Analysis of Genetic Relationships of Calathea Species and Cultivars by AFLP Markers

Abstract

Calathea, the largest genus in the family Marantaceae, is composed of 100 species native to tropical America in moist or swampy forest habitats. Because of their brilliant patterns of leaf color and different textures plus ability to tolerate low light levels, calatheas have been widely produced as ornamental foliage plants for interiorscaping. Thus far, genetic relationships among its species and cultivars have not been documented. This study analyzed the relationships of 34 cultivars across 14 species using amplified fragment length polymorphism (AFLP) markers. Six EcoR I + 2/Mse I + 3 primer set combinations were used in this investigation. Each selected primer set generated 105 to 136 scorable fragments. A total of 733 AFLP fragments were detected of which 497 were polymorphic (68%). A dendrogram was constructed using the unweighted pair-group method of arithmetic averages (UP-GMA) technique and a principal coordinated analysis (PCOA) was used to analyze the relationships. The 34 cultivars were divided into four clusters. Cluster I had 19 cultivars derived from C. roseo-picta and C. loesnerii with Jaccard's similarity coefficients from 0.74 to 0.97, of which six are somaclonal variants or sports and two cultivars are genetic identical. Only C. kennedeae `Helen' is positioned in cluster II. Cluster III had 10 cultivars across seven species; Jaccard's similarity coefficients among them varied from 0.41 to 0.63. Four species were situated in cluster IV with Jaccard's similarity between 0.27 to 0.41. Results from this study indicate that broadening of genetic diversity is needed for cultivars in cluster I as they are the most commonly grown calatheas but genetically are very close.