Morphological Characterization and Evaluation of Agroeconomic Traits of Annatto (Bixa orellana L.) Crops from the Social Program Sembrando Vida in Campeche, Mexico

Our study aims to characterize morphologically the annatto crops from the social program Sembrando Vida in the State of Campeche based on qualitative and quantitative descriptors. The goal is to identify plants with superior agroeconomic traits related specifically to seed yields and bixin content. We evaluated 6 qualitative and 10 quantitative descriptors, focusing primarily on the flowers, fruit, and seeds from annatto plants of three different plantations: Calkini, Becal, and Bacabchen. The qualitative descriptors grouped the plants into four varieties: Criolla, Criolla roja, and Peruana roja morphotypes 1 and 2. The cluster analysis of the quantitative descriptors supported this classification. Cluster 3 presents the highest average seed yield per tree (0.61 kg) and bixin content (4.49%), and consists of Peruana roja morphotype 2. In contrast, clusters 1 and 4 exhibit the lowest seed yield (0.29 kg) and bixin content (2.41%), and are comprised of the Criolla varieties. A second cluster analysis identified five individual Peruana roja morphotype 2 from the Bacabchen locality, with an average bixin content of 6%, suggesting that these individuals have superior agroeconomic potential. In addition, we found a positive correlation between bixin content and seed yield ( r = 0.58, P ≤ 0.001). Both variables correlated positively with fruit height, seed width, seed number per fruit, and seed weight per fruit, suggesting that these traits could serve as criteria for selecting plants in the field. Our work facilitates the accurate identification and selection of annatto plants with high agroeconomic potential, paving the way for a future genetic improvement program.