Análise multivariada com mapa de calor para ranqueamento de vigor em trigo

Abstract

Wheat is one of the main cereals cultivated globally, with significant economic importance. Thus, the use of high-quality and high-vigor seeds is essential to the success of its production. Ranking seed lots according to their vigor is essential for seed companies to simultaneously analyze different lots. Given this, the aim was to evaluate the physiological potential of wheat seed varieties and to verify the effect of the Dendrogram with heatmap to determine seed vigor in wheat. The experimental design was completely randomized, and treatments consisted of five wheat varieties (BRILHANTE, DUQUE, BRS404, BRS394, and BRS264) and four repetitions of 50 seeds, totaling 20 experimental units. The seeds were then sown on blotting paper moistened with water at a volume equivalent to 2.5 times the weight of the dry paper, placed in Transparent Gerbox Boxes (11 cm x 11 cm x 3.5 cm), and kept in a B.O.D. Incubator (Biological Oxygen Demand) for eight days at 20 °C. The ranking of wheat varieties by seed physiological quality was conducted using the 'MultivariateAnalysis' package and HeatPlot function, presenting a heatmap for the interpretation of the Dendrogram (an object created by the ‘Dendrogram’ function) in R version 4.4.1. Varieties BRS404, BRS264, and DUQUE were presented in the same cluster, while varieties BRS394 and BRILHANTE were in separate clusters. Observed in the dendrogram, based on color patterns and germination and vigor results, varieties BRS404, BRS264, and DUQUE showed high vigor, BRS394 showed medium vigor, and BRILHANTE showed low vigor. Under field conditions, the BRILHANTE variety might potentially exhibit slower development and uneven phenological stages, which could hinder management. The Dendrogram allows for the rapid identification of seed vigor in wheat varieties, showing BRS404, BRS264, and DUQUE in the same cluster.