Phenotypic Identification of Landraces of Phaseolus lunatus L. from the Northeastern Region of Brazil Using Morpho-Colorimetric Analysis of Seeds

Abstract

Phaseolus lunatus L. is a species of landrace bean widely cultivated in Northeast Brazil. The integration of new technologies in the agricultural sector has highlighted the significance of seed images analysis as a valuable asset in the characterization process. The objective was to assess the morphology of 18 P. lunatus varieties gathered from four states in the Brazilian Northeast. To achieve this, 100 seeds from each variety were utilized, and their images were acquired using a flatbed scanner with a digital resolution of 400 dpi. Subsequently, the images were processed using the ImageJ software package for analyzing seed size, shape and color characteristics. Statistical analyses were performed with SPSS software applying stepwise Linear Discriminant Analysis (LDA). The overall accuracy rate for correct identification was 80.5%. Among the varieties, the lowest classification percentage was attributed to the ‘Coquinho Vermelha’ variety (39%), while the highest rates were observed for ‘Fava Roxa’ and ‘Fava de Moita’ (98%). The morpho-colorimetric classification system successfully discriminated the varieties of P. lunatus produced in the northeastern region of Brazil, highlighting the -+*/high degree of diversity within them. In particular, seeds with uniform coloring or clearly defined secondary color patterns were easier to classify. The varieties showed low correlation, forming distinct groups based on background color, secondary color, or seed size.