: parents, F2´s populations of the combinations obtained; reciprocal F2’s populations, according to method I proposed by Griffing (1956). Epistatic and significant proportions were observed, showing that the color of the seed coat and the seed shape are genetically controlled by 3 to 5 genes, respectively. The estimates of the genotypic differential associated with the effects of the general combining ability were significant for all traits; on the other hand, the estimates of the genotypic differential associated with the effects of the specific combining ability showed significance for the number of mature pods, total number of gynophores and number of gynophores in the lower third, indicating that the parents differ with respect to the additive and genetic effects. combinations for additive and non-additive gene effects. The reciprocal effect, which expresses extrachromosomal inheritance and / or maternal effect, was significant for the total number of gynophores, the number of gynophores in the lower third and height of the main stem. Non-additive gene effects predominated in the genetic control of the characters, except for the number of mature pods and pod width. The genotypic determination coefficient varied from 41.52% for pod width and 92.65% for pod length. The estimated number of genes responsible for controlling these characters ranged on average from 1.73 to 14.82. Therefore, there are characters that have relatively simple inheritance and others that are complex, requiring different breeding strategies to maximize the achievement of superior genotypes.