Morphometric Analysis of 21 Pitahaya (Hylocereus undatus) Genotypes


  • Onécimo Grimaldo-Juárez
  • Teresa Terrazas
  • Armando García-Velásquez
  • Manuel Cruz-Villagas
  • Juan Francisco Ponce-Medina


Cactaceae, cacti, canonical discriminant analysis, edible fruit, pitahayas, principal-component analysis, stem variation.


Morphological variation was studied in 21 pitahaya genotypes using multivariate analysis. Genotypes were classified by the color of the skin and pulp of the fruit into white, red, magenta, and yellow in order to determine whether other characteristics would also help discriminate among them. The results of principal-component analysis based on 47 features showed three groups of pitahayas, while canonical discriminant analysis analyzing only 28 features selected by the principal-component analysis gave four groups. In both analyses, the magenta and red pitahaya types were assigned to different groups, while yellow and white types, although classified into different groups, were more similar. The differentiation between groups was mainly related to stem features, such as the size of the concave angle, height of the angle vertex, undulation height, and spine number and length. The number and length of internal perianth segments were the most important flower features. Variation in stem features corresponded to variation in H. undatus. The four groups were thus considered to belong to this species.






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