Imagens RGB obtidas por VANT na fenotipagem de alto rendimento para seleção de genótipos de soja

Abstract

The current promising soybean scenario in Brazil reflects the contributions of numerous areas, including biotechnology, precision agriculture and advances in plant breeding programs. In the current phase of plant breeding, high-throughput phenotyping (HTP) stands out to be a promising tool, enabling the evaluation of multiple variables with a high level of spatial and temporal detail, what showed to mean until now unattainable with traditional methodologies. The objective of this research aimed not only to select superior soybean genotypes in different growing and sowing seasons by applying direct, indirect and selection index, but also to evaluate the use of RGB images obtained with UAVs in the analysis of agronomic variables in soybean for genetic breeding purposes, in Buriti Alegre city - GO. The experiments were conducted on the field of this city, with sowings carried out on November 30, 2023, December 10, 2023, December 30, 2023, December 10, 2024, and December 30, 2024. 60 soybean genotypes, 41 lines and 19 control cultivars were used for this purpose. The studied genotypes were subjected to different selection techniques, considering the genotype x environment interaction, involving direct and indirect selection as well as selection indices by sum of ranks, for the following variables: plant height at maturity, number of days to maturity and grain yield. A principal component analysis (PCA) indicated the distribution of soybean genotypes (dots) and its evaluated variables (arrows), of the agronomic variables: plant height at maturity, number of days to maturity, number of pods, productivity and vegetation indices obtained from RGB images (ExG, NGRDI and VARI) at different phenological stages (R5 to R8). The study of BLUPs reinforced the selection criteria indicated by the vegetation indices, mainly VARI and NGRDI. Different numbers of relative maturity groups of genotypes were observed, ranging from 5, 4, 2, 4, and 3 groups, respectively, for the sowing dates: 11/30/2023, 12/20/2023, 12/30/2023, 12/10/2024, and 12/30/2024, which strongly means that the relative maturity was influenced by the environment. The heritability study revealed that the specifically agronomic variables number of days to maturity and plant height at maturity exceeded the heritability value for grain yield. Furthermore, the application of high-performance phenotyping (HTP) using RGB images proved to be an efficient, non-destructive and low-cost strategy for the phenotypic evaluation of soybean genotypes. Moreover, the vegetation indices ExG, VARI and NGRDI submitted evidence of a strong relation with the agronomic variables average plant height (APM), number of pods (NV), grain yield (PROD) and number of days to maturity (NDM), setting forth potential for its application in the indirect selection of promising genotypes.