AFLP analysis of genetic relationships among Calathea species and cultivars

Calatheas (Calathea Mey.) have been largely produced as ornamental foliage plants for interiorscaping due to their brilliant patterns of leaf color and different leaf textures as well as the ability to tolerate low light levels. Genetic relationships among Calathea species and cultivars, however, have not been documented. This study analyzed the genetic relatedness of 34 commonly grown cultivars across 15 species using amplified fragment length polymorphism (AFLP) markers with near-infrared fluorescence-labeled primers. Six EcoRI + 2 bases/MseI + 3 bases primer set combinations were used in this investigation. Each selected primer set generated 105-136 scorable fragments. A total of 733 AFLP fragments were detected, of which 497 were polymorphic (67.8%). An unweighted pair-group method of the arithmetic averages (UPGMA), principal coordinate analysis (PCOA), and bootstrap analysis were used to analyze the genetic relationships. The 34 cultivars were separated into four clusters. Cluster I contains 19 cultivars that are either from C. roseopicta or C. loesnerii with Jaccard's similarity coefficients ranging from 0.51 to 0.99. Among the 19 cultivars, at least nine are derived from somaclonal variants or sports. Only C. kennedeae 'Helen' is positioned in cluster II. Cluster III has 10 cultivars across seven species; Jaccard's similarity coefficients varied from 0.26 to 0.63. Four species are situated in cluster IV with Jaccard's similarity ranging from 0.19 to 0.41. This study establishes the genetic relationships of commonly cultivated calatheas, provides genetic evidence supporting that C. fasciata, C. orbifolia, C. rotundifolia, C. insignis, and C. ornata are independent species, and raises a concern over genetic vulnerability of cultivars in cluster I because of their close genetic similarities. (c) 2005 Elsevier Ireland Ltd. All rights reserved.