A Numerical Taxonomic Study of the Avocado (Persea americana Mill.)1

Abstract

Principal components and cluster analyses, based on 67 characters, were applied to 38 cultivars, which collectively exemplified the 3 races of avocado and their racial hybrids. Diagrams constructed from principal component analysis clearly showed the phenetic diversity of the 3 races and their racial hybrids. Correlation and distance phenograms from cluster analyses did not show overall phenetic diversity as well as principal component diagrams. The phenograms were most useful, however, in showing phenetic similarities among closely related cultivars, which were obscure in principal component analysis. The 2 methods are, thus, complementary, and both methods are recommended in studying patterns of variation with species such as avocado.